Anesthesia and analgesia
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Anesthesia and analgesia · Jun 1999
Randomized Controlled Trial Clinical TrialAdding clonidine to lidocaine for intravenous regional anesthesia prevents tourniquet pain.
Tourniquet pain often complicates the use of the pneumatic tourniquet during surgical procedures performed under IV regional anesthesia. Clonidine-containing local anesthetic solutions have better analgesic properties than plain solutions when used for spinal, epidural, or peripheral blocks. We tested the hypothesis that the addition of clonidine may improve the quality of IV regional anesthesia, especially tourniquet tolerance. Forty patients were allocated randomly in a double-blinded, randomized study to receive 40 mL of 0.5% lidocaine and either 1 mL of isotonic saline or clonidine (150 microg). A double-cuffed tourniquet was kept inflated until patients complained of pain, leading to release of the distal cuff. Pain at the tourniquet site, at the surgical site, and in the distal part of the arm was rated on a visual analog scale (VAS) and a verbal rating scale (VRS) every 15 min during tourniquet placement and every 15 min for 1 h after tourniquet deflation. Motor blockade, sedation, arterial pressure, and heart rate were also recorded. VAS and VRS scores were significantly lower in the clonidine group 30 and 45 min after tourniquet inflation. The tolerance for the distal tourniquet was also significantly longer in the clonidine group (median [range]: 22 [10-40] vs 10 [5-20] min; P < 0.05); motor blockade was comparable between the two groups. Pain was not different in the two groups after tourniquet release. The clonidine group experienced a higher degree of sedation. We conclude that clonidine improves tourniquet tolerance when added to a local anesthetic solution. ⋯ A 150-microg dose of clonidine added to lidocaine improved tourniquet tolerance during IV regional anesthesia.
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Anesthesia and analgesia · Jun 1999
Randomized Controlled Trial Comparative Study Clinical TrialMucosal pressure, mechanism of seal, airway sealing pressure, and anatomic position for the disposable versus reusable laryngeal mask airways.
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Anesthesia and analgesia · Jun 1999
Randomized Controlled Trial Comparative Study Clinical TrialPreoperative oral antiemetics for reducing postoperative vomiting after tonsillectomy in children: granisetron versus perphenazine.
In a prospective, randomized, double-blinded trial, we evaluated the efficacy of two antiemetics given orally, granisetron and perphenazine, for preventing postoperative vomiting after tonsillectomy with or without adenoidectomy in children. One hundred pediatric patients, ASA physical status I, aged 4-10 yr, received either granisetron 40 microg/kg or perphenazine 70 microg/kg (n = 50 each) orally 1 h before surgery. We used a standard general anesthetic technique. The rate of complete response, defined as no emesis and no need for rescue antiemetic medication, during 0-3 h after anesthesia was 86% with granisetron and 60% with perphenazine; the corresponding rate 3-24 h after anesthesia was 86% and 62%, respectively (P < 0.05). No serious adverse events were observed in any of the groups. In conclusion, preoperative oral granisetron is more effective than perphenazine for preventing postoperative vomiting in children undergoing tonsillectomy with or without adenoidectomy. ⋯ We compared the efficacy of granisetron and perphenazine given orally for preventing postoperative vomiting after tonsillectomy with or without adenoidectomy in children. Preoperative oral granisetron was more effective than perphenazine.
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Anesthesia and analgesia · Jun 1999
Randomized Controlled Trial Clinical TrialThe effects of clonidine on sensitivity to phenylephrine and nitroprusside in patients with essential hypertension recovering from surgery.
Clonidine reduces postoperative circulatory instability in patients with essential hypertension. It also increases the sensitivity to vasopressors before and during anesthesia. We investigated blood pressure responses to phenylephrine and nitroprusside pre- vs postoperatively and the effect of clonidine on these responses in patients with essential hypertension. Twenty patients received clonidine 6 microg/kg orally 120 min before anesthesia and 3 microg/kg IV over the final hour of surgery or an identical placebo. During increasing bolus doses of phenylephrine and nitroprusside (30-300 microg), the maximal systolic pressure responses were recorded at baseline on the day before surgery, before the induction of anesthesia, and 1 and 3 h postoperatively. Sensitivity to phenylephrine and nitroprusside was interpolated from linear regression of the data. There was no difference between preoperative and postoperative sensitivity to phenylephrine or nitroprusside in either group. Clonidine increased sensitivity to phenylephrine versus placebo before and after surgery (response to dose of 1.5 microg/kg: 42+/-14 vs 27+/-8 mm Hg preinduction, 37+/-10 vs 26+/-8 mm Hg 3 h postoperatively; both P < 0.01), but not to nitroprusside (38+/-6 vs 37+/-10 mm Hg preinduction and 40+/-6 vs 39+/-8 mm Hg postoperatively). Clonidine increases the sensitivity to phenylephrine but not nitroprusside at baseline and postoperatively in hypertensive patients. ⋯ Clonidine increases the sensitivity to bolus injections of the vasoconstrictor phenylephrine, but not the vasodilator sodium nitroprusside, before and after surgery in patients with preexisting hypertension. The doses of vasopressors should be reduced accordingly in hypertensive patients receiving perioperative clonidine.
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Anesthesia and analgesia · Jun 1999
Randomized Controlled Trial Comparative Study Clinical TrialGranisetron/dexamethasone combination for reducing nausea and vomiting during and after spinal anesthesia for cesarean section.
We compared the efficacy of granisetron plus dexamethasone with that of granisetron alone for preventing nausea and vomiting in parturients undergoing cesarean section under spinal anesthesia. In a randomized, double-blinded manner, 120 patients received either granisetron 3 mg (Group I, n = 60) or granisetron 3 mg plus dexamethasone 8 mg (Group II, n = 60) IV immediately after clamping of the fetal umbilical cord. A complete response, defined as no emetic symptoms and no need for another rescue antiemetic medication in the intraoperative, postdelivery period was 83% in Group I and 98% in Group II (P = 0.008); the corresponding rates during the first 24 h after surgery was 85% and 98% (P = 0.016). No clinically serious adverse events were observed in any of the groups. In conclusion, the prophylactic use of a granisetron/dexamethasone combination is more effective than granisetron alone for reducing nausea and vomiting in patients during and after spinal anesthesia for cesarean section. ⋯ Intraoperative, postdelivery, and postoperative nausea and vomiting are distressing to patients undergoing cesarean section under spinal anesthesia. The combination of granisetron plus dexamethasone was evaluated and found to be effective for preventing these emetic symptoms.