Kj Ramsay

Continuous Small-Dose Tranexamic Acid Reduces Fibrinolysis but not Transfusion Requirements During Orthotopic liver Transplantation

Tranexamic acid (TA) is a synthetic drug that inhibits fibrinolysis.It has been administered to decrease the use of blood products during cardiac surgery and orthotopic liver transplantation when infused in larger doses. A small-dose infusion of aprotinin causes a reduction in fibrinolysis and blood product requirement during orthotopic liver transplantation without apparent risk of intravascular thrombosis. This prospective study was designed to investigate whether a small-dose infusion of TA would be equally effective in reducing fibrinolysis and blood product transfusions during orthotopic liver transplantation. A double-blind, controlled study was undertaken to compare the efficacy of a small-dose TA infusion with that of a placebo. Thirty-two consecutive patients were randomized either to the TA group (n = 16), which received an intravenous infusion of 2 mg [center dot] kg-1 [center dot] h-1, or to the control group (n = 16), which received an identical volume of normal saline. Coagulation values were measured, a field rating was made by the surgeon, and a thrombelastogram was produced at four predetermined intervals throughout the case-before TA infusion was started, after portal vein ligation, 10 min after reperfusion, and at the end of surgery. Intraoperative transfusion requirements were recorded during the procedure and for the first 24 h postoperatively. A record was kept of any intraoperative epsilon-aminocaproic acid administered for uncontrolled fibrinolysis. The thrombelastogram clot lysis index was significant for lysis in the control group during both the anhepatic and the neohepatic phases (P < 0.01 and P < 0.05, respectively) when compared with the TA group. Fibrin degradation products were significantly increased (>20 micro g/mL) in the control group at reperfusion (P < 0.03) and at the end of surgery (P < 0.01). D-dimers were also significantly increased (>1 mg/L) in the control group at the end of surgery (P < 0.04). Nine of the 16 control patients versus 3 of the 16 TA patients required epsilon-aminocaproic acid rescue for fibrinolysis. There were no other significant differences between groups. Transfusion requirements during surgery and for the first 24 h postoperatively did not differ significantly between the two groups. We conclude that the use of small-dose TA reduces fibrinolysis but not transfusion requirements during orthotopic liver transplantation. (Anesth Analg 1997;85:281-5)

Duration of rocuronium-induced neuromuscular block during liver transplantation: A predictor of primary allograft function

The prolongation of vecuronium-induced neuromuscular block has been reported as a predictor of hepatic allograft dysfunction. This study investigates the duration of action of rocuronium, which also relies on hepatic clearance, to examine whether it also is prolonged with allograft dysfunction. Fifty-seven patients undergoing orthotopic liver transplant were given rocuronium (0.6 mg/kg) prior to allograft placement and the recovery of contraction of the orbicularis oculi muscle to a 2-Hz train-of-four stimulus was recorded. Fifteen minutes after reperfusion of the allograft, rocuronium (0.6 mg/kg) was administered and the time to recovery of muscle contraction to a train-of-four stimulus (train-of-four time) was again recorded. The patients were divided into two groups according to posttransplant liver function. Group I consisted of 50 patients with immedite normal liver function. Group II contained 7 patients with primary dysfunctional livers. Primary dysfunction was determined by peak serum aspartate amino-transferase and alanine aminotransferase levels > 2000 U/L, and prothrombin time > 16 s. The train-of-four time in Group II was prolonged compared with Group I (P < 0.05). Immediate graft function testing using the recovery time from rocuronium of > 150 min has a positive predictive value of 100% and a negative predictive value of 96%. The sensitivity and specificity is 71% and 100%, respectively. Receiver operating characteristic analysis supports this conclusion. (Anesth Analg 1997;84:870-4)

Paradoxical Role of Inhaled Nitric Oxide in Advanced Liver Disease

From the Departments of Internal Medicine (Simpson), Anesthesiology and Pain Management (M. Ramsay, K. Ramsay, and Hein), Pulmonary Services (Lynch and Black), Gastroenterology (Crippin and Sarles), Cardiology (East and Escobar), and Baylor Institute of Transplantation Sciences (Goldstein, Husberg, Levy, and Klintmalm), Baylor University Medical Center, Dallas, Texas; and the Department of Anesthesiology and Pain Management, The University of Texas Southwestern Medical Center at Dallas (M. Ramsay).

Efficacy and Safety of Administering Fibrinolysis Inhibitors During Repeat Cardiac Surgery

Aprotinin, a serine protease inhibitor, and tranexamic acid, a synthetic lysine analogue, are both used in cardiac surgery to reduce blood loss and transfusion of blood products. Concern has arisen...