Retrospective Study
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Hepatol. Jun 28, 2017; 9(18): 823-832
Published online Jun 28, 2017. doi: 10.4254/wjh.v9.i18.823
Early acute kidney injury after liver transplantation: Predisposing factors and clinical implications
Suehana Rahman, Brian R Davidson, Susan V Mallett
Suehana Rahman, Susan V Mallett, Royal Free Perioperative Research Group, Department of Anaesthesia, Royal Free Hospital, Royal Free NHS Foundation Trust, London NW3 2QG, United Kingdom
Brian R Davidson, Department of Surgery, Royal Free Hospital, Royal Free NHS Foundation Trust, London NW3 2QG, United Kingdom
Author contributions: Rahman S designed and performed the research and wrote the paper; Mallett SV designed the research and supervised the report; Davidson BR supervised the report.
Institutional review board statement: Formal institutional approval was not deemed necessary because anonymised data routinely collected in the liver transplant database were used.
Informed consent statement: All patients had consented a priori to data collection for research purposes when they had consented to liver transplantation.
Conflict-of-interest statement: The authors have no financial relationships to disclose.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Suehana Rahman, MBBS FRCA, Consultant in Anaesthesia, Royal Free Perioperative Research Group, Department of Anaesthesia, Royal Free Hospital, Royal Free NHS Foundation Trust, Pond Street, London NW3 2QG, United Kingdom. suehana.rahman@nhs.net
Telephone: +44-207-7940500 Fax: +44-207-8302245
Received: January 28, 2017
Peer-review started: February 9, 2017
First decision: March 7, 2017
Revised: March 28, 2017
Accepted: April 18, 2017
Article in press: April 19, 2017
Published online: June 28, 2017
Processing time: 142 Days and 16.4 Hours
Abstract
AIM

To investigate the additional clinical impact of hepatic ischaemia reperfusion injury (HIRI) on patients sustaining acute kidney injury (AKI) following liver transplantation.

METHODS

This was a single-centre retrospective study of consecutive adult patients undergoing orthotopic liver transplantation (OLT) between January 2013 and June 2014. Early AKI was identified by measuring serum creatinine at 24 h post OLT (> 1.5 × baseline) or by the use of continuous veno-venous haemofiltration (CVVHF) during the early post-operative period. Patients with and without AKI were compared to identify risk factors associated with this complication. Peak serum aspartate aminotransferase (AST) within 24 h post-OLT was used as a surrogate marker for HIRI and severity was classified as minor (< 1000 IU/L), moderate (1000-5000 IU/L) or severe (> 5000 IU/L). The impact on time to extubation, intensive care length of stay, incidence of chronic renal failure and 90-d mortality were examined firstly for each of the two complications (AKI and HIRI) alone and then as a combined outcome.

RESULTS

Out of the 116 patients included in the study, 50% developed AKI, 24% required CVVHF and 70% sustained moderate or severe HIRI. Median peak AST levels were 1248 IU/L and 2059 IU/L in the No AKI and AKI groups respectively (P = 0.0003). Furthermore, peak serum AST was the only consistent predictor of AKI on multivariate analysis P = 0.02. AKI and HIRI were individually associated with a longer time to extubation, increased length of intensive care unit stay and reduced survival. However, the patients who sustained both AKI and moderate or severe HIRI had a longer median time to extubation (P < 0.001) and intensive care length of stay (P = 0.001) than those with either complication alone. Ninety-day survival in the group sustaining both AKI and moderate or severe HIRI was 89%, compared to 100% in the groups with either or neither complication (P = 0.049).

CONCLUSION

HIRI has an important role in the development of AKI post-OLT and has a negative impact on patient outcomes, especially when occurring alongside AKI.

Keywords: Hepatic ischaemia reperfusion injury; Liver transplantation; Perioperative care; Acute kidney injury; Marginal grafts

Core tip: Acute kidney injury (AKI) is common after liver transplantation (LT), and has a significant impact on patient outcomes. It is multifactorial in aetiology and has been shown to correlate with the use of higher risk grafts, due to an increased risk of hepatic ischaemia reperfusion injury. In context of the growing use of marginal grafts to meet demands, this study has demonstrated that hepatic ischaemia reperfusion injury was the only variable that predicted early AKI post-LT and that the presence of both HIRI and AKI led to worse clinical outcomes and higher mortality than either complication alone.