05/07/2012 08:27 am ET

Surgeons' Brains Must Work Harder When Sleep-Deprived: Study

Sleep-deprivation may hamper surgeons' ability to deal with unexpected events, according to a new simulation-based study, though sleep-deprivation didn't seem to affect their abilities to carry out tasks.

Research published in the American Journal of Surgery shows that surgeons who don't get enough sleep can learn new tasks or do learned tasks as well as surgeons who've rested up. However, the researchers also found that the sleep-deprived surgeons' cognitive workload -- meaning, how hard their brains had to work -- was much higher.

"Interestingly, these reports conflict with the results of sleep disruption on non-medical simulated tasks," study researcher Dr. Jonathan Tomasko, M.D., of Penn State College of Medicine, said in a statement. "The ability to fly a plane, operate a locomotive and drive an automobile have all been shown in studies to be significantly affected by sleep disruptions. Two such studies showed impairment in simulated performance equivalent to moderate blood alcohol levels."

For this study, researchers tested one well-rested group of medical students (in this study, that was defined as having six or more hours of sleep a day) and one sleep-deprived group of medical students (defined as having fewer than two hours of sleep). The medical students were tested on a virtual reality simulator.

The researchers conducted several tests with them, where they were required to do simulated tasks on the virtual reality simulator, including some unexpected tasks. The researchers also used the NASA Task Load Index to see how hard their brains had to work during the tasks (in order to compare the sleep-deprived group with the well-rested group).

"We demonstrated no difference in ability to perform a previously learned simulated surgical task or to learn a new simulated surgical task while moderately sleep deprived," Tomasko said in a statement. "However, in order to achieve the same level of performance, sleep-deprived subjects demonstrated increased cognitive workload compared to their rested counterparts."

Past research on sleep deprivation and surgeries has shown scarier results. A recent study in the Journal of the American Medical Association showed that the risk of complications occurring during surgical procedures increases among doctors who have had six or fewer hours of sleep, compared with those who get more sleep.

Recently, doctors wrote in the New England Journal of Medicine saying that patients should be told if their surgeons had not gotten enough sleep before doing an elective surgery, LiveScience reported.

"Working while fatigued has been part of the culture of medicine for a long time," editorial author Dr. Michael Nurok, an intensive care physician at the Hospital for Special Surgery in New York City, told MyHealthNewsDaily. "We now know that there are risks to patients when they are cared for by fatigued physicians."

LiveScience reported that medical residents are required to spend eight hours off-duty between their shifts, but that there is no rule for doctors post-residency.