Study warns of sleeping pill risk for astronauts

[Buster's Uncle]

Study warns of sleeping pill risk for astronauts
AFP
By Richard Ingham  47 minutes ago



This December 22, 2013 NASA image shows an astronaut participating in a spacewalk designed to troubleshoot a faulty coolant pump on the International Space Station (AFP Photo/)



Paris (AFP) - Widespread use of sleeping pills by slumber-deprived astronauts could hamper vigilance in the high-risk environment of space, a study warned on Friday.

NASA-funded researchers collected data from 64 astronauts involved in 26 flights on the US space shuttle, and 21 others from 13 missions to the International Space Station (ISS).

A wrist-worn device called an actigraph monitored sleep and wake cycles, and the astronauts kept a daily log of their alertness and sleep quality.

In all, more than 4,000 nights of sleep on Earth and 4,200 in space were recorded, making this the most extensive investigation yet of shut-eye in orbit.

The data pointed to a chronic lack of sleep among space travellers which begins during pre-flight training, about three months prior to launch.

On average, astronauts slept just under six hours a night on both shuttle flights and ISS missions -- far short of NASA's 8.5-hour guideline.

Just 12 percent of "sleep episodes" on shuttle missions and 24 percent on ISS missions lasted seven hours or more, the research found.

When the astronauts returned home, their seven-hour-plus sleeps rose to 42 and 50 percent respectively.

"Sleep deficiency is pervasive among crewmembers," said Laura Barger from Brigham and Women’s Hospital at the Harvard Medical School in Massachusetts.

"It’s clear that more effective measures are needed to promote adequate sleep in crew members, both during training and spaceflight, as sleep deficiency has been associated with performance decrements in numerous laboratory and field-based studies."


- Crew performance 'jeopardised' -

The paper, published in The Lancet Neurology, found that three-quarters of astronauts used standard sleeping aids like zolpidem (whose brand names include Stilnox and Ambien) and zaleplon (marketed under names like Sonata and Andante) while in space.

On one night in six of using sleep drugs, astronauts took a double dose to try to get some shut-eye.

On shuttle missions, medication was used on more than half the nights. On four of the 13 shuttle missions, all crew members took sleeping drugs on the same night six percent of the time.

Routine use of these drugs is "of particular concern," given their potential side-effects on mental alertness and motor coordination, said Barger.

"The ability for a crew member to optimally perform if awakened from sleep by an emergency alarm may be jeopardised by the use of sleep-promoting pharmaceuticals,” she said.

Orbital spaceflight -- where the Sun rises and sets every 90 minutes -- is a tough environment for sleep.

Astronauts, who used sleeping bags on the shuttle and individual quarters on the ISS, cited light and noise among the sleep hindrances.

But sleep disturbance continued after the ISS was fitted with quiet, dark "sleep stations", suggesting the problem may lie with the gravity-free conditions of space, the researchers said.

Pointing to plans for long-duration flights to Mars, the study said it was imperative to find ways to boost sleep in space.

Changes to behavioural routines and work schedules, and "strategically-timed" exposure to specific wavelengths of light, may encourage the right kind of drowsiness, it said.

The probe did not include Russian cosmonauts due to differences in US and Russian policies for participation in research, the paper said.


http://news.yahoo.com/study-warns-sleeping-pill-risk-astronauts-233946774.html

[Buster's Uncle]

Sleepless in Space: Getting Shut-Eye Is Tough Out There
LiveScience.com
By Rachael Rettner, Senior Writer  1 hour ago



Astronauts often suffer from sleep deprivation during space flight and in the months leading up to a mission, a new study finds.

In addition, about three-quarters of astronauts in the study said they took sleeping pills while they were in space — with some taking the pills just a few hours before they woke up — a finding that is concerning because the drugs may impair alertness and the ability to respond to emergency situations, the researchers said.

"The ability of a crew member to perform at their best if awakened from sleep by an emergency alarm could be jeopardized by use of sleep-promoting drugs," the researchers wrote in their study published in the Aug. 8 issue of the journal the Lancet Neurology.

The findings highlight the need to develop better ways to help astronauts sleep, both during training and in space flight, the researchers said.

In the study, researchers analyzed information from 64 astronauts who were aboard space shuttle flights between 2001 and 2011, and from 21 astronauts who stayed at the International Space Station (ISS) between 2006 and 2011.

The astronauts wore devices on their wrists called actigraphs to track their sleep, and also kept a sleep diary. Overall, the researchers collected sleep data from more than 4,200 nights in space and 4,000 nights on Earth.

Astronauts got less sleep in the months leading up to their mission, and during space flight, than they did in the week after a mission.

For example, about three months before a space flight, astronauts averaged less than 6.5 hours of sleep a night (as recorded by the actigraph) — which is about half an hour less than the average American, and about 40 minutes less than the time they spent sleeping when they got back from the mission.

Such sleep loss often occurs when people have a high-stakes event in the near future, or a heavy workload, the researchers said. "It is not unlike what happens on Earth when you have stress, and a lot to do before difficult work, or an exam or an athletic event or travel," said study researcher Laura Barger, an associate physiologist at the Brigham and Women's Hospital Division of Sleep and Circadian Disorders in Boston.

During space flight, astronauts got around six hours of sleep per night. Space shuttle crewmembers got eight hours of sleep on only 0.3 percent of nights they were in space.

Astronauts reported that they had difficulty sleeping because of high workloads, noise and uncomfortable temperatures (either too hot to too cold), Barger told Live Science. The "weightlessness" that astronauts experience may also affect sleep (astronauts attach themselves to walls or the ceiling to sleep).

Seventy-five percent of astronauts aboard the ISS, and 78 percent aboard the space shuttle, reported using sleep aids at some point during their time in space. What's more, although the astronauts said that they fell asleep faster when they took sleep medication, the study found that the pills did not help them sleep any longer.

"Such a marginal benefit should be balanced against the risks associated with use of hypnotic drugs," the researchers wrote. Future research will also look into whether sleep drugs work as well in space as they do on Earth, Barger said.

Changes in sleep schedules, as well as exposure to certain wavelengths of light, may be alternative ways to improve sleep in space, the researchers said. Short wavelengths of light, in the blue range, promote alertness, so avoiding this wavelength of light before bed may help promote sleep, Barger said.

Studies on Earth show that sleep deprivation is linked with impaired performance on tasks. However, the new study was not able to assess whether sleep loss led to more errors or problems with performance in space, and this will be examined by future research, the researchers said.


http://news.yahoo.com/sleepless-space-getting-shut-eye-tough-232735826.html