Wednesday, August 27, 2014

Astronauts and sleep

This article discusses a study published in the journal Lancet about the sleep patterns of astronauts in space. Since I don't have access to the Lancet article, I don't have all of the details. The article however states that the astronauts are scheduled to get 8.5 hours per day of sleep. On average, they managed to sleep about 6 hours. And 78% of them used sleeping pills about half of the time.

The article goes on to quote someone from NASA who states that the study demonstrates valuable insights into sleep deprivation experienced by astronauts in space. However, I'm not sure it does, but I am basing this on the article, not the actual study. The article doesn't give me any insight, only leads to more questions. Why are astronauts expected to sleep 8.5 hours per night? Who came up with that number? How was sleep measured in the astronauts? Subjective or objective information? For the astronauts that did not sleep the full 8.5 hours, were they sleepy in the daytime? Did they actually exhibit any signs of sleep deprivation? Why did the astronauts take sleep aids? Was it because they were told they needed to sleep 8.5 hours, but most realized they would not be able to do that because the amount of sleep they actually need is less?

Wednesday, August 20, 2014

Drowsy driving

Driving while drowsy continues to be a significant problem. It affects drivers of all age. I'm just referring to drivers who fall asleep at the wheel - also drivers who are sleep deprived enough to impair their reaction times on the road. This level of impairment can be difficult for a driver to recognize. Therefore a sleepy driver may push on, continuing to drive because they have not actually fallen asleep.

Here is a link to recent statistics from the National Highway Traffic Safety Association citing that approximately one in four motor vehicle accidents is due to drowsy driving. Someday, sleep researchers may come up with a reliable and simple test of sleepiness that drivers could use to determine if they shouldn't drive. They could take a brief nap first. Although, this all may be moot if Google makes driver-less cars a reality.

Wednesday, August 13, 2014

Weight gain after tonsil removal for obstructive sleep apnea

Children with obstructive sleep apnea (OSA) can have reduced growth rates. The primary treatment of OSA in children is removing the tonsils adenoids, referred to as an adenotonsillectomy. After this procedure, studies have shown an increase in weight. However, some kids that are overweight before adenotonsillectomy put on even more weight after the surgery.

This study looked at two groups of children, ages 5-10 years old, who had OSA. One group got adenotonsillectomy and the other group received no treatment - just watchful waiting. Sleep studies and height / weight measurements were repeated 7 months later. Results showed that body weight and body mass index (BMI) increased in both groups of patients. This may be because the sleep apnea severity improved in both groups. It's unclear why that happened, especially with the weight gain. I would think that would make the sleep apnea severity worse in the untreated group.

What was remarkable about the study, however, was that after adjusting for baseline weight and other variables, the weight gain experienced by those that had the adenotonsillectomy was significantly greater than the group that received no treatment. In those children who were already overweight at the start of the study, 52% became obese after adenotonsillectomy vs 21% in the group that did not receive treatment. The researchers proposed several mechanisms for weight gain after adenotonsillectomy: increased calories consumed, unhealthy food choices, decreased energy burned due to reduced work of breathing, improvement in blood oxygen levels, and increased growth hormone secretion.

The authors recommend monitoring weight, nutritional counseling, and encouragement of physical activity after adenotonsillectomy for OSA in children.

Wednesday, August 6, 2014

Sleep apnea surgery

Continuous positive airway pressure (CPAP) remains the most effective treatment for obstructive sleep apnea (OSA). As many of you may know, CPAP is not well tolerated and usage of CPAP remains a significant problem. Some patients decide to pursue upper airway surgery for their OSA. However, surgery tends to be the least effective option for adults. In children, surgery is often the treatment of choice - it works quite well in fact. In adults, the more common procedure is called a uvulopalatopharyngoplasty or UP3. This involves removing the tonsils, the uvula, and part of the soft palate. A newer procedure called coblation channeling of the tongue or CCT involves surgically reducing the volume of the tongue. This article discusses research out of Australia showing a combination of UP3 with CCT may be more effective than either procedure alone. This may provide better results to patients who suffer from OSA but can not tolerate CPAP.