Thomas H. Swygert

Continuous Small-dose Aprotinin Controls Fibrinolysis During Orthotopic Liver Transplantation

Large doses of aprotinin (1,000,000-2,000,000 kallikrein inhibitor units [KIU] initial dose and a 500,000 KIU/h infusion) have been used during orthotopic liver transplantation (OLT) to reduce the incidence and severity of fibrinolysis. This double-blinded study was designed to investigate whether a small-dose infusion of aprotinin (200,000 KIU/h) would control fibrinolysis. A controlled study was undertaken to compare small-dose aprotinin with a placebo in patients undergoing OLT with veno-venous bypass. Forty-four patients were randomized either to the aprotinin group (n = 21), which received an intravenous infusion of 200,000 KIU/h without an initial dose, or to a control group (n = 23), which received normal saline. Coagulation variables, thrombelastograms, and postoperative blood drainage were measured. Blood levels of fibrin degradation products (FDP) were significantly higher in the control group (95% > 20 micro gram/mL) at the end of surgery compared to the aprotinin group (53% > 20 micro gram/mL, P < 0.01). The transfusion of cryoprecipitate units was more in the control group versus the aprotinin (12.6 +/- 12.8 vs 5.7 +/- 7.5; P < 0.04), as was the number of fresh frozen plasma units (6.6 +/- 3.5 vs 3.6 +/- 6.1; P < 0.05). We conclude that an infusion of a small dose of aprotinin can safely control fibrinolysis during liver transplantation with a concomitant reduction in transfusion of blood products. (Anesth Analg 1996;82:1122-5)

Temperature Corrected Thrombelastography in Hypothermic Patients

Thrombelastograms and other coagulation studies are performed at 37 degrees C, regardless of the patients body temperature.This prospective study of 45 patients undergoing orthotopic liver transplantation was conducted to evaluate the effect on the thrombelastogram performed at the patients actual body temperature compared with a control thrombelastogram heated in the standard fashion to 37 degrees C. Thrombelastograms were obtained after the induction of anesthesia and at various times throughout the operation when clinically indicated. A freshly drawn sample of the patients blood was divided into two aliquots and run simultaneously on two thrombelastographs; one thrombelastograph was modified with a thermostat to perform the test at the patients body temperature and the other was unmodified to serve as a control. The temperature of the patients in this study ranged from 36.9 degrees C to 32 degrees C. The variables of the thrombelastogram measured were: r (reaction time in minutes), r + K (coagulation time in minutes), alpha (coagulation rate in degrees), and MA (maximum amplitude in millimeters). Whenever the patients body temperature was less than 37 degrees C, statistically significant prolongation of the reaction time, coagulation time, and decrease in the clot formation rate occurred compared with control variables at 37 degrees C. Overall means were as follows: r for control, 8.24 +/- 0.28 min; r for temperature corrected, 9.32 +/- 0.27 min; r + K for control, 15.4 +/- 0.65 min; r + K for temperature corrected, 17.5 +/- 0.81 min; and alpha for control, 39.8 +/- 1.22 degrees; alpha for temperature corrected, 37.7 +/- 1.23 degrees. The MA was not significantly different between the temperature corrected thrombelastograms and the control thrombelastograms regardless of the patients body temperature. These changes suggest that performing thrombelastograms in the standard fashion may overestimate the quality of the coagulation system in vivo when the patients temperature is less than 37 degrees C. (Anesth Analg 1995;81:608-11)

Oral transmucosal fentanyl citrate for premedication in adults

This study was designed to assess the efficacy of oral transmucosal fentanyl citrate (OTFC) for premedication in an adult population and to determine its effects on anxiety, sedation, gastric volume, and gastric fluid acidity.The fentanyl citrate is incorporated in a lozenge mounted on a handle (oralet). The effects of OTFC, placebo oralet, and no premedication were compared in a prospective, double-blind study on 90 adult ASA physical status I and II patients undergoing same-day admission surgery. Patients were randomly assigned to one of three groups: OTFC group (n = 30), placebo group (n = 30), and control group (n = 30). Arterial blood pressure, heart rate, respiratory frequency, and oxygen saturation determined by pulse oximetry were recorded before any premedication was given, and then every 10 min until the patient was taken to the operating room. Baseline anxiety and sedation levels were assessed to ensure group similarity immediately before premedication was given and at the more anxiety-provoking phase upon entering the operating room. Anxiety levels were rated using the Spielberger State-Trait Anxiety Inventory short form and sedation levels were assessed with the Ramsay scale. Side effects, as reported by the patients, were also recorded. Gastric contents were aspirated via an orogastric tube after induction of anesthesia and were measured for volume and pH. No significant differences were found among the three groups in mean arterial pressure, heart rate, or respiratory frequency. Initial oxygen saturation levels in all groups decreased after 30 min but not less than 96% except for one patient in the OTFC group, who decreased to 88%. On entering the operating room, the OTFC group demonstrated significantly higher levels of anxiolysis than the control group, but no significant differences were seen between the OTFC and the placebo groups or the placebo and control groups. Mean gastric volumes (OTFC, 29 mL; placebo, 26 mL; control, 24 mL) and pH (OTFC, 2.0; placebo, 1.8; control, 2.1) were similar in all groups. There were no significant differences among the groups in levels of sedation achieved. Mild dizziness or light-headedness was the most commonly reported side effect in 23% of the OTFC group. In the OTFC group, 71.4% liked the premedicant effect as compared to 46.4% of the placebo group. Most of the groups found the oralet method of premedicant delivery very acceptable. This study demonstrates that the OTFC oralet is an effective anxiolytic in adults. It has minimal side effects and is prepared in an acceptable format. There was no measurable increase in gastric contents or acidity in the oralet groups, compared to those patients who were given nothing by mouth. (Anesth Analg 1996;82:158-61)

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...