Aprotinin reduces red blood cell transfusion in orthotopic liver transplantation: a prospective, randomized, double-blind study

Preoperative preparation of patients with advanced liver disease

OBJECTIVE

To review the characteristic features of patients with advanced liver disease that may lead to increased perioperative morbidity and mortality rates.

DESIGN

Literature review.

RESULTS

Patients with end-stage liver disease are at high risk of major complications and death following surgery. The most common complications are secondary to acute liver failure and include severe coagulopathy, encephalopathy, adult respiratory distress syndrome, acute renal failure, and sepsis. The degree of malnutrition, control of ascites, level of encephalopathy, prothrombin time, concentration of serum albumin, and concentration of serum bilirubin predict the risk of complications and death following surgery. Other determinants of adverse outcome include emergency surgery, advanced age, and cardiovascular disease. Portal hypertension is a prominent feature of advanced liver disease, and it predisposes the patient to variceal hemorrhage, hepatorenal syndrome, hepatopulmonary syndrome, and uncontrolled ascites. Portal hypertension can be ameliorated by percutaneous or surgical portasystemic shunting procedures. If well-defined contraindications are not present, patients with advanced liver disease should be evaluated for orthotopic liver transplantation from a cadaver donor or possible living-related liver transplantation.

CONCLUSIONS

Optimal preparation, which addresses the common features of advanced liver disease, may decrease the risk of complications or death following surgery. Preparation should include correcting coagulopathy, minimizing preexisting encephalopathy, preventing sepsis, and optimizing renal function.

Transfusion predictors in liver transplant

In this study we sought to determine the factors influencing red blood cell (RBC) transfusions and to study the transfusion practice of anesthesiologists during liver transplants. A retrospective study of 206 successive liver transplants was undertaken during a period of 52 mo. Transfused blood products were identified. Twenty variables were analyzed in a univariate fashion. For the multivariate analysis, the cases were divided in 2 subgroups: more than 4 RBC units transfused and 4 or less RBC units transfused. The average number of RBC units transfused during a liver transplant was 2.8 (+/- 3.5) per patient, 32.0% did not receive any RBC, and 19.4% did not receive any blood products during the transplant. Three variables were related to the number of RBC units transfused: the starting International Normalized Ratio value, the starting platelet count, and the duration of surgery. We found that there was a wide difference in the transfusion practice of the anesthesiologists involved in this series of liver transplants. It was difficult to identify predictive factors for RBC transfusions when the transfusion rate was small and because of the variability in human factors. Plasma transfusion did not decrease the rate of RBC transfusions; sometimes it was the contrary.

IMPLICATIONS

This is a retrospective study of 206 liver transplants over 52 mo to identify the predictive factors of red blood cell transfusions and the anesthesiologists' transfusion strategies. We conclude that there is a wide difference in transfusion practices among anesthesiologists.

The prophylactic use of tranexamic acid and aprotinin in orthotopic liver transplantation: a comparative study

The efficacy of tranexamic acid (TA) and aprotinin (AP) in reducing blood product requirements in orthotopic liver transplantation (OLT) was compared in a prospective, randomized and double-blind study. One hundred and twenty seven consecutive patients undergoing OLT were enrolled; TA was administered to 64 OLT patients at a dose of 10mg /kg/h and aprotinin was administered to 63 OLT patients at a loading dose of 2 x 10(6) KIU followed by an infusion of 500,000 KIU/h. The portocaval shunt could not be performed in 14 OLT patients in the TA group and in 13 OLT patients in the AP group. However, all OLT patients that received either drug were included in the analysis. Perioperative management was standardized. Hemogram, coagulation tests, and blood product requirements were recorded during OLT and during the first 24 hours. No differences in diagnosis, Child score, preoperative coagulation tests, and intraoperative data were found between groups. No significant differences were observed in hemogram and intraoperative coagulation tests with the exception of activated partial thromboplastin time (aPTT). Similarly, there were no intergroup differences in transfusion requirements. Thromboembolic events, reoperations and mortality were similar in both groups. In conclusion, administration of regular doses of TA and AP during OLT did not result in large differences between the two groups.

Intraoperative red blood cell transfusion in liver transplantation: influence on patient outcome, prediction of requirements, and measures to reduce them

Objectives of this study are to quantify the need for blood transfusion during liver transplantation (LT) and confirm the importance of intraoperative blood transfusion as an independent prognostic factor for postoperative outcome. Furthermore, we try to detect useful variables for the preoperative identification of patients likely to require transfusion of packed red blood cell units (PRCUs) and identify measures to reduce transfusion needs. Data were collected prospectively between September 1998 and November 2000. One hundred twenty-two LTs were included in the study. Forty-two patients (34%) did not require transfusion of PRCUs. In multivariate analysis, transfusion of more than three PRCUs was found to be the only significant variable associated with prolonged hospital stay. In addition, excluding perioperative deaths, PRCU transfusion, using a cutoff value of six units, was the only variable to reach statistical significance (P =.008; risk ratio, 4.93; 95% confidence interval, 15 to 15.9) to predict survival in a multivariate analysis that also included Child's class and United Network for Organ Sharing (UNOS) classification. Moreover, only preoperative hemoglobin (Hb) level was found to significantly predict the need for transfusion of one or more PCRUs. Finally, only UNOS classification and placement of an intraoperative portacaval shunt were found to be statistically significant to predict the need to transfuse more than six PRCUs. We found the requirement of even a moderate number of blood transfusions is associated with longer hospital stay, and transfusion of more than six PRCUs is associated with diminished survival. Preoperative normalization of Hb levels and placement of an intraoperative portacaval shunt can diminish the number of blood transfusions during LT.

Anaesthetic management of coronary artery bypass grafting in a patient with central core disease and susceptibility to malignant hyperthermia on statin therapy

Central core disease and malignant hyperthermia (MH) are both associated with mutations in the RYR1 gene. We report the anaesthetic management of one such patient presenting for coronary artery bypass grafting. Her medication included aspirin 75 mg, atorvastatin 20 mg, isosorbide mononitrate 60 mg, atenolol 25 mg and glyceryl trinitrite sublingual spray as required. The use of aprotinin, statins and moderate hypothermia in patients with central core disease and known susceptibility to MH has not been documented.

Pharmacological strategies to decrease transfusion requirements in patients undergoing surgery

Surgical procedures are inevitably associated with bleeding. The amount of blood loss may vary widely between different surgical procedures and depends on surgical as well as non-surgical factors. Whereas adequate surgical haemostasis may suffice in most patients, pro-haemostatic pharmacological agents may be of additional benefit in patients with (diffuse) surgical bleeding or in patients with a specific underlying haemostatic defect. In general, surgical haemostasis and pharmacological therapies can be complementary in controlling blood loss. The use of pharmacological therapies to reduce blood loss and blood transfusions in surgery has historically been restricted to a few drugs. Antifibrinolytic agents (aprotinin, tranexamic acid and aminocaproic acid) have the best evidence supporting their use, especially in cardiac surgery, liver transplantation and some orthopaedic surgical procedures. Meta-analyses of randomised, controlled trials in cardiac patients have suggested a slight benefit of aprotinin, compared with the other antifibrinolytics. Desmopressin is the treatment of choice in patients with mild haemophilia A and von Willebrand disease. It has also been shown to be effective in patients undergoing cardiac surgery who received aspirin up to the time of operation. However, overall evidence does not support a beneficial effect of desmopressin in patients without pre-existing coagulopathy undergoing elective surgical procedures. Topical agents, such as fibrin sealants have been successfully used in a variety of surgical procedures. However, only very few controlled clinical trials have been performed and scientific evidence supporting their use is still limited. Novel drugs, like recombinant factor VIIa (eptacog alfa), are currently under clinical investigation. Recombinant factor VIIa has been introduced for the treatment of haemophilia patients with inhibitors, either in surgical or non-surgical situations. Preliminary data indicate that it may also be effective in surgical patients without pre-existing coagulation abnormalities. More clinical trials are warranted before definitive conclusions can be drawn about the safety and the exact role of this new drug in surgical patients. Only adequately powered and properly designed randomised, clinical trials will allow us to define the most effective and the safest pharmacological therapies for reducing blood loss and transfusion requirements in surgical patients. Future trials should also consider cost-effectiveness because of considerable differences in the costs of the available pro-haemostatic pharmacological agents.

The effect of aprotinin on transfusion requirements in pediatric orthotopic liver transplantation

The use of aprotinin to reduce blood loss by inhibiting fibrinolysis thereby decreasing transfusion requirements during orthotopic liver transplantation (OLT), is well-documented in adults. We set out to test the hypothesis that the prophylactic use of aprotinin reduced blood product requirements during pediatric OLT. A retrospective study was performed, reviewing data from 24 OLTs performed over a 4-yr period. Six patients did not receive aprotinin (group 1), while 18 (group 2) received a weight-based dose of aprotinin. Both groups were comparable with respect to demographics, baseline characteristics and surgical variables except for a significantly more prolonged activated partial thromboplastin time (APTT) in the aprotinin group (p = 0.015). Despite the fact that median values for transfused volumes of red blood cells (78.3 vs. 36.7 mL/kg) and fresh frozen plasma (51.9 vs. 23.7 mL/kg) were more than halved in the aprotinin group, there was no statistical difference demonstrated. The failure to reach statistical significance can probably be explained by the small number in group 1 and a high level of scatter. All patients in group 1 required intraoperative transfusion of RBC and fresh frozen plasma (FFP) while two patients in group 2 did not require RBC and seven received no FFP. There were four patients in group 1 and 17 in group 2 who did not receive platelets while five in group 1 and 12 in group 2 did not receive cryoprecipitate. The differences between the groups in avoidance of these blood products did not reach statistical significance. There was little difference between groups with respect to albumin and crystalloid requirements. No statistical difference was demonstrated in intraoperative hematologic profiles between the two groups except during the anhepatic phase of surgery when there was a statistically significant more prolonged prothrombin time (p = 0.04) and a greater international normalized ratio (p = 0.027) in group 2.

Aprotinin reduces vasoactive medication use during adult liver transplantation

STUDY OBJECTIVE

To determine whether aprotinin use during adult liver transplantation results in an improvement in hemodynamic stability.

DESIGN

Review of data collected during a prospective, randomized, double-blind trial.

SETTING

Liver transplantation program in a tertiary referral institution.

PATIENTS

63 adult patients undergoing orthotopic liver transplantation (OLT).

INTERVENTIONS

Patients were randomized to receive either aprotinin (1,000,000 KIU loading dose, followed by an infusion of 250,000 KIU/hr) for the duration of the surgery or a placebo infusion (normal saline).

MEASUREMENTS

Hemodynamic parameters (mean systemic blood pressure, cardiac output, systemic vascular resistance, mean pulmonary artery (PA) pressure, and PA occlusion pressure) were compared at set time points during the procedure. The use of vasoactive medications during and after the reperfusion period was compared.

MAIN RESULTS

There were no significant differences in any of the measured hemodynamic parameters at any time point. Vasoactive infusions were used in 1 of 33 patients in the aprotinin group and in 6 of 30 patients in the control group (p < 0.05). Bolus doses of pressor medications during the recirculation period did not differ between groups.

CONCLUSION

Aprotinin infusion during adult liver transplantation results in less requirement for vasoactive intervention.