Basic life support in microgravity: evaluation of a novel method during parabolic flight.
BACKGROUND
If a cardiac arrest occurs in microgravity, the aim of current emergency procedures is to treat the patient using a medical restraint system within 2 min. The patient may require treatment while medical equipment is being deployed. The capability for one person, unaided, to successfully perform cardiopulmonary resuscitation (CPR) is, therefore, of paramount importance. A new technique has been developed whereby the practitioner encircles the thorax of the patient with his/her legs to restrain the patient to allow CPR to be performed in microgravity.


METHODS
Two investigators performed both this method (during parabolic microgravity) and traditional CPR (at +1 Gz) on an instrumented CPR mannequin. The mannequin was modified to ensure accurate chest compression and ventilation measurements during microgravity.


RESULTS
The mean (+/-SE) depth and rate of chest compression were 44.0+/-4.99 mm and 68.3+/-17.0 compressions x min(-1) respectively. Although the mean microgravity rate of compression proved significantly less (p < 0.05) than the +1 Gz mean (97.1+/-3.4 compressions x min(-1)), chest compression depth did not differ (p > 0.05) from +1 Gz measures (43.6+/-0.59 mm). The mean (+/-SE) microgravity tidal volume (VT) was 491+/-50.4 ml, which also did not differ (p > 0.05) from +1 Gz values (507.6+/-11.5 ml).


CONCLUSIONS
Although difficulties in performing this method during parabolic flight primarily affected compression rate, it may be possible to conduct basic life support using this technique in any microgravity environment.
Evetts
Simon N
SN
Human Physiology Department, King's College, London, UK. snevetts@btopenworld.com
Evetts
Lisa M
LM
Russomano
Thais
T
Castro
João C
JC
Ernsting
John
J
D000328:Adult; D000337:Aerospace Medicine / Q000379:methods*; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D006801:Humans; D008348:Manikins; D010865:Pilot Projects; D013026:Space Flight; D013990:Tidal Volume; D016896:Treatment Outcome; D014893:Weightlessness