Anesthesia and analgesia
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Anesthesia and analgesia · Feb 1998
Randomized Controlled Trial Clinical TrialThe effect of timing of ondansetron administration on its efficacy, cost-effectiveness, and cost-benefit as a prophylactic antiemetic in the ambulatory setting.
Although ondansetron (4 mg I.V.) is effective in the prevention and treatment of postoperative nausea and vomiting (PONV) after ambulatory surgery, the optimal timing of its administration, the cost-effectiveness, the cost-benefits, and the effect on the patient's quality of life after discharge have not been established. In this placebo-controlled, double-blind study, 164 healthy women undergoing outpatient gynecological laparoscopic procedures with a standardized anesthetic were randomized to receive placebo (Group A), ondansetron 2 mg at the start of and 2 mg after surgery (Group B), ondansetron 4 mg before induction (Group C), or ondansetron 4 mg after surgery (Group D). The effects of these regimens on the incidence, severity, and costs associated with PONV and discharge characteristics were determined, along with the patient's willingness to pay for antiemetics. Compared with ondansetron given before induction of anesthesia, the administration of ondansetron after surgery was associated with lower nausea scores, earlier intake of normal food, decreased incidence of frequent emesis (more than two episodes), and increased times until 25% of patients failed prophylactic antiemetic therapy (i.e., had an emetic episode or received rescue antiemetics for severe nausea) during the first 24 h postoperatively. This prophylactic regimen was also associated with the highest patient satisfaction and lowest cost-effectiveness ratios. Compared with the placebo group, ondansetron administered after surgery significantly reduced the incidence of PONV in the postanesthesia care unit and during the 24-h follow-up period and facilitated the recovery process by reducing the time to oral intake, ambulation, discharge readiness, resuming regular fluid intake and a normal diet. When ondansetron was given as a "split dose," its prophylactic antiemetic efficacy was not significantly different from that of the placebo group. In conclusion, the prophylactic administration of ondansetron after surgery, rather than before induction, may be associated with increased patient benefits. ⋯ Ondansetron 4 mg I.V. administered immediately before the end of surgery was the most efficacious in preventing postoperative nausea and vomiting, facilitating both early and late recovery, and improving patient satisfaction after outpatient laparoscopy.
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Anesthesia and analgesia · Feb 1998
Pharmacokinetics and side effects of milrinone in infants and children after open heart surgery.
We investigated the pharmacokinetics and side effects of milrinone in infants and children (< or = 13 yr) after open heart surgery in this prospective, open-label study. Milrinone binding to cardiopulmonary bypass (CPB) circuitry was also examined in out two groups. Children in the small dose group (n = 11) received two 25-microg/kg boluses with a final infusion rate of 0.5 microg kg(-1) x min(-1); those in the large dose group (n = 8) received a 50-microg/kg bolus and a 25-microg/kg bolus with a final infusion rate of 0.75 microg x kg(-1) x min(-1). Blood samples for milrinone concentration were drawn 30 min after each bolus, at steady state, and after discontinuing the milrinone infusion. Pharmacokinetics were evaluated using traditional and nonlinear mixed effects modeling analysis. Milrinone kinetics best fit a two-compartment model. Steady-state plasma levels in the small and large dose groups were within the adult therapeutic range (113 +/- 39 and 206 +/- 74 ng/mL, respectively). The volumes of distribution (Vbeta) in infants (0.9 L/kg) and children (0.7 L/kg) were not different, but infants had significantly lower milrinone clearance (3.8 vs 5.9 mL x kg(-1) x min(-1)). Thrombocytopenia (defined as platelet count < or = 100,000 mm(-3)) occurred in 58%, and the risk increased significantly with duration of infusion. Tachyarrythmias were noted in two patients. Milrinone did not bind to CPB circuitry. We conclude that milrinone is cleared more rapidly in children than in adults. The major complication was thrombocytopenia. ⋯ Most pediatric dosing is based on data published for adults. Infants and children have kinetics that differ from adults. We studied the distribution of I.V. milrinone in infants and children after open heart surgery. Milrinone had a larger volume of distribution and a faster clearance in infants and children than in adults, and dosing should be adjusted accordingly.
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Anesthesia and analgesia · Feb 1998
Pneumoperitoneum as a risk factor for endobronchial intubation during laparoscopic gynecologic surgery.
Patients undergoing gynecological surgery under laparoscopic guidance usually receive general anesthesia with endotracheal intubation and mechanical ventilation. The creation of a pneumoperitoneum and the Trendelenburg position, both of which are used to improve visualization, are associated with cephalad movement of the diaphragm. This may increase the risk of endobronchial intubation. We studied the change in the distance from the tip of the endotracheal tube (ETT) to the carina with a fiberoptic bronchoscope in 30 patients aged 21-40 yr who were undergoing laparoscopic tubal ligation (n = 28) or hysterectomy (n = 2). Measurements were taken in the supine and Trendelenburg positions before and after pneumoperitoneum. The average distance from the ETT to the carina in the supine position was 2.1 +/- 0.8 cm and in the Trendelenburg position was 1.8 +/- 0.8 cm (P = not significant). After insufflation of the abdominal cavity, the mean distance decreased to 0.7 +/- 1.4 cm in the supine position (P < 0.05) and was associated with endobronchial intubation in eight patients. The addition of the Trendelenburg position to an established pneumoperitoneum resulted in minimal displacement (0.54 +/- 1.4 cm, P < 0.05) and one additional endobronchial intubation. We conclude that the insufflation of gas in the abdominal cavity, and not the change in patient position, is the main risk factor for endobronchial intubation in patients undergoing laparoscopic gynecologic surgery. ⋯ This study demonstrated that in anesthetized women, the insufflation of gas into the abdomen during laparoscopy for gynecologic surgery is the main risk factor for migration of the endotracheal tube into a bronchus.
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Anesthesia and analgesia · Feb 1998
A multimodal approach to control postoperative pathophysiology and rehabilitation in patients undergoing abdominothoracic esophagectomy.
This two-armed study was designed to determine whether recovery after esophageal resection may be improved by introducing a new multimodal approach. For 8 mo after the new approach was introduced, all patients undergoing abdominothoracic esophageal resection were studied (Group 2; n = 42). For comparison, a retrospective analysis was also conducted using the data of all patients who had undergone this operation in the 8 mo before the introduction of the new regimen, when the traditional therapy was still in use (Group 1; n = 49). All patients received an epidural catheter at the level of T6-9 before the induction of general analgesia. Afterward, Group 1 patients were operated under general anesthesia. For postoperative pain relief, a mixture of bupivacaine 1.25 mg/mL and sufentanil 1 microg/mL was administered during 5 days without titration of the quality of analgesia. Patients in Group 2 received a preoperative bolus of 10-15 mL bupivacaine 2.5 mg/mL and 20-30 microg sufentanil. After sensory block up to T4 was confirmed, general anesthesia was introduced and intraoperatively combined with a continuous infusion of 5 mL/h of a solution containing bupivacaine 1.75 mg/mL and sufentanil 1 microg/mL. Postoperatively, the epidural infusion rate was adjusted to the need of the individual patients, who were able to administer themselves additional bolus doses of 2 mL with a lockout time of 20 min. Early tracheal extubation and forced mobilization were pursued to improve recovery. Demographic data of both groups were comparable. The pain relief of Group 2 patients was superior to that of patients in Group 1. The nitrogen balance of a subgroup of nine matched pairs of patients with comparable nutritional status was less negative in Group 2 patients on Postoperative Days 1 and 2. Patients in Group 2 were tracheally extubated earlier (mean 6.7 vs 25.1 h after admission to the intensive care unit [ICU]), mobilized earlier (mean 1.2 vs 2.0 days after surgery), discharged from the ICU earlier (mean 1.7 vs 4.0 days), and fulfilled criteria for discharge from the ICU (mean 1.8 vs 4.1 days) and from the intermediate care unit earlier (4.9 vs 6.4 days). We conclude that the multimodal approach may improve recovery and thus reduce costs after abdominothoracic esophageal resection. ⋯ Analgesia and blockade of the perioperative stress response, combined with other aspects of postoperative therapy, may improve recovery after surgery. The intensive care unit stay after esophageal resection was reduced by a new regimen (thoracic epidural analgesia, early tracheal extubation, forced mobilization). This approach may influence the cost of major surgery.
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Anesthesia and analgesia · Feb 1998
Randomized Controlled Trial Comparative Study Clinical TrialFast-track eligibility after ambulatory anesthesia: a comparison of desflurane, sevoflurane, and propofol.
This study was designed to test the hypothesis that using the less soluble volatile anesthetics, desflurane and sevoflurane, as alternatives to propofol for maintenance of anesthesia facilitates the ability of outpatients to achieve postanesthesia care unit (PACU) discharge criteria (i.e., fast-track eligibility) on arrival in the PACU after laparoscopic surgery. One hundred-twenty consenting women undergoing laparoscopic tubal ligation procedures were randomly assigned to one of three treatment groups. After a standardized induction of anesthesia and tracheal intubation sequence, anesthesia was maintained with either desflurane 2%-6%, sevoflurane 0.6%-1.75%, or propofol 50-150 microg x kg(-1) x min(-1) in combination with nitrous oxide 60% in oxygen. Recovery times, postanesthesia recovery scores, and the number and type of therapeutic interventions in the PACU were recorded. Compared with the propofol group, the times to awakening and to achieve a recovery score of 10 were significantly shorter, and the percentage of patients judged fast-track eligible on arrival in the PACU was significantly higher, in the desflurane and sevoflurane groups (90% and 75% vs 26%). In conclusion, compared with propofol, the use of desflurane and sevoflurane for the maintenance of general anesthesia resulted in a higher percentage of patients being judged fast-track eligible after outpatient laparoscopic tubal ligation procedures. ⋯ Bypassing the recovery room by transferring outpatients directly to the step-down unit after ambulatory surgery ("fast-tracking") could result in significant cost-savings. We examined the effects of three different maintenance anesthetics--desflurane, sevoflurane, and propofol--on the fast-track eligibility of outpatients after laparoscopic tubal ligation surgery. Compared with propofol, desflurane and sevoflurane resulted in a higher percentage of outpatients being judged eligible for fast-tracking.