title: Comparison between bubble CPAP and ventilator-derived CPAP in rabbits.
abstract: BACKGROUND
  Continuous positive airway pressure (CPAP) is used in infants with respiratory distress and apnea. Bubble CPAP (B-CPAP) and ventilator-derived CPAP (V-CPAP) are two of the most popular CPAP modes, and use different pressure sources. However, few studies have been performed to compare their differences and effectiveness. This study was to determine whether B-CPAP and V-CPAP would have different effects on vital signs and arterial blood gas analysis.
  
  
  METHODS
  We performed a randomized crossover study to measure vital signs, including mean blood pressure (MBP), heart rate (HR), and respiratory rate (RR), in 12 ketamine-anesthetized healthy rabbits receiving endotracheal intubation by tracheostomy with B-CPAP or V-CPAP. Arterial blood was also sampled and analyzed for PaO2, PaCO2, HCO3 and pH.
  
  
  RESULTS
  We observed statistically significant decreases in RR, pH and PaO2 with corresponding incrases in PaCO2 and HCO3 during the V-CPAP; however, no significant changes from baseline were observed for B-CPAP. Neither modality resulted in statistically significant changes in MBP or HR. Both forms of CPAP altered vital signs and arterial blood gases in a similar manner. There was a trend towards a lower percentage of change from baseline in all variables in B-CPAP compared with V-CPAP.
  
  
  CONCLUSIONS
  Our results suggest that B-CPAP seems to be superior to V-CPAP in terms of its effect on arterial blood gases and vital signs. We speculate that B-CPAP could have certain protective effects that better preserve both arterial blood gases and vital signs when compared to V-CPAP. However, the results of this study still need to be tested by clinical study.
authors.affiliation: Department of Pediatrics, Tri-Service General Hospital and National Defense Medical Center, Taipei, Taiwan.
authors.forename: Wen-Chin
authors.initials: WC
authors.lastname: Huang
authors.forename: Yi-Ming
authors.initials: YM
authors.lastname: Hua
authors.forename: Chuen-Ming
authors.initials: CM
authors.lastname: Lee
authors.forename: Chun-Cheng
authors.initials: CC
authors.lastname: Chang
authors.forename: Yeong-Seng
authors.initials: YS
authors.lastname: Yuh
mesh_terms: D000818:Animals; D001794:Blood Pressure; D045422:Continuous Positive Airway Pressure / Q000379:methods*; D018592:Cross-Over Studies; D006339:Heart Rate; D011817:Rabbits; D012143:Respiratory Physiological Phenomena