Impact of the duration of posttransplant renal replacement therapy on bacterial infections in liver transplant recipients

Impact of Renal Replacement Therapy on Rejection among Liver Transplant Recipients

Introduction: Renal dysfunction in liver transplant recipients is associated with an increased risk of morbidity and mortality, with an even higher risk among patients requiring renal replacement therapy. There is limited data evaluating rejection outcomes in patients requiring renal replacement therapy after liver transplant. Program evaluation aims: To evaluate the incidence of biopsy-proven acute rejection, recipient and graft survival, infection, renal dysfunction, and immunosuppression practices. Design: This was a single-center, retrospective, cohort study. To be eligible, patients were deceased donor liver transplant recipients ≥18 year of age transplanted between January 2017 and August 2019 who received steroid-only induction and tacrolimus as part of their initial immunosuppression regimen. Results: Recipients that required renal replacement therapy (N  =  86) were compared to those who received no renal replacement therapy (N  =  158). Biopsy-proven acute rejection at 1-year posttransplant was significantly higher among those requiring renal replacement therapy (36% vs 13%, P < .001). Patient survival at 12 months was 77% for those requiring renal replacement therapy and 94% for those not requiring renal replacement therapy (P < .001). Infection (HR 3.8, 95% CI 1.6-8.8; P < .001), but not rejection (HR 0.7, 95% CI 0.3-1.7; P  =  .5) was an independent predictor of mortality. The use of renal replacement therapy after liver transplant necessitated careful titration of immunosuppression to balance the detrimental risks of infection versus rejection in this high-risk population.

Continuous Renal Replacement Therapy after Liver Transplantation: Peri-Operative Associated Factors and Impact on Survival

Continuous renal replacement therapy (CRRT) following orthotopic liver transplantation (OLT) is usually started for multifactorial reasons, with variable incidence among series. This paper presents a single-center retrospective observational study on the early use (within one week) of CRRT after consecutive cadaveric OLT from January 2008 to December 2016. Preoperative patient characteristics and intraoperative data were collected, and patients were divided into two groups (CRRT and no CRRT) to explore the factors associated with the use of CRRT. Repeated measurements of postoperative creatinine were analyzed with generalized estimating equation (GEE) models. Among 528 OLT patients, 75 (14.2%) were treated with CRRT at least once in the first week. Patients treated with CRRT showed lower survival in a Kaplan−Meier curve (log-rank p value < 0.01). Patients treated with CRRT had a more severe preoperative profile, with a significantly higher age, MELD, BUN, creatinine, and total bilirubin, as well as a longer surgery time and a higher number of transfusions of red blood cells, plasma, and platelets (all p values < 0.05). In a stepwise multiple analysis, the following characteristics remained independently associated with the use of CRRT: the MELD score OR 1.12 (95% CL: 1.07−1.16), p value < 0.001, and the preoperative value for blood urea nitrogen OR 1.016 (95% CL: 1.010−1.023), p value < 0.001. The early use of CRRT after OLT occurred at a low rate in this large cohort; however, it was associated with worse outcomes. Apart from the preoperative severity, repeated intraoperative hypotension episodes, which were likely modifiable or preventable, were associated with the increased use of CRRT and higher postoperative creatinine.

Pre-Operative Delta-MELD is an Independent Predictor of Higher Mortality following Liver Transplantation

Clinical decompensation immediately prior to liver transplantation may affect post-liver transplant (LT) outcomes. Using the serial Model for End-Stage Liver Disease (MELD) scores recorded in the United Network for Organ Sharing national registry (2010-2017), we analyzed post-LT mortality among adult LT recipients based on the degree of fluctuation in MELD score during the 30-day period prior to LT surgery. Delta-MELD (D-MELD) was defined as recipient MELD score at LT minus lowest MELD score within the preceding 30 days. Impact of D-MELD as a continuous and categorical variable (D-MELD 0-4, 5-10, >10) on early, 30-day post-LT mortality was assessed. Overall, a total of 12,785 LT recipients were analyzed, of which 8,862 (67.9%) had a pre-operative D-MELD 0-4; 2,574 (20.1%) with a D-MELD 5-10; and 1,529 (12.0%) with a D-MELD > 10. One-point incremental increase in pre-operative D-MELD (adjusted HR, 1.07, 95% CI: 1.04-1.10) was associated with higher 30-day post-LT mortality. Moreover, pre-operative D-MELD > 10 was associated with nearly a two-fold increased risk for 30-day post-LT mortality (adjusted HR, 1.89, 95% CI: 1.30-2.77) compared to D-MELD 0-4. The increased risk of pre-LT mortality associated with severity of clinical decompensation assessed by the magnitude of pre-operative D-MELD persists in the early post-LT period.

Early Postoperative Infections After Liver Transplant

OBJECTIVES

Despite surgical advances and effective prophylactic strategies in liver transplant, infection is still a major cause of morbidity and mortality. Up to 80% of liver recipients will develop at least 1 infection during the first year after liver transplant. The spectrum and manifestations of these infections are broad and variable. Their diagnosis and treatment are often delayed because immunosuppressive therapy diminishes inflammatory responses. However, if an infection is not identified early enough and treated properly, it can have devastating consequences. In addition, prophylactic approaches remain controversial. Our aim was to review our early postoperative infection management after liver transplant.

MATERIALS AND METHODS

We retrospectively evaluated infections that occurred during the first hospital stay of transplant patients. Infections were grouped as surgical site and nonsurgical site infections. Consequences and treatment protocols of infections were stratified according to the Clavien scale.

RESULTS

Between December 1988 and January 2017, we performed 561 liver transplants at our center (patient age range, 6 months to 64 years), which included 401 living-donor (72%) and 160 deceaseddonor (28%) liver transplants. Early postoperative infections were detected in 131 patients (23.3%), comprising 67 surgical site (51%), 56 nonsurgical site (43%), and 8 combined surgical and nonsurgical site infections (6%). Although no mortalities occurred in patients with single nonsurgical or surgical site infections, there were 4 mortalities in patients with combined surgical and nonsurgical site infections. In the 4 other patients with combined infections, 3 patients required endoscopic or radiologic intervention and 1 recovered from single-organ dysfunction.

CONCLUSIONS

Initiation of appropriate prophylactic and therapeutic protocols at the right time decreases morbidity and mortality due to infection in liver transplant recipients. Increased understanding and effective approaches to prevent infection are essential to improving both graft and recipient survival.

Bacterial infection after liver transplantation

Infectious complications are major causes of morbidity and mortality after liver transplantation, despite recent advances in the transplant field. Bacteria, fungi, viruses and parasites can cause infection before and after transplantation. Among them, bacterial infections are predominant during the first two months post-transplantation and affect patient and graft survival. They might cause surgical site infections, including deep intra-abdominal infections, bacteremia, pneumonia, catheter-related infections and urinary tract infections. The risk factors for bacterial infections differ between the periods after transplant, and between centers. Recently, the emergence of multi-drug resistant bacteria is great concern in liver transplant (LT) patients. The instructive data about effects of infections with extended-spectrum beta lactamase producing bacteria, carbapenem-resistant gram-negative bacteria, and glycopeptide-resistant gram-positive bacteria were reported on a center-by-center basis. To prevent post-transplant bacterial infections, proper strategies need to be established based upon center-specific data and evidence from well-controlled studies. This article reviewed the recent epidemiological data, risk factors for each type of infections and important clinical issues in bacterial infection after LT.