Anesthesia and analgesia
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Anesthesia and analgesia · Aug 1999
Early outpatient preoperative anesthesia assessment: does it help to reduce operating room cancellations?
Increased understanding of the high cost associated with operating room (OR) cancellations has led to efforts by healthcare providers to decrease case cancellations on the day of surgery. To investigate whether preoperative evaluations within 24 h of surgery were associated with more frequent OR cancellations than those completed 2-30 days before surgery, we prospectively studied OR cancellations for 3 mo. Of the 529 patients in the study, 166 were seen within 24 h of surgery (standard group), and the remaining 363 patients were seen 2-30 days before surgery (early group). There were 70 OR cancellations on the day of surgery, and the largest single group of cancellations was related to administrative problems. The standard group and the early group were similar in terms of gender, age, ASA physical status, and percentage of patients undergoing major surgery. The OR cancellation rates were also comparable between groups: 13.3% for the standard group and 13.2% for the early group. These data suggest that patients can be evaluated in an outpatient preoperative evaluation clinic in a timeframe that is convenient for the patient without adversely affecting the cancellation rate on the day of surgery. ⋯ The operating room cancellation rate for outpatients evaluated 2-30 days before surgery was compared with the cancellation rate for outpatients who received their anesthesia evaluation within 24 h of surgery. Because both groups had similar rates, outpatients may be seen at a convenient time without adversely affecting operating room cancellations.
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Anesthesia and analgesia · Aug 1999
Randomized Controlled Trial Multicenter Study Comparative Study Clinical TrialThe effects of rapacuronium on histamine release and hemodynamics in adult patients undergoing general anesthesia.
Neuromuscular blocking drugs may have variable effects on heart rate (HR) and blood pressure. Rapacuronium is a rapid-acting, steroidal-derived neuromuscular blocking drug whose hemodynamic effects have not been characterized. We studied the effects of 1, 2, and 3 mg/kg rapacuronium on histamine release, HR, and blood pressure in 47 ASA physical status II or III adult patients after the induction of anesthesia with etomidate/fentanyl/N2O. Plasma histamine concentrations were measured before induction and immediately before and 1, 3, and 5 min after the rapid administration of rapacuronium. Mean arterial pressure (MAP) decreased after rapacuronium administration, but there were no significant differences among the groups for changes in HR or MAP, and there was no correlation between changes in MAP or HR and increases in histamine levels. There were no changes in HR or MAP among five patients who had significant (> or = 1 ng/mL) increases in histamine from baselin. Seven patients had bronchospasm without increases in plasma histamine levels. Rapacuronium 2-3 mg/kg increased plasma histamine levels. However, clinically significant histamine-related sequelae did not occur in this population with 1- to 3-mg/kg doses of rapacuronium, and cardiovascular changes were not directly correlated with histamine release. Rapacuronium administration can produce hypotension via mechanisms that do not seem to be related to histamine release. ⋯ Rapacuronium, a new steroidal-derived muscle relaxant, may release histamine and produce slight changes in blood pressure and heart rate after administration.
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Anesthesia and analgesia · Aug 1999
Randomized Controlled Trial Clinical TrialEarly and late reversal of rocuronium and vecuronium with neostigmine in adults and children.
We investigated the influence of the timing of neostigmine administration on recovery from rocuronium or vecuronium neuromuscular blockade. Eighty adults and 80 children were randomized to receive 0.45 mg/kg rocuronium or 0.075 mg/kg vecuronium during propofol/fentanyl/N2O anesthesia. Neuromuscular blockade was monitored by train-of-four (TOF) stimulation and adductor pollicis electromyography. Further randomization was made to control (no neostigmine) or reversal with 0.07 mg/kg neostigmine/0.01 mg/kg glycopyrrolate given 5 min after relaxant, or first twitch (T1) recovery of 1%, 10%, or 25%. Another eight adults and eight children received 1.5 mg/kg succinylcholine. At each age, spontaneous recovery of T1 and TOF was similar after rocuronium and vecuronium administration but was more rapid in children (P < 0.05). Spontaneous recovery to TOF0.7 after rocuronium and vecuronium administration in adults was 45.7 +/- 11.5 min and 52.5 +/- 15.6 min; in children, it was 28.8 +/- 7.8 min and 34.6 +/- 9.0 min. Neostigmine accelerated recovery in all reversal groups (P < 0.05) by approximately 40%, but the times from relaxant administration to TOF0.7 were similar and independent of the timing of neostigmine administration. Recovery to T1 90% after succinylcholine was similar in adults (9.4 +/- 5.0 min) and children (8.4 +/- 1.1 min) and was shorter than recovery to TOF0.7 in any reversal group after rocuronium or vecuronium administration. Recovery from rocuronium and vecuronium blockade after neostigmine administration was more rapid in children than in adults. Return of neuromuscular function after reversal was not influenced by the timing of neostigmine administration. These results suggest that reversal of intense rocuronium or vecuronium neuromuscular blockade need not be delayed until return of appreciable neuromuscular function has been demonstrated. ⋯ These results suggest that reversal of intense rocuronium or vecuronium neuromuscular blockade need not be delayed until return of appreciable neuromuscular function has been demonstrated. Although spontaneous and neostigmine-assisted recovery is more rapid in children than in adults, in neither is return of function as rapid as after succinylcholine administration.
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Anesthesia and analgesia · Aug 1999
Randomized Controlled Trial Clinical TrialAnalgesia, pruritus, and ventilation exhibit a dose-response relationship in parturients receiving intrathecal fentanyl during labor.
Several studies have characterized the 50% and 95% effective doses (ED50 and ED95, respectively) of intrathecal sufentanil for labor analgesia. Few have investigated these same criteria for the less expensive alternative, fentanyl. In addition, the ventilatory effects of intrathecal fentanyl at clinically relevant doses are unclear. We performed this study to establish the dose-response relationship of intrathecal fentanyl for both analgesia and ventilatory depression. Ninety parturients in active early labor (< or = 5 cm dilation) received intrathecal fentanyl 5, 7.5, 10, 15, 20, or 25 micrograms in a double-blinded, randomized fashion (n = 15 patients in each group). Parturients were monitored for degree of pain (measured using a 100-mm visual analog pain scale), blood pressure, arterial oxygen saturation (SaO2), respiratory rate, ETCO2, and fetal heart rate 0, 1, 5, 10, 15, 20, 25, and 30 min after the administration of intrathecal fentanyl. An absolute visual analog pain scale score < or = 25 mm was defined a priori as analgesic success. The percentage of parturients who achieved analgesic success was used to construct quantal dose-response curves, from which the ED50 and ED95 values were derived for the total population (mixed parity) and the nulliparous and multiparous subpopulations separately. Overall ED50 and ED95 values (95% CI) were 5.5 (3.4-7.2) and 17.4 (13.8-27.1) micrograms, respectively. Nulliparous values were lower (5.3 and 15.9 micrograms, respectively) than multiparous values (6.9 and 26.0 micrograms, respectively) but were within the 95% CIs of the total population. Pruritus incidence in parturients with analgesic success displayed a dose-response relationship identical to that seen for analgesia. ETCO2 displayed a dose-related increase, particularly at doses > or = 15 micrograms, without concomitant changes in respiratory rate or SaO2, which suggests a decrease in tidal volume. Even in the absence of overt signs or symptoms of somnolence, intrathecal fentanyl at doses within the effective analgesic range induced a change in ventilation that may last longer than the 30-min period we studied. ⋯ Intrathecal fentanyl induces rapid and satisfying dose-dependent analgesia in early labor; however, it also produces dose-related decreases in ventilation in the absence of overt somnolence.