Canadian journal of anaesthesia = Journal canadien d'anesthésie
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The purpose of this study was to evaluate the effects of pretreatment with propranolol on the cardio-respiratory toxicity of bupivacaine, either plain or with epinephrine 1:200,000 (5 micrograms.ml-1) added. Adult male Sprague Dawley rats, anaesthetized with intraperitoneal pentobarbital, were divided into four groups. Groups I and III were pretreated with iv propranolol 150 micrograms.kg-1, and Groups II and IV received iv NS as a placebo. ⋯ Addition of epinephrine to the bupivacaine eliminated the protective effect of propranolol. All rats pretreated with propranolol (Group III) or NS (Group IV) died when given bupivacaine with epinephrine. In conclusion, acute propranolol pretreatment reduced the fatal cardiotoxicity due to iv bupivacaine in male Sprague Dawley rats, but the addition of epinephrine 5 micrograms.ml-1 to bupivacaine eliminated the protective effect of propranolol.
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Randomized Controlled Trial Clinical Trial
Epidural fentanyl does not influence intravenous PCA requirements in the post-caesarean patient.
Forty ASA physical status I or II patients scheduled for elective Caesarean delivery were studied to determine the effect of epidural fentanyl on post-Caesarean delivery analgesic requirements as administered by intravenous patient-controlled analgesia (PCA). Following delivery of the infant, under epidural anaesthesia with lidocaine 2% with 1/200,000 epinephrine, patients were randomly assigned to receive either 10 ml of preservative-free normal saline via the epidural catheter or 100 micrograms of fentanyl with 8 ml preservative-free normal saline in a double-blinded fashion. ⋯ No differences were observed in any values between the groups. It is concluded that a single bolus of epidural fentanyl does not provide an advantage for postoperative pain relief in this patient population.
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The pharmacodynamics and pharmacokinetics of a new non-depolarizing neuromuscular blocking agent, Org 9426, were investigated. Ten patients undergoing elective head and neck surgery and anaesthetized with nitrous oxide, halothane and fentanyl, received a bolus dose of Org 9426 (1 mg.kg-1, 3 x ED90). The isometric contractions of the adductor pollicis muscle following ulnar nerve stimulation (0.1 Hz and intermittent TOF) were measured. ⋯ Within 24 h, 33 (37)% of Org 9426 was excreted unchanged in the urine. Metabolites were absent both in plasma and urine. We conclude that the difference in potency between Org 9426 and vecuronium is similar to the difference between their effective concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)