Abdominal obesity and prolonged prone positioning increase risk of developing sclerosing cholangitis in critically ill patients with influenza A-associated ARDS

BACKGROUND: Secondary sclerosing cholangitis is a severe disease of the biliary tract. Over the last decade, several cases of sclerosing cholangitis in critically ill patients (SC-CIP) were reported. Reports in the literature so far are characterized by a wide variety of underlying causes of critical illness, thereby hindering a risk-factor analysis. We report on a homogenous cohort of critically ill patients with influenza A (H1N1) pneumonia and severe acute respiratory distress syndrome (ARDS), of whom a subgroup developed sclerosing cholangitis, allowing for probing of risk factors associated with SC-CIP. METHODS: Twenty-one patients (5 female, 16 male, 46.3 ± 10.8 years) with severe ARDS due to H1N1 pneumonia were retrospectively divided into two groups, characterized by the presence (n = 5) and absence of SC-CIP (n = 16). A large array of clinical data, laboratory parameters, and multi-detector computed tomography-derived measures were compared. RESULTS: Both patient groups showed severe pulmonary impairment. Severity of disease on admission day and during the first 14 days of treatment showed no difference. The patients developing SC-CIP had a higher body mass index (BMI) (37.4 ± 6.0 kg/m(2) vs. 29.3 ± 6.8 kg/m(2); P = 0.029) and a higher volume of intraperitoneal fat (8273 ± 3659 cm(3) vs. 5131 ± 2268 cm(3); P = 0.033) and spent a longer cumulative period in the prone position during the first 14 days (165 ± 117 h vs. 78 ± 61 h; P = 0.038). CONCLUSION: Our results suggest that obesity, intraperitoneal fat volume, and a longer cumulative duration spent in the prone position may put patients with ARDS at risk of developing SC-CIP. These results lead us to propose that the prone position should be carefully deployed, particularly in abdominally obese patients, and that frequent checks be made for early hepatic dysfunction.