Published online Feb 28, 2017. doi: 10.4254/wjh.v9.i6.318
Peer-review started: July 29, 2016
First decision: September 28, 2016
Revised: December 23, 2016
Accepted: January 11, 2017
Article in press: January 14, 2017
Published online: February 28, 2017
To investigate the relationship between baseline platelet count, clauss fibrinogen, maximum amplitude (MA) on thromboelastography, and blood loss in orthotopic liver transplantation (OLT).
A retrospective analysis of our OLT Database (2006-2015) was performed. Baseline haematological indices and intraoperative blood transfusion requirements, as a combination of cell salvage return and estimation of 300 mls/unit of allogenic blood, was noted as a surrogate for intraoperative bleeding. Two groups: Excessive transfusion (> 1200 mL returned) and No excessive transfusion (< 1200 mL returned) were analysed. All data analyses were conducted using IBM SPSS Statistics version 23.
Of 322 OLT patients, 77 were excluded due to fulminant disease; redo transplant or baseline haemoglobin (Hb) of < 80 g/L. One hundred and fourteen (46.3%) were classified into the excessive transfusion group, 132 (53.7%) in the no excessive transfusion group. Mean age and gender distribution were similar in both groups. Baseline Hb (P ≤ 0.001), platelet count (P = 0.005), clauss fibrinogen (P = 0.004) and heparinase MA (P = 0.001) were all statistically significantly different. Univariate logistic regression with a cut-off of platelets < 50 × 109/L as the predictor and Haemorrhage as the outcome showed an odds ratio of 1.393 (95%CI: 0.758-2.563; P = 0.286). Review of receiver operating characteristic curves showed an area under the curve (AUC) for platelet count of 0.604 (95%CI: 0.534-0.675; P = 0.005) as compared with AUC for fibrinogen level, 0.678 (95%CI: 0.612-0.744; P ≤ 0.001). A multivariate logistic regression shows United Kingdom model for End Stage Liver Disease (P = 0.006), Hb (P = 0.022) and Fibrinogen (P = 0.026) to be statistically significant, whereas Platelet count was not statistically significant.
Platelet count alone does not predict excessive transfusion. Additional investigations, e.g., clauss fibrinogen and viscoelastic tests, provide more robust assessment of bleeding-risk in thrombocytopenia and cirrhosis.
Core tip: Current literature describing bleeding risk in thrombocytopenia and cirrhosis does not take into account the impact of fibrinogen. The minimal platelet count to form a clot with normal strength is unknown, and would be influenced by fibrinogen. Viscoelastic testing, particularly maximum amplitude (MA, thromboelastography) or maximum-clot-firmness (MCF, thromboelastometry), reflects platelet-fibrinogen interaction and allows assessment of clot strength. Low platelet count and low fibrinogen levels lead to low MA/MCF and correlate strongly with increased bleeding tendency. Assessment of platelet count alone does not accurately predict bleeding, but is useful in conjunction with other indices such as clauss fibrinogen and MA/MCF.