JAMA 17 Nov 2010 Vol 304
Like all doctors who survived their hospital jobs in the 1970s, I have some shocking memories. Oddly enough, though, some of them are happy too, as the shocks saved lives. The woman dragged out of a freezing canal with a core temperature of 28ºC who survived intact after 16 defibrillations; the 43-year old man with chest pain who went into VF just as we were putting the leads on his chest: all of us can still remember these kinds of event, while our futile attempts go forgotten days after. Surely an automated defibrillator must beat a sleep-deprived, dishevelled house doctor at achieving survival following in-hospital cardiac arrest? Actually no: another massive US cardiac outcomes study looks at the results of introducing automated defibrillators on to the wards of 204 hospitals and finds that results actually tend to be worse.
The harmful effects of low-dose ionizing radiation are not well understood, but from about 100mSv upwards we are no longer talking about low doses, but the kind of exposures about which we have data from Hiroshima and Nagasaki. Alarmingly, such doses were received by a third of patients in this study of repeated myocardial perfusion scanning. OK, the majority of these people were over 60 and had heart disease, and would escape long-term harm: but it suggests that we are getting too gung-ho about exposing people to high energy photons from X-ray machines and unstable isotopes, and the cumulative damage which they cause.
Pseudomonas aeruginosa is a bacterium that demands respect: it has a vast genome and eats anything from shower curtains to human lungs. It can change its weapons to attack new victims. It reproduces fast. It drives a big black Merc in dark glasses and comes for you when you least expect it. Such is the Liverpool epidemic strain of pseudomonas, which is spreading rapidly through the UK and Canada. When isolated from the lungs of people with cystic fibrosis, it increases the odds of death or lung transplantation.
“Diagnosis, Microbial Epidemiology, and Antibiotic Treatment of Acute Otitis Media in Children : A Systematic Review” – sounds like the kind of paper every GP needs to mull over: and mull I did, even as I waited for the next kid with earache to arrive on my shift. The questions of importance to me were “are there any clinical features that I am capable of eliciting that will predict a response to antibiotics?”, and “given that all parents bringing in kids with earache have already tried paracetamol and ibuprofen, is there any alternative to the irrational prescription of an antibiotic?” This review does not answer these questions. Instead it takes a laborious and sometimes circular tour through all the evidence, basing the diagnosis of OM on the presence of an effusion, which requires tympanometry. That evening I wrote several prescriptions for amoxicillin, which according to this article carries a NNT of 9, but all the while I wished I had access to something as simple as lidocaine ear drops, which were shown some years ago to relieve most otalgia while nature takes its course and the otitis cures itself.
NEJM 18 Nov 2010 Vol 363
In more pious times, it would have been considered faintly blasphemous to give the title Alpha Omega to a trial of fortified margarine, since AΩ is a traditional symbol for Christ in Glory, coming to judge the world at the end of time (Revelation 22;13). Does this trial of margarine containing fish and vegetable oils contain any Revelations? Only that they have no additional protective effect following myocardial infarction in modern patients who are given antiplatelet agents, statins, β-blockers, ACE inhibitors etc. The key words this week are eicosapentaenoic, docosahexaenoic and alpha-linolenic. If you can correctly spell all three fatty acids without cheating in five minutes’ time, award yourself a tub of margarine.
“The ideal influenza vaccine would be one that is safe, elicits humoral and cellular responses identical to those triggered by a natural infection, provides long-lasting and cross-strain protection, and can be manufactured rapidly in large amounts under well-controlled conditions.” At the moment, flu vaccine manufacture involves collecting wild strains in December and growing them on in hundreds of millions of embryonated hens’ eggs until they’re ready for vaccine production in time for October. The New England Journal is giving free access to this review article about influenza vaccines for the future, and I’d advise you to take them up on it: it’s so clearly written that you can sit down and read it in less than ten minutes, understanding every word and learning a great deal about flu viruses and how people can tinker with them. Classic blobby NEJM artwork as well.
Lancet 20 Nov 2010 Vol 376
Like many doctors in the 1990s, I went through a phase of taking low dose aspirin and recommending it to many of my patients with high blood pressure and/or type 2 diabetes. Then came a series of trials which showed that it doesn’t work for primary prevention of cardiovascular events, even in groups who are at increased risk. But it does prevent about 25% of bowel cancer, according to this long-term follow up study of participants in 5 large aspirin trials, matched at a median of 18.3 years with mortality registers. The results suggest that you need to take about 75mg of aspirin for at least 5 years to achieve such protection, and the effect may be specific to the proximal colon. Thus in theory universal aspirin consumption, combined with a universal programme of screening sigmoidoscopy, could prevent most bowel cancer. However, an analysis like this can tell us little about adverse events, and we will only know for certain after a prospective trial lasting at least ten years.
An Australian systematic review tells us what I hope most GPs already knew: that corticosteroid injections for tennis elbow give immediate relief at the expense of long-term recurrence. This has now been demonstrated in several hundred trials: in fact the review team looked at all the trials they could find of interventions for all kinds of tendinopathy and found 3824, of which 42 met their inclusion criteria. So this is a great data-mine for all who like to get out their vials and needles at the first mention of localised periarticular pain. I once belonged to their number, but I must caution you to sit still when patients point to the sides of their elbows. Leap not for the lidocaine and triamcinolone: leaving alone is best for lulling long-term localised lateral epicondylalgia.
BMJ 20 Nov 2010 Vol 341
I thought I had waved a welcome farewell to venous ulcer disease when I left daytime general practice earlier this year, but it continues to pop up regularly in the out-of-hours work I still do. Soggy dressings, bleeding, cellulitis; dispiriting work: send in the district nurse, get out the flucloxacillin. This excellent review article maintains the high standards of the whole series, and comes from Gouda in the Netherlands and the European Vascular Centre Aachen-Maastricht, in “Maastricht, Germany”. Now I thought that Maastricht was in Belgium, and Aachen in Germany: but perhaps in these happy times, they take it in turns. This would certainly please Charlemagne, who made Aachen the capital of his Holy Roman Empire at the end of the 8th century: Kaiser Wilhelm and Adolf Hitler, however, might think differently.
Ann Intern Med 15 Nov 2010 Vol 153
To begin with, I was a bit fazed at this trial of giving healthy middle-aged men two years of dihydrotestosterone (DHT) to see if it would reduce prostatic hypertrophy. Surely this is the stuff that increases prostatic growth? And so it does, when it is produced locally inside the prostate by the action of α-reductase in prostate tissue on circulating testosterone. But if you give DHT by mouth, that reduces circulating ordinary testosterone by feedback inhibition, so less DHT ends up being generated locally within the prostate. In theory this should be good: the ageing chap gets his circulating hormones, keeps his sex life, but doesn’t have to get up to pee in the night. Alas, the Australian and NZ males who took part in this trial got no such benefits: in fact they suffered a small decrease in vertebral bone density, probably due to suppression of oestrogen production by the exogenous DHA.
Plant of the Week: Daphne bholua
I lose track of the number of times I have commended this plant in these reviews, but I make no apology. It is easily the best of all winter-flowerers, and if we ever had to move house, this would be the first shrub we would plant. Its divinely sweet, penetrating scent wafts about all through the winter, in the fiercest gale and the most penetrating frost. When we first planted it, it was half a metre high: now it is getting on for 3 metres and is showing no signs of stopping. It is covered in healthy evergreen leaves and pink starry flowers, which will be produced in succession until March. They may be covered in ice later in the winter, and mostly drop off: but others will come to replace them.
This plant does through the nose what a light box does through the eyes: it invigorates the pineal and dispels seasonal affective sadness. If I am beginning to sound mad, that’s because I am, about this plant. Some time in the 1950s, retired Indian Army majors and the like started bringing down specimens from the foothills of the Himalaya – places to the north of Darjeeling, Upper Burma, and so forth, about which you probably share my vagueness. Many failed to survive their first winter in England, but others flourished, and from these we have the named varieties which are at last finding their way to British gardens. Pink-flowered Jacqueline Postill still leads the field, and is the one which has inspired this account: but there are exquisite white-flowered kinds too, lumped together as “Alba”, and we have high hopes of these too.