Risk factors for consequent kidney impairment and differential impact of liver transplantation on renal function

Pre-transplant kidney function predicts chronic kidney disease after liver transplant: meta-analysis of observational studies

BACKGROUND

Chronic kidney disease is a common problem in long-term survivors after liver transplantation. Several studies to clarify the risk factors for incidence of chronic kidney disease among liver transplant recipients, including preoperative kidney function, have yielded conflicting results.

AIM

The aim of this study was to conduct a systematic review of the published medical literature on the impact of pre-transplant kidney function on the occurrence of chronic kidney disease after liver transplantation.

METHODS

Study-specific relative risks were weighted by the inverse of their variance to obtain fixed- and random-effects pooled estimates for incidence of chronic kidney disease across the published studies. The relative risk of chronic kidney disease after liver transplantation according to pre-transplant glomerular filtration rate was regarded as the most reliable outcome end-point.

RESULTS

We identified seven studies (38,036 unique liver transplant recipients). A stratified analysis including only studies provided with glomerular filtration rate at transplant reported that the summary estimate of relative risk and 95% confidence intervals (CIs) for developing chronic renal failure among liver transplant recipients with diminished renal function at transplant was 2.12 (95% CI, 1.01; 4.46) (random-effects model). The p value for study heterogeneity was significant (p = 0.0001). Post-transplant chronic kidney disease shows impact on survival; the summary estimate for the adjusted relative risk of all-cause mortality with chronic kidney disease after liver transplant was 4.35 (95% confidence Intervals, 3.34; 5.66), p = 0.0001 (random-effects model).

CONCLUSIONS

An increased risk of chronic kidney disease frequently exists among liver transplant recipients with reduced renal function at transplant. The occurrence of chronic kidney disease after liver transplantation has a major impact on mortality. Additional studies are needed to understand better the natural history of chronic kidney disease among liver transplant recipients.

Critical care issues in patients after liver transplantation

The majority of patients who undergo liver transplantation (LT) spend some time in the intensive care unit during the postoperative period. For some, this is an expected part of the immediate posttransplant recovery period, whereas for others, the stay is more prolonged because of preexisting conditions, intraoperative events, or postoperative complications. In this review, 4 topics that are particularly relevant to the postoperative intensive care of LT recipients are discussed, with an emphasis on current knowledge specific to this patient group. Infectious complications are the most common causes of early posttransplant morbidity and mortality. The common patterns of infection seen in patients after LT and their management are discussed. Acute kidney injury and renal failure are common in post-LT patients. Kidney injury identification, etiologies, and risk factors and approaches to management are reviewed. The majority of patients will require weaning from mechanical ventilation in the immediate postoperative period; the approach to this is discussed along with the approach for those patients who require a prolonged period of mechanical ventilation. A poorly functioning graft requires prompt identification and appropriate management if the outcomes are to be optimized. The causes of poor graft function are systematically reviewed, and the management of these grafts is discussed.

Sluggish decline in a post-transplant model for end-stage liver disease score is a predictor of mortality in living donor liver transplantation

Background

The pre-transplant model for end-stage liver disease (pre-MELD) score is controversial regarding its ability to predict patient mortality after liver transplantation (LT). Prominent changes in physical conditions through the surgery may require a post-transplant indicator for better mortality prediction. We aimed to investigate whether the post-transplant MELD (post-MELD) score can be a predictor of 1-year mortality.

Methods

Perioperative variables of 269 patients with living donor LT were retrospectively investigated on their association with 1-year mortality. Post-MELD scores until the 30th day and their respective declines from the 1st day post-MELD score were included along with pre-MELD, acute physiology and chronic health evaluation (APACHE) II, and sequential organ failure assessment (SOFA) scores on the 1st post-transplant day. The predictive model of mortality was established by multivariate Cox's proportional hazards regression.

Results

The 1-year mortality rate was 17% (n = 44), and the leading cause of death was graft failure. Among prognostic indicators, only post-MELD scores after the 5th day and declines in post-MELD scores until the 5th and 30th day were associated with mortality in univariate analyses (P < 0.05). After multivariate analyses, declines in post-MELD scores until the 5th day of less than 5 points (hazard ratio 2.35, P = 0.007) and prolonged mechanical ventilation ≥24 hours were the earliest independent predictors of 1-year mortality.

Conclusions

A sluggish decline in post-MELD scores during the early post-transplant period may be a meaningful prognostic indicator of 1-year mortality after LT.