Thursday, November 12, 2009

I can tell by the way you snore...

Wouldn't it be great if we didn't have to do expensive polysomnograms, read incomprehensible charts, and (in the public setting) wait for months for a sleep study? All just to diagnose OSA and say to a patient ok, now we are sure you need treatment. Especially when he's been falling asleep in your waiting room or just come in with head bandaged after his lorry overturned. You know he has OSA.

Well, it seems the people in Brisbane have found a way.

I have been thinking along the lines of a biochemical marker or something that might be detected in the breath. Imagine bus drivers having to check in for a urine test or breathalyser test before they board and you get the idea.

The sleep team in University of Queensland have reported they can HEAR that you have OSA.

I guess I have always had this hunch. Haven't you? There's a rhythmic hiss in the meeting room and you thought it was the air-condition vent until the guy next to you starts nodding. You think the ventilator is leaking when you realise your assistant in OR is stertoring. You know. Nothing scientific. No data to base this on. Just that visceral hunch that there's no way you can be breathing right during sleep if you are hissing with every breath through the day.

But these guys down under have made a science of it and claim over 90% sensitivity and specificity by simply analysing the audio recording of your snore!

Read the Article at

Review the scientific papers related to snoring by their lead researcher Dr. Udantha Abeyratne.

Tuesday, November 10, 2009

Post exposure prophylaxis for Varicella?

The author of this blog is currently in day 7 of illness, suffering from a moderate form of varicella. In spite of starting acyclovir (thanks to vigilant and quick-acting wife) on the day of eruptions, the disease process was not halted and vesicles are florid. While we are taking precautions against pneumonia, encephalitis, and other adult-onset associated complications, it is my 2yr old that I agonise about.

He is an 'exposed' individual. Varicella infections in children are mild and rarely complicated. Being an otolaryngologist, however, we know that Ramsay-Hunt (herpes zoster oticus; i.e. reactivation of virus in facial nerve) syndrome causes debilitating facial palsy - sometimes irreversible. Shingles is painful, too. My question is, should I bother vaccinating him now? He was planned for his jab next week, but now that he is exposed, shouldn't I just wait and see if he develops the infection which would obviate vaccination altogether?

Well, this is where the evidence is really useful:

According to the Cochrane review of randomized trials evaluating varicella vaccine in children and adults; from 3 trials with 110 healthy siblings of household contacts where they received post-exposure prophylaxis (PEP) within 3 days of exposure or not at all:
- varicella developed in 18% (PEP) vs. 78% (no PEP) (p < 0.05)
- moderate to severe varicella developed in 2% (PEP) vs. 76% (no PEP) (p < 0.05)
- PEP group who developed varicella had mild disease (< 50 skin lesions)
- no trials reported on adverse events following immunization

Also, for all my healthcare worker friends out there, don't be a hero (or a chicken, depending why you're delaying.) Get yourself jabbed now! Varicella vaccine is recommended for those who have never had chickenpox and are seronegative for varicella antibodies. The caveat (or bonus) is 1-5% adult develop varicella-like rashes that shed the virus and should be removed from patient contact (perfect excuse for holiday, no?) [Am Fam Physician 1997 Dec;56(9):2291]