Risk factors for pneumonia caused by multidrug-resistant Gram-negative bacilli among liver recipients.

Pneumonia caused by multidrug-resistant (MDR) Gram-negative bacilli is associated with a higher mortality rate. The appropriate empiric therapy is based on the understanding of local etiology and MDR pattern. This study was to evaluate the spectrum of Gram-negative bacilli, MDR rate, risk factors and mortality in 475 liver transplantation (LT) recipients. In the first six months after LT, the incidence of bacterial pneumonia was 21.3% (101/475). The overall infectious incidence during the first post-transplant month was 80.2%. The most frequent pneumonia isolates were Enterobacteriaceae, Acinetobacter baumannii, Pseudomonas aeruginosa and Staphylococcus aureus. Gram-negative bacilli accounted for 69.6% of all pneumonia pathogens. Of the main 124 Gram-negative bacilli isolates, MDR rate was 58.9%. Four risk factors for post-LT pneumonia caused by MDR Gram-negative bacilli were LT candidates with grade II-IV encephalopathy (OR 2.275, 95%CI 1.249-4.124, p = 0.006), prolonged duration of endotracheal intubation (OR 8.224, 95%CI 4.276-15.815, p = 0.013), tracheostomy (OR 4.929, 95%CI 1.099-18.308, p = 0.027) and post-LT episode(s) of reoperations (OR 10.597, 95%CI 3.726-30.134, p < 0.001). MDR Gram-negative bacterial pneumonia-related mortality was significantly higher than that because of antibiotic-susceptible bacilli (45.6% vs. 11.4%, p = 0.010). Our data suggest that pneumonia caused by MDR Gram-negative bacilli after LT is common, and associated with the severity of underlying disease, prolonged mechanical ventilation and upper abdominal surgery.