Anesthesia and analgesia
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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 Comparative Study Clinical TrialThe efficacy, side effects, and recovery characteristics of dexmedetomidine versus propofol when used for intraoperative sedation.
We evaluated the cardio-respiratory effects of equi-sedative doses of dexmedetomidine and propofol for intraoperative sedation. Secondary comparison end points were time to achieve and terminate sedation and postoperative analgesia and psychomotor performance. Forty patients scheduled for elective surgery provided informed consent and were randomized equally to receive either dexmedetomidine (1 microg/kg initial loading dose for 10 min; maintenance, 0.4-0.7 microg. kg(-1). h(-1)) or propofol (75 microg. kg(-1). min(-1) x 10 min; maintenance, 12.5-75 microg. kg(-1). min(-1)). Hemodynamic variables (heart rate and mean arterial blood pressure), sedation (visual analog scale and Observer Assessment of Alertness/Sedation), bispectral index score of sedation, ventilation (respiratory rate, O2 sat, and ETCO2), psychomotor performance (digital symbol substitution test), and pain (visual analog scale) were determined during surgery and up to 95 min after surgery. Intraoperative sedation levels were targeted to achieve a bispectral index score of 70-80. Patient demographics, ASA class, surgical procedure, and baseline cardio-respiratory variables were similar between groups. Sedation was achieved more rapidly with propofol but was similar between groups 25 min after initiating infusions. The average infusion rate for dexmedetomidine was 0.7 microg. kg(-1). h(-1) and 38 microg. kg(-1). min(-1) for propofol. There were no differences between groups in psychomotor performance and respiratory rate during recovery. The previous use of dexmedetomidine resulted in more sedation, lower blood pressure, and improved analgesia (less morphine use) in recovery. ⋯ Dexmedetomidine may be useful for perioperative sedation. It has a slower onset and offset of sedation compared with propofol. Dexmedetomidine was associated with improved analgesia and less morphine use in the postoperative period.
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Anesthesia and analgesia · Aug 2002
Randomized Controlled Trial Comparative Study Clinical TrialHemodynamic responses to tracheal intubation with laryngoscope versus lightwand intubating device (Trachlight) in adults with normal airway.
Lightwand devices are effective and safe as an aid to tracheal intubation. Theoretically, avoiding direct-vision laryngoscopy could allow for less stimulation by intubation than the conventional laryngoscopic procedure. We designed this prospective randomized study to assess the cardiovascular changes after either lightwand or direct laryngoscopic tracheal intubation in adult patients anesthetized with sevoflurane. Sixty healthy adult patients with normal airways were randomly assigned to one of three groups according to intubating procedure under sevoflurane/nitrous oxide anesthesia (fraction of inspired oxygen = 0.33) (n = 20 each). The lightwand group received tracheal intubation with Trachlight, the laryngoscope-intubation group received tracheal intubation with a direct-vision laryngoscope (Macintosh blade), and the laryngoscopy-alone group received the laryngoscope alone. Heart rate and systolic blood pressure were recorded continuously for 5 min after tracheal intubation or laryngoscopy with enough time to intubate. All procedures were successful on the first attempt. The maximum heart rate and systolic blood pressure values obtained after intubation with Trachlight (114 +/- 20 bpm and 143 +/- 30 mm Hg, respectively) did not differ from those with the Macintosh laryngoscope (114 +/- 20 bpm and 138 +/- 23 mm Hg), but they were significantly larger than those in the laryngoscopy-alone group (94 +/- 19 bpm and 112 +/- 21 mm Hg) (P < 0.05). Direct stimulation of the trachea appears to be a major cause of the hemodynamic changes associated with tracheal intubation. ⋯ The magnitude of hemodynamic changes associated with tracheal intubation with the Trachlight is almost the same as that which occurs with the direct laryngoscope. Hemodynamic changes are likely to occur because of direct tracheal irritation rather than direct stimulation of the larynx.
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Anesthesia and analgesia · Aug 2002
Randomized Controlled Trial Clinical TrialTemperature control and recovery of bowel function after laparoscopic or laparotomic colorectal surgery in patients receiving combined epidural/general anesthesia and postoperative epidural analgesia.
We compared the effects of a laparoscopic (n = 23) versus laparotomic (n = 21) technique for major abdominal surgery on temperature control in 44 patients undergoing colorectal surgery during a combined epidural/general anesthesia. A thoracic epidural block up to T4 was induced with 6-10 mL of 0.75% ropivacaine; general anesthesia was induced with thiopental, fentanyl, and atracurium IV and maintained with isoflurane. Core temperature was measured with a bladder probe and recorded every 15 min after the induction. In both groups, core temperature decreased to 35.2 degrees C (range, 34 degrees C-36 degrees C) at the end of surgery. After surgery, normothermia returned after 75 min (60-120 min) in the Laparoscopy group and 60 min (45-180 min) in the Laparotomy group (P = 0.56). No differences in postanesthesia care unit discharge time were reported between the two groups. The degree of pain during coughing was smaller after laparoscopy than laparotomy from the 24th to the 72nd observation times (P < 0.01). Morphine consumption was 22 mg (2-65 mg) in the Laparotomy group and 5 mg (0-45 mg) in the Laparoscopy group (P = 0.02). The time to first flatus was shorter after laparoscopy (24 h [16-72 h]) than laparotomy (72 h [26-96 h]) (P = 0.0005), and the first intake of clear liquid occurred after 48 h (24-72 h) in the Laparoscopy group and after 96 h (90-96 h) in the Laparotomy group (P = 0.0005). Although laparoscopic surgery provides positive effects on the degree of postoperative pain and recovery of bowel function, the reduction in heat loss produced by minimizing bowel exposure with laparoscopic surgery does not compensate for the anesthesia-related effects on temperature control, and active patient warming must also be used with laparoscopic techniques. ⋯ This prospective, randomized, controlled study demonstrates that laparoscopic colorectal surgery results in less postoperative pain and earlier recovery of bowel function than conventional laparotomy but does not reduce the risk for perioperative hypothermia. Accordingly, active warming must be provided to patients also during laparoscopic procedures.
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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.