Observational Study
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Hepatol. Feb 28, 2017; 9(6): 318-325
Published online Feb 28, 2017. doi: 10.4254/wjh.v9.i6.318
Thrombocytopenia in cirrhosis: Impact of fibrinogen on bleeding risk
Sonali V Thakrar, Susan V Mallett
Sonali V Thakrar, Susan V Mallett, Royal Free Perioperative Research Group, Department of Anaesthesia, Royal Free London, London NW3 2QG, United Kingdom
Author contributions: Thakrar SV and Mallett SV contributed equally to this work in designed and coordinated the research and writing the manuscript.
Institutional review board statement: This work was reviewed and approved by the Royal Free London Research and Development department and was deemed not to require ethics approval.
Informed consent statement: All data retrieved from our transplant database was anonymised. The data has been previously collected (prior to the study commencing), and was collected as part of standard care. Only those persons involved in clinical care had access to our database. No patient interventions were performed as part of this study. As a result, it was deemed unnecessary to require patient consent.
Conflict-of-interest statement: There are no conflicts of interest to declare.
Data sharing statement: Technical appendix, statistical code, and dataset available from the corresponding author at s.thakrar1@nhs.net. Participant onsent was not obtained but the presented data are anonymised and risk of identification is low.
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: Sonali V Thakrar, MBBS, BSc (Hons), MRCP, FRCA, Clinical Research Fellow, Royal Free Perioperative Research Group, Department of Anaesthesia, Royal Free London, Pond Street, London NW3 2QG, United Kingdom. s.thakrar1@nhs.net
Telephone: +44-207-77940500
Received: July 27, 2016
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
Processing time: 214 Days and 14.2 Hours
Abstract
AIM

To investigate the relationship between baseline platelet count, clauss fibrinogen, maximum amplitude (MA) on thromboelastography, and blood loss in orthotopic liver transplantation (OLT).

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Keywords: Thrombocytopenia; Cirrhosis; Haemostasis; Fibrinogen; Liver transplantation

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.