Anesthesia and analgesia
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Anesthesia and analgesia · Jan 1998
Meta AnalysisDoes acute normovolemic hemodilution reduce perioperative allogeneic transfusion? A meta-analysis. The International Study of Perioperative Transfusion.
The objective of this study was to systematically review the literature and to statistically summarize the evidence evaluating acute normovolemic hemodilution (ANH). Prospective, randomized, controlled trials of ANH that reported either the proportion of patients exposed to allogeneic blood or the units of allogeneic blood transfused were included. All types and languages of publication were eligible. Of 1573 identified publications, 24 trials (containing a total of 1218 patients) were included in the meta-analysis. When all trials were pooled, ANH reduced the likelihood of exposure to allogeneic blood (odds ratio [OR] 0.31, 95% confidence interval [CI] 0.15, 0.62) and the total units of allogeneic blood transfused (weighted mean difference [WMD] -2.22 U, 95% CI -3.57, -0.86). However, there was marked heterogeneity of the results. In trials using a protocol to guide perioperative transfusion, ANH failed to reduce either the likelihood of transfusion (OR 0.64, 95% CI 0.31, 1.31) or the units administered (WMD -0.25 U, 95% CI -0.60, 0.10). Adverse events were incompletely reported. It is possible that biased experimental design is, in part, responsible for the reported efficacy of this technique. ⋯ after a systematic literature review, 24 randomized trials examining the role of acute normovolemic hemodilution were identified, pooled, and summarized using statistical techniques. Many studies reported an impressive reduction in blood transfused. Closer examination suggests that these reductions in blood exposure may be due to flawed study design.
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Anesthesia and analgesia · Jan 1998
Randomized Controlled Trial Clinical TrialPremedication of pediatric tonsillectomy patients with oral transmucosal fentanyl citrate.
We assessed the safety and efficacy of oral transmucosal fentanyl citrate (Fentanyl Oralet; Abbott Laboratories, Abbott Park, IL), administered preoperatively to provide both preoperative sedation and postoperative analgesia, in a randomized, double-blind, placebo-controlled study in 40 children, 2-10 yr of age, scheduled for tonsillectomy. In the preoperative holding area, one group (Group O) received Fentanyl Oralet (fentanyl 10-15 micrograms/kg), and the other (Group IV) received only the candy matrix. Patients in Group O received an i.v. injection of saline, and those in Group IV received an i.v. injection of fentanyl (2 micrograms/kg) after removal of the first tonsil. Except for the opioid, patients received a standard anesthetic. Preoperative sedation and cooperation were assessed. Postoperative pain was evaluated using an objective pain scale. Patients in Group O were more sedated but no more cooperative at the induction of anesthesia compared with those in Group IV. No patient vomited preoperatively or experienced preoperative or postoperative desaturation. Time to postanesthesia care unit (PACU) discharge was not different between groups. There was no significant difference in the number of patients requiring morphine in the PACU (6 of 21 in Group O versus 10 of 19 in Group IV). Plasma fentanyl concentrations were not a reliable indicator of the need for postoperative morphine. Among the patients who required morphine postoperatively, there was an 11-fold variation in plasma fentanyl concentrations at the time of morphine administration. Derived pharmacokinetic parameters were similar to those previously reported in children; bioavailability of the fentanyl in Fentanyl Oralet was 0.33. We conclude that premedication with Fentanyl Oralet did not differ with i.v. fentanyl in regard to the induction of anesthesia and postoperative analgesia. ⋯ In this double-blind, randomized study, we studied the efficacy of Fentanyl Oralet (10-15 micrograms/kg) preoperatively for providing postoperative analgesia in children undergoing tonsillectomy. We found no incidence of preoperative desaturation or vomiting in any patient. This is in contrast to other studies, in which there was a longer time interval between Fentanyl Oralet completion and induction of anesthesia. The bio-availability of the fentanyl in Fentanyl Oralet was estimated to be 33%, which is less than that reported in adults (approximately 50%). There was no difference in postoperative opioid requirements between patients who received 2 micrograms/kg of fentanyl i.v. and those who received Fentanyl Oralet.
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Anesthesia and analgesia · Jan 1998
Randomized Controlled Trial Clinical TrialPostoperative analgesia by D-myo-inositol-1,2,6-trisphosphate in patients undergoing cholecystectomy.
D-myo-inositol-1,2,6-trisphosphate (1,2,6-IP3) possesses antiinflammatory properties, such as reduced eicosanoid synthesis and inhibition of inflammation-induced edema. These properties suggest possible analgesic effects. The analgesic effect of 1,2,6-IP3 was evaluated in a double-blind, randomized study in 24 patients undergoing cholecystectomy. Ten patients received 1,2,6-IP3 as an intravenous (i.v.) bolus dose of 240 mg, followed by a continuous i.v. infusion at 90 mg/h for 24 h. The placebo group (n = 14) received corresponding volumes of isotonic saline. Postoperative pain (visual analog pain scale; VAS) and opiate analgesic requirements (ketobemidon) were evaluated during five postoperative days. Results showed significantly reduced pain during the first five postoperative days in patients treated with 1,2,6-IP3, as measured by using a VAS (P < 0.05). The requirements of opioid analgesics were significantly reduced during the first three postoperative days (P < 0.05). No drug-related side effects were observed. Results of the present study demonstrate a potent and long-lasting analgesic effect of 1,2,6-IP3, possibly related to its antiinflammatory properties. ⋯ A new antiinflammatory drug under investigation, inositol-1,2,6-trisphosphate, was evaluated as a possible analgesic in a pilot study during the postoperative period in cholecystectomized patients. Results showed significantly lower pain assessment and opioid consumption, which should encourage further studies.
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Anesthesia and analgesia · Jan 1998
Randomized Controlled Trial Clinical TrialThe efficacy and safety of a clonidine/bupivacaine combination in caudal blockade for pediatric hernia repair.
We evaluated the analgesic efficacy and hemodynamic and respiratory safety of clonidine when added to bupivacaine for caudal blocks in 58 children aged 38 +/- 2 mo (mean +/- SEM). Patients scheduled for ambulatory hernia repair were randomly given a caudal injection (0.75 mL/kg) of either saline placebo (P group), bupivacaine, 0.25% (B group), bupivacaine plus epinephrine 1:200,000 (BE group), bupivacaine plus clonidine 1 microgram/kg (BC1 group), or bupivacaine plus clonidine 2 micrograms/kg (BC2 group). Postoperative measurements included duration of analgesia, hemodynamics, and respiratory monitoring for 6 h. Thereafter, parents assessed their child's analgesic requirements at home every 3 h for 18 h. The duration of analgesia (median [range]) was significantly longer (P < 0.05) in the BC1 and BC2 groups (360 [270-360] min and 360 [355-360] min, respectively) compared with the P (77[45-190]), B (346[105-360]), or BE group (300[75-360]). Similarly, the BC1 and BC2 groups required less additional analgesic within the first 24 h. All groups showed a significant decrease in mean arterial pressure compared with baseline values, but the differences among the groups were not significant. Bradycardia and respiratory depression were not observed. Clonidine 1 and 2 micrograms/kg can be safely added to bupivacaine caudal blockade in small children for ambulatory hernia repair to achieve an increased duration of analgesia compared with bupivacaine alone or bupivacaine plus epinephrine. ⋯ The addition of clonidine, an antihypertensive drug with analgesic properties, to local anesthetics in caudal blocks prolongs postoperative pain relief and reduces the need for additional pain treatment in children after hernia operation.