Wednesday, June 8, 2011

Operative Mortality Rates and Sleep Deprivation

To add some spice to the never-ending debate on the effects of sleep deprivation on surgeons are two recent papers published in respected journals.

“Prospective evaluation of consultant surgeon sleep deprivation and outcomes in more than 4000 consecutive cardiac surgical procedures” was published ahead of print in Archives of Surgery in May. This was a prospective study of the sleep patterns of six consultant [senior attending] cardiac surgeons in Canada over a six-year period. Of the over 4000 cardiac operations performed, there was no difference in the rates of mortality or complications whether the surgeon had less than 3 hours of sleep, 3 to 6 hours of sleep or more than 6 hours of sleep.

“Association of operative time of day with outcomes after thoracic organ transplant” appeared in the Journal of the American MedicalAssociation on June 1. This was a retrospective study of over 27,000 heart or lung transplant operations divided into two groups based on whether their procedures were performed from 7 am to 7 pm (days) or 7 pm to 7 am (nights). Almost exactly 50% of the operations were performed during each time period. Mortality rates at 30 days and one year were not statistically significantly different whether the procedure was done during days or nights.

Even the most ardent crusader against “tired surgeons” would have to admit that these are well-executed studies of rather complex operative procedures. In addition, there are not enough transplant or cardiac surgeons around to allow for shift work. As shown by the data in the transplant paper, half of all such procedures occur at night. Someone has to perform these operations when the organ and the recipient are available, not the next day.

The transplant paper was the subject of a New York Times blog and it drew the usual number of ridiculous comments. I don’t know why I read them because they are so infuriating. Here are some of the more inane ones:

“This is part of the "doctors are superhuman" myth that is simply unsupported in the real world.” Never mind the data.

“Are the ‘qualified surgeons’ in the business of eliminating possible competition, for example?” In response to the fact that there are not that many transplant surgeons.

“A heart transplant in the US costs roughly $145,000. Figure the chief surgeon makes $100K and 9 "helpers" make $5K each for a 5-hour operation. That works out to be $10,000/hr for the doc and $1,000/hr. for each assistant.” And the hospital does not receive any payment?

“Surgery requires superb eye-hand coordination which deteriorates with fatigue. Airline pilots have co-pilots and extensive mechanical controls on the plane and on the ground. Transplant surgeons do not.” Never mind the data.

Feel free to add your own comments [preferably not infuriating, and your math].


Vickie@Demand_Euphoria said...

Don't give me definitive studies that contradict my instincts! I want my doctors to get 8 hours of sleep immediately before any operation I have! And they should also do yoga and get massages. But I don't want to pay any extra for any of this. (sarcasm)

Thirsty said...

If there were an effect of timing / fatigue on performance, I would expect to see it most in the surgeons who were the least trained / least experienced (a la the paper from last year that showed that patients operated on by residents had more morbidity but less mortality ... I don't recall the exact details). I wouldn't expect transplant surgeons (often fellows or attendings) or senior attending cardiothoracic surgeons (6-7 year training + multiple years on staff) to be nearly as susceptible to fatigue and/or error.

That data (relative experience of the operating surgeon) seems like it might be difficult to come by. Do you know of a decent proxy for this? For instance, teaching hospital appy's in July (PGY-2's going into the OR ...)? Just thinking of ways to exploit natural experiments to test my hypothesis.

If there is a good natural experiment, maybe I'll write it up as a research proposal at University Med School ...


Skeptical Scalpel said...


I apologize for missing your comment for over a month. Maybe I was tired :-)

I don't know of any research regarding experience vs. the effect of sleep-deprivation. It's a great idea for a study.

Anonymous said...

A quick google.

Have seen other studies show no change in patient outcomes from reduced hours. Do any show worse patient outcomes from reduced hours?

Skeptical Scalpel said...


Thanks for the comment. I have not seen a study that shows worse outcomes with reduced working hours. There are no good studies comparing reduced hours to more frequent hand-offs and there probably won't be.

NY Times had an interesting article about this ( that hand-offs may be more of a problem.

Obsinguod said...

Now, if the surgeon tied the ventricles off with a bog standard surgeon's knot, installed stents like mad (ordering spares) and perforated the central line thrice, that's when the anesthetist tells her she's tired. If you want a natural experiment, you'd pick the boggy things (Proctology, put your hand down) like bile sac troubles, suppurations, maybe spleen or kidney injury; or shoulder surgery with insertion repair (test test test!)

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