Relationship between Acute Lung Injury and the Pressure-Flow Curv - Abstract
Background: Recently, the open-lung concept has been used in the respiratory care of patients with Acute Lung Injury (ALI), however, the expiratory phase in ALI patients has not yet been studied in detail. In this study, we paid attention to the pressure-flow curves that can be generated using the P/V tool on the Hamilton-G5 mechanical ventilator.
Methods: We conducted a comparative analysis of the Maximum Expiratory Flow Rate (MEFR), pressure at MEFR, etc., in 5 adult control patients who were scheduled to undergo surgery, and 13 ALI patients, including 5 with postoperative respiratory failure, 5 with pneumonia, 2 with interstitial pneumonia, and 1 with acute pancreatitis. The P/V loops were recorded after the induction of anesthesia in the control subjects and after the diagnosis of ALI in the ALI patients.
Results: At the time of the P/V loop measurement, the compliance (31.8 and 78.2 ml/hPa in the ALI and control groups, respectively), MEFR (-169.4 and -404.0 ml/s, respectively), and pressure at MEFR (10.6 and 4.2 hPa, respectively) were significantly different between the ALI and control groups.
Conclusion: Thus, analysis of pressure-flow curves may be helpful in grasping the pathogenesis of ALI.