Anesthesia and analgesia
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Anesthesia and analgesia · Sep 1998
Randomized Controlled Trial Clinical TrialEffective analgesia after bilateral tubal ligation.
Postpartum bilateral tubal ligation is a brief surgical procedure with minimal tissue injury, yet postoperative recovery times and analgesia requirements are often disproportionately large. To evaluate the analgesic efficacy of local anesthetic infiltration, 20 parturients scheduled for elective minilaparotomy and bilateral tubal ligation with either spinal or epidural anesthesia participated in this prospective, randomized, controlled, double-blind trial. All patients received IV metoclopramide 10 mg and ketorolac 60 mg intraoperatively, as well as preincisional infiltration of the infraumbilical skin incision with 0.5% bupivacaine. Infiltration of bilateral uterine tubes and mesosalpinx was performed with either 0.5% bupivacaine (n = 10) or isotonic sodium chloride solution (saline) (n = 10). IV meperidine (25 mg every 3 min as needed) was given to treat pain in the postanesthesia care unit (PACU). The total amount of meperidine administered in the PACU was significantly larger in the saline group than in the bupivacaine group. Pain scores at 30, 45, 60, 75, and 90 min postoperatively and on the seventh postoperative day were significantly lower in the bupivacaine group than in the saline group. During tubal ligation, infiltration of uterine tubes and mesosalpinx with 0.5% bupivacaine significantly enhanced analgesia both in the immediate postoperative setting and on the seventh postoperative day compared with infiltration with sodium chloride. ⋯ During bilateral tubal ligation with either spinal or epidural anesthesia, preemptive analgesia using IV ketorolac, IV metoclopramide, and infiltration of the incised skin and uterine tubes with 0.5% bupivacaine allowed 9 of 10 patients to recover with no pain, nausea, vomiting, or cramping and to maintain good analgesia for 7 days postoperatively.
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Anesthesia and analgesia · Sep 1998
Randomized Controlled Trial Clinical TrialThe effect of fresh gas flow and anesthetic technique on the ability to control acute hemodynamic responses during surgery.
We evaluated the effect of the fresh gas flow (FGF) rate and the anesthetic technique on the ability to control the acute hyperdynamic response to a specific surgical stimulus during surgery in 90 consenting ASA physical status I-III patients undergoing lower abdominal procedures. After the administration of midazolam 2 mg IV, anesthesia was induced in all patients with propofol 1.5 mg/kg IV and fentanyl 1 microg/kg IV and was initially maintained with desflurane or isoflurane, 0.7 minimum alveolar anesthetic concentration, at total FGF rates of either 1 or 3 L/min. In response to the surgical stimulation of skin incision and retropubic dissection, an increase in mean arterial pressure (MAP) >20% above the preincision baseline MAP value provoked a stepwise increase in the inspired concentration of the volatile anesthetic or the IV administration of a variable-rate infusion of esmolol. At both FGF rates, the acute hemodynamic response to surgical stimulation was more efficiently treated by increasing the inspired concentration of desflurane than isoflurane. At 1 L/min, the average time to control the increase in MAP was significantly shorter with desflurane (17+/-12 min) compared with isoflurane (29+/-16 min), with 60% of the patients in the isoflurane group requiring rescue therapy. When an esmolol infusion was used to control the increase in MAP, supplementation with fentanyl was required in 40% and 53% of patients anesthetized with desflurane and isoflurane, respectively. In conclusion, desflurane provided more rapid and reliable control of acute hemodynamic responses to surgical stimulation than isoflurane or esmolol when the volatile anesthetics were administered at low FGF rates. ⋯ At low fresh gas flow rates (1 L/min), desflurane more successfully and rapidly controlled the acute hemodynamic responses to painful surgical stimuli than isoflurane.
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Anesthesia and analgesia · Sep 1998
Randomized Controlled Trial Clinical TrialIntrathecal, but not intravenous, clonidine reduces experimental thermal or capsaicin-induced pain and hyperalgesia in normal volunteers.
Clonidine is approved for intraspinal administration in the treatment of neuropathic cancer pain. Some studies have suggested an analgesic effect after systemic clonidine administration. The purpose of this study was to compare the analgesic effects of intrathecal and IV clonidine with acute noxious stimulation and with hyperalgesia from intradermal capsaicin injection in volunteers. Sixteen healthy volunteers received intradermal injections of capsaicin (100 microg) before and after the IV or intrathecal injection of clonidine 50 or 150 microg in a randomized, double-blind manner. Pain and areas of mechanical hyperalgesia and allodynia were determined at specified intervals. In addition, pain to noxious heat stimulation was determined. The capsaicin injection produced pain, followed by hyperalgesia and allodynia. The intrathecal, but not IV, injection of 150 microg of clonidine reduced capsaicin-induced pain and area of hyperalgesia. Intrathecal clonidine (150 microg) reduced pain to heat stimulation, whereas IV clonidine did not. The groups did not differ in hemodynamic or sedative effects from clonidine. These data support the value of intraspinal administration of clonidine for the treatment of acute pain and of pain states associated with hyperalgesia. Similarly, they suggest that analgesia from the systemic administration of this alpha2-adrenergic agonist, if any, is weak in doses that produce sedation and reduce blood pressure. ⋯ To the extent that the experimental pain conditions used in this study reflect those in patients with acute and chronic pain, these data support the spinal rather than IV injection of clonidine for analgesia.
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Anesthesia and analgesia · Sep 1998
Randomized Controlled Trial Multicenter Study Clinical TrialIntrathecal clonidine and fentanyl with hyperbaric bupivacaine improves analgesia during cesarean section.
Seventy-eight pregnant women at term, scheduled for elective cesarean section, were enrolled in this multicenter trial to compare the analgesic efficacy and side effect profile of a spinal block with hyperbaric bupivacaine alone (Group B) or combined with 75 microg of clonidine (Group BC) or with clonidine 75 microg and fentanyl 12.5 microg (Group BCF). Intraoperatively, clonidine increased the spread of the sensory block and decreased pain (pain scores 23+/-7 mm vs 17+/-6 and 2+/-1 mm for Group B versus Groups BC and BCF; P < 0.05) and analgesic supplementation. This improved analgesia was best with the clonidine-fentanyl combination (Group BC versus Group BCF; P < 0.05). Postoperative analgesia was prolonged only in Group BCF (215+/-79 min vs 137+/-35 and 183+/-80 min for Group BCF versus Groups B and BC; P < 0.05). Blood pressure and heart rate changes were not significantly different among groups, whereas sedation and pruritus were significantly more frequent in Group BCF. Nausea and vomiting were decreased in Groups BC and BCF. Apgar scores and umbilical artery blood pH were not different among groups. We conclude that adding a small dose of intrathecal clonidine to bupivacaine increases the quality of intraoperative analgesia and decreases pain during cesarean section. Combining clonidine with fentanyl further improved analgesia. ⋯ In this study, we demonstrate improved intraoperative spinal analgesia by adding 75 microg of clonidine to bupivacaine; side effects were not increased. The combination of clonidine and fentanyl further improved analgesia but moderately increased sedation and pruritus.
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Anesthesia and analgesia · Sep 1998
Randomized Controlled Trial Clinical TrialOral antihistamines reduce the side effects from rapid vancomycin infusion.
Rapid infusion of vancomycin causes histamine-mediated side effects, hypotension, and rash, known as "red man syndrome." In this prospective, randomized, double-blind, placebo-controlled study, we examined the ability of oral antihistamines to attenuate three clinical end points: rash, hypotension, and vancomycin discontinuation, and we compared these findings with those of a similar study using IV antihistamines. Patients (ASA physical status I-III) who required vancomycin prophylaxis for elective arthroplasty received either oral antihistamines (diphenhydramine < or = 1 mg/kg and cimetidine < or = 4 mg/kg, n = 20) or placebo (n = 10) 1 h before rapid vancomycin infusion (1 g over 10 min). The vancomycin infusion was discontinued if the mean arterial blood pressure decreased by > or = 20% or if itching was intolerable for the patient. Clinically significant hypotension developed in no treated patients, compared with five (50%) patients in the placebo group (P = 0.001). Rapid infusion was stopped for one treated patient (5%) and for five (50%) patients in the placebo group (P = 0.004). Incidence (P = 0.011) and severity of rash (P = 0.015) were also reduced in treated patients. Peak histamine levels were increased but were similar for patients in both groups (mean +/- SD, 1.9+/-2.5 vs 1.6+/-2.4 ng/mL; P = 0.75). Oral antihistamines were as effective as IV antihistamines. In conclusion, oral H1 and H2 antihistamine pretreatment is a practical, safe, and inexpensive option to attenuate histamine-mediated side effects associated with rapid vancomycin infusion. ⋯ Clinicians often must administer vancomycin faster than the 1-h recommended time, which can cause "red man syndrome" (rash, itching, hypotension). Our randomized, double-blind, placebo-controlled study showed that oral H1 and H2 antihistamine pretreatment significantly reduced the histamine-related side effects of rapid vancomycin infusion.