Anesthesia and analgesia
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Anesthesia and analgesia · Jan 2002
Randomized Controlled Trial Clinical TrialAlkalinization of intracuff lidocaine improves endotracheal tube-induced emergence phenomena.
We sought to evaluate the effect of filling an endotracheal tube cuff with 40 mg lidocaine alone (Group L) or alkalinized lidocaine (Group LB) in comparison to an Air Control group (Group C) on adverse emergence phenomena in a randomized controlled study (n = 25 in each group). The incidence of sore throat was decreased for Group LB in comparison to Group L during the 24 postextubation hours. The difference between Group L and Group C remained significant in the two postextubation hours only. Plasma lidocaine levels increased when lidocaine was alkalinized (C(max) were 62.5 +/- 34.0 ng/mL and 3.2 +/- 1.0 ng/mL for Groups LB and L, respectively). Cough and restlessness before tracheal extubation were decreased in Group LB compared with Group L and in Group L compared with Group C. Nausea, postoperative vomiting, dysphonia, and hoarseness were increased after extubation in Group C compared with the liquid groups, and a better tolerance was recorded with Group LB compared with Group L. The increase of arterial blood pressure and cardiac frequencies during the extubation period was less in the liquid groups than in the control group and less in Group LB compared with Group L. We concluded that use of intracuff alkalinized lidocaine is an effective adjunct to endotracheal intubation. ⋯ Use of 40 mg of alkalinized lidocaine, rather than lidocaine or air, to fill the endotracheal tube cuff reduces the incidence of sore throat in the postoperative period. This approach also decreases hemodynamic effects, restlessness, dysphonia, and hoarseness.
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Anesthesia and analgesia · Jan 2002
Randomized Controlled Trial Clinical TrialEsmolol and anesthetic requirement for loss of responsiveness during propofol anesthesia.
The administration of esmolol decreases the propofol blood concentration, preventing movement after skin incision during propofol/morphine/nitrous oxide anesthesia. However, interaction with esmolol has not been tested when propofol is infused alone. Accordingly, we tested the hypothesis that esmolol decreases the propofol blood concentration, preventing response to command (CP50-awake) when propofol is infused alone in healthy patients presenting for minor surgery. With approval and consent, we studied 30 healthy patients, who were randomized to esmolol bolus (1 mg/kg) and then infusion (250 microg x kg(-1) x min(-1)) or placebo. Five minutes later, a target-controlled infusion of propofol was commenced. Ten minutes later, responsiveness was assessed by a blinded observer. Oxygen saturation, heart rate, and noninvasive arterial blood pressure were recorded every 2 min. Arterial blood samples were taken at 5 and 10 min of propofol infusion for propofol assay. Results were analyzed with a generalized linear regression model: P <0.05 was considered statistically significant. The probability of response to command decreased with increasing propofol blood concentration (CP50-awake = 3.42 microg/mL). Esmolol did not alter the relative risk of response to command. We conclude that the previously observed effect of esmolol on propofol CP50 was not caused by an interaction between these two drugs. ⋯ There is no evidence to suggest that esmolol, an ultra-short-acting cardioselective beta-blocker, affects anesthetic requirement for loss of responsiveness during propofol anesthesia.
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Anesthesia and analgesia · Jan 2002
Randomized Controlled Trial Clinical TrialThe clinical efficacy and pharmacokinetics of intraperitoneal ropivacaine for laparoscopic cholecystectomy.
Postoperative pain after laparoscopic surgery is less than after laparotomy, and patients may benefit from an intraperitoneal injection of local anesthetic. Thirty-seven ASA physical status I or II patients received in double-blinded fashion 20 mL of 0.9% saline solution (placebo), ropivacaine 0.25% (Rop 0.25%), or ropivacaine 0.75% (Rop 0.75%) immediately after trocar placement and at the end of surgery. We measured pain and morphine consumption until 20 h after surgery. Plasma ropivacaine concentrations were measured. The three groups were comparable for shoulder pain, parietal pain, and incidence of side effects. Visceral pain at rest, during cough, and on movement and total consumption of morphine were significantly smaller in Groups Rop 0.25% and Rop 0.75% when compared with Placebo. Although no adverse effect occurred in any patient, the largest dose led to large plasma concentrations of ropivacaine (2.93 +/- 2.46 microg/mL and 3.76 +/- 3.01 microg/mL after the first and second injection, respectively). We conclude that intraperitoneal administration of ropivacaine before and after surgery significantly decreases postoperative pain. Because the smaller dosage (2 x 50 mg) provided similar analgesia and was associated with significantly smaller plasma concentrations than the larger dosage (2 x 150 mg), this smaller dosage seems more appropriate. ⋯ Intraperitoneal ropivacaine 100 mg injected during laparoscopic cholecystectomy significantly decreased postoperative pain when compared with injection of intraperitoneal placebo. At this dose, plasma concentrations remained in the nontoxic range,
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Anesthesia and analgesia · Jan 2002
Randomized Controlled Trial Clinical TrialOral midazolam premedication in preadolescents and adolescents.
We sought to determine the influence of preoperative oral midazolam on 1) sedation score, 2) measures of anesthetic emergence, 3) recovery times, and 4) bispectral index (BIS) measurements during sevoflurane/N(2)O anesthesia in adolescent patients. Fifty ASA I and II patients 10-18 yr of age were enrolled in a prospective double-blinded study. Patients were randomized to receive either 20 mg of midazolam (M group) or midazolam vehicle (P group) as premedication. Before the induction, sedation scores and BIS values were determined in all patients. After inhaled induction and intubation, expired sevoflurane was stabilized at 3% in 60% N(2)O and the corresponding BIS (BIS I) recorded. Upon completion of surgery, sevoflurane was stabilized at 0.5% and the BIS (BIS E) again recorded. Plasma midazolam levels were measured at the time of BIS I and BIS E. There were no significant differences between groups in awakening time, sevoflurane/N(2)O awakening concentrations, time to postanesthesia care unit discharge, or BIS I and BIS E measurements. Sedation scores and preinduction BIS values were significantly lower in Group M than in Group P, although only 40% of midazolam-treated patients exhibited detectable sedation, with marked interindividual variability in achieved plasma midazolam levels. Detectable preoperative sedation was predictive of delayed emergence. ⋯ We demonstrated a measurable sedative effect of oral midazolam in adolescents which correlated with simultaneous bispectral index (BIS) measurement. Considering the overall group, midazolam premedication did not affect intraoperative BIS, emergence times, or recovery times compared with placebo controls. Detectable preoperative sedation, and not merely midazolam administration, was predictive of prolonged emergence.
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Anesthesia and analgesia · Jan 2002
Randomized Controlled Trial Clinical TrialCisapride does not prevent postoperative vomiting in children.
The peripherally acting prokinetic drug cisapride can overcome opioid-induced gastrointestinal paresis and may thereby eliminate a stimulus for postoperative vomiting. We conducted a prospective, randomized, double-blinded, controlled trial of 96 children undergoing inguinal surgery to determine whether cisapride would reduce the incidence of postoperative vomiting after general anesthesia supplemented with morphine. Group C1 patients (n = 38) received cisapride 0.3 mg/kg orally 1 h before surgery and placebo 6 h later, Group C2 (n = 28) received cisapride both before and after surgery, and Group P (n = 30) received placebo. Mean age (5.0 +/- 2.7 yr) and weight (21.0 +/- 8.6 kg), median pain scores and parent satisfaction scores, and incidence of rescue analgesic administration were similar across groups. Contrary to our hypothesis, incidences of postoperative vomiting in the hospital (32% vs 20%, P = 0.33) and at home (53% vs 46%, P = 0.33) did not vary by treatment group (with [C1 and C2] and without [P] cisapride, respectively). There was a trend toward more severe postoperative vomiting (three or more episodes) in children who received cisapride versus those who did not, both in hospital (6% vs 0%, P = 0.3) and at home (22% vs 8%) (P = 0.13). We conclude that cisapride does not prevent postoperative vomiting in this patient population and speculate that factors other than reduced gastrointestinal motility associated with general anesthesia and opioids are more important determinants of postoperative vomiting. ⋯ Cisapride does not prevent postoperative vomiting in children and may increase its severity.