Wednesday, August 30, 2006

Snippets that I Ought to Turn Into a Post on LABAs

LABAsBut, I haven't finished thinking about them enough. Thinking, like my sleep, is disturbed by the nasty stage of a freezing shoulder. It's still freezing because I have movement at some angles, but not others. However, I definitely have the pain.

There is more discussion about the safety of salmeterol. It is an excellent drug when used appropriately and effective for many people. There are people for whom it may be less effective to the point of being harmful. I'm wondering if it is time for a revision to the SIGN guidelines or are we waiting for further pronouncements?

One, currently impractical, solution would be pharmacognetic testing: the genetic testing of an individual to custom-make drugs to an individual's needs. The testing evaluates DNA samples for unusual variations of genes and mis-spellings of the genetic code. The samples would then be compared to a database to predict which genetic variations and code mis-spellings are more likely to result in a good response to the medication or sensitivities. When hundreds/thousands of patients are treated with a medication, some will demonstrate an excellent response, some will have no response; others will have minor or tolerable side effects, and still others will have side effects that are distressing or make them very ill.

Edited 31.08 to include: Samuel Blackman of Blog MD has commented on an New York Times piece on this topic and neatly sums it up,
Research has now substantiated what physicians have observed for quite some time now: some drugs work well for certain people but not so well for others...if you metabolize a certain chemotherapeutic too quickly, then you may not keep enough in your body to fight the cancer adequately. If you metabolize a certain drug too slowly, then you may experience more of the toxicities associated with the drug.
He recommends a fine piece in the San Francisco Chronicle, New age of medicine: Treatment tailored to your DNA, enzymes. It is a thought-provoking article that highlights the current emphasis on standardized dosages and regimes that are suitable for RCTs while arguing that the future lies in compounding niche formulations according to genetic make-up.

Genetic variants may one cause. Pharmocogenetics may be one solution. But it is not an affordable reality for common or chronic illnesses although there are hospitals such as St. Jude Children’s Research Hospital in Memphis that finds it cost-effective to assess likely responses to leukaemia medications. According to Dr. Mary Relling, head of the department of pharmaceutical sciences at St. Jude, the testing costs are minor compared to the savings gained by avoiding drug reactions, blood transfusions and additional hospitalisations for that group of patients.

Medpundit has written an interesting post about the stealthy victory of drug companies in framing the debate about successful outcomes:
I am ready to throw in the towel and admit defeat. The drug companies have won. They've suceeded in dominating the debate about which medicine to use for what and when. Professional judgement and experience, and scientific evidence have failed to check their promotional assaults. They've won the battle, and maybe the war.
Sydney also writes about concerns that the ability to test outstrips the ability to use the tests wisely. In my mind, there is a tug-of-war that some patients do nag their doctors into prescribing particular medications and/or don't necessarily take them as prescribed. I have met people with asthma who are only using a LABA, they are not using an ICS. I have to assume that they were prescribed an ICS but have not understood the importance of using it, and whoever is monitoring their prescriptions or progress has not noticed. But,I am aware that I have met some GPs who are not following this year's ins and outs of the discussions about LABAs in general and salmeterol in particular. They are probably spending a lot of time following the ins and outs of the revision to the hypertension guidelines on which Dr. Crippen has blogged extensively (March 23 entry, June 30 entry are some of the discussions).

For more information about the images used in the illustration, click on it or visit the detail on Flickr.

Sunday, August 27, 2006

Paediatric Grand Rounds 1.10 Is Up: Did You Know

Dr. Mom Poster for cough

Paediatric Grand Rounds 1:10 is up, courtesy of Hannah of Milliner's Dream.

Children are not small adults but the full richness of human drama is present in this issue of PGR. We have a whirlwind of offerings from breast-feeding and (in two different stories) why an Apgar score is not the full story, to the responsibility of telling a family that their child has Down's Syndrome, to a fascinating brace of discussions about language development and developmental milestones-speaking of which, Philip Gordon suspects that he is undergoing a metamorphosis.

It is fascinating selection of posts from the paediatrichealth blogosphere. I commend Paediatric Grand Rounds 1:10 to you.

I will also drop an early reminder that I am the host of the next PGR. So remember that when you're writing over the next few days, please, and keep me in mind for mailing your entries.

For more information about the image used in the illustration, click on it or visit the detail on Flickr.

Asthma: A Multi-Headed Hydra or Misunderstood Genus?

Mosaic of letters reads AsthmaIs asthma a multi-headed hydra or is it a genus that is mis-labelled/misunderstood as a single entity? I recently wrote about the enthusiastic media coverage of some interesting research into lung-proteins that over-hyped it as the end of asthma. So, I was somewhere between deja vu and a double-take when I read an editorial in The Lancet that calls for an end to asthma as a single disease concept.

Most of this issue of The Lancet is dedicated to asthma. The editorial offers an interesting summary of asthma statistics. Worldwide, there are 300 million people living with asthma; at current projections, there will be 400 million by 2025. Asthma deaths account for 1 in 250 deaths worldwide.

The editorial also gives an overview of progress in the treatment of asthma. In the 1960s, researchers identified chronic airway inflammation as an underlying factor in asthma. That research finding is the rationale for inflammation management such as inhaled corticosteroids. Despite much research optimism,
progress in understanding predisposition, underlying pathology, disease triggers and progression, and response to treatment has been slow and confusing with many contradictory findings.
For the last 20 years, throughout the world, and particularly in countries that already have or are adopting a 'western lifestyle', there is an increase in asthma, particularly among children.

The editorial highlights particular controversies such as the hygiene hypothesis. The hygiene hypothesis suggests that cleaner environments mean fewer challenges to children's immune systems during their development. The children's immature immune systems develop over-sensitive inflammatory responses to everyday allergens and other environmental irritants. In support of this, allergies such as eczema and hayfever are increasing, worldwide among young children. But in some countries (such as the UK) asthma rates are still rising, while countries like Australia are reporting a plateau among older children (ages 13-14).

This latest study is in line with other research studies that raise questions but can not provide definitive answers for parents. House dust mite (HDM) droppings are know to be a common irritant for many people with asthma and allergies, but recent research does not support conventional management strategies, such as HDM avoidance. There are controversies about whether breast-feeding beyond 6 months protects infants from developing asthma or makes them more vulnerable. Are antibiotics not a risk factor in the development of asthma, are they protective, or pre-disposing?

I recently wrote about criticisms about the validity of claims made for the results of some sponsored drugs trials for asthma. In the Lancet editorial, they note that
[e]ven large drug trials are often hampered by imprecise definitions and are seldom comprable in terms of inclusion criteria, symptom or disease type or severity, and outcome measures.
The editorial gives an overview of research that is identifying different wheezing or asthma phenotypes in children who do not go on to develop asthma. Because standard lung function tests are not practical for young children these differences have led some doctors and researchers to prefer the diagnosis of pre-school wheeze rather than asthma in young children. N.B., I accept what The Lancet tells me but I have never met a parent who told me that their child has pre-school wheeze; all of them have told me that the diagnosis is asthma.

Similarly, for some time, researchers have suggested that research into asthma in adults may be providing conflicting results because asthma is not a single disease entity.
[P]erhaps, asthma as a symptom is really only the clinical manifestation of several distinct diseases. As Martinez explains, until the 19th century fever was regarded as a disease and maybe in 20, 30, or 50 years' time we will look back at asthma in the same way.
Other researchers speculate that the simplest explanation for the different phenotypes is that they are different time points in the progression of a single pathology, that of airway inflammation. People's progress along the timeline reflects their genetic predisposition and vulnerability to various triggers.

The editorial concludes with a rallying call to abolish the concept of asthma as a single disease entity.
[W]hy wait? Rather than confusing scientists, doctors, and patients even further, is it not time to step out of the straightjacket of a seemingly unifying name that has outlived its usefulness? The conclusion should surely be that it is best to abolish the term asthma altogether.
For some time the categories of asthma have been expanding to include categories such as pregnancy-related asthma, and many new varieties of occupational asthma. I have some sympathies with the argument that there are so many varieties of asthma that it is no longer a useful concept, but I would have like the editorial writers to at least have made some suggestions about the new diagnoses and categories. Is pre-school wheeze to be distinguished from hyper-reactive upper-airways syndrome in children? For some time, received wisdom says that new-onset allergic asthma rarely happens in the over-30s but there seems to have been an upswing in older adults presenting with allergic asthma.

The concept of asthma may have outlived its usefulness but it is premature to abandon it before we have useful categories with which to replace it.

Edit 28 Aug: I'm grateful to a correspondent who suggests that this might create branding problems for Asthma UK because Lots-of-different-disorders-some-possibly-allergy-driven UK doesn’t really have the same catchy appeal. I'm in favour of The Disease Formerly Known As Asthma if that's not too 90s.

For more information about the images used in the illustration, click on it or visit the detail on Flickr.

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Saturday, August 26, 2006

Worldwide Trends in Asthma and Allergy for Children

Mosaic of letters read ISAACChildren throughout the world are more vulnerable to common allergies; the rates of asthma, hayfever and eczema increased more often than they decreased between 1991-2003. These are the findings of a large-scale project has reported current trends in common allergies among children in 56 countries:Worldwide time trends in the prevalence of symptoms of asthma, allergic rhinoconjunctivitis, and eczema in childhood: ISAAC Phases One and Three repeat multicountry cross-sectional surveys.

Researchers evaluated two age groups. They questioned the parents of more than 193,400 6-7 year-olds and spoke to more than 300,000 children aged 13-14 to collect information about symptoms.

Young children were the most likely to be affected by allergies. The increases were greatest for eczema in the younger age group and hayfever in both age groups. Pooling the results for all of the research centres, the asthma symptoms decreased among older children, who had previously been a high-risk group for the disease.

However, in the UK, where researchers collected data on 1,700 children, asthma prevalence increased from 18.4% to 20.9%, hayfever from 9.8% to 10.1%, and eczema from 13% to 16%.

Combining the results from all of the research centres, there was a slight increase in children who reported symptoms of more than one disorder.

Speaking about the findings, Professor Innes Asher, from the University of Auckland in New Zealand, said:
The data have direct relevance for health service delivery in the countries included in the study, as well as providing a basis for understanding these disorders.

In almost all centres, there was a change in prevalence of one or more disorders over time. Although changes in mean annual prevalence to the order of 0.5% might sound small, such changes could have substantial public health implications, especially since the increases took place most commonly in heavily populated countries.

For more information about the images used in the illustration, click on it or visit the detail on Flickr.

Wednesday, August 23, 2006

Severe OSA Leads to Changes in the Brains of Children

Mosaic of children asleep in odd places plus a father and sonGood quality sleep is essential to the normal development of children. I run the Breath Spa for Kids project because of my interest in the impact of sleep-disordered breathing (SDB) on the physical, cognitive, emotional and behavioural well-being of children. SDB is an assortment of ways in which children have difficulties with breathing when they are asleep. The conditions range from simple snoring to obstructive sleep apnoea (OSA).

Apnoea means that somebody has stopped breathing for a brief time. OSA indicates that there is a repeated, temporary blockage of the flow of air to the lungs. OSA in children has some different criteria to those of adults; e.g., it may involve partial rather than total blockage in children. OSA tends to happen in children who have enlarged tonsils, chronic allergies or obesity. About 2 in every 100 children have OSA; of them, an estimated 17% have severe OSA (number based on the assessment of children who attend a specialist clinic). Several symptoms are characteristic of OSA:
  • loud snoring or snorting at night
  • breathing stops and starts; breathing may sound laboured
  • coughing; the child may sound as if they are gulping or choking
  • disrupted, fitful or restless sleep; maybe restless legs
  • excessive night-time sweating; persistent bed-wetting in children older than 6
  • grogginess or undue tiredness during the day for the apparent hours of sleep
  • hyperactivity, irritability or difficulties in concentration.
The confirmatory test for OSA is a sleep study (polysomnography; the American Sleep Apnea Association offers a discussion of sleep studies for children). However, researchers report that sleep studies do not always identify children with SDB or OSA; habits such as habitual mouth-breathing during the day may be clinically relevant in conjunction with other symptoms.

Research indicates that if OSA is untreated, it is associated with later long-term problems with health and learning. An overview of the research in SDB in children indicates that it is linked to: memory problems, underperformance on intelligence tests; impaired decision-making and executive function (the ability to adapt to new situations and to apply older memories and learning to new tasks); emotional and behavioural problems that resemble those of attention deficit disorder (ADD) and attention deficit hyperactivity disorder (ADHD); long-term health conditions such as hypertension, cardiovascular disease or diabetes.

Research shows that adults with OSA display abnormalities in parts of their brain, specifically the frontal cortex (difficulties in organisation; undue perseveration), cerebellum (balance and movement; attention and understanding), and hippocampus (memory and spatial navigation). There are no studies that document similar changes in children. Observational studies indicate that children with OSA may have quantifiable cognitive deficits but there is a need for research to confirm that this is attributable to neural changes.

So, at the risk of sounding like I don't have a life, it was exciting to learn that researchers from Johns Hopkins have discovered changes in the brains of children with severe, untreated, OSA. Childhood Obstructive Sleep Apnea Associates with Neuropsychological Deficits and Neuronal Brain Injury is this bed-time thriller. And I have a feeling that it will feature in the overview section of my upcoming presentation at a sleep-disorders workshop. If it seems like I'm overstating this, Dr. Ronald Chervin, the director of the University of Michigan Sleep Disorders Center, wasn't involved with the study, but commented on the results to Health Day:
This is paving new ground, scary new ground. The fact that children with sleep apnea would score worse on neurocognitive testing than normal children is not new. The new part is actually showing evidence of neurochemical changes in the brain.
The researchers compared the brains of healthy children and those with OSA to investigate whether there was any evidence of changes in the brain and to assess whether these changes were associated with any learning problems. They studied 31 children aged from 6–16 years: 19 with moderate-to-severe OSA and 12 non-snoring, healthy controls. (N.B., there is no general agreement on the categorisation of mild, moderate or severe OSA in children and the criteria are different to those used in the assessment of adults.)

The children participated in polysomnography and neuropsychological assessments, such as IQ tests and tests of their ability to carry out tasks that involve decision making. The researchers collected a lot of interesting respiratory data about apnoea rates, drops in oxygen levels, increases in carbon dioxide levels, and other measurements that I would ordinarily find to be fascinating in themselves if they weren't overshadowed by other findings.

Some of the children went on to have specialised scans of their brains (proton magnetic resonance spectroscopic imaging MRSI). The children with OSA showed changes in particular brain regions that are associated with higher brain function: the hippocampus and the right frontal cortex.

The MRSI measured the levels of particular neuronal metabolites—substances that are by-products of brain activity. The scans revealed that the children had ratios of certain brain chemicals that suggest injury to brain cells: they calculated the ratios of each two from N-aceytl aspartate, creatine and choline. The degree of neurochemical change resembles the changes that are typical of diseases in which there is damage to brain cells.

The researchers looked at the neuropsychological assessment scores and the neurochemical measurements. The children with OSA scored lower on the IQ tests (mean scores of 85 v. 101): they also performed worse on the standard tests of verbal working memory (8 v. 15) and verbal fluency (9.7 v. 12) and similarly, for other executive functions like decision making. The researchers have established a link between changes in two brain structures and measurable, statistically significant, deficits in cognitive performance.

Interestingly, and in contrast to previous findings in adults with OSA, the researchers report that some executive functions associated with these brain areas (i.e., problem solving, planning, inhibitory control, and sustained attention) were not affected in children with severe OSA.

Research on sleep-quality and SDB in children shows that fragmented sleep, SDB and low oxygen levels are linked to lower ability to concentrate and poor performance at school. However, Dr. Ann Halbower, the lead researcher, believes that this study is the first to demonstrate quantifiable changes in the brain’s chemistry and to link it to OSA. Discussing the findings, she cautions,
We cannot say with absolute certainty that sleep apnea caused the injury, but what we found is a very strong association between changes in the neurons of the hippocampus and the right frontal cortex and IQ and other cognitive functions in which children with OSA score poorly. This should be a wake-up call to both parents and doctors that undiagnosed or untreated sleep apnea might hurt children’s brains. This is truly concerning because we saw changes that suggest brain injury in areas of the brain that house critical cognitive functions, such as attention, learning and working memory.
There is a lot of research that documents the correlation of untreated OSA and SDB with cardiovascular disorders and learning and memory problems in both children and adults. However, many researchers speculate that OSA is more damaging to children than adults and might interfere with critical development. Because the frontal cortex matures during adolescence through until the 30s, researchers are apprehensive that early insult to this region might result in persistent, long-term cognitive deficits that have a significant effect on a person's social and economic well-being. Halbower and her colleagues
speculate that untreated childhood OSA could permanently alter the trajectory of a developing child's ultimate cognitive potential, resulting in a lifetime of health and economic impacts.
The researchers intend to evaluate whether treating the OSA will reverse the neurochemical changes in the children's brains and if the performance deficits will disappear. They also have several interesting questions about the influence of gender and age on vulnerability to the effects of OSA. Their final thoughts echo those of the authors of Snoring in children: still many questions, only a few answers.

OSA happens because there is a partial or complete obstruction of the airways during sleep; there may be anatomical and/or neuromotor factors. In children, OSA tends to occur because of swollen tonsils and adenoids, and the commonest treatment is surgery to remove them. (Tara Smith offers an interesting speculation that the surgery is helpful not only because it removes an obstruction but because it removes the tonsils that may be a source of strep. infections: she discusses some Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections that have a range of cognitive, emotional and behavioural symptoms.)

Previous studies indicate that OSA-related impaired neurocognitive functions are mostly reversible following AT. Another study reported that there was a maintained reduction in behavioural abnormalities after treatment. Children with OSA also tend to have lower quality of life (QOL) as measured on various scales; QOL improves after AT.

However, adenotonsillectomy (AT) is not a risk-free procedure for children with severe OSA. In one study of urgent AT, 60% of the children had postoperative respiratory complications that required a medical intervention; 20.3% needed a major intervention. Even in the control group who had had a sleep study and an elective AT, 36.4% children had postoperative respiratory complications leading to a medical intervention; 6% required a major medical intervention.

Children don't always experience relief from OSA following surgery: persistent, residual mild OSA will be found in more than a third of children following an AT. The authors suggest that such children might benefit from anti-inflammatory treatment such as intranasal steroids and anti-leukotrienes.

Children who do not improve after AT, or for whom surgery is contra-indicated, may be among those who benefit from a CPAP machine to maintain a positive pressure to keep the airways open and the airstream flowing to the lungs.

Dr. Halbower and her colleagues suggest:
There may be a spectrum of SDB, from sleep fragmentation, to mild disease, to more severe disease. However, chronic sleep disruption during active brain development could potentially lead to permanent decreased cognitive potential, thus causing as serious a situation as oxygen deprivation to the brain.
I have had some success in my pilot project to re-train the breathing of children with SDB; their parents report an improvement in their children's symptoms. However, I don't have funding for sleep studies or 24 hour ambulatory monitoring so this is 'anecdata' that is in search of a larger-scale and appropriate study. I have never worked with a child with OSA that has been verified by a sleep study. I am searching for a collaboration with an ENT specialist who has children with SDB/OSA on a waiting list for surgical treatment. It would be interesting to re-train the breathing of those children and then re-run the sleep studies.

For more information about the images used in the illustration, click on it or visit the detail on Flickr.

Monday, August 21, 2006

Replacing Mattresses and Ventilating Bedrooms Reduces Dust Mite Levels

We sleep in a house dust mite (HDM) latrine. Like the worst of home-wrecking vandals they leave their (albeit invisible) sewage all around our homes: they particularly favour our humid, warm and cosy soft-furnishings. Continued exposure to high levels of HDM allergens is thought to be a risk factor for sensitisation to HDM (or, more accurately/euphemistically, their droppings) and the development of asthma in people with a relevant family history.

Mattresses are a principal source of HDM allergens in people's living environments. Mattresses are exposed to hours of our body heat and our perspiration and then left to stew for more hours. The Tooth Fairy does not have a Bed-Making Fairy colleague that airs the mattress and bedding for people who neglect to do this for themselves. So, the HDM breed happily in all those tropical temperatures, snacking the while on our discarded skin flakes and then taking a line from all the "Do the woods" jokes, they deposit their waste in the mattress, pillows and bedclothes. It is no wonder that after a few years use, HDM and their droppings make up 10% of the weight of the average mattress.

Earlier this year, we learned that specific mattress characteristics affect the concentration of HDMs. Researchers sampled HDM concentration in mattresses and, at the same time, measured the humidity and temperature of the bedroom. They discovered that a synthetic upper layer of the mattress went hand in hand with a higher level of HDM when compared with a cotton upper layer (2.6 vs. 0.8 microg/g). A higher relative humidity (RH) was also linked to higher concentrations and density of HDM.

Oddly enough, the assocation between the nature of the upper layer of the mattress and the concentration of HDM had not been described before. They identified two factors in their research that seem to lead to lower levels of HDM in mattresses:
  • a cotton upper layer of the mattress compared with a layer of synthetic material
  • lower RH at the time of sampling.
The authors hope to carry out further research that would be of practical benefit to mattress makers and purchasers in identifying ways to reduce HDM allergen concentration.

So, from the UBO, we now have studies that advise us that we can reduce the level of dust mites in the bedroom if we replace old mattresses and increase a room’s ventilation.

Distribution and determinants of house dust mite allergens in Europe: The European Community Respiratory Health Survey II: researchers wanted to determine the distribution of two common HDMs and the conditions that would affect the level of those allergens in each home.

They collected more than 3,500 samples of dust from mattresses found in homes in 22 different study centers throughout Europe: they analysed the samples for different HDM allergens. The samples were obtained by stripping the mattress of bedclothes: they placed an 80cm x 125cm template on the area where the participant usually slept, and vacuumed to collect the dust samples.

The researchers report that Der 1 and Der 2 HDM allergens were present in 68% and 53% of all samples, respectively. There were large differences in HDM allergen levels among the study centers and geographic regions. Significant risk factors for high HDM allergen levels included an older mattress, a lower floor level of the bedroom, limited ventilation of the bedroom and, for one of the dust mites sampled, the level of dampness in the bedroom. Zock and his colleagues advise that HDM allergen exposure may be reduced by replacing the mattress regularly and increasing ventilation in the bedroom, particularly in winter.

The take-home message is that beds and bedrooms are not self-regulating environments: they need to be managed.
  • Mattresses and pillows may need HDM-proof covers: they also need to be replaced on a regular basis.
  • Bedding should be washable and changed regularly.
  • The bedclothes should be aired each day by hanging the duvet and top sheet over the bottom of the bed, or even out of the bedroom window (depending on the design of the window and your proximity to major roads).
  • The room should be aired - again, taking local traffic patterns into account.
  • Soft-furnishings should be kept a minimum in bedrooms.

Sunday, August 20, 2006

Paediatric Grand Rounds Wants Your Post, Please

Mock-up cover for Standing Baby magazineYes, it is out with the begging bowl, as I shamelessly rattle the post collection bag and ask you for your contributions to Paediatric Grand Rounds 1:10. As you can see from the magazine cover, we are open to conventional and more off-beat topics.

Our host is Hannah of Milliner's Dream.

Please send the posts to Hannah by Saturday August 26.

Clark Bartram is looking for hosts for future PGRs. You can consult both the hosting schedule and earlier editions in the Paediatric Grand Rounds archive.

For more information about the image used in the illustration (from Tedsblog), click on it or visit the detail on Flickr.

Saturday, August 19, 2006

Breastfeeding Beyond 9 Months Increases Allergies and Asthma In Some Groups

Mosaic of babies, feeding and at rest
Yes, it is another one of those studies that is partially modifying received wisdom and filling the newspapers although I haven't yet succeeded in tracking the journal paper (assuming it exists). There is no question that wherever possible, Breast Is Best, but for how long? And is this uniformly true or does it have different consequences for babies born into families with a history of allergy or not? A study by a Finland hospital reports that when babies are fed exclusively on breast milk for more than nine months they may have an increased risk of allergies and asthma.

Previous studies revealed that babies who are exclusively breast-fed for the first six months of their lives have a decreased risk of allergies including eczema and asthma. However, it seems as if when babies are fed only breast milk for nine months or longer they show an increased incidence of allergies and asthma.

20 years ago, scientists asked 200 mothers to breast-feed their babies for as long as practical. The researchers then assessed the children for allergies at the ages of 5 years, 11 years and 20 years. More than half of the children who were exclusively breast fed for 9 months or longer and had a family history of allergy were showing symptoms of allergies by age 5, compared to fewer than than a fifth of those who were breast-fed for 2-6 months.

All of which may seem either welcome news or useless noise in the general discussion about breast-feeding. Breast is best but are there limits? Now, the usual guidelines advise that a mother should breast-feed an infant exclusively for the first 6 months. This is said to populate her baby with the beneficial effect of her own immune system until the baby's immune system is mature. The current speculation is that where there is a family history of allergy, if a baby is breast-fed beyond 6 months then there is too little challenge to the baby's immune to allow it to develop properly.

Well, just to muddy the waters further, it is not that straightforward. A recent australian study examined the issue: Atopic disease and breast-feeding--cause or consequence? The authors argued that:
Early signs of atopic disease might prolong the duration of exclusive breast-feeding. This could mask a protective effect of breast-feeding or even result in breast-feeding appearing to be a risk factor for the development of atopic diseases. Future investigation of the relationship between breast-feeding and atopic diseases should consider this possibility.
A recent review, Primary prevention of childhood asthma and allergic disorders, summarised the difficulties.
In the prevention of these [allergies and asthma], the effects of breastfeeding are controversial, with studies showing a protective effect in children without allergic predisposition, but other studies showing no effect or even the potential for an increased asthma risk.
Further to the above, newspapers report a separate study at Stockholm's Karolinska Institute that babies who are breastfed are able to cope with stress later in life better than bottle-fed babies. Newspapers that don't give enough information to allow me to trace the paper on Entrez Pubmed are fast becoming a pet peeve. Anyway, I found the paper, Breast feeding and resilience against psychosocial stress. The researchers looked at a long-term study of UK schoolchildren and found that children who had been bottle-fed displayed more anxiety following their parents divorce/separation than children who had been breastfed. They report that:
[b]reast feeding is associated with resilience against the psychosocial stress linked with parental divorce/separation. This could be because breast feeding is a marker of exposures related to maternal characteristics and parent-child interaction.
If you have a newborn whom you are breast-feeding, and you have a family history of allergy or asthma, then it may be worth discussing how long you should breast-feed for with your doctor or Health Visitor. However, so far, all of the research reinforces the general message that, wherever practical, Breast is best.

For more information about the images used in the illustration, click on it or visit the detail on Flickr.

Friday, August 18, 2006

Defective Yeti, Terrorists, Teenagers and Behaviour Detection

Range of facial expressions depicting negative emotionsA hat-tip to the always enjoyable Defective Yeti for his irreverent coverage of the role of behaviour detection officers at airports. I work with a lot of teenagers who refuse to come out from their hooded tops or baseball caps. They speak in monosyllables and spend a lot of time in shoe-gazey mode, particularly when accompanied by parents. Courtesy of the photographs, I now know that they spend a lot of time torn between disgust and anger.

Matthew astutely observes that the average teenager would never be allowed to fly anywhere if these rules were applied rigorously.
in addition to having to forgo your iPod and hair gel you will now be required to check in your teen prior to boarding
As ever, the comments are great fun.

The photograph and quotation from Matthew's post is distributed under Creative Commons.

Thursday, August 17, 2006

Systemic Steroids Outperform Inhaled Steroids In Mild-to-Moderate Exacerbations

Mosaic of letters reads AsthmaCorticosteroid therapy is the treatment of choice for preventing asthma flare-ups. However, the recommendation is that children should take the minimum effective dosage at which asthma symptoms are well-controlled. When a child is using inhaled corticosteroid (ICS) therapy then parents should be aware of the symptoms of adrenal suppression; this is particularly true if a child needs repeated courses of steroid tablets.

So, it is a little difficult to know what to do with a trial that reports steroid tablets (prednisolone) is superior to high doses of ICS (fluticasone) for children who present to the ER with mild-to-moderate acute asthma exacerbations.

High-dose inhaled fluticasone does not replace oral prednisolone in children with mild to moderate acute asthma is an interesting paper. Dr. Schuh and her colleagues had conducted an earlier study in which they discovered that oral steroids were (unsurprisingly) more helpful than increasing ICS doses in managing an acute severe asthma exacerbation. However, when they ran a trial to examine whether the same is true for mild-to-moderate asthma in children, they found that steroid tablets were, again, more effective. Dr. Schuh is reported to have said,
Oral corticosteroids therefore appear to be the formulation of choice in both mild and severe disease.
Researchers assessed 69 children aged 6-17 years who presented at the ER for asthma care. The lung function (FEV1) ranged from 50% to 79% of predicted values for height, age and gender.

All patients were treated with a short-acting reliever (albuterol). They also received used a high-dose ICS (2 mg of fluticasone via a metered dose inhaler) or 2 mg/kg of oral prednisolone: as appropriate for the masking, there were placebo pills or inhalers.

All patients took salmeterol home with them at discharge plus a steroid maintenance regime of half of the acute dose. The ICS group received a dry powder fluticasone inhaler with instructions to administer 500 mcg twice daily for 5 days and the 'appropriate dosage' of prednisolone placebo. The prednisolone group continued with 1mg/kg of oral prednisolone for 5 days along with the 'correct dosage' of ICS placebo.

4 hours after the initial emergency intervention, lung function increased by 19.1% (+/- 12.7%) in the ICS group and 29.8% (+/- 15.5%)in the prednisolone group. It is very annoying that the abstract does not include the p values for this. Response was assessed as excellent in 76.7% of the prednisolone children versus 46.7% of the ICS group.

At 48 hours, the difference was not significant, and by 6 days the researchers reported that it was "negligible". Counterbalancing this however, at 48 hours, four (12.5%) of the ICS children had relapsed versus none of the prednisolone group.

The researchers argue that ICS such as fluticasone are not recommended because children improve "faster on oral than inhaled corticosteroids" during an exacerbation. I need to reserve my judgment for the full paper. However, I'm not convinced that the researchers have taken the potential risks of repeated courses of oral corticosteroids into account. A 1996 study evaluated factors that might be associated with increased risk of death in a sample of 108 children or young adults who had died, and in whom death was preceded by an acute asthma exacerbation. Adrenal suppression was found in 18.7% of these cases although the people reviewed here had taken several courses of systemic corticosteroids (e.g., they had taken tablets). Although the mechanisms are not understood, the researchers
conclude that, in addition to established risk factors, complications associated with the use of systemic steroids may contribute to the risk for sudden death in this age group.
I have some reservations because this trial, by necessity, involved a convenience sample of children who reported to a tertiary level ER. A high number of families refused to participate in the study. It may be that courses of oral steroids are preferable when there is a history of non-compliance with ICS but I would like to see some evidence that the wider landscape than the research question has been taken into account.

I do feel conflicted on this issue because if children have been known to deteriorate quickly, I do suggest that parents should discuss with a GP/specialist whether they need to have a course of oral steroids available to administer quickly. In my experience, one of the best compromises is having a supply of steroid tablets, and knowing that they can contact the GP or an out-of-hours service to check whether it is appropriate to give them.

Yes, oral steroids may be superior in the first 4-48 hours, but does this have wider implications and consequences for the child's future health if all of their exacerbations are treated with tablets rather than higher doses of ICS? It is interesting that the ICS group showed such a high relapse rate. Nonetheless, I doubt that this research will force a revision of the guidelines until it is demonstrated that the benefits outweigh the risks.

Wednesday, August 16, 2006

Back To School Preparation Includes Remaining Free Of Colds And Flu

A snuffle of soft-toy viruses and bacteria: mostly upper-respiratory tractBack to school can mean back to what seems like a permanent cold for many children (and the families who catch the viruses from them). For children with asthma, colds and flu are more than inconvenient; in children, 80% of asthma attacks are linked to colds [1-2]*. Colds and flu seem inevitable but there is a lot that can be done to minimise the risk of contracting the viruses.

They may be common, but there are lots of misunderstandings about colds and flu. A cold is an upper respiratory tract infection: the symptoms include a sore throat, a running or stuffed nose, headaches, sinus pain and low-grade fever (the Common Cold website is an excellent resource). Flu is generally accompanied by a higher fever, a sore throat, a cough and general aches and pains throughout the body. Symptoms are the body's response to viral infection. Although colds and flu are viral, they can be accompanied by secondary bacterial infections; the risk of this is much greater with flu. Flu can have serious complications in high-risk individuals like asthmatics, the very young and the elderly: rarely, people with severe symptoms may need to be hospitalised.

Adults have an average of 2 to 3 colds per year; children have 6 to 10, depending on their age and exposure**. There are almost 200 different cold viruses. Rhinoviruses cause at least half of colds. Children's noses are the major source of cold viruses. There are some preparations that you can help your child with before returning to school: these preparations can minimise the impact of these infections on your children and reduce any illness-related absences from school.

There are 3 flu viruses with many strains. In the UK, 4-15% of people over 20 years old have flu each year. In the UK, more than 150 million working days are lost each year because of flu-related illnesses at an estimated cost of £6.75 billion.

True and false for colds and flu:
  • The best way to prevent a cold is to wash your hands.
    • True. If you are vulnerable then avoid people with colds. People generally understand the need to keep fingers away from the nose and mouth but may not know that the same advice applies to eyes. We all have nasolacrimal ducts; these ducts allow tears to drain from the eyes to the nose. That's why we may have a "runny nose" when we cry. So, we should avoid touching our eyes: viruses on fingers can be transmitted from the eye to the nasolacrimal duct to the nose and throat.
  • Cold viruses can contaminate environmental surfaces such as doorknobs, pens etc..
    • True. A cold virus can only reproduce in living cells. However, environmental surfaces can be contaminated with cold viruses where they can survive for 30s up to several hours to be picked up by the next user who will then be contaminated. The cold virus is transported to the front of the nasal passages by contaminated fingers or inhaled in droplets from coughs and sneezes. As few as 1-30 particules of virus are enough to produce infection in the vulnerable. (Alternatively, if you wipe your eyes with contaminated fingers, you can transmit the virus to the nose in that way and the rest of the mechanism is the same.)
      The virus is then transported to the back of the nose and onto the adenoid area by the nose itself.
  • You can catch a cold by staying outside in the cold too long.
    • False. Being in the cold can lower our resistance to cold viruses with which we are already contaminated or it can weaken our defence mechanisms: being cold doesn't give us a cold infection. One of the reasons that we develop more colds in the winter is that because we might spend more time indoors and in contact with other people. In an interesting experiment, the results indicate that your mother was right if she told you to wear a scarf in the winter, particularly over your nose and mouth. Read about why you should keep your nose warm and why you should breathe through your nose to maximise the body's anti-viral defences.
  • Antibiotics can cure a cold or the flu.
    • False. A cold or flu is a virus, and, therefore, cannot be treated with antibiotics. Antibiotics are only useful if there is a secondary bacterial infection. There are medications that can improve the symptoms of colds or flu and make us feel better. If you are in a high-risk group then you should talk to your doctor about flu vaccination. There is no vaccine for the common cold.
      There are anti-viral drugs for flu that can reduce symptoms and reduce the length of time for which it lasts. The anti-virals need to be taken within 48 hours of the onset of symptoms. If your child is in one of the vulnerable groups or is facing exams then you might ask your GP whether it is appropriate for your child. The anti-virals are most appropriate for high-risk groups (the elderly, people with lung disease, heart disease, kidney disease, diabetes, or those with a compromised immune system or people who live in nursing, residential or long-stay homes).
  • If you have the flu, you should stay away from work/school.
    • True. Going to work/school can expose others to infection. The best advice is to rest and recover. Cold symptoms can be managed with various OTC products if they are inconvenient.
  • Cover your mouth with your hands when you cough/sneeze.
    • False. Maybe. There is a new cough/sneeze etiquette. If you can cover your hands with a handkerchief then you should sneeze into the handkerchief, dispose of it quickly and appropriately and then wash your hands. (A handkerchief contains 15,000 germs after just 30s use.) If this isn't practical, then the new advice is to cough/sneeze/wipe your nose on your sleeve which keeps your hands free from contamination.
      Make sure that an older child knows how to blow the nose properly (hat-tip to the excellent Flea for this guide).
      Encourage children to breathe in and out through the nose wherever practical (even when asleep): there are substantial benefits.
  • Flu shots can give you the flu.
    • False. Flu vaccines are deactivated forms of the virus. Flu shots may produce very mild flu-like symptoms for a short period, but this is rare. Flu vaccination is essential for vulnerable groups.

*A longitudinal study that assessed more than 100 children identified the predominant underlying viruses that are responsible for asthma exacerbations (table taken from reference 1). Respiratory viruses were detected in 83% of the patients.

Table- Underlying viruses responsible for asthma exacerbations.

Micro-organism Percentage (%)
Rhinovirus (RV) 46
Respiratory sinsitial virus 18
Mycoplasm pneumonia 14
Corona virus 12
Chlamydia 5
Influenza 3
Para influenza 1
Adenovirus 1

1. Johnston, S.L., Pattemore, P.K., Sanderson, G., Smith, S. Lampe, F., Josephs, L, Symington, P., O'Toole, S., Myint, S.H.,Tyrrell, S.A. et al. Community study of role of viral infections in exacerbations of asthma in 9-11 year old children. Br Med J 1995; 310: 1225–9.
2. Copenhaver, C.C., Gern, J.E., Li, Z., Shult, P.A., Rosenthal, L.A., Mikus, L.D., Kirk, C.J., Roberg, K.A., Anderson, E.L., Tisler, C.J., DaSilva, D.F., Hiemke, H.J., Gentile, K., Gangnon, R.E. & Lemanske, R.F Jr. Cytokine response patterns, exposure to viruses, and respiratory infections in the first year of life. Am J Respir Crit Care Med 2004; 170: 175-80

**These numbers vary. According to on the common cold: "on average, preschool children have 9 colds a year; those in kindergarten, 12 colds a year; and adolescents and adults, 7 colds per year". Teachers, doctors and others with extensive contact with children tend to have more than their fair share of colds. If you are one of these adults, and have no contra-indications, you might consider experimenting with nasal irrigation to see if it reduces your symptoms or vulnerability.

Monday, August 14, 2006

Back To School Preparation Includes Sleep Patterns

Mosaic of children asleep in odd places plus a father and sonYou may be buying school uniforms and bribing the children with logo'd stationery. You may even be planning ahead for packed school lunches and re-checking school run arrangments. But, if the children have been staying up late and sleeping in, have you thought that you may need to get them back into a sleep routine that means they are well-rested for school?

Some children are remarkably adaptable; they will quickly change-over to a new back-to-school sleep schedule. Other children may find it difficult to adjust to earlier bed times and wake-up times. They may be tired and irritable and find it difficult to concentrate at school.

Prepare for the school year. If your children have time-shifted their bed-time and waking-time until later, encourage them to shift the times back. Start off by encouraging the children to go to bed 30 minutes earlier, and to rise 30 minutes earlier. Continue to make the gradual adjustments until the children have established their new sleep routines before the start of term.

The US National Sleep Foundation recommends the following hours of sleep per day for children, adolescents and teenagers:
  • Preschoolers: 11-13 hours
  • Elementary school students: 10-12 hours
  • Pre-teens: 9 - 11 hours
  • Teens 8 1⁄2 - 9 hours.
It is widely accepted that lifestyle changes mean that many children and teenagers are chronically sleep-deprived. The duration of their sleep and the quality of their sleep may contribute to physical, emotional and behavioural problems, and difficulty in concentrating at school. Some researchers link sleep deprivation and obesity in a vicious circle.

There are some ways that parents can encourage good sleep habits for children and teenagers.
  • Establish a bedtime routine. Young children need a reliable wind-down routine to help them fall asleep at the agreed time. Younger children may have a bath and bed-time reading routine. For older children, parents need to encourage a winding-down of stimulating activities: e.g., discourage intense activity, heavy eating, television and using the computer or video games.
  • Keep a regular routine for bedtime and wake-up time. If your child has sleep problems, or difficulty at school then keep the same sleep routine, even over the weekend. If your child does not have difficulty in adjusting, then the times can be more flexible.
    • Keep the routine at weekend; don't use them to catch up on sleep. The disruption to the sleep pattern of going to bed late or sleeping in can create sleep problems, especially for adolescents. Allowing this variation can set the ground for regular insomnia.
  • Discuss your child's homework and activities schedule with him/her. Help your child to organise their timetable to allow them to carry out their work, other activities and have adequate time for sleep.
  • Model the behaviour that you want. Parents can benefit from regular sleep habits and keeping a home environment that allows good sleep (e.g., no television in the bedroom; no loud music in the smalls of the morning).
  • When you check on the children while they're asleep, make a note of whether they are snoring, show other signs of sleep-disordered breathing or are particularly restless. Depending on what you observe, you may wish to talk to your family doctor, particularly if your child regularly shows signs of tiredness, hyperactivity, difficulty concentrating etc. during the day. If the children snore 3 or 4 times a week, then you may need to ask your family doctor to assess the adenoids and tonsils.
Back to school preparation may involve improving the sleep patterns of everyone in the family, not just the children. But the more that researchers discover about the role of poor quality sleep and obesity, metabolic disorders, cardiovascular disease etc., the more we realise that sleep is essential to our well-being and our performance. And that this is true for children as well as adults.

For more information about the images used in the illustration, click on it or visit the detail on Flickr.

Sunday, August 13, 2006

Paediatric Grand Rounds 1:9 Is Up! A Testing Experience

Mosaic of images of young children with asthma, blocked nose, breathing well or playingPaediatric Grand Rounds Review and Education Program (PGRREP) is up, courtesy of Clark Bartram of Unintelligent Design.

I've said before that reading Clark Bartram's robustly sceptical posts reminds me of a family friend who is a prosecutor for the Crown Prosecution Service. A while ago, his son was prattling on about the huge 'incey-wincey' in the bath and explaining that this was why his bed-time was delayed. Scenting rannygazoo, his father refused to buy into this explanation and in all seriousness said, "I put it to you that this alleged spider is no more than an artifice". His wife intervened after about a minute of the remorseless cross-examination: "He's 2 years old. 2 year-olds aren't capable of alleging anything. He believes in talking steam trains". The father was abashed, but I feel that in a similar position, Clark would have replied, "Name your source that 2 year-olds can't allege. And, what's your point?".

So, perhaps I shouldn't be too surprised that CB has decided to tack a review and education programme onto the PGR. It is educational, informative, thought-provoking and entertaining. We learn that after all the recent terrorist alerts, there are more reasons than ever for babies to be breastfed. We learn that if someone says there is no family history of asthma you may still need to ask some follow-up questions.

From personal experience, I know what it is like to contemplate organ donation while waiting for a relative to die. There is the present grief and the thought of bringing life and hope to others. I can not imagine what it is like to handle all those thoughts and emotions while awaiting the death of a child. Moreena's child is offered a liver transplant: we learn about her emotions and those she imagines for the family of the donor.
We were told the donor was a teen-ager and from somewhere just outside Chicago. That family's grief and our reprieve were bound together, now through the tenuous connection of a telephone line, but soon to be through the most physical connection imaginable.
On a much lighter note, we all know that Tiggers can do everything. Apparently, that includes helping out Dr. Jest with his young patients.

I commend the Paediatric Grand Rounds to you!

For more information about the images used in the illustration, click on it or visit the detail on Flickr.

Saturday, August 12, 2006

Can You Enjoy Good Phrases And Ignore The Source?

Mosaic reads, context-free quotingCan context-free quoting ever be guilt-free? I come across a well-written or well-articulated phrase several times a month. I enjoy these phrases or entire sentences. I collect them. I seldom use them because I don't always want to check the source and it's not worth the potential hassle of using the quotation without the check.

Does the fact that someone might have views to which you strongly object mean that you can not approve of even a turn of expression by that person? Can you attribute a quotation without appearing to buy into the originator's complete world view or belief system?

I came across a blog discussion on the increase in the murder rate following the abolition of the death penalty in the UK. I've obtained permission from one of the commenters to quote part of his comment.
Sunstein and Vermeule discussed economists' analysis of the death penalty in the Stanford Law Review. The paper asks Is Capital Punishment Morally Required?.

Peter Martin offers a good overview of the paper and the discussion that it generated. In brief, the showcased finding was that each execution results in 18 fewer murders. It was argued that any state that refuses to impose the death penalty was complicit in the murder of 18 other people.

Other lawyers argued against the moral equivalence claims. Another economist re-examined the data and found a way to interpret it so that it could substantiate the hypothesis that each execution carries the cost of an extra 18 deaths. Dononhoe and Wolfers admit that their statistical proof is as partial as that in the studies that they criticise. They nicely quote Dezhbakhsh with respect to John Lott's research on guns: "The academic survival of a flawed study may not be of much consequence. But, unfortunately, the ill-effects of a bad policy, influenced by flawed research, may hurt generations." (pg 845; available in pdf form and worth a read although it is 56 pages. I should add that I don't fully understand the context as I am ignorant of Lott's research: it is just that the comment matches my own opinion of some published research and its impacts).
I like the Dezhbakhsh quotation. I can think of circumstances where I would like to use it. But, for blog purposes, am I interested enough to read through that document, discover the source, obtain and read the source to locate the quotation? It would be different if I were writing for academic publication or even if I were blogging about an topic that interests me (rather than entertains me or fleetingly catches my attention). I was just reminded of it today because I came across Tim Lambert's opinion of John Lott's research. I've no idea what I would think of the Dezhbaksh - maybe I will look it up one day. I do like the way it is expressed - I just feel that I can't use it in a 'serious' setting because I don't know the context.

A review of Half Nelson in the New York Times sparked some of this speculation. It quoted some writing that I really enjoyed but have no realistic chance of tracking down.
The poet W. S. Di Piero once described the work of the Sicilian novelist Leonardo Sciascia as “inquiries into the impossibility of justice and the terminal intellectual fatigue caused by disillusionment.”...A junior high school history teacher, Dan lives with his cat in an apartment filled with books, pages from an unfinished project and furniture that looks dragged in off the street. It’s the kind of apartment that the poor hold onto until they can’t hold on any longer, the kind of dump that cops break into so they can pull out the dead, which makes it the perfect home for a death wish.

Dan wants to save one child at a time, like 13-year-old Drey...but he’s committing suicide one crack vial at a time. He’s plagued by such contradictions, some inherited, others self-generated, teaching in a part of Brooklyn that still looks like Brooklyn, trying to do good in the very neighborhood where he buys his drugs.
Now, I only mean the Di Piero comment on Sciascia but I enjoyed the rest so much that I wanted to quote it.

Can we enjoy elegant or pithy writing but resign ourselves to not quoting it because we don't know the context or the originator has other beliefs that don't accord with our own? There was a story line in The West Wing where a nominee for the Supreme Court was being held accountable for the opinions in an anonymous Law Review piece that he had written 30 years earlier. Now, the nominee hadn't changed his stance but this is a striking example of writing that can be used to undermine everything else that you've done.

Now, we can all aspire to make progress with critical thinking and good writing: I doubt that anyone can achieve it all the time. But there does seem to be a movement towards the position that if you can lampoon an idea or some bad writing, then all of the ideas can be dismissed without consideration. I thought about this when reading Ben Goldacre's lampoon of Deconstructing the evidence-based discourse in health sciences: truth, power and fascism.. You will have a flavour of the paper if I quote the following:
Drawing on the work of the late French philosophers Deleuze and Guattari, the objective of this paper is to demonstrate that the evidence-based movement in the health sciences is outrageously exclusionary and dangerously normative with regards to scientific knowledge. As such, we assert that the evidence-based movement in health sciences constitutes a good example of microfascism at play in the contemporary scientific arena.
We can already hear the objections. The term fascism represents an emotionally charged concept in both the political and religious arenas.
The full paper is quoted in the comments if you really want to put yourself through the whole piece. The writing is egregious and I found it unpleasant to read the paper. I disagree with much of it. Nonetheless, the authors made some points that it might have been interesting to discuss. E.g., do some people award the Cochrane Systematic Reviews (CSR) iconic status? Do the CSRs increasingly define what the outcomes should be for research? Do we have useful, benchmarked outcomes or outcomes about which there is little agreement? Are there valid criticisms of the CSRs or trial methods that do not rely upon claims of microfascism? Will this unreadable paper become the prism that distorts any attempt to discuss the current state of research in evidence-based medicine?

Can we enjoy good phrases and ignore the source? Can we object to bad writing but think that the authors make some useful points that deserve discussion - albeit, not in that forum?

For more information about the images used in the illustration, click on it or visit the detail on Flickr.

Friday, August 11, 2006

Third-Hand Smoke: Logical Or An Alarm Too Far?

Cookie Monster smokes a cigarette
I grew up in a household of smokers: I loathe smoking with a passion that is related to a childhood of tobacco-exacerbated ENT problems. However, even I am caught between nodding my head and rolling my eyes at the news that researchers are warning parents about the dangers of third-hand smoke. Is this just a logical extension of the dangers that we already understand about exposing children to tobacco smoke or is it an alarm too far that will alienate parents who already know that they shouldn't be smoking around their children?

If parents smoke, children depend on their goodwill to take measures to protect them from environmental tobacco smoke (ETS). According to a study in Sweden, one of the commonest strategies is for parents to smoke outdoors.
Smoking outdoors with the door closed was not a total but the most effective way to protect children from environmental tobacco-smoke exposure. Other modes of action had a minor effect.
The researchers emphasised that there is no known "safe" level of ETS. They suggested that their results lend weight to earlier reports that children with
outdoor-smoking parents tend to have a higher prevalence of ear infections and respiratory symptoms than children of nonsmokers but less than children of indoor smokers.
They suggested that parents should be advised that
smoking outdoors with the door closed is a meaningful way of ETS protection, whereas other precautions indoors have little or no effect. Whether outdoor smoking is as good as nonsmoking remains to be shown.
Also publishing in 2004, Prof. Matt of San Diego University and his colleagues reported on a study that found that tobacco by-products were trapped in household dust, carpets, ceiling tiles, soft furnishings etc. and therefore increased children's exposure. These smoking by-products can have a legacy for several months after smoking occurred. Matt and his team used nicotine monitors in the child's bedroom and the main living room. They analysed dust, surfaces, the child's hair and urine for the chemical compounds associated with tobacco smoke.

A column of cigarette smoke passes from one open mouth to another: written under the smoke are the words 'Die with me'Even in homes where the parents smoke outside, the levels of tobacco contaminants were up to 7x greater than in homes where neither parent smokes. In homes where the adults smoke inside, the tobacco toxicity levels are up to 8x greater than in homes where parents smoke outside.

The researchers argue that children are more vulnerable to inhaling this type of third-hand smoke because they:
  • spend more time indoors
  • are in close physical contact with the smoker (e.g., cuddling, changing)
  • breathe more frequently than adults
  • may swallow contaminated items.
Recent news items suggest that an update of this study is on the way that confirms that babies absorb tobacco by-products even when parents smoke outside. Matt reports that up to 90% of the nicotine in tobacco smoke sticks to walls, surfaces, soft furnishings, clothes, hair and skin. We come into contact with this third-hand smoke but babies are at particular risk. Babies touch, inhale, and swallow these chemicals as they crawl about, touching surfaces (e.g., furniture, carpets), or when they hug adults who smoke. Researchers found that these babies had cotinine (a by-product of ETS) in their urine and hair analysis: the higher levels were found even when parents smoke outside the house. In line with the earlier findings, the levels were 7x greater than those found in babies with non-smoking parents and low levels of ETS.

According to the Daily Mail, Ash Anand of the baby charity Tommy's said:
This is certainly worrying news and we would urge parents of babies and young children to cut down, if not give up smoking altogether.
Eh, yes. I don't know when someone is going to offer workshops in how to discourage other adults from smoking around your children. I've never known an adult to accept a request to not smoke: whether or not they are in the overwhelming minority. Dissuading adults from smoking in the open air just seems like an eye roll too far. Picture the scene. There is a family get-together at your in-laws or a play-group social. The children perform their party-pieces. There is a picnic: there is good food, beer and wine. In post-prandial bliss (or during it if you're really unlucky) smokers light up their digestif.

You silently object because a) you don't like it and b) there are children present. But, it is outdoors, how much harm can there be and you're tired of hearing the comparison between exposure to ETS and traffic fumes. Plus, you've never managed to dissuade someone from smoking at the dinner-table - why are they going to be receptive to a request to not smoke outdoors?

So you socialise with your family or other parents and keep your own counsel. When you arrive home you realise that all of you reek of tobacco smoke. The children are snuffly. If you're really unlucky, they are in for sinus problems and ear infections. And you agreed to this on their behalf.

Only parents can make the relative risk assessment for their children. They know how much ETS exposure the children get on a regular basis and what their home environment is like. They know the child's medical history and whether or not they are especially vulnerable (e.g., they have asthma or repeated ear infections).

There is help available for people who are trying to stop smoking. The research indicates that smoking outside with the door closed does reduce children's ETS exposure but it does not eliminate it and there is no known safe level.

Most parents know that the best practice is to give up smoking. If parents feel that this is not the right time, or they are on the run-in to the time when they have decided that they will stop, then minimising children's exposure by smoking outside with the door closed does make sense. It might also be worth considering the use of alternative smokeless-tobacco products when at home that do not expose children to ETS. Bringing up children in a smoke-free home is one of the most significant contributions to children's health that a parent can make.

For more information about the images used in the illustrations, click on them.

Tuesday, August 08, 2006

Shinga Is Off-line

Just a small note from Shinga's husband. She hurt her shoulders when she was doing some DIY (slipped on a ladder) and seems to have pulled her ligaments and various bits and pieces. She is taking ibuprofen etc. but so far it is not helping. I am forcibly removing her from the PC for a day or so to see if she will heal.

Normal service will be resumed as soon as possible.

Sunday, August 06, 2006

Paediatric Grand Rounds Wants Your Post, Please

Mocked-up Magazine Cover For Paediatric Grand Rounds

PGR Founder Clark Bartram is the host of the next Paediatric Grand Rounds on August 13 at his Unintelligent Design where the issues are varied and scepticism is strong.

Reading Clark Bartram's robustly sceptical posts reminds me of a family friend who is a prosecutor for the Crown Prosecution Service. A while ago, his son was prattling on about the huge 'incey-wincey' in the bath and explaining that this was why his bed-time was delayed. Scenting rannygazoo, his father refused to buy into this explanation and in all seriousness said, "I put it to you that this alleged spider is no more than an artifice". His wife intervened after about a minute of the remorseless cross-examination: "He's 2 years old. 2 year-olds aren't capable of alleging anything. He believes in talking steam trains". The father was abashed, but I feel that in a similar position, Clark would have replied, "Name your source that 2 year-olds can't allege. And, what's your point?".

Clark Bartram invites your recommendations and submissions for the next issue on August 13: there is a strong possibility of an ABBA gallery if he doesn't get what he wants - pronto.

Please send the posts to Clark Bartram by Saturday August 12.

Clark Bartram is looking for hosts for future PGRs. You can consult both the hosting schedule and earlier editions in the Paediatric Grand Rounds archive.

Friday, August 04, 2006

New Asthma Test For Children Under 6

Mosaic of images of young children with asthma, blocked nose, breathing well or playingRespiratory disease is the most commonly reported long-term illness in children - in the UK, breathing difficulties account for 34% of weekly GP consultations and 15% of hospital admissions of children. Large and growing numbers of children are labelled and treated as asthmatic because of their symptoms. Doctors are anxious not to miss or under-treat asthma because undiagnosed asthma can have a significant impact on children's development and quality of life.

However, confirmation of an asthma diagnosis depends on spirometry, and that is not practical for use with the under-6s. So, although many children are being treated correctly, and accordance in their symptoms, there is a concern that children who have asthma-like virus-related wheeze are being treated with asthma medications (there are recent suggestions that a substantial number of these cases may be related to whooping-cough). Even though asthma medications are generally safe, there are concerns about even the small risks involved in using them if they are inappropriate.

In the US, the FDA has just approved a new test that involves oscillometry, and is suitable for use in children as young as 2-years-old.

WXPI of Pittsburgh is carrying a story about a young boy who has just used this new test. In a story that will be familiar to many parents, 4-year-old Sam Gerlach had experienced breathing problems and asthma-like symptoms since the age of 18-months. His parents had heard the word "asthma" mentioned frequently, but doctors cautioned them that it is not possible to confirm the diagnosis in such a young child.

Sam's problems led to several trips to the ER and hospitalisations. Management of young children is always a particular problem in the absence of a confirmed diagnosis. This may be changing in the US following the extension of oscillometry testing.

The above link offers a video in which Dr. Deborah Gentile, an allergist and asthma specialist at Allegheny General Hospital in Pittsburgh, explains and demonstrates how oscillometry works with young children and how it can be used to assess asthma.
This device allows them to breathe in and out normally and then it shoots sound waves into their airways and then depending on how it echoes back it measures how open things (airways) are.
The computer calculates the degree of airway resistance; airway resistance is an assessment of asthma. In the video, we see Sam take the test. He is comfortable and follows the instructions easily. Dr. Gentile explains the results on the screen:
His breathing tests are excellent, and his airways are wide open. He's very likely to out grow this problem by the time he starts school.
Dr. Gentile comments that about 50% of children who wheeze will eventually outgrow the problem: those children are virus-induced wheezers. Oscillometry helps doctors to distinguish between those children and others who have persistent narrow airways and a confirmed diagnosis of asthma. It is the latter group who would be at risk of damaging their lungs as they grow. Dr. Gentile expresses her hope:
If we're able to diagnose it early and treat it aggressively the thought is we'll prevent some of the long-term damage we see and actually improve outcomes over time.
This is an interesting development and, if it is widely available, early diagnosis will make a substantial difference to paediatricians and those who are responsible for managing asthma in children.

Respiratory symptoms can be dramatic in children and are distressing both for them and their parents. It is worthwhile teaching children basic hygiene and healthy breathing habits in addition to other techniques that can reduce the impact of these symptoms and make them less vulnerable to viruses. The following tips may be useful if your child has persistent episodes of breathing problems and in general:
  1. Keep your child away from places where he/she is exposed to tobacco smoke.
  2. Talk to your doctor or nurse about techniques for clearing the nose of very young children (there is a wide assortment on the market from simple bulb aspirators to intimidating but widely-recommended gadgets that connect to a vacuum cleaner) and whether it is appropriate for your child.
  3. Teach an older child how to blow the nose properly (hat-tip to the excellent Flea for this guide).
  4. Learn the new cough etiquette. It's not what your mummy taught you. If you can't cover your mouth and nose with a tissue, use your upper sleeve whenever you cough or sneeze. Do not cover your mouth and nose with your hand. Dispose of the tissue carefully and quickly, and then clean your hands.
  5. Encourage children to breathe in and out through the nose wherever practical (even when asleep): there are substantial benefits.
  6. Doctors are understandably reluctant to prescribe antibiotics for a virus: they are inappropriate in the absence of a secondary (bacterial) infection or other relevant medical history. Some doctors will cave in to pressure from parents but this is not necessarily in the interest of the child's health. Follow your doctor's advice.
  7. Encourage your child to play/exercise in the open air every day. Standard restrictions would be that you take account of:
  8. Teach children proper hand-washing techniques etc. to reduce the spread of viruses.

For more information about the images used in the illustration, click on it or visit the detail on Flickr.

Thursday, August 03, 2006

I Can Cope Program: Reducing Stress Triggers And Asthma In Children

A drop of water bounces off jelly: it won't survive another impactHere at Breath Spa we run up a tidy monthly bill in bubble solution, bicarbonate of soda, vinegar and clean-up cloths for our workshops. We do a lot of bubble work (both large and small) to teach children about the size of breath and breathing rate. The children learn how mixing things together can release energy: yes, the soda volcano is not going out of fashion on our watch. We sing songs that are adapted from nursery rhymes for younger children or gross-out numbers for older children (I'm still trying to purchase a recording of the brilliant, Rhinotillexomania). Other people run tidier, quieter and less messy workshops, but it can entirely depend on the age-group with which you are working. And the number of boys. Unless they are painting Warhammer figures or doing something else that fully absorbs their attention, boys tend to be rambunctious.

The Breath Spa Project re-trains the breathing of children who have sleep-disordered breathing: the majority of the children with whom we work also have asthma. We work with children from aged 2 years and up, so we simple emphasise behavioural techniques with children. I've previously described a workshop for young children. When we work with older children, we keep the experiments and the games but include some biofeedback, primarily in the form of their end-tidal carbon dioxide levels (ETCO2), their breathing rate and various other breathing-related data. The children tend to be fascinated to learn that their posture, their emotional state, or how they concentrate when they are performing various tasks can all change these data. E.g., when children are asked to recall a time when they felt safe and happy, in general, their ETCO2 may move up a few points (depending on the baseline)and the breathing-rate may drop. If children are asked to complete a pop quiz in maths, they might have a lot of muscular tension, they may breath-hold or increase their breathing rate and various other changes.

Breath Spa mostly concentrates on behavioural interventions with children and their families. Parents and significant adults have to consent to the programme and participate in it so that they know which new habits we want them to re-inforce and which habits we would like their help to extinguish. We try to involve all of the signicant adults and family members because we need their help in making sure that they children practise good breathing habits and learn how to breathe well and appropriately all of the time. I'm interested in breathing re-training that helps children to breathe well, even when asleep, and at other times when the breathing is not under conscious control. I am wary of programs that teach breathing techniques that are only used as a rescue remedy or as an intervention when symptoms have already started. I think that it is difficult enough for adults to be collected enough to remember to use these techniques when they are already experiencing symptoms, it is that much harder for children.

I am interested in the role of stress in children's asthma flare-ups, as well as asthmatic children's response to environmental exposure to hostility and aggression. I have wondered if there is a role for some form of combined resilience training (something like the popular schools-based Penn Resiliency Program) and the breathing re-training. I favour schools-based programmes rather than individual sessions, because my experience is that it improves take-up of the programme but I am open to different approaches with different emphases.

So, I was very intrigued to read about a new project in Pittsburgh, I Can Cope (ICC). ICC works with children between the ages of 8 and 12 who have a diagnosis of moderate, persistent asthma. The purpose of ICC is to evaluate the effectiveness of a program that is designed to teach children more robust ways of coping with the stresses and daily challenges that affect them. The researchers hope that increasing the children's coping skills will reduce the frequency and severity of asthma symptoms or attacks.

In overview, the program consists of six training sessions over the course of three months. The children attend the university for the sessions. During these one-on-one sessions, the children are coached in different methods of coping with emotions and handling challenges. They learn how to relax and breathe well at times when they are upset or experiencing symptoms of asthma.

All of the children in the program complete a daily diary for four weeks: two weeks at the beginning of the study and two weeks at the end. The diary includes questions about stress, medications and asthma symptoms experienced each day. Children record their peak flow measurement every evening by blowing into a peak flow meter. The children also collect saliva samples, which are used to estimate levels of cortisol, and are understood to be a biological measure of stress.

I have some reservations about the usefulness of measuring cortisol levels. I would need to know more about the study inclusion criteria before I could comment fully. If the children use the commonest reliever or preventer medications on a regular basis then I would question the usefulness of the cortisol levels. Relievers tend to be beta2-agonists, and would therefore stimulate the sympathetic system and perhaps promote the release of cortisol. Similarly, inhaled corticosteroids (ICS) might also provide an artificial bump to steroid production. ICS use has been known to flatten the body's natural cortisol slope. So, I do need to know a lot more about the timing of the saliva collection and the significance that is attributed to the cortisol levels.

Parents and their children are asked to complete a series of questionnaires about their mood and current stresses. The children need to visit the supervising hospital twice, once at the beginning of the study and once at the end, for breathing tests.

The Pittsburgh Post-Gazette recently published a story that gives some insight into the content of the sessions. A 9-year-old girl, Hayley Hardcastle, sits in a darkened room. She imagines that she is a turtle, at rest, on a rock by a peaceful pond. Kirstin Long, the graduate student who runs the sessions, tells her that she senses danger and directs Hayley to pull in her head for safety.

Hayley tenses her neck and shoulder muscles, then relaxes them as the imagined threat disappears. Hayley has sensors on her shoulder that pick up the muscle tension of stress, and display this on a computer screen, giving her visual biofeedback on her body's reaction to stress. This exercise and similar activities are intended to help children like Hayley to cope with their asthma by changing their response to feelings that could leave them upset.

The ICC program helps children to understand how their thoughts, actions and feelings can work together to affect their asthma. The course manual tells them:
How you are feeling or what you are thinking does not cause you to have asthma. But you are more likely to have an asthma attack or begin wheezing at times when you are upset, scared or excited.

By learning to cope with these feelings, you can learn to be in charge of your asthma and to reduce the chance of asthma attacks.
They children use what they have learned to note the stressful situations they encounter in their diaries and reflect on how they can respond more positively. The children are coached in ways that they can stop themselves from making their unpleasant feelings worse, such as talking to a friend or shifting their attention to something else.

The course teaches common relaxation techniques such as "belly breathing" that emphasise slow breathing using the diaphragm. In the training sessions, the children use biofeedback exercises to experience how their emotions can affect the body's functions and different measurements. Hayley practised tensing and relaxing muscles but she also completed an activity during which her hand temperature rose as she grew more relaxed. Watching their biofeedback can be very motivating for children and it can help to emphasise the reality of what they are being taught: e.g., that how you feel or what you are doing can make changes in your body.

Allegheny County is the setting for the study: the asthma rate among children was 10.2% in the 2003-04 school year, up from 7 percent in 1997-98. The study's medical director is Dr. David Skoner, director of allergy, asthma and immunology at Allegheny General Hospital. In an interview with the newspaper, he said, "We think there is tremendous potential benefit".

Dr. Skoner commented that asthma is particularly common among children in inner cities. He acknowledged that in children, 80% of asthma attacks are linked to colds, and allergies are a common factor. However, he is interested in studies that associate stress with a greater risk of catching a cold, and those that indicate that stress may be a trigger for asthma flare-ups.

Dr. Skoner estimates that stress may lead to asthma exacerbations in 5-10% of children with asthma, and it may contribute to symptoms suffered by many others. As part of their sessions, and to help them explore the idea that tension can lead to asthma episodes, the children work with images of a 'worked-up person'. Being 'worked-up' has the classic signs of a churning stomach, pounding heart, irregular breathing, tense muscles and clammy hands.

Dr. Anna Marsland is the study's principal investigator and an assistant professor of psychology, nursing and psychiatry. She created the I Can Cope (ICC) program. Dr. Marsland told the newspaper that a few studies have used relaxation techniques with younger asthma patients as the primary intervention to help them to manage stress. She decided to base ICC on cognitive behaviour therapy (CBT). CBT incorporates several techniques that help people to recognise negative patterns of thinking and reacting to events: they are encouraged to replace these thoughts and actions with more constructive ones.

However, there is not much research on the effectiveness of CBT with children, particularly not for children with asthma. Nonetheless, Dr. Peter Michelson, clinical director of pulmonary medicine at Children's Hospital, is referring children to the study. Talking to the newspaper, he said that if ICC works, CBT could be a "tremendous resource," and reduce the children's need for medications, emergency room visits and other health care services.

Whatever the implications, Hayley and her mother would both recommend the program. Speaking to the newspaper, Mrs Hardcastle said that allergies, sports and stress all contributed to Hayley's asthma attacks, and she "seemed to be heading to the school nurse a lot for breathing treatments." She supported a study that would help Hayley "calm herself down". Mrs Hardcastle reported Hayley has used some of her medications less frequently since her participation in the study. Hayley also reported improvements, "I've learned what stress really is and how it affects my asthma".

ICC sounds like an interesting study and I would like to know more about it.

For more information about the images used in the illustration, click on it or visit the detail on Flickr.