RT Journal Article
SR Electronic
T1 Effects of Continuous Positive Airway Pressure/Positive End-Expiratory Pressure and Pressure-Support Ventilation on Work of Breathing, Using an Animal Model
JF Respiratory Care
FD American Association for Respiratory Care
SP 689
OP 696
VO 48
IS 7
A1 Mark J Heulitt
A1 Shirley J Holt
A1 Tracy L Thurman
A1 Sterling Wilson
A1 Renée A Hall
YR 2003
UL http://rc.rcjournal.com/content/48/7/689.abstract
AB OBJECTIVE: Evaluate the effects of continuous positive airway pressure (CPAP)/positive endexpiratory pressure (PEEP) and pressure support ventilation (PSV) on work of breathing (WOB). METHODS: With 13 anesthetized lambs we measured WOB with an esophageal balloon and flow signals. All the animals were sedated, intubated, and ventilated, using 2 pediatric ventilators (Servo 300 and VIP Bird). Ventilator settings were CPAP of 0, 5, and 10 cm H2O and PSV of 5 and 10 cm H2O with PEEP of 0, 5, and 10 cm H2O. Data were analyzed with 2-way analysis of variance. RESULTS: With the Servo 300 the total WOB (WOBT) increased between CPAP/PEEP of 0 and 10 cm H2O (p ≤ 0.0001) and between CPAP/PEEP of 5 and 10 cm H2O (p ≤ 0.0002). With the Servo 300 the addition of PSV decreased WOBT (p ≤ 0.003). With the VIP Bird the WOBT significantly increased between CPAP/PEEP of 0 and 10 cm H2O (p ≤ 0.02) and between CPAP/PEEP of 5 and 10 cm H2O (p ≤ 0.03). With PSV the WOBT was lower only at PSV 10 cm H2O (p ≤ 0.0001). CONCLUSIONS: WOBT increased as CPAP/PEEP was increased, and PSV lowered WOBT. We hypothesize that in a healthy animal model increased CPAP/PEEP may cause alveolar overdistention.