Viscoelastic versus conventional coagulation tests to reduce blood product transfusion in patients undergoing liver transplantation

Abstract

BACKGROUND Recent literature suggests viscoelastic test (VET)-guided transfusion management could be associated with reduced blood product administration in patients undergoing liver transplantation. OBJECTIVE(S)To assess the effectiveness of coagulation management guided by VETs compared with conventional coagulation tests (CCTs) in reducing blood product transfusion in patients undergoing liver transplantation.DESIGN Systematic review and meta-analysis of randomised (RCTs) and nonrandomised clinical trials performed according to PRISMA guidelines. The protocol was previously published (PROSPERO: CRD42021230213) DATA SOURCES The Cochrane Central Library, PubMed/ MEDLINE, Embase and the Transfusion Evidence Library were searched up to 30 th January 2022.ELIGIBILITY CRITERIA Setting: operating room. Patients: liver transplantation recipients. Intervention: use of VETs versus CCTs. Main outcome measures: the primary outcome was the mean number of transfused units for each blood product including red blood cells (RBCs), fresh frozen plasma (FFP), platelets (PLTs) and cryoprecipitate. Secondary outcomes included mortality rate, intensive care unit (ICU) and hospital length of stay (LOS).RESULTS Seventeen studies (n ¼ 5345 patients), 15 observational and two RCTs, were included in this review. There was a mean difference reduction in RBCs [mean difference: À1.40, 95% confidence interval (95% CI), À1.87 to À0.92; P < 0.001, I 2 ¼ 61%) and FFP units (mean difference: À2.98, 95% CI, À4.61 to À1.35; P ¼ < 0.001; I 2 ¼ 98%) transfused in the VETs group compared with the CCTs one. A greater amount of cryoprecipitate was administered in the VETs group (mean difference: 2.71, 95% CI, 0.84 to 4.58; P ¼ 0.005; I 2 ¼ 91%). There was no significant difference in the mean number of PLT units, mortality, hospital and ICU-LOS.CONCLUSION Our meta-analysis demonstrated that VETs implementation was associated with reduced RBC and FFP consumption in liver transplantation patients without effects on mortality and hospital and ICU-LOS. The certainty of evidence ranged from moderate to very low. Further well conducted RCTs are needed to improve the certainty of evidence.

Viscoelastic testing: Critical appraisal of new methodologies and current literature

“…Use of VET has become routine in liver transplantation with multiple small studies suggesting the benefit of VET-based transfusion algorithms to better predict bleeding compared to CCT 10 as well as to reduce the volume of transfused products, notably plasma and red blood cell units. 81 VET-based transfusion algorithms generally increase the transfusion of platelets and cryoprecipitate in this context. 38 An RCT of ROTEM versus CCT in 81 liver transplantation patients showed that a VET-guided transfusion algorithm significantly reduced plasma and TXA use, increased fibrinogen supplementation, and had no effect on ICU re-admission or mortality.…”

“…The evolution of these phases occurs quickly, in the span of minutes. Use of VET has become routine in liver transplantation with multiple small studies suggesting the benefit of VET‐based transfusion algorithms to better predict bleeding compared to CCT 10 as well as to reduce the volume of transfused products, notably plasma and red blood cell units 81 . VET‐based transfusion algorithms generally increase the transfusion of platelets and cryoprecipitate in this context 38 …”

Abdominal Organ Transplantation: Noteworthy Literature in 2022

“…Aceto et al performed a systematic review and meta-analysis of RCTs and nonrandomized clinical trials reported up to January 30, 2022. 76 They identified 17 studies (5345 patients), including 15 observational studies and 2 RCTs. There was a mean difference reduction in RBCs (mean difference: −1.40 units, 95% CI, −1.87 to −.92; P < .001, I 2 = 61%) and fresh frozen plasma (FFP) units (mean difference: −2.98 units, 95% CI, −4.61 to −1.35; P < .001; I 2 = 98%) transfused in the VET group compared with the SLT group.…”

“…Cardiovascular Issues Epidemiology, risk assessment, and risk mitigation: Izzy et al 62 A comprehensive review of the existing literature published between 1990 and 2021 addresses epidemiology, risk assessment, and risk mitigation of coronary heart disease, arrhythmia, heart failure, and valvular heart disease, and formulated practice-based recommendations. Coagulation/Transfusion Viscoelastic test-guided blood management: Aceto et al 76 A systematic review and meta-analysis showed that VET-guided LT management resulted in decreased usage of RBC (À1.40 units) and FFP (À2.98 units) compared with the SLT group. However, it resulted in increased transfusion of cryoprecipitate (2.71 units).…”

Coagulation support during perioperative bleeding management

“…However, studies comparing VET with conventional coagulation testing to guide transfusion support in liver transplant surgery have demonstrated mixed results. In one recent VET-guided liver transplant surgical study, RBCs and FFP transfusions were reduced, and there were no differences in platelet transfusions, but cryoprecipitate administration was increased [ 13 ]. After trauma-induced bleeding, transfusion strategies with VET compared to conventional coagulation assays have also been reported to reduce mortality [ 14 ].…”