Anesthesia and analgesia
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Anesthesia and analgesia · Aug 2002
Randomized Controlled Trial Comparative Study Clinical TrialA comparison of 0.1% and 0.2% ropivacaine and bupivacaine combined with morphine for postoperative patient-controlled epidural analgesia after major abdominal surgery.
Ropivacaine (ROPI), which is less toxic and produces less motor block than bupivacaine (BUPI), seems attractive for epidural analgesia. Few data are available concerning dose requirements of epidural ROPI when combined with morphine. In this study, we compared the dose requirements and side effects of ROPI and BUPI combined with small-dose morphine after major abdominal surgery. Postoperatively, 60 patients were randomly allocated (double-blinded manner) to four groups: patient-controlled epidural analgesia with the same settings using 0.1% or 0.2% solution of ROPI or BUPI combined with an epidural infusion of 0.1 mg/h of morphine. Pain scores, side effects, motor block, and local anesthetic consumption were measured for 60 h. Pain scores and the incidence of side effects did not differ among the groups. Consumption of ROPI and BUPI were similar in both 0.1% groups. Doubling the concentration significantly reduced the consumption (milliliters) of BUPI (P < 0.05) but not of ROPI. Consequently, using ROPI 0.2% significantly increased the dose administered as compared with ROPI 0.1% (ROPI 0.1% = 314 +/- 151 mg and ROPI 0.2% = 573 +/- 304 mg at Hour 48; P < 0.05). Patient-controlled epidural analgesia with the 0.1% or 0.2% solution of ROPI or BUPI combined with epidural morphine resulted in comparable analgesia. As compared with ROPI 0.1%, the use of ROPI 0.2% increased consumption of local anesthetic without improving analgesia. ⋯ Small-dose (0.1%) ropivacaine and bupivacaine have similar potency and result in comparable analgesia and incidence of side effects.
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Anesthesia and analgesia · Aug 2002
Randomized Controlled Trial Clinical TrialAn evaluation of the analgesic efficacy of intravenous regional anesthesia with lidocaine and ketorolac using a forearm versus upper arm tourniquet.
Intravenous regional anesthesia (IVRA) using a forearm tourniquet may be a potentially safer technique compared with using an upper arm tourniquet. Ketorolac is a useful adjuvant to lidocaine for IVRA. In this study, we assessed the analgesic efficacy of administering IVRA lidocaine and ketorolac with either a forearm or upper arm tourniquet for outpatient hand surgery. Upper arm IVRA was established using 40 mL of a solution containing 200 mg of lidocaine and ketorolac 20 mg (0.5 mg/mL). Forearm IVRA was established using 20 mL of a solution containing 100 mg of lidocaine and ketorolac 10 mg (0.5 mg/mL). Onset and duration of sensory block as well as postoperative pain and analgesic use were recorded. The patients who received forearm IVRA had a significantly longer period during which they required no analgesics (701 +/- 133 min) compared with 624 +/- 80 min for the upper arm IVRA ketorolac patients (P = 0.032). Onset of sensory block was similar between the two groups; however, recovery of sensation was significantly longer in the Forearm IVRA (22 +/- 5 min) group compared with the Upper Arm IVRA (13 +/- 3 min) group (P < 0.05). There were no differences in postoperative analgesic use or pain scores between the two groups. We conclude that forearm IVRA with lidocaine and ketorolac provides safe and effective perioperative analgesia for patients undergoing ambulatory hand surgery. This technique results in a longer duration of sensory block and prolonged postoperative analgesia compared with upper arm IVRA while using one-half the doses of both lidocaine and ketorolac. ⋯ Forearm tourniquet intravenous regional anesthesia (IVRA) with 50% less lidocaine and ketorolac provides for both a longer duration of sensory block and prolonged postoperative analgesia compared with upper arm IVRA.
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Anesthesia and analgesia · Aug 2002
Randomized Controlled Trial Multicenter Study Clinical TrialAprotinin versus placebo in major orthopedic surgery: a randomized, double-blinded, dose-ranging study.
We conducted a prospective, multicenter, double-blinded, dose-ranging study to compare the risk/benefit ratio of large- and small-dose aprotinin with placebo after major orthopedic surgery. Fifty-eight patients were randomized into three groups: Large-Dose Aprotinin (4 M kallikrein inactivator unit [KIU] bolus before surgery followed by a continuous infusion of 1 M KIU/h until the end of surgery), Small-Dose Aprotinin (2 M KIU bolus plus 0.5 M KIU/h), and Placebo. Bleeding was measured and calculated. Bilateral ascending venography was systematically performed on the third postoperative day. Measured and calculated blood loss decreased in the Large-Dose Aprotinin group (calculated bleeding, whole blood, hematocrit 30%, median [range], 2,023 mL [633-4,113] as compared with placebo, 3,577 mL [1,670-21,758 mL]). The total number of homologous and autologous units was also significantly decreased in the Large-Dose Aprotinin group (2 U [0-5 U] as compared with placebo, 4 U [0-42 U]). No increase in deep vein thrombosis or pulmonary embolism was observed in the aprotinin groups. Large-dose aprotinin was safe and effective in dramatically reducing the measured and calculated bleeding and the amount of transfused red blood cell units after major orthopedic surgery. ⋯ Large doses of aprotinin decrease blood loss and transfusion amount in major orthopedic surgery.
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Anesthesia and analgesia · Aug 2002
Clinical Trial Controlled Clinical TrialThe effect of midazolam on stress levels during simulated emergency medical service transport: a placebo-controlled, dose-response study.
Patients in the emergency medical service (EMS) may have increased endogenous catecholamines because of pain or fear and may benefit from sedation similar to premedication in the hospital. During a simulated EMS scene call, 72 healthy male volunteers were either transported by paramedics from a third-floor apartment through a staircase with subsequent EMS transport with sirens (three stress groups of n = 12; total, n = 36) or asked to sit on a chair for 5 min and lie down on a stretcher for 15 min (three control groups of n = 12; total, n = 36). Catecholamine plasma samples were measured in the respective stress and control groups at baseline and after placebo IV (n = 12) or 25 (n = 12) or 50 (n = 12) microg/kg of midazolam IV throughout the experiment, respectively. Statistical analysis was performed with analysis of variance; P < 0.05 was considered significant. The Placebo Stress versus Control group, but not the 50 microg/kg Stress Midazolam group, had both significantly increased epinephrine (73 +/- 5 pg/mL versus 45 +/- 5 pg/mL; P < 0.001) and norepinephrine (398 +/- 34 pg/mL versus 278 +/- 23 pg/mL; P < 0.01) plasma levels after staircase transport. After EMS transport, the Placebo Stress versus Control group had significantly increased epinephrine (51 +/- 4 pg/mL versus 37 +/- 4 pg/mL; P < 0.05) but not norepinephrine (216 +/- 24 pg/mL versus 237 +/- 18 pg/mL) plasma levels, whereas no significant differences in catecholamine plasma levels occurred between groups after either 25 or 50 microg/kg of midazolam. In conclusion, simulated EMS patients may be subject to more stress during staircase transport than during transport in an EMS vehicle. Titrating sedation with 25 microg/kg of midazolam significantly reduced endogenous catecholamines but not heart rate. ⋯ Simulated emergency medical service patients were more likely to be stressed when being transported by paramedics through a staircase than in an ambulance. Accordingly, it may be beneficial to inject sedative drugs before initiating transport to ensure patient comfort and safety.
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Anesthesia and analgesia · Aug 2002
Comparative Study Clinical Trial Controlled Clinical TrialEarly postoperative respiratory acidosis after large intravascular volume infusion of lactated ringer's solution during major spine surgery.
In this study, we compared the effects of large intravascular volume infusion of 0.9% saline (NS) or lactated Ringer's (LR) solution on electrolytes and acid base balance during major spine surgery and evaluated the postoperative effects. Thirty patients aged 18-70 yr were included in the study. General anesthesia was induced with 5 mg/kg thiopental and 0.1 mg/kg vecuronium IV. Anesthesia was maintained with oxygen in 70% nitrous oxide and 1.5%-2% sevoflurane. In Group I, the NS solution, and in Group II, the LR solution were infused 20 mL. kg(-1). h(-1) during the operation and 2.5 mL. kg(-1). h(-1), postoperatively. Electrolytes (Na+, K+, Cl-) and arterial blood gases were measured preoperatively, every hour intraoperatively and at the 1st, 2nd, 4th, 6th, and 12th hours postoperatively. In the NS group, pHa, HCO3 and base excess decreased, and Cl- values increased significantly at the 2nd hour and Na+ values increased at the 4th hour intraoperatively (P < 0.001). The values returned to normal ranges at the 12th hour postoperatively. In the LR group, blood gas analysis and electrolyte values did not show any significant difference intraoperatively, but the increase in PaCO2 and the decrease in pHa and serum Na+ was significant at the 1st hour postoperatively. Although intraoperative 20 mL. kg(-1). h(-1) LR infusion does not cause hyperchloremic metabolic acidosis as does NS infusion, it leads to postoperative respiratory acidosis and mild hyponatremia. ⋯ The infusion of large-volume lactated Ringer's solution does not cause hyperchloremic metabolic acidosis as does 0.9% saline during major surgery, but leads to postoperative mild hyponatremia and respiratory acidosis.