In this double-blind study, we have allocated randomly 40 ASA I-III patients to one of four groups. After a standard anaesthetic induction, patients received vecuronium 0.08 mg kg-1 or 0.10 mg kg-1, or atracurium 0.4 mg kg-1 or 0.5 mg kg-1. Using an electromyogram (Datex Relaxograph) the train-of-four (TOF) response was measured during onset of and recovery from neuromuscular block. A greater degree of fade of TOF was observed with atracurium during onset of neuromuscular block than with equivalent doses of vecuronium. During recovery of neuromuscular transmission, vecuronium was associated with more fade than atracurium. The differences in the TOF profiles of these two drugs may be important when judging the adequacy of antagonism of neuromuscular block using the TOF response.

Recovery and psychomotor performance were studied in 80 ASA physical status I-III adult patients undergoing outpatient surgery. Patients were divided into four equal groups: thiopental induction of anesthesia followed by desflurane in nitrous oxide and oxygen (Th-DES-N2O/O2), thiopental induction of anesthesia followed by isoflurane in nitrous oxide and oxygen (Th-ISO-N2O/O2), thiopental induction of anesthesia followed by desflurane in oxygen (Th-DES-O2), and desflurane inhaled induction followed by desflurane in oxygen (DES-DES-O2). Patients were excluded from analysis if they required opioids or antiemetics postoperatively. The use of desflurane was associated with more rapid awakening compared with isoflurane (time to eye opening 9.45 +/- 0.67 min [Th-DES-N2O/O2] and 13.8 +/- 1.59 min [Th-ISO-N2O/O2], P less than 0.05). Psychomotor performance was measured using the choice reaction time and critical flicker fusion threshold. At 30 min after discontinuing anesthesia, five patients in the Th-ISO-N2O/O2 group and one patient in the Th-DES-N2O/O2 group were too sleepy to perform psychomotor tests. In addition, five patients who received Th-DES-O2 and one patient who received the inhaled induction and maintenance of anesthesia with desflurane in oxygen were too sleepy to perform tests at 30 min. Patients receiving Th-DES-N2O/O2 showed less impairment of choice reaction time than those receiving Th-ISO-N2O/O2. Critical flicker fusion threshold, however, showed no difference between groups. The use of thiopental was associated with delayed recovery. Compared with isoflurane, desflurane anesthesia is associated with more rapid initial awakening and less impairment of choice reaction time.

Three doses of ocfentanil (1, 3, and 5 μg/kg), a new narcotic, were compared with fentanyl (5 μg/kg) as a supplement to general anesthesia. Sixty adult ASA I-III patients undergoing elective surgery were studied. The drugs were given as a bolus injection during induction of anesthesia in a double-blind manner. With the stimulus of tracheal intubation, systolic arterial blood pressure increased (mean ± se) from 127 ± 6.9 to 183 ± 7.4 mm Hg and heart rate increased from 82.1 5 4.8 to 104 ± 6.4 beats/min in patients who had received 1 μg/kg of ocfentanil intravenously. In comparison to patients who received 1 & kg of ocfentanil, the increases in heart rate and systolic arterial blood pressure at the time of tracheal intubation were less with 3 and 5 μg/kg of ocfentanil and 5 μg/kg of fentanyl (P < 0.05). At incision, heart rate decreased after the intravenous administration of 5 μg/kg of ocfentanil when compared with patients who received 1 μg/kg of ocfentanil. There were differences between study groups in the mild increase in arterial blood pressure observed at incision. The authors conclude that ocfentanil and fentanyl appear to be similar in action, with 3 μg/kg of ocfentanil being approximately equivalent in effect to 5 μg/kg of fentanyl.