Urinary Neutrophil Gelatinase–Associated Lipocalin (NGAL) Distinguishes Sustained From Transient Acute Kidney Injury After General Surgery

This prospective study tests the hypothesis that after general surgery urinary neutrophil gelatinase–associated lipocalin (NGAL) can distinguish between sustained acute kidney injury (AKI), typical of nephron damage, and transient AKI, commonly seen with hemodynamic variation and prerenal azotemia. Methods: Urine was collected in 510 patients within 2 to 3 hours after general surgery, and urinary NGAL was determined using enzyme-linked immunosorbent assay. Patients who met AKIN stage 1 criteria of AKI were subclassified into those with sustained AKI (serum creatinine elevation for at least 3 days) and those with transient AKI (serum creatinine elevation for less than 3 days). Results: Seventeen of 510 patients (3.3%) met the stage 1 AKIN criteria within 48 hours of surgery. Elevations in serum creatinine were sustained in 9 and transient in 8 patients. Urinary NGAL was significantly elevated only in patients with sustained AKI (204.8 ± 411.9 ng/dl); patients with transient AKI had urinary NGAL that was indistinguishable from that of patients who did not meet AKIN criteria at all (30.8 ± 36.5 ng/dl vs. 31.9 ± 113 ng/dl). The area under the curve of the receiver operating characteristic curve of urinary NGAL to predict sustained AKI was 0.85 (95% confidence interval: 0.773–0.929, P < 0.001). Discussion: Urinary NGAL levels measured 2 to 3 hours after surgery were able to distinguish the kinetics of creatinine (sustained AKI vs. transient AKI) over the subsequent week. Transient AKI is an easily reversible state that is likely not associated with substantial tubular injury and therefore NGAL release. Using AKIN criteria, both transient and sustained AKI are classified as AKI even though our data demonstrate that they are possibly different entities

Complex Hepatectomy under Total Vascular Exclusion of the Liver: Impact of Ischemic Preconditioning on Clinical Outcomes

Hepatic inflow clamping during hepatectomy introduces ischemia–reperfusion (I/R) injury, and many authors regard the addition of caval occlusion as adding increased risk. Ischemic preconditioning (IPC) is one of the protective strategies employed to reduce I/R injury in animal experiments and limited clinical series. The aim of the present study was to determine the impact of systematic adoption of IPC in patients undergoing complex hepatectomy under total hepatic vascular exclusion (TVE) based on outcomes review.The records of 93 patients who underwent major hepatectomy involving TVE at our center from February 1998 to December 2008 were reviewed. These patients were divided into two groups: group 1 (n = 55, TVE alone) and group 2 (n = 38, TVE with IPC). IPC was performed by portal triad clamping for 10 min followed by 3–5 min of reperfusion prior to TVE and resection.The two groups were comparable regarding demographics, underlying liver diseases, indications for hepatectomy, duration of TVE, and preoperative liver and kidney function tests. Overall postoperative laboratory results of liver function tests were not significantly different between the two groups. Creatinine levels and prothrombin times were not significantly different between the groups. The use of IPC had no impact on the duration of the operation, blood loss, or hospital stay. The morbidity rates were 37.5 and 34.2 %, respectively.Our adoption of IPC as a protective strategy against I/R injury under TVE did not affect operative or laboratory parameters and clinical outcomes when compared to continuous clamping for comparable ischemic periods

Perioperative fluid management and outcomes in adult deceased donor liver transplantation: a systematic review of the literature and expert panel recommendations

Background: Fluid management practices during and after liver transplantation vary widely among centers despite better understanding of the pathophysiology of end-stage liver disease and of the effects of commonly used fluids. This reflects a lack of high quality trials in this setting, but also provides a rationale for both systematic review of all relevant studies in liver recipients and evaluation of new evidence from closely related domains, including hepatology, non-transplant abdominal surgery and critical care. Objectives: To develop evidence-based recommendations for perioperative fluid management to optimize immediate and short-term outcomes following liver transplantation. Data sources: Ovid MEDLINE, Embase, Scopus, Google Scholar, and Cochrane Central. Methods: Systematic review following PRISMA guidelines and recommendations using the GRADE approach derived from an international expert panel. Studies included those evaluating the following postoperative outcomes: acute kidney injury, respiratory complications, operative blood loss/red cell units required and intensive care length of stay. PROSPERO protocol ID: CRD42021241392. Results: Following expert panel review, 18 of 1624 screened studies met eligibility criteria for inclusion in the final quantitative synthesis. These included six single center RCTs, 11 single center observational studies, and one observational study comparing centers with different fluid management techniques. Definitions of interventions and outcomes varied between studies. Recommendations are therefore based substantially on expert opinion and evidence from other clinical settings. Conclusions: A moderately restrictive or 'replacement only' fluid regime is recommended, especially during the dissection phase of the transplant procedure. Sustained hypervolemia, based on absence of fluid responsiveness, elevated filling pressures and/or echocardiographic findings, should be avoided. (Quality of Evidence: Moderate | Grade of Recommendation: Weak for restrictive fluid regime. Strong for avoidance of hypervolemia). Mean Arterial Pressure (MAP) should be maintained at >60-65 mmHg in all cases. (Quality of Evidence: Low | Grade of Recommendation: Strong). There is insufficient evidence in this population to support preferential use of any specific colloid or crystalloid for routine volume replacement. However, we recommend against the use of 130/.4 HES given the high incidence of AKI in this population

Acute kidney injury in liver transplant candidates: A position paper on behalf of the Liver Intensive Care Group of Europe

Abstract INTRODUCTION: Acute kidney injury is associated with high mortality in the perioperative period of liver transplantation. The aim of this position paper was to provide an up-to-date overview with special emphases on diagnosis, risk factors, and treatment. EVIDENCE ACQUISITION: The Liver Intensive Care Group of Europe nominated a panel of recognized international experts who reviewed the available literature published from 1990 to January 2016 and produced clinical recommendations. The level of evidence and strength of recommendation were judged according to the Grading of Recommendations Assessment Development and Evaluation system. EVIDENCE SYNTHESIS: Diagnosis of AKI should be based on the KDIGO criteria. The preoperative risk factors are more related to the patient's predisposing factors and post-operative risk factors tend to be difficult to control. Therefore, focusing on intra-operative risk factors it would be important to maintain an adequate hemodynamics and to keep inferior vena cava clamping as short as possible. Biomarkers to identify AKI at an early stage are available; however, there is a lack of robust data that indicates their true beneficial effect. Intraoperative renal replacement therapy may be beneficial in some selective cases whereas its postoperative timing is still under debate. CONCLUSIONS: Perioperative liver transplant risk factors for acute kidney injury are difficult to control. Therefore, the focus should be on intra-operative hemodynamics and nephrotoxic drugs avoidance. Prospective randomized trials are needed to show the beneficial effect of early replacement therapy. In this context, the new biomarkers would be helpful in identifying kidney injury earlier

Perioperative Coagulation Management in Liver Transplant Recipients

We review contemporary coagulation management for patients undergoing liver transplantation. A better understanding of the complex physiologic changes that occur in patients with end-stage liver disease has resulted in significant advances in anesthetic and coagulation management. A group of internationally recognized experts have critically evaluated current approaches for coagulopathy detection and management. Strategies for blood component and factor replacement have been evaluated and recommended therapies proposed. Pharmacologic treatment and prevention of coagulopathy, management of patients receiving antiplatelet medications, and the role of transesophageal echocardiography for early detection and management of thromboses are presented