RESUMO
Alfentanil and sufentanil are used in the anesthetic management of patients undergoing orthotopic liver transplantation (OLT) and are extensively metabolized by the liver. We examined the influence of OLT on the removal of these opioids. 14 patients undergoing OLT were given either alfentanil (40 micrograms/kg intravenous [IV] bolus) or sufentanil (5 micrograms/kg IV bolus) during the induction of anesthesia, followed by infusion during surgery (1 microgram.kg-1.min-1 alfentanil or 0.01 microgram.kg-1.min-1 sufentanil) and the postoperative period (0.5 microgram.kg-1.min-1 or 0.005 microgram.kg-1.min-1). A catheter was inserted into the hepatic vein to determine the drugs' hepatic extraction coefficient and hepatic clearance. The hepatic extraction coefficient was 0.14 for alfentanil and 0.35 for sufentanil. The total and hepatic clearance of alfentanil were similar, while the hepatic clearance of sufentanil was 50% of the total clearance (P < 0.05). The total clearance of alfentanil was significantly linked to its hepatic clearance (r2 = 0.81, P < 0.001). We conclude that the total clearance of sufentanil is greater than its hepatic clearance. This difference suggests that there is extrahepatic metabolism of sufentanil in patients undergoing OLT.
Assuntos
Alfentanil/farmacocinética , Anestésicos Intravenosos/metabolismo , Transplante de Fígado , Fígado/metabolismo , Sufentanil/farmacocinética , Adulto , Anestesia , Feminino , Humanos , Testes de Função Hepática , Masculino , Pessoa de Meia-IdadeRESUMO
Pregnancy in a patient suffering from high spinal cord lesions is unusual and can lead to serious autonomic hyperreflexia during delivery. Epidural anaesthesia has been suggested as a means of decreasing such a risk. This clinical report presents the case of a paraplegic patient with lesions above the T3 level who had spinal anaesthesia for a Caesarean section. Her first delivery, six years earlier and without spinal anaesthesia was complicated by serious autonomic hyperreflexia with severe hypertension, seizures and inhalation. These symptoms were at first interpreted as eclampsia. For the Caesarean section, spinal anaesthesia using 0.25% bupivacaine in divided doses presented no difficulty, in spite of important lordosis, and permitted the delivery of a newborn with an Apgar score of 10 at one minute. The upper sympathetic level reached (T4-T6) was assessed by the discontinuing of muscular spasticity and contractures elicited by cutaneous stimuli. At the present time, spinal anaesthesia is the best method for preventing autonomic hyperreflexia. General anaesthesia, especially with halothane, is effective, but requires a deeper anaesthesia with the risk of serious hypotension and its possible repercussions on the fetus. Moreover it does not decrease the risk of autonomic hyperreflexia during the postoperative period.