Anesthesia and analgesia
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Anesthesia and analgesia · Sep 1998
Randomized Controlled Trial Comparative Study Clinical TrialA double-blind comparison of ropivacaine, bupivacaine, and mepivacaine during sciatic and femoral nerve blockade.
No study has evaluated the efficacy of ropivacaine in peripheral nerve block of the lower extremity. The purpose of this prospective, randomized, double-blind study was to compare ropivacaine, bupivacaine, and mepivacaine during combined sciatic-femoral nerve block. Forty-five ASA physical status I or II patients scheduled for elective hallux valgus repair with thigh tourniquet were randomized to receive combined sciatic-femoral block with 0.75% ropivacaine (ROPI, n = 15), 0.5% bupivacaine (BUPI, n = 15), and 2% mepivacaine (MEPI, n = 15). Time required for onset of sensory and motor block on the operated limb (readiness for surgery) and resolution of motor block, as well as onset of postsurgical pain and time of first analgesic requirement, were recorded. The three groups were similar with regard to demographic variables, duration of surgery, and measured visual analog pain scores. Onset of sensory and motor blockade was similar in Groups ROPI and MEPI and significantly shorter than in Group BUPI (P = 0.002 and P = 0.001, respectively). Resolution of motor block occurred later in Groups ROPI and BUPI than in Group MEPI (P = 0.005 and P = 0.0001, respectively). Duration of postoperative analgesia was significantly longer in Groups ROPI (670+/-227 min) and BUPI (880+/-312 min) compared with Group MEPI (251+/-47 min) (P = 0.0001), with a significant decrease in postoperative pain medication requirements (P < 0.05). We conclude that for sciatic-femoral nerve block, 0.75% ropivacaine has an onset similar to that of 2% mepivacaine and a duration of postoperative analgesia between that of 0.5% bupivacaine and 2% mepivacaine. ⋯ Quick onset of block with prolonged postoperative analgesia is an important goal in peripheral nerve blockade. We evaluated the clinical properties of 0.5% bupivacaine, 2% mepivacaine, and 0.75% ropivacaine for sciatic-femoral nerve block and demonstrated that ropivacaine has an onset similar to that of mepivacaine but allows for postoperative analgesia between that of bupivacaine and mepivacaine.
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Anesthesia and analgesia · Sep 1998
Randomized Controlled Trial Clinical TrialThe effects of maternal position during induction of combined spinal-epidural anesthesia for cesarean delivery.
Combined spinal-epidural anesthesia (CSE) is a popular technique for cesarean delivery. Regional blocks in obstetrics are often performed with the parturient in the sitting position because the midline may be recognized more easily than in the lateral decubitus position. When conventional spinal anesthesia is performed in the sitting position, the patient is placed supine immediately after drug injection. In contrast, when CSE is performed with the woman sitting, there is a delay in assuming the supine position because of epidural catheter placement, which may affect the incidence of hypotension. Healthy women, at term of pregnancy, about to undergo an elective cesarean section under CSE, were randomly assigned to the sitting or lateral recumbent position for initiation of the block. All parturients were given 1000 mL of lactated Ringer's solution in the 15 min preceding induction and an additional 300-500 mL while the actual block was being performed. On completion of the CSE, they were turned to the supine position with left uterine displacement. A second anesthesiologist, blinded to the woman's position during CSE, evaluated the sensory level of anesthesia, maternal heart rate, blood pressure, oxygen saturation, need for ephedrine, and occurrence of nausea and vomiting. Results are expressed as mean +/- SD. Twelve women were studied in the sitting group and 10 were studied in the lateral recumbent group. The severity and duration of hypotension were greater in those parturients who had CSE induced in the sitting (47%+/-7% and 6+/-3 min, respectively) compared with the lateral recumbent position (32%+/-14% and 3+/-2 min, respectively). Women in the sitting group also required twice as much ephedrine (38+/-18 mg) to correct hypotension compared with the other group (17+/-12 mg). In conclusion, the severity and duration of hypotension were greater when CSE was induced in the sitting compared with the lateral decubitus position. ⋯ We studied the induction of combined spinal-epidural anesthesia (CSE) in the sitting versus lateral recumbent positions in healthy women undergoing a scheduled cesarean delivery. The severity and duration of hypotension were greater when CSE was induced in the sitting position. Thus, the position used for induction of CSE should be among the factors considered when there is greater maternal or fetal risk from hypotension.
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Anesthesia and analgesia · Sep 1998
Randomized Controlled Trial Clinical TrialWidespread application of topical steroids to decrease sore throat, hoarseness, and cough after tracheal intubation.
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Anesthesia and analgesia · Sep 1998
Randomized Controlled Trial Clinical TrialSimulation of an epidural test dose with intravenous isoproterenol in sevoflurane- and halothane-anesthetized children.
Isoproterenol has been suggested as an alternative marker for epidural test dosing in children receiving halothane anesthesia. The purpose of this prospective, randomized, double-blind study was to determine the chronotropic response to IV isoproterenol in sevoflurane-anesthetized children. Thirty-six ASA physical status I children (0.5-8 yr) were anesthetized with either halothane or sevoflurane at 1 minimum alveolar anesthetic concentration adjusted for age in 70% nitrous oxide. Patients received incremental IV injections of isoproterenol until their heart rate increased > or = 20 bpm above baseline. The minimal effective dose of isoproterenol required to produce an increase of > or = 20 bpm was 55 ng/kg (42-72 ng/kg; 95% confidence interval) in sevoflurane-anesthetized children and 32 ng/kg (26-38 ng/kg; 95% confidence interval) in halothane-anesthetized children (P < 0.05). This dose-response study suggests that sevoflurane antagonizes beta-adrenergic-mediated chronotropic responses to isoproterenol more than halothane. These observations also suggest that larger doses of isoproterenol will be necessary for epidural test dosing in children receiving sevoflurane rather than halothane anesthesia. ⋯ Isoproterenol has been suggested as an alternative marker for epidural test dosing in children receiving halothane anesthesia. This isoproterenol dose-response study indicates that larger doses of isoproterenol will be necessary for epidural test dosing in children undergoing sevoflurane rather than halothane anesthesia.
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Anesthesia and analgesia · Sep 1998
Randomized Controlled Trial Clinical TrialThe influence of scalp infiltration with bupivacaine on hemodynamics and postoperative pain in adult patients undergoing craniotomy.
After craniotomy, hypertension may contribute to intracerebral hemorrhage. We studied whether scalp infiltration with bupivacaine during craniotomy reduces postoperative pain and hypertension. In a double-blind fashion, 36 adult patients (ASA physical status II or III) undergoing elective craniotomy were randomly assigned to receive scalp infiltration with either bupivacaine (0.25%) and epinephrine (1:200,000) or saline/ epinephrine (1:200,000) for skeletal fixation, skin incision, and wound closure. Heart rate (HR) and mean arterial pressure (MAP) were measured after anesthesia induction, after skull-pin insertion, after scalp infiltration, during dural closure, during skin closure, on admission to postanesthesia care unit (PACU), and 1 h after admission. Visual analog pain scores were recorded in the PACU. MAP was significantly greater in the saline group at scalp infiltration. HR was significantly faster in the saline group at dural and skin closure. The bupivacaine group reported significantly less pain than the saline group at PACU admission and 1 h after admission. Pain scores did not correlate with hemodynamic measurements. We conclude that scalp infiltration with 0.25% bupivacaine with 1:200,000 epinephrine blunts certain intraoperative hemodynamic responses and reduces postoperative pain but has no effect on postoperative hemodynamics. ⋯ We sought to evaluate whether scalp infiltration with bupivacaine and epinephrine at the beginning and end of craniotomy would afford more intra- and postoperative hemodynamic stability and influence immediate postoperative pain. We found that intraoperative hemodynamics were not influenced greatly; however, craniotomy patients do have significant postoperative pain, which does not seem to have an influence on hemodynamics in the postanesthesia care unit.