Methods  Clinical data of 171 liver transplant recipients were retrospectively analyzed, and they were divided into the non-infection (n=52) and infection groups (n=119) according to the bacterial culture results at postoperative 2 weeks. In the infection group, KP was not detected in 86 cases (non-KP infection group), and KP was cultured in 33 cases (KP infection group). Preoperative, intraoperative and postoperative data were statistically compared between the non-infection and infection groups, and between the non-KP infection and KP infection groups. The risk factors of early KP infection after liver transplantation and the influencing factors of long-term survival of the recipients were analyzed.

  Results  Compared with the non-infection group, model for end-stage liver disease (MELD) score and total bilirubin level were higher, the operation time was longer, the length of postoperative intensive care unit (ICU) stay and the length of hospital stay were longer, the amount of intraoperative red blood cell transfusion was higher, the hospitalization expense was higher, the incidence of severe complications was higher, white blood cell count, absolute neutrophil cell count and neutrophil-to-lymphocyte ratio at postoperative 14 and 30 d were higher, absolute lymphocyte count at postoperative 14 d was lower and hemoglobin level at postoperative 30 d was lower in the infection group. The differences were statistically significant (all P<0.05). Compared with the non-KP infection group, MELD score, total bilirubin level and aspartate aminotransferase (AST) level were higher, the operation time and the length of postoperative ICU stay were longer, the hospitalization expense was higher, the 90-d fatality was higher, the albumin level at postoperative 14 d was lower, and total bilirubin level at postoperative 30 d was higher in the KP infection group. The differences were statistically significant (all P<0.05). Among 33 recipients with KP infection, 16 cases were resistant to carbapenem antibiotics, and 7 of them died within postoperative 90 d. Seventeen cases were intermediate or sensitive to carbapenem antibiotics, and 4 of them died within postoperative 90 d. Preoperative MELD score ≥17 and operation time＞415 min were the independent risk factors for KP infection after liver transplantation (both P<0.05). The length of postoperative ICU stay ≥44 h and KP infection were the independent risk factors for long-term prognosis of liver transplantation (both P<0.05).

  Conclusions  KP infection is an independent risk factor for death after liver transplantation. High preoperative MELD score and long operation time are the independent risk factors for early KP infection after liver transplantation.