Conference 7.286::space

678.0. "New treatment eases effects of space motion sickness" by 4347::GRIFFIN (Dave Griffin) Thu Nov 29 1990 19:09

11/29/90:  NEW TREATMENT EASES EFFECTS OF SPACE MOTION SICKNESS

RELEASE: 90-155

     Physicians at NASA's Johnson Space Center (JSC), Houston, 
have instituted a new treatment for space motion sickness that 
has markedly decreased the severity of the illness in 
crewmembers.

     Promethezine, an intramuscular treatment administered after 
the onset of symptoms, has helped decrease the symptoms of space 
motion sickness on 14 occasions since NASA's return to flight in 
September 1988, according to Dr. Sam Pool, Chief of the Medical 
Sciences Division at JSC.

     Medical researchers believe changes in the body's vestibular 
system contribute significantly to space motion sickness.  The 
vestibular system regulates the body's sense of balance and, when 
the tiny stones in the inner ear called otoliths no longer have 
weight in a microgravity environment, the brain may misinterpret 
the sensations an individual may feel while moving around in 
microgravity.  The unusual visual cues experienced during 
floating in the Shuttle orbiter cabin may further confuse the 
brain's perceptions and produce symptoms.

     Since the early days of space flight, many space travelers 
have experienced this space motion sickness.  Symptoms resemble 
those of Earth-based motion sickness and may include headache, 
malaise, lethargy, stomach awareness, loss of appetite, nausea 
and/or episodic vomiting.  Symptoms tend to worsen during body 
movement, especially movements of the head. 

     In the first 24 missions of the Space Shuttle program, about 
67 percent of the 85 crew members making their first flight 
reported symptoms of space motion sickness.  About 30 percent 
reported mild symptoms; 24 percent, moderate symptoms; and 13 
percent severe symptoms.  Most recovered by the end of the third 
day in space.  In one extreme case in the Soviet Salyut 6 
mission, however, one crewmember was ill for 14 days.  The 
incidence of space motion sickness among those making a second 
flight dropped to 46 percent.

     During the first 24 Shuttle missions, scopolamine and a 
combination of scopolamine and dextroamphetamine, given orally, 
were used to treat space motion sickness.  Recent studies at the 
JSC Biomedical Operations and Research Branch by Drs. Nitza 
Cintron and Lakshmi Putcha, however, have shown that the oral 
absorption of scopolamine and other medications in weightlessness 
is unpredictable.

     Since the initiation of intramuscular promethazine therapy, 
Shuttle crewmembers have not experienced severe cases of space 
motion sickness and almost all have been essentially symptom free 
by the end of the second flight day.  Crewmembers now receive 
training in administering the medication should space motion 
sickness develop during Shuttle flights.  Research for space 
motion sickness is sponsored by NASA's Office of Space Science 
and Applications.