title: Three methods of manual external chest compressions during microgravity simulation.
abstract: BACKGROUND
  Cardiopulmonary resuscitation (CPR) in microgravity is challenging. There are three single-person CPR techniques that can be performed in microgravity: the Evetts-Russomano (ER), Handstand (HS), and Reverse Bear Hug (RBH). All three methods have been evaluated in parabolic flights, but only the ER method has been shown to be effective in prolonged microgravity simulation. All three methods of CPR have yet to be evaluated using the current 2010 guidelines.
  
  
  METHODS
  There were 23 male subjects who were recruited to perform simulated terrestrial CPR (+1 G(z)) and the three microgravity CPR methods for four sets of external chest compressions (ECC). To simulate microgravity, the subjects used a body suspension device (BSD) and trolley system. True depth (D(T)), ECC rate, and oxygen consumption (Vo2) were measured.
  
  
  RESULTS
  The mean (+/- SD) D(T) for the ER (37.4 +/- 1.5 mm) and RBH methods (23.9 +/- 1.4 mm) were significantly lower than +1 G(z) CPR. However, both methods attained an ECC rate that met the guidelines (105.6 +/- 0.8; 101.3 +/- 1.5 compressions/min). The HS method achieved a superior D(T) (49.3 +/- 1.2 mm), but a poor ECC rate (91.9 +/- 2.2 compressions/min). Vo2 for ER and HS was higher than +1 Gz; however, the RBH was not.
  
  
  CONCLUSIONS
  All three methods have merit in performing ECC in simulated microgravity; the ER and RBH have adequate ECC rates, and the HS method has adequate D(T). However, all methods failed to meet all criteria for the 2010 guidelines. Further research to evaluate the most effective method of CPR in microgravity is needed.
authors.forename: Lucas
authors.initials: L
authors.lastname: Rehnberg
authors.forename: Alexandra
authors.initials: A
authors.lastname: Ashcroft
authors.forename: Justin H
authors.initials: JH
authors.lastname: Baers
authors.forename: Fabio
authors.initials: F
authors.lastname: Campos
authors.forename: Ricardo B
authors.initials: RB
authors.lastname: Cardoso
authors.forename: Rochelle
authors.initials: R
authors.lastname: Velho
authors.forename: Rodrigo D
authors.initials: RD
authors.lastname: Gehrke
authors.forename: Mariana K P
authors.initials: MK
authors.lastname: Dias
authors.forename: Rafael R
authors.initials: RR
authors.lastname: Baptista
authors.forename: Thais
authors.initials: T
authors.lastname: Russomano
mesh_terms: D000293:Adolescent; D000328:Adult; D000337:Aerospace Medicine; D000704:Analysis of Variance; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008348:Manikins; D010101:Oxygen Consumption / Q000502:physiology; D012123:Pulmonary Ventilation / Q000502:physiology; D018474:Weightlessness Simulation; D055815:Young Adult