title: Evaluation of a novel basic life support method in simulated microgravity.
abstract: BACKGROUND
  If a cardiac arrest occurs in microgravity, current emergency protocols aim to treat patients via a medical restraint system within 2-4 min. It is vital that crewmembers have the ability to perform single-person cardiopulmonary resuscitation (CPR) during this period, allowing time for advanced life support to be deployed. The efficacy of the Evetts-Russomano (ER) method has been tested in 22 s of microgravity in a parabolic flight and has shown that external chest compressions (ECC) and mouth-to-mouth ventilation are possible.
  
  
  METHODS
  There were 21 male subjects who performed both the ER method in simulated microgravity via full body suspension and at +1 Gz. The CPR mannequin was modified to provide accurate readings for ECC depth and a metronome to set the rate at 100 bpm. Heart rate, rate of perceived exertion, and angle of arm flexion were measured with an ECG, elbow electrogoniometers, and Borg scale, respectively.
  
  
  RESULTS
  The mean (+/- SD) depth of ECC in simulated microgravity was lower in each of the 3 min compared to +1 G2. The ECC depth (45.7 +/- 2.7 mm, 42.3 +/- 5.5 mm, and 41.4 +/- 5.9 mm) and rate (104.5 +/- 5.2, 105.2 +/- 4.5, and 102.4 +/- 6.6 compressions/min), however, remained within CPR guidelines during simulated microgravity over the 3-min period. Heart rate, perceived exertion, and elbow flexion of both arms increased using the ER method.
  
  
  CONCLUSIONS
  The ER method can provide adequate depth and rate of ECC in simulated microgravity for 3 min to allow time to deploy a medical restraint system. There is, however, a physiological cost associated with it and a need to use the flexion of the arms to compensate for the lack of weight.
authors.affiliation: Centre of Human and Aerospace Physiological Sciences, Kings College London, London, United Kingdom. lukirehnberg@googlemail.com
authors.forename: Lucas
authors.initials: L
authors.lastname: Rehnberg
authors.forename: Thaws
authors.initials: T
authors.lastname: Russomano
authors.forename: Felipe
authors.initials: F
authors.lastname: Falcão
authors.forename: Fabio
authors.initials: F
authors.lastname: Campos
authors.forename: Simon N
authors.initials: SN
authors.lastname: Everts
mesh_terms: D022561:Advanced Cardiac Life Support / Q000379:methods; D000337:Aerospace Medicine / Q000379:methods*; D001132:Arm / Q000502:physiology; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D004562:Electrocardiography; D004634:Emergency Medical Technicians; D006323:Heart Arrest / Q000628:therapy*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D005082:Physical Exertion / Q000502:physiology; D014893:Weightlessness; D055815:Young Adult