title: Comparison of rectilinear biphasic waveform with biphasic truncated exponential waveform in a pediatric defibrillation model.
abstract: OBJECTIVE
  To compare the rectilinear biphasic waveform with a biphasic truncated exponential waveform for pediatric defibrillation.
  
  
  METHODS
  Prospective, randomized study.
  
  
  METHODS
  Experimental laboratory of a university-affiliated research institute.
  
  
  METHODS
  Male domestic piglets (4-24 kg).
  
  
  METHODS
  Eleven piglets (4-8 kg), which represented a patient <1 yr old, and ten piglets (16-24 kg), which represented a pediatric patient between the ages of 2 and 8 yrs, were anesthetized, intubated, and mechanically ventilated. Ventricular fibrillation was induced and maintained for 30 secs, and a predetermined shock was then delivered to defibrillate. Following defibrillation, the animal was permitted to stabilize hemodynamically for 4 mins. Fifty shocks were applied to each animal using a randomization schedule based on a predetermined permutation of 50. The 50 shocks were 25 shocks for each rectilinear biphasic and biphasic truncated exponential waveforms, comprising five shocks at five energy settings. Each group of five shocks was fixed at a predetermined energy value, depending on the body weight of the animal. Dose-response curves were constructed using logistic regression. Aortic pressure, electrocardiogram, left ventricular pressure, and left ventricular pressure value of 40 mm Hg were continually measured.
  
  
  RESULTS
  Dose-response curves determined defibrillation thresholds at 50% (D50) and 90% (D90) probability of success. The rectilinear biphasic waveform defibrillated with <90% of the D50 and D90 energies required for a biphasic truncated exponential waveform. The rectilinear biphasic waveform also successfully defibrillated with significantly less energy per body weight and per heart weight compared with a biphasic truncated exponential waveform.
  
  
  CONCLUSIONS
  The rectilinear biphasic waveform has superior defibrillation performance compared with a biphasic truncated exponential waveform in a piglet defibrillation model for young children.
authors.affiliation: Weil Institute of Critical Care Medicine, Rancho Mirage, CA, USA.
authors.forename: Jinglan
authors.initials: J
authors.lastname: Wang
authors.forename: Wanchun
authors.initials: W
authors.lastname: Tang
authors.forename: James E
authors.initials: JE
authors.lastname: Brewer
authors.forename: Gary
authors.initials: G
authors.lastname: Freeman
authors.forename: Yun-Te
authors.initials: YT
authors.lastname: Chang
authors.forename: Max Harry
authors.initials: MH
authors.lastname: Weil
mesh_terms: D000818:Animals; D004554:Electric Countershock / Q000379:methods*; D006323:Heart Arrest / Q000628:therapy*; D006801:Humans; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D010372:Pediatrics; D011897:Random Allocation; D012449:Safety; D013552:Swine