X rayted

The radiation exposure from a lumbosacral Xray study was dismissed by someone as relatively trivial: akin to that received on a flight from Melbourne to Sydney. But according to the United States' National Oceanic and Atmospheric Administration website 3.25 microSievert per hour occurs at 30,000 feet. A lumbar spine study produces about 1 milliSievert. Thus a lumbar spine (AP and lateral) Xray has the similiar radiation exposure of 300 hours at 30,000 feet.
Comparisons of medical diagnostic radiology to aviation exposure are not valid.

Abstractions

I quite like viewing the abstracts from the major international meetings. In particular the clinical investigations often have a freshness a practicality that you don't find in the published articles. From the abstracts of the ASA in New Orleans 2009 are some interesting conclusions:

• 5% glucose after laparoscopic surgery reduced PONV.
• Crystalloids may be better than colloids for spinal anaesthesia cesarean section
• In the UK there has been a 200% increase in RA to GA conversions for CS
• They are ultrasounding the airway now instead of a Mallampatti score
• ED 95 of intrathecal bupivacaine for CS in morbidly obese is even higher than non-obese (!)
• Avoid RA in parturients with Budd-Chiari malformation
• TAP blocks on cesarean patients who also had 150 mcg intrathecal morphine was of no benefit

and more!

What makes a good anaesthesiologist

From the BBC

An Australian psychology expert who has been studying emotions has found being grumpy makes us think more clearly.

In contrast to those annoying happy types, miserable people are better at decision-making and less gullible, his experiments showed.

While cheerfulness fosters creativity, gloominess breeds attentiveness and careful thinking, Professor Joe Forgas told Australian Science Magazine.

Explains a few things about our specialty, and me too I suppose.

Oxycodone Musings

More oxymoronics from me:

this time on oxycodone

BIS biz

Often seems another distracting number which doesn't add to the scheme of anaesthesia, but BIS can be a handy tool of reassurance when there may be doubts about adequate cerebral perfusion. In particular it can indicate adequate cerebral perfusion and function when position and high venous pressure might compromising. Recent cases when it has reassured me have been a thoracic level laminectomy and a prolonged gyne laparoscopy when the relatively low positions of the head caused estimated venous pressures of 20 - 30 cmH2O. In addition to measures to maintain arterial pressure and minimise cerebral vasodilatation normal BIS values and waveform indicated we could safely persevere with surgery in the desired position.

Oxytocin Musings

Some musings on oxytocin



http://docs.google.com/Doc?docid=0Af2UxQuLjznjZGhzYmp4eHNfMzI3Zmt0OWRmZnE&hl=en_GB

Porcine influenza

H1N1 is everywhere now and we're all pretty sanguine about it. But pregnancy appears to be a real risk factor for serious morbidity and mortality. We should have it on the differential diagnosis list for pregnant women with premature labour with fever: it may not be chorioamnionitis. Pregant contacts of flu cases should be given osteltamivir, and the pregnant woman with flu symptoms should be closely watched for worsening pneumonia.