Anesthesia and analgesia
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Anesthesia and analgesia · Apr 2003
Randomized Controlled Trial Clinical TrialA liberalized fasting guideline for formula-fed infants does not increase average gastric fluid volume before elective surgery.
Recommended preoperative fasting intervals for infant formula vary from 4 to 8 h. We conducted a prospective, randomized, observer-blinded trial of 97 ASA physical status I and II infants scheduled for elective surgery to determine whether average gastric fluid volume (GFV) recovered from infants formula-fasted for 4 h (liberalized fast, Group L) differed from that recovered from infants allowed clear liquids up until 2 h, but fasted 8 h for formula and solids (traditional fast, Group T). In Group L, 31 of 39 subjects followed protocol and ingested formula 4-6 h before surgery. In Group T, 36 of 58 subjects followed protocol, taking clear liquids 2-5 h before the induction of anesthesia. Thirty subjects had prolonged fasts and were included only in a secondary intent-to-treat analysis. Respective mean age (5.7 +/- 2.3 versus 6.4 +/- 2.4 mo; range, 0.7-10.5 mo), weight (7.5 +/- 1.8 versus 7.5 +/- 1.1 kg), and volume of last feed (4.9 +/- 2.2 versus 4.0 +/- 2.3 oz.) did not vary between Groups L and T. GFV (L: 0.19 +/- 0.38 versus T: 0.16 +/- 0.30 mL/kg) and gastric fluid pH (L: 2.5 +/- 0.5 versus T: 2.9 +/- 1.3) did not vary. For all subjects, GFV (mL/kg) increased with age (Spearman correlation coefficient = +0.23, P = 0.03). Infant irritability and hunger and parent satisfaction were similar between groups. We conclude that average GFV after either a 4- to 6-h fast for infant formula or 2-h fast after clear liquids is small and not significantly different between groups. On the basis of these findings, clinicians may consider liberalizing formula feedings to 4 h before surgery in selected infants. ⋯ Healthy infants aged < or =10.5 mo may drink formula up to 4 h before surgery without increasing gastric fluid volume compared with infants allowed clear liquids up to 2 h and formula 8 h before surgery.
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Anesthesia and analgesia · Apr 2003
Randomized Controlled Trial Clinical TrialCosts and effectiveness of rofecoxib, celecoxib, and acetaminophen for preventing pain after ambulatory otolaryngologic surgery.
We designed this randomized, double-blinded, placebo-controlled study to compare the analgesic effect of the cyclooxygenase-2 inhibitors rofecoxib and celecoxib with acetaminophen when administered before outpatient otolaryngologic surgery in 240 healthy subjects. Patients were assigned to one of four study groups: Group 1, control (vitamin C 500 mg); Group 2, acetaminophen 2 g; Group 3, celecoxib 200 mg; or Group 4, rofecoxib 50 mg. The first oral dose of the study medication was administered 15-45 min before surgery, and a second dose of the same medication was given on the morning after surgery. Recovery times, side effects, pain scores, and the use of rescue analgesics were recorded. Follow-up evaluations were performed at 24 and 48 h after surgery to assess postdischarge pain, analgesic requirements, nausea, and patient satisfaction with their postoperative pain management and quality of recovery. The need for rescue analgesia and peak pain scores were used as the primary end points for estimating efficacy, and the costs to achieve complete satisfaction with analgesia were used for the cost-efficacy comparisons. Premedication with oral rofecoxib (50 mg) or celecoxib (200 mg) was more effective than placebo in reducing postoperative pain scores and analgesic requirements in the postoperative care unit and after discharge. The analgesic efficacy of oral acetaminophen (2 g) was limited to the postdischarge period. Patient satisfaction with pain management was improved in all three treatment groups compared with placebo but was higher with celecoxib and rofecoxib compared with acetaminophen. Rofecoxib was also more effective than celecoxib in reducing pain and improving patient satisfaction after otolaryngologic surgery. Rofecoxib achieved complete satisfaction with pain control in one additional patient, who would not have otherwise been satisfied, at lower incremental costs to the institution compared with celecoxib. We conclude that rofecoxib 50 mg orally is more cost-effective for reducing postoperative pain and improving patient satisfaction with their postoperative pain management than celecoxib (200 mg) or acetaminophen (2 g) in the ambulatory setting. ⋯ Oral premedication with rofecoxib (50 mg) was more effective than celecoxib (200 mg) and acetaminophen (2 g) in reducing postoperative pain and in improving the quality of recovery and patient satisfaction with pain management after outpatient otolaryngologic surgery with only a small increase in cost of care.
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Anesthesia and analgesia · Apr 2003
Randomized Controlled Trial Clinical TrialMinimum analgesic doses of fentanyl and sufentanil for epidural analgesia in the first stage of labor.
In this study, we sought to determine the minimum analgesic doses and relative potencies of fentanyl and sufentanil when they are used as the sole epidural analgesic during the first stage of labor. Nulliparous parturients (n = 66) in spontaneous labor at term gestation and requesting epidural analgesia were enrolled into this prospective, double-blinded, randomized, sequential-allocation study. Each woman received fentanyl or sufentanil diluted with 0.9% wt/vol saline to a volume of 10 mL. The initial dose was arbitrarily chosen to be 125 microg for fentanyl and 25 microg for sufentanil, with subsequent doses being determined by the response of the previous patient (testing interval, 5 microg for fentanyl and 1 microg for sufentanil). Efficacy was accepted if the visual analog score decreased to < or =10 mm on a 100-mm scale within 30 min. The minimum analgesic dose or median effective dose was 21.1 microg (95% confidence interval [CI], 20.2-21.9 microg) for sufentanil and 124.2 microg (95% CI, 118.1-130.6 microg) for fentanyl (P < 0.0001). The sufentanil/fentanyl potency ratio was 5.9 (95% CI, 5.6-6.3). In conclusion, we have established the equivalent doses and relative potencies of fentanyl and sufentanil for epidural analgesia in the first stage of labor. ⋯ This study determined the minimum analgesic doses of fentanyl and sufentanil for epidural anesthesia in the first stage of labor. The sufentanil/fentanyl potency ratio was 5.9. This ratio may be used to establish the equivalent doses for fentanyl and sufentanil for epidural analgesia in labor.
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Anesthesia and analgesia · Apr 2003
Randomized Controlled Trial Clinical TrialSingle-dose tranexamic acid reduces postoperative bleeding after coronary surgery in patients treated with aspirin until surgery.
Tranexamic acid reduces postoperative bleeding after coronary artery bypass grafting. We evaluated the effects of a single dose of tranexamic acid given immediately before cardiopulmonary bypass (CPB) in patients treated with aspirin until the day before surgery. The study was a prospective, randomized, double-blinded, placebo-controlled, parallel-group trial. Eighty patients were included and divided into two groups: one group received tranexamic acid 30 mg/kg, and one group received placebo (0.9% NaCl) as a bolus injection before CPB. Postoperative blood loss was recorded for 16 h. Transfusions of blood products were recorded for the whole hospital stay. Transfusions of packed red cells were given when the hematocrit value was less than 20% during CPB and less than 25% after surgery. The patients in the tranexamic acid group had significantly less postoperative bleeding compared with the patients in the placebo group (mean [SD]) (475 [274] mL versus 713 [243] mL; P < 0.001). An effective inhibition of fibrinolysis was found in patients receiving tranexamic acid. Tranexamic acid reduces postoperative bleeding in coronary artery bypass grafting patients treated with aspirin until the day before surgery. ⋯ Continuation of aspirin medication until the day before coronary artery bypass grafting may increase postoperative bleeding. The administration of a single dose of tranexamic acid (30 mg/kg) immediately before cardiopulmonary bypass significantly reduced postoperative bleeding and inhibited fibrinolysis in these patients.
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Anesthesia and analgesia · Apr 2003
Comparative StudyThe memory effects of general anesthesia persist for weeks in young and aged rats.
Studies demonstrate lasting cognitive impairment in elderly persons after anesthesia and surgery. We tested the hypothesis that general anesthesia contributes to this cognitive impairment. Six- and 18-mo-old Fischer 344 rats were trained in a 12-arm radial arm maze and were then randomized to anesthesia for 2 h with 1.2% isoflurane/70% nitrous oxide/30% oxygen or a control treatment consisting of 30% oxygen. Rats recovered for 24 h and then were tested daily on the radial arm maze for 8 wk. Performance of young control rats was stable throughout the experiment. In contrast, aged control rats improved their performance as measured by time to complete the maze but not by error rate. After anesthesia, time to complete the maze did not change in young rats, but error rate decreased (P < 0.05 at 1 and 3 wk), indicating improved performance. In contrast, previously anesthetized aged rats failed to improve with repeated testing and took longer to complete the maze than aged control rats (P < 0.05 at 1 and 3 wk). These data demonstrate that general anesthesia with isoflurane and nitrous oxide improves the memory performance on an established spatial memory task in young rats, but in aged rats it attenuates the improvement in performance that otherwise occurs with repeated testing. Therefore, isoflurane and nitrous oxide anesthesia produces a sustained learning impairment in aged rats. ⋯ This study demonstrates that general anesthesia with isoflurane and nitrous oxide improves spatial memory in young rats but impairs it in aged rats for at least 3 wk, indicating that it can influence memory for much longer than previously recognized and may adversely affect memory processes in the aged.