Comparison between bubble CPAP and ventilator-derived CPAP in rabbits.
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.
Huang
Wen-Chin
WC
Department of Pediatrics, Tri-Service General Hospital and National Defense Medical Center, Taipei, Taiwan.
Hua
Yi-Ming
YM
Lee
Chuen-Ming
CM
Chang
Chun-Cheng
CC
Yuh
Yeong-Seng
YS
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