Anesthesia and analgesia
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Anesthesia and analgesia · May 1994
Randomized Controlled Trial Comparative Study Clinical TrialPropofol for ambulatory gynecologic laparoscopy: does omission of nitrous oxide alter postoperative emetic sequelae and recovery?
The role of nitrous oxide in postoperative emesis is controversial. This prospective randomized study was performed to compare the emetic sequelae and quality of recovery between a group of patients anesthetized with propofol alone and a group anesthetized with propofol plus nitrous oxide. Seventy patients, ASA grade I or II, scheduled for ambulatory gynecologic laparoscopy under general anesthesia were included. ⋯ Otherwise, the recovery variables were comparable between the two groups. We conclude that supplementing propofol with nitrous oxide in patients undergoing ambulatory laparoscopy reduces the requirements of propofol, expedites immediate recovery (emergence), and does not increase the incidence of postoperative emesis. This tends to confirm that there is no clinical advantage to omitting nitrous oxide.
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Anesthesia and analgesia · May 1994
Randomized Controlled Trial Clinical TrialUse of forced-air warming during and after outpatient arthroscopic surgery.
According to a two-phase protocol, 127 patients undergoing arthroscopic knee surgery were randomly assigned to receive intraoperative warming from a forced-air blanket (n = 69) or conventional warmed cotton blankets (n = 58). During the initial phase (Phase I), active warming was applied during the intraoperative period only, permitting double-blind assessment of postoperative events. In Phase II, warming was continued into the recovery area, which unblinded the assessment. ⋯ However, significantly fewer actively warmed patients experienced prolonged postoperative shivering. The addition of postoperative warming appeared to provide little, if any, additional benefit. Despite the decreased duration of postoperative shivering in the actively warmed group, we were unable to demonstrate any reduction in the PACU stay.
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Anesthesia and analgesia · May 1994
Randomized Controlled Trial Clinical TrialRenal function and proteinuria after cardiopulmonary bypass: the effects of temperature and mannitol.
We studied three groups of patients without previous renal impairment, undergoing elective coronary artery bypass surgery. Group H (n = 7) underwent open heart surgery using moderate hypothermia (28 degrees C); Groups N and M (n = 8, each) were managed at normothermia. The extracorporeal circuit was primed with Hartmann's solution 2.5 L with the addition of mannitol 0.5 g/kg in Group M. ⋯ However, there were overall significant changes in measured variables over time compared to baseline. We conclude that CPB is associated with a significant alteration in renal function as shown by increased FENA, microalbuminuria, and urinary NAG. The use of hypothermic or normothermic CPB and the use of prophylactic mannitol did not produce any significant modification of these changes.
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Anesthesia and analgesia · May 1994
Mild intraoperative hypothermia does not change the pharmacodynamics (concentration-effect relationship) of vecuronium in humans.
To investigate the effect of mild hypothermia on the neuromuscular junction sensitivity to vecuronium, we determined the pharmacodynamics (concentration-effect relationship) of vecuronium in 10 patients (ASA physical class I or II; age range, 21-46 yr; weight range, 54-104 kg), during isoflurane-nitrous oxide-fentanyl anesthesia. Five were cooled to a mean temperature of 34.4 degrees C and five were maintained normothermic at a mean temperature of 36.8 degrees C. Neuromuscular function was monitored by measuring the evoked mechanical response of the adductor pollicis muscle after supramaximal train-of-four stimulation of the ulnar nerve at the wrist. ⋯ Results for the hypothermic and normothermic groups were compared by Mann-Whitney U-test. There were no differences in any pharmacodynamic variable between the hypothermic and normothermic patients. For the hypothermic and normothermic patients, respectively, steady-state plasma concentrations of vecuronium producing 50% neuromuscular block (Css50) were 73 +/- 13 ng/mL (mean +/- SD) and 79 +/- 31 ng/mL; the rate constants for equilibration of vecuronium between the plasma and the neuromuscular junction (Keo) were 0.27 +/- 0.14 per min-1 and 0.26 +/- 0.11 per min, and the power functions representing the slope of the concentration-effect relationship (gamma) were 5.7 +/- 1.9 and 4.4 +/- 1.8.(ABSTRACT TRUNCATED AT 250 WORDS)
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Anesthesia and analgesia · May 1994
An effectiveness study of a new piezoelectric sensor for train-of-four measurement.
We have developed an easy-to-use, noninvasive piezoelectric sensor for quantitative monitoring of neuromuscular block. In a clinical evaluation with 23 patients, the piezo sensor was objectively compared to a mechanomyogram (MMG) for its ability to measure train-of-four (TOF) ratio from the adductor pollicis. After administration of succinylcholine (120-200 mg intravenously [i.v.]) to facilitate intubation, neuromuscular block was maintained with vecuronium by either boluses (1-2 mg i.v.) or an infusion (0.4-1.0 micrograms.kg-1.min-1 i.v.). ⋯ The sensitivity of the piezo sensor for detecting recovery based on a TOF ratio greater than 0.70 was shown to be 0.74 with specificity of 0.91. Under the conditions tested, the piezo sensor was not as accurate as the MMG. However, it was able to predict recovery of neuromuscular block with better accuracy than shown previously by manual evaluation of the TOF ratio, making it a reasonable, convenient alternative for quantitative monitoring of recovery from neuromuscular block.