Increased anticoagulation during cardiopulmonary bypass by prostaglandin E1

The Best Anticoagulation Strategy for Cirrhotic Patients who Underwent Splenectomy: A Network Meta-Analysis

Objective

To determine the best anticoagulation strategy for the patients who underwent splenectomy with cirrhosis through network meta-analysis.

Methods

We conducted a systematic review of the literature in PubMed, Embase, and the Cochrane Library database. We extracted data on incidence of Portal vein system thrombosis (PVST) from studies that compared various anticoagulation strategies for use with patients who underwent splenectomy with cirrhosis. Network meta-analysis was conducted in ADDIS by evaluating the different incidence of PVST. Consistency and inconsistency models were developed to identify differences among the therapeutic strategies. Cumulative probability was utilized to rank the strategies under examination. Results. A total of 11 studies containing 1153 patients were included in the network meta-analysis. The results revealed that the application of Antithrombin III was the best anticoagulation option for patients who underwent splenectomy with cirrhosis (P = 0.59). The data of consistency and inconsistency models exhibited basically consistent and showed good convergence.

Conclusions

Application of Antithrombin III seemed to be the best anticoagulation strategy for cirrhotic patients who underwent splenectomy and should be considered a first-choice clinical reference.

Antiplatelet agents can promote two-peaked thrombin generation in platelet rich plasma: mechanism and possible applications

BACKGROUND

Thrombin generation assay is a convenient and widely used method for analysis of the blood coagulation system status. Thrombin generation curve (TGC) is usually bell-shaped with a single peak, but there are exceptions. In particular, TGC in platelet-rich plasma (PRP) can sometimes have two peaks.

OBJECTIVE

We sought to understand the mechanism underlying the occurrence of two peaks in the PRP thrombin generation curve.

METHODS

Tissue factor-induced thrombin generation in PRP and platelet-poor plasma (PPP) was monitored using continuous measurement of the hydrolysis rate of the thrombin-specific fluorogenic substrate Z-Gly-Gly-Arg-AMC. Expression of phosphatidylserine (PS) and CD62P on the surface of activated platelets was measured by flow cytometry using corresponding fluorescently labeled markers.

RESULTS

The addition of the P(2)Y(12) receptor antagonist MeS-AMP (160 µM), 83 nM prostaglandin E(1) (PGE(1)), or 1.6% DMSO to PRP caused the appearance of two peaks in the TGC. The PS exposure after thrombin activation on washed platelets in a suspension supplemented with DMSO, PGE(1) or MeS-AMP was delayed, which could indicate mechanism of the second peak formation. Supplementation of PRP with 1.6% DMSO plus 830 nM PGE(1) mediated the disappearance of the second peak and decreased the amplitude of the first peak. Increasing the platelet concentration in the PRP promoted the consolidation of the two peaks into one.

CONCLUSIONS

Procoagulant tenase and prothrombinase complexes in PRP assemble on phospholipid surfaces containing PS of two types--plasma lipoproteins and the surface of activated platelets. Thrombin generation in the PRP can be two-peaked. The second peak appears in the presence of platelet antagonists as a result of delayed PS expression on platelets, which leads to delayed assembly of the membrane-dependent procoagulant complexes and a second wave of thrombin generation.

Cardiac surgery and the coagulation system

This review focuses on the activation of the haemostatic system during cardiopulmonary bypass. The interaction of different cascade systems are examined, in particular the relation of inflammation with haemostasis. Novel strategies to supplement or replace heparin for anticoagulation during cardiopulmonary bypass have recently been described. Drug approaches to reduce activation of haemostasis reported during the review period are already well established. Their influence on the inflammatory response may offer interesting perspectives for the future.