Massive haemorrhage in liver transplantation: Consequences, prediction and management

Abstract

From its inception the success of liver transplantation has been associated with massive blood loss. Massive transfusion is classically defined as > 10 units of red blood cells within 24 h, but describing transfusion rates over a shorter period of time may reduce the potential for survival bias. Both massive haemorrhage and transfusion are associated with increased risk of mortality and morbidity (need for dialysis/surgical site infection) following liver transplantation although causality is difficult to prove due to the observational design of most trials. The blood loss associated with liver transplantation is multifactorial. Portal hypertension secondary to cirrhosis results in extensive collateral circulation, which can bleed during hepatectomy particular if portal pressures are increased. Avoiding volume loading and maintenance of a low central venous pressure together with the use of vasopressors have been shown to reduce blood loss and transfusion during liver transplantation, but may increase the risk of renal impairment post-operatively. Coagulation defects may be present pre-transplant, but haemostasis is often re-balanced due to a deficit in both pro- and anti-coagulation factors. Further derangement of haemostasis may develop in the anhepatic and neohepatic phases due to absent hepatic metabolic function, hyperfibrinolysis and platelet sequestration in the donor liver. Point-of-care tests of coagulation such as the viscoelastic tests rotation thromboelastometry/thromboelastometry allow and more accurate and rapid assessment of these derangements in coagulation and guide the use of factor replacement and antifibrinolytics. Transfusion protocols guided by these tests have been shown to reduce transfusion rates compared with conventional coagulation tests, but have not shown improvements in mortality or morbidity. Pre-operative factors associated with massive transfusion include previous surgery, re-do transplantation, the aetiology and severity of liver disease. Intra-operatively the use of piggy-back technique and avoiding veno-veno bypass has been shown to reduced blood loss.

Intraoperative blood loss and transfusion during primary pediatric liver transplantation: A single‐center experience

“…Intraoperative blood loss is an established risk factor for mortality after LT in adults . In adult LTs, independent risk factors for intraoperative bleeding include the presence of ascites and INR ≥ 1.6 .…”

“…In adult LTs, independent risk factors for intraoperative bleeding include the presence of ascites and INR ≥ 1.6 . Other studies have identified prolonged operative time, warm ischemia time, and bilirubin levels as significant risk factors for intraoperative transfusion requirement in adult LTs . Unfortunately, pediatric LT studies investigating these risk factors are limited.…”

“…Children that undergo LT are at a significant risk for both hemorrhage and thrombotic complications due to the hemodynamic derangements characteristic of a diseased liver. While a fair amount of literature exists to characterize thrombosis in pediatric LT, there are limited data on the incidence of massive intraoperative blood loss and its effect on morbidity and mortality post‐operatively …”

“…Adult LT studies have demonstrated that the volume of intraoperative blood transfusion impacts patient outcomes and that prolonged warm ischemia time and operative time are risk factors for massive EBL in the adult population . Similar studies in the pediatric population are limited, and little is known about the risk factors for and consequences of massive EBL in PLT recipients.…”

Preoperative thrombelastography maximum amplitude predicts massive transfusion in liver transplantation

“…Massive transfusion was defined as ≥10 units of red blood cells transfused within 24 hours of surgery(15), and intra- operative mortality was also recorded as an outcome.…”