BACKGROUND: Only few studies have attempted to evaluate the pulmonary function in the early phase of acute pancreatitis (AP), although pulmonary dysfunction is the most frequent complication in the early phase of AP. We aimed to evaluate the changes in pulmonary function tests during the early phase of AP.

METHODS: Prospective cohort study including 44 patients (52% men; median age 54 years) admitted with first attack of AP and 22 healthy controls. Patients underwent assessments on day 1, 2, 3, 6, and 10 as well as one month after discharge. Pulmonary function tests included the % predicted: forced expiratory volume during the first second (FEV1), forced vital capacity (FVC), total lung capacity (TLC), diffusion lung capacity (DLCO) and the ratio between DLCO and alveolar volume (DLCO/VA).

RESULTS: In total, 9% developed severe acute pancreatitis, 7% died, and 14% required treatment at the intensive or semi-intensive care unit. From admission, patients had impaired FEV1, FVC, DLCO, and TLC compared with controls (p < 0.0001 in all analyses). Patients with CRP >150 mg/L had significantly lower lung function tests. One month after discharge, lung function tests improved but patients had lower FEV1 (p = 0.014), FVC (p = 0.022), TLC (p = 0.020), and DLCO (p < 0.001) compared with controls.

CONCLUSION: This study found that patients with AP had evidence of pulmonary impairment from the first day after hospital admission. The impairment lasted several weeks after hospital discharge.