An in vitro study comparing two dose regimes of fresh frozen plasma on conventional and thromboelastographic tests of coagulation after major hepatic resection

BACKGROUND: After hepatic resection, post-operative increases in international normalised ratio (INR) are frequent, but rarely associated with bleeding complication. Coagulation as assessed by thrombin generation may be normal, despite the increased INR. This study tests the hypothesis that viscoelastic tests (VET) of coagulation remain normal, despite mild elevations in INR, examines the efficacy of fresh frozen plasma (FFP) in reversing prolongation of INR in such patients and determines the effect of FFP on VET. METHODS: A prospective cohort study of 47 patients undergoing major hepatectomy. In vitro spiking with FFP (7·5 and 15 mL kg(-1)) was carried out if post-operative day 2 (POD2) INR levels were ≥1·5. Thromboelastography (TEG®) and INR were measured before and after FFP spiking. RESULTS: Blood from patients with an INR ≥ 1·5 on POD2 was spiked with FFP. There was a significant reduction in the INR from 1·94 [standard deviation (SD): 0·59] to 1·46 (SD: 0·27, P = 0·005) and 1·36 (SD: 0·18, P = 0·0007) with FFP 7·5 or 15 mL kg(-1), respectively. At baseline, the TEG R-time [6·17 min (NR, 9-27 min)] and maximum amplitude (MA) [66·9 mm (NR, 44-64 mm)] were hypercoagulable, and remained so on POD2 for the R-time (6·7 min), but fell to within the normal range for the MA (54·0 mm). FFP spiking had no significant effect on TEG variables. CONCLUSIONS: Despite the rise in INR after hepatectomy, VET do not show evidence of hypocoagulability. In vitro addition of FFP had no significant effect on TEG parameters. Clinical use of FFP in this situation is questionable.