- Meeting abstract
- Open Access
The optimal pressure of sustained inflation for alveolar recruitment
© Biomed central limited 2001
- Published: 1 March 2002
- Lung Injury
- Airway Pressure
- Oxygen Tension
- Lung Volume
- Acute Respiratory Distress Syndrome
To determine the optimal recruitment pressure of sustained inflation (SI) in treatment of rabbits with acute respiratory distress syndrome (ARDS).
SI was applied at pressures of 1 ~ 6 times of mean airway pressure (Pm) for 20 s to saline-lavaged adult New Zealand rabbits. Hemodynamics, pulmonary mechanics and gas exchange were observed before SI, during, and 2 min, 5 min after applying SI. Lung histology was observed after experiment.
When the pressure of SI was higher than 3 Pm, arterial oxygen tension (PaO2) and arterial oxygen saturation were improved. The difference of PaO2 before and during SI were (75 ± 39)mmHg and (52 ± 25)mmHg respectively in the 5 Pm and 6 Pm group, which were higher than 1 Pm group significantly ([-5 ± 4]mmHg, P < 0.05). The difference of dynamic pulmonary compliance before and during SI in 5 Pm group was increased markedly ([1.90 ± 0.20]ml/cmH2O in 5 Pm group, [-0.02 ± 0.04]ml/cmH2O in 1 Pm group, P < 0.05). 5 Pm resulted in immediate increased significantly in lung volume ([3.1 ± 2.1]ml/kg in the group, 5 Pm [8.3 ± 0.7]ml/kg in the 1 Pm group). Histologically, Smith lung injury score was 4.03 ± 1.79 in the 5 Pm group, which was less than the score in the group of ARDS model (6.10 ± 0.77). SI with 6 Pm led to alveolar overdistention. With the increasing of SI pressure, mean arterial pressure decreased markedly.
5 Pm (25 ~ 35 cmH2O) may be the optimal recruitment pressure of SI in rabbits with ARDS.