Transplanting patients with active bacterial infection

Risk Factors for E2SKAPE Infections and Mortality Among Liver Transplant Recipients

PURPOSE

Infections caused by Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp (ESKAPE) plus Escherichia coli (E2SKAPE), in particular multidrug-resistant (MDR) E2SKAPE infections, occur frequently and pose a life-threatening to liver transplant (LT) recipients. To prevent E2SKAPE infections and improve the prognosis of LT recipients, the identification of risk factors for E2SKAPE infections and mortality is necessary.

METHODS

E2SKAPE pathogens were isolated and identified from clinical samples following standard microbiological procedures. All episodes of E2SKAPE infections and mortality documented among LT recipients were analyzed.

FINDINGS

A total of 83 episodes of E2SKAPE infections, including 75 (90.4%) episodes of MDR-E2SKAPE infections, occurred in 23.1% (53/229) of LT recipients. E. faecium was the dominant causative bacterium (37/83; 44.6%). The most common site of infections was the urinary tract (14/53; 26.4%). Sixteen (7%) patients died within 2 months after LT, and 7 deaths were E2SKAPE infections-related. Multivariate logistic regression analysis revealed that female sex [odds ratio (OR) = 3.665, 95% confidence interval (CI): 1.614-8.321, P = 0.002], duration of surgery ≥ 400 min [OR = 2.328, 95%CI: 1.151-4.707, P = 0.019], intraoperative red blood cell (RBC) transfusion ≥ 12U [OR = 2.542, 95%CI: 1.218-5.306, P = 0.013] and indwelling urethral catheter use ≥ 3 days [OR = 3.96, 95%CI: 1.309-11.981, P = 0.015] were independent risk factors for E2SKAPE infections after LT, and that only exposure to more than 2 intravenous antibiotics post-LT [OR = 0.318, 95%CI: 0.15-0.674, P = 0.003] was negatively associated with acquisition of E2SKAPE infections. The predictors of crude mortality included female sex [OR = 4.822, 95%CI: 1.299-17.904, P = 0.019], creatinine on day 3 post-LT > 1.5 mg/dL [OR = 11.014, 95%CI: 2.985-40.637, P < 0.001], mechanical ventilation post-LT [OR = 10.724, 95%CI: 2.695-42.676, P = 0.001] and recipients with E2SKAPE infections [OR = 4.112, 95%CI: 1.169-14.47, P = 0.028].

IMPLICATIONS

A high incidence of E2SKAPE infections was noted in the early post-LT period. The most common infection site was the urinary tract, and the dominant pathogenic bacterium was E. faecium. Female sex, prolonged surgery time, massive RBC transfusion, or delayed urethral catheter removal were associated with E2SKAPE infections. Only exposure to more than 2 intravenous antibiotics post-LT was negatively related to the acquisition of E2SKAPE infections. The predictors of mortality included female sex, creatinine on day 3 post-LT>1.5 mg/dL, mechanical ventilation post-LT, and recipients with E2SKAPE infections.

Infections After Liver Transplant -Timeline, Management and Prevention

Liver transplantation (LT) is the standard treatment for end- stage liver disease. Patient and graft survival have improved significantly in the last three decades owing to improvement in surgical technique, better perioperative management and better immunosuppressive regimens. However, LT recipients are at increased risk of infections, particularly in the first year after transplantation. The risk of infection is directly proportional to immunosuppressive regimen and graft function. In this review, we will briefly discuss the timeline of infections after liver transplant, preventive strategies and management of infectious complications.

Impact of bacterial infections prior to liver transplantation on post-transplant outcomes in patients with cirrhosis

Background & Aims

Bacterial infections are frequent in patients with cirrhosis and increase the risk of death and drop-out from liver transplant (LT) waiting list. In patients with bacterial infections, LT is frequently delayed because of the fear of poor outcomes. We evaluated the impact of pre-LT infections on post-LT complications and survival.

Methods

From 2012 to 2018, consecutive patients transplanted at the Hospital of Padua were identified and classified in two groups: patients surviving an episode of bacterial infection within 3 months before LT (study group) and patients without infections before LT (control group). Post-LT outcomes (complications, new infections, survival) were collected.

Results

A total of 466 LT recipients were identified (study group n = 108; control group n = 358). After LT, the study group had a higher incidence of new bacterial (57% vs. 20%, p <0.001) and fungal infections (14% vs. 5%, p = 0.001) and of septic shock (8% vs. 2%, p = 0.004) than the control group. Along with the model for end-stage liver disease (MELD) score and alcohol-related cirrhosis, bacterial infection pre-LT was an independent predictor of post-LT infections (odds ratio = 3.92; p <0.001). Nevertheless, no significant difference was found in 1-year (88% vs. 89%, p = 0.579) and 5-year survival rates (76% vs. 75%, p = 0.829) between the study group and control group. Within the study group, no association was found between the time elapsed from infection improvement/resolution to LT and post-LT outcomes.

Conclusions

Patients with pre-LT infections have a higher risk of new bacterial and fungal infections and of septic shock after LT. However, post-LT survival is excellent. Therefore, as soon as the bacterial infection is improving/resolving, transplant should not be delayed, but patients with pre-transplant bacterial infections require active surveillance for infections after LT.

Impact and Implications

Bacterial infections increase mortality and delay transplant in patients with cirrhosis awaiting liver transplantation (LT). Little is known about the impact of adequately treated infections before LT on post-transplant complications and outcomes. The study highlights that pre-LT infections increase the risk of post-LT infections, but post-LT survival rates are excellent despite the risk. These findings suggest that physicians should not delay LT because of concerns about pre-LT infections, but instead should actively monitor these patients for infections after surgery.