[Dynamic pressure-volume curve predicts the optimal positive end-expiratory pressure in patients with acute respiratory distress syndrome].
OBJECTIVE
To predict the best positive end-expiratory pressure (PEEP) in acute respiratory distress syndrome (ARDS) patients with dynamic lung pressure-volume (P-V) curve.


METHODS
Dynamic and static lung P-V curves were determined in 8 patients with ARDS. The pressure of lower inflection point from dynamic lung P-V curve (Pinfd) was compared with the pressure of lower inflection point from static lung P-V curve (Pinfs). The effect of PEEP on hemodynamics, lung mechanics and gas exchange was observed.


RESULTS
When PEEP increased from Pinfd -6 cm H2O to Pinfd +6 cm H2O, partial pressure of arterial oxygen, saturation of arterial oxygen, peak inspiratory pressure and mean airway pressure increased significantly (P < 0.05). Dynamic compliance was improved markedly with PEEP at Pinfd -4 cm H2O when compared with PEEP at Pinfd +6 cm H2O. Cardiac index reduced at Pinf +6 cm H2O. Oxygen delivery was increased at Pinfd -4 cm H2O. When Pinfs and Pinfd were (11.0 +/- 3.2) cm H2O and (12.8 +/- 3.2) cm H2O, they were well correlated (r = 0.99, P < 0.05) and the regression equation was Pinfd = 1.66 + 1.01 x Pinfs. According to the regression equation, it was evident that Pinfd -4 cm H2O equaled to Pinfs -2 cm H2O.


CONCLUSIONS
When ARDS patients are treated with mechanical ventilation, Pinfd -4 cm H2O and Pinfs -2 cm H2O may yield the best PEEP and show maximal oxygen delivery.
Qiu
H
H
Department of Critical Care Medicine, Zhong-Da Hospital and Clinical Medical College, Southeast University, Nanjing 210009, China.
Zhou
S
S
Guo
F
F
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D005260:Female; D006439:Hemodynamics; D006801:Humans; D007231:Infant, Newborn; D008170:Lung Compliance; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D011175:Positive-Pressure Respiration; D012127:Respiratory Distress Syndrome, Newborn / Q000378:metabolism / Q000503:physiopathology*; D012129:Respiratory Function Tests