Lung complications in acute pancreatitis.

CONTEXT Severe acute pancreatitis has long been known to be a cause of pulmonary dysfunction and multisystem organ failure. OBJECTIVE We evaluated the spectrum of pulmonary dysfunction in acute pancreatitis. METHODS Over a period of one year, 60 patients referred to us with a diagnosis of acute pancreatitis on the basis of clinical findings, CT and elevated serum amylase level were studied prospectively. The computed tomography severe index (CTSI) was used to assess the severity of the pancreatitis. Arterial blood gas analysis and chest X-rays were performed in all patients at admission and at intervals, when clinically indicated. RESULTS The mean age was 42.9+/-15.9 years (range: 18-80 years) and the etiology of the pancreatitis was gallstones in 29 patients, alcohol in 22 patients while no cause could be ascertained in 9. At presentation to our hospital, 48.3% had mild hypoxemia while 18.3% had moderate to severe hypoxemia (PaO2 less than 60 mmHg). The patients who were hypoxemic at presentation had a higher incidence of organ failure during the course of the disease. Pleural effusion at admission was noticed in 50%, atelectasis in 25%, and pulmonary infiltrates in 6.7%. Respiratory failure developed in 48.3% and the mean+/-SD CTSI in these patients was 8.20+/-2.29. Patients with more than 50% necrosis had more pulmonary dysfunction and needed ventilatory support. The development of consolidation during the course of the disease correlated with the occurrence of respiratory failure (P=0.068) but not with mortality (P=0.193). Similarly, the onset of adult respiratory distress syndrome also correlated with respiratory failure (P<0.001) but, unlike consolidation, adult respiratory distress syndrome correlated with mortality (P<0.001). On logistic regression analysis, the development of respiratory failure and other organ dysfunctions were independent risk factors for mortality. CONCLUSION Our study on patients who were referred to a tertiary care center points out that hypoxemia at presentation predicts a poor outcome which could be due to the high incidence of associated cardiac and renal failure. At presentation, the presence of pleural effusion but not atelectasis and consolidation correlates with the development of respiratory failure and mortality. Among the respiratory complications developing during the course of acute pancreatitis, consolidation and adult respiratory distress syndrome correlate with respiratory failure while adult respiratory distress syndrome alone leads to poor survival.