| Abstrakt: |
INTRODUCTION: Being selected as an astronaut comes with an understanding that one is willing to undergo physical discomfort. As commercial orbital and suborbital flights increase, the range of individuals who become space flight participants, and thus experience the physically unpleasant circumstances of space flight will increase. TOPIC: 'Space motion sickness,' is caused by modification of signals, due to microgravity, in the neuro-vestibular and visual systems. A multi-modal approach to this neurogenic problem incorporates multiple interventions, each of which may have a weak effect but when combined may potentiate each other. APPLICATION: This presentation will review various non-pharmaocolgic and pharmaocolgic interventions to space motion sickness. Non-pharmacologic interventions are ideal due to the decreased potential for side-effects and can be started weeks prior to the anticipated flight. One of the simplest approaches is avoidance of recreational alcohol. A more complex intervention is motion exposure. This could be as basic as spinning for a few minutes daily in a roller-chair, or as intense as using a spatial disorientation trainer (which spins a person in multiple axes but at low speed) for several hours a day in the weeks leading up to the flight. Eating ginger candy, and wearing bracelets that apply pressure to the P6 acupressure point are also useful during the actual motion. Pharmacologic interventions all have potential side effects, but could be used under the supervision of a physician or other medical officer. Famotidine works on the H1 receptor to decrease stomach acid, and a single dose has relatively few side effects. Other drugs may be more efficacious, but have the potential for sedation, which precludes use in pilots and other crew members who are essential for flight safety. Ondansetron is a serotonin receptor antagonist used for peri-operative nausea treatment and prophylaxis, however it can cause some sedation, headache, and constipation and is contraindicated in patients with long QT syndrome. Diphenhydramine and other H2 blockers, as well as scopolamine, an anticholinergic, cause significant sedation along with a dry mouth and dizziness. Dextroamphetamine is a stimulant, but should be avoided when possible due to the potential for addiction and sudden cardiac death. A risk for polypharmacy and unanticipated side-effects also exists if multiple drugs are used. Learning Objectives 1. Similar to other neurogenic problems, space motion sickness benefits from a multimodal approach, in which several interventions may potentiate each other. 2. Non-pharmacologic modalities to prevent and treat space motion sickness have fewer side effects. In the weeks before the flight, these may include avoidance of recreational alcohol and motion exposure. During the flight, eating ginger candy, and wearing bracelets that apply pressure to the P6 acupressure point are also useful. 3. Pharmacologic interventions for space motion sickness require medical supervision, and may be contraindicated in some travelers. Famotidine, ondansetron, scopolamine, and diphenhydramine will be discussed. [ABSTRACT FROM AUTHOR] |
