Anesthesia and analgesia
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Anesthesia and analgesia · Dec 2003
Randomized Controlled Trial Comparative Study Clinical TrialThe effect of cerebral monitoring on recovery after general anesthesia: a comparison of the auditory evoked potential and bispectral index devices with standard clinical practice.
The use of cerebral monitoring may improve the ability of anesthesiologists to titrate anesthetic drugs. However, there is controversy regarding the impact of the alleged anesthetic-sparing effects of cerebral monitoring on the recovery process and patient outcome. We designed this prospective double-blinded, sham-controlled study to evaluate the impact of intraoperative monitoring with the electroencephalogram bispectral index (BIS) or auditory evoked potential (AEP) device on the usage of desflurane and the time to discharge from the recovery room, as well as on patient satisfaction with their anesthetic experience and recovery. Ninety healthy patients undergoing laparoscopic general surgery procedures using a standardized anesthetic technique were randomly assigned to one of three monitoring groups: standard clinical practice (control), BIS-guided, or AEP-guided. Both the BIS and AEP monitors were connected to all patients before induction of general anesthesia. In the control group, the anesthesiologists were not permitted to observe the BIS or AEP index values during the intraoperative period. In the BIS-guided group, the volatile anesthetic was titrated to maintain a BIS value in the range of 45-55. In the AEP-guided group, the targeted AEP index range was 15-20. The BIS and AEP indices, as well as end-tidal desflurane concentration, were recorded at 3-5 min intervals. Recovery times to awakening, tracheal extubation, fast-track score >or=12, and postanesthesia care unit (PACU) discharge criteria were recorded at 1-10 min intervals. In addition, patient satisfaction with anesthesia and quality of recovery were evaluated on 100- and 18-point scales, respectively, at 24 h after surgery. The AEP- and BIS-guided groups were administered significantly smaller average end-tidal desflurane concentrations than the control group (3.8 +/- 0.9 and 3.9 +/- 0.6 versus 4.7 +/- 1.7, respectively) (P < 0.01). Although the emergence times to eye opening, tracheal extubation, and obeying commands were consistently shorter in the AEP and BIS groups (6 +/- 4 and 6 +/- 5 versus 8 +/- 8 min; 6 +/- 5 and 6 +/- 4 versus 11 +/- 10 min; and 8 +/- 4 and 7 +/- 4 versus 12 +/- 9 min, respectively), only the extubation times were significantly different from the control group (P < 0.05). More importantly, the length of the PACU stay was significantly shorter in both the AEP- and BIS-guided groups (79 +/- 43 and 80 +/- 47 versus 108 +/- 58 min, respectively) (P < 0.05). The patients' quality of recovery was also significantly higher in the two monitored groups (15 +/- 2 versus 13 +/- 3 in the control group, P < 0.05). We concluded that cerebral monitoring with either the BIS or AEP devices reduced the maintenance anesthetic (desflurane) requirement, resulting in a shorter length of stay in the PACU and improved quality of recovery after laparoscopic surgery. However, there were no significant outcome differences between the two cerebral monitored groups. ⋯ Compared with standard monitoring practices, use of an auditory evoked potential or bispectral index monitor to titrate the volatile anesthetic led to a significant reduction in the anesthetic requirement. The anesthetic-sparing effect of cerebral monitoring resulted in a shorter postanesthesia care unit stay and improved quality of recovery from the patient's perspective.
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Anesthesia and analgesia · Dec 2003
Randomized Controlled Trial Clinical TrialThe effect of intraoperative use of esmolol and nicardipine on recovery after ambulatory surgery.
There is controversy regarding the optimal technique for maintaining hemodynamic stability during anesthesia. We designed this prospective, randomized, double-blinded study to test the hypothesis that the technique used for maintaining hemodynamic stability during general anesthesia can influence recovery after ambulatory surgery. Forty-five healthy consenting women undergoing gynecologic laparoscopy procedures were randomly assigned to 1 of 3 treatment groups: Group 1 (control, n = 15) received normal saline 5 mL and 1 mL, followed by a saline infusion at a rate of 0.005 mL x kg(-1) x min(-1); Group 2 (n = 15) received esmolol 50 mg and saline 1 mL, followed by an esmolol infusion 5 microg x kg(-1) x min(-1); and Group 3 (n = 15) received esmolol 50 mg and nicardipine 1 mg, followed by an esmolol infusion 5 microg x kg(-1) x min(-1). The study drugs were administered after the induction of anesthesia with fentanyl 1.5 microg/kg, and propofol 2 mg/kg I.V. Tracheal intubation was facilitated with vecuronium 0.12 mg/kg I.V. Anesthesia was initially maintained with desflurane 2% end-tidal and N(2)O 67% in oxygen in all 3 groups. During surgery, the mean arterial blood pressure (MAP) was maintained within +/-15% of the baseline value by varying the study drug infusion rate and the inspired concentration of desflurane. In addition to MAP and heart rate values, electroencephalogram bispectral index values were recorded throughout the perioperative period. Recovery times and postoperative side effects were assessed. Compared with the control group, adjunctive use of esmolol and nicardipine attenuated the increase in heart rate (in Group 2) and MAP (in Group 3) after tracheal intubation. Furthermore, the use of an esmolol infusion as an adjunct to desflurane to control the acute autonomic responses during the maintenance period significantly decreased emergence times (4 +/- 2 versus 7 +/- 4 min), decreased the need for postoperative opioid analgesics (43% versus 80%), and reduced the time to discharge (209 +/- 89 versus 269 +/- 100 min). We conclude that the adjunctive use of esmolol alone or in combination with nicardipine during the induction of anesthesia reduced the hemodynamic response to tracheal intubation. Furthermore, use of an esmolol infusion as an adjuvant to desflurane-N(2)O anesthesia for controlling the acute hemodynamic responses during the maintenance period improved the recovery profile after outpatient laparoscopic surgery. ⋯ The adjunctive use of the beta-adrenergic blocker esmolol to control the acute sympathetic responses during desflurane-based anesthesia provided a more rapid awakening from anesthesia, reduced the postoperative opioid analgesic requirement, and decreased the time to discharge home after ambulatory laparoscopic surgery.
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Anesthesia and analgesia · Dec 2003
Randomized Controlled Trial Clinical TrialPreincisional treatment to prevent pain after ambulatory hernia surgery.
We designed this study as a randomized comparison of postoperative pain after inguinal hernia repair in patients treated with triple preincisional analgesic therapy versus standard care. Triple therapy consisted of a nonsteroidal antiinflammatory, a local anesthetic field block, and an N-methyl-D-aspartate inhibitor before incision. The treatment group (n = 17) received rofecoxib, 50 mg PO, a field block with 0.25% bupivacaine/0.5% lidocaine, and ketamine 0.2 mg/kg IV before incision; controls (n = 17) received a placebo PO before surgery. The anesthetic protocol was standardized. Postoperative pain was treated by fentanyl IV and oxycodone 5 mg/acetaminophen 325 mg PO as required for pain. Pain scores (0-10) and analgesic were recorded for the first 7 days after surgery. Pain scores were 47% lower in the treatment group before discharge (3.1 +/- 0.6 versus 5.9 +/- 0.6, P = 0.0026) (mean +/- SE) and 18% less in the first 24 h after discharge (5.6 +/- 0.4 versus 6.8 +/- 0.5, P = 0.05); oral analgesic use was 34% less in the treatment group (4.6 +/- 0.8 doses versus 7.1 +/- 0.7 doses, P = 0.02) in the first 24 h after surgery. We conclude that triple preincisional therapy diminishes pain and analgesic use after outpatient hernia repair, and encourage further evaluation of this technique. ⋯ Outpatients undergoing inguinal hernia repair under general anesthesia report moderate-to-severe pain after surgery. Triple preincisional therapy that included rofecoxib, 50 mg PO, ketamine, 0.2 mg/kg IV, and local anesthetic field block reduced pain scores and analgesic use in the first 24 h after discharge.
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Anesthesia and analgesia · Dec 2003
Randomized Controlled Trial Comparative Study Clinical TrialThe effect of antiemetics on pupillary reflex dilation during epidural/general anesthesia.
The effect of dopamine D2 receptor antagonists, such as chlorpromazine and haloperidol, on pupil size in awake subjects suggests that these drugs might also alter pupillary reflex dilation and pupil size during general anesthesia. Forty-seven patients undergoing lower abdominal surgery under combined epidural/general anesthesia were randomized to receive one of the 5 following open labeled drugs: 10 mL saline, 0.13 mg/kg ondansetron, 0.25 mg/kg metoclopramide, 0.5 mg/kg metoclopramide, or 0.02 mg/kg droperidol. Three measurements of reflex dilation were taken at 5-min intervals and after the last measurement (time 0) the drug was administered. Measurements were then taken 5, 10, 20, and 40 min after I.V. drug administration. Reflex dilation was induced by intermittent noxious stimulation of the C5 dermatome with a tetanic electric current (60-70 mamp, 100 Hz, 3-s duration) after a stable level of epidural analgesia had been established with 3/8% bupivacaine and maintained with a continuous infusion. Metoclopramide produced a small decrease in pupil diameter and transiently depressed reflex dilation, whereas droperidol decreased pupil size at 10 min and depressed reflex dilation throughout the 40-min study period. Maximal change in reflex dilation was -6.6 +/- 3.3 mm-sec after droperidol. Ondansetron had no effect on pupil diameter or reflex dilation. When pupillary diameter measurements are used to gauge opioid levels during experimental conditions or during surgical anesthesia, antiemetic medication acting on the dopamine D2 receptor should be avoided. ⋯ Miosis is often considered an effect of opioid administration during general anesthesia, but other drugs, such as antiemetics, might produce a similar effect on the pupil. This study demonstrates that 2 antiemetics, droperidol and metoclopramide, constrict the pupil and block the pupillary dilation brought about by nociceptive stimuli.
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Anesthesia and analgesia · Dec 2003
Randomized Controlled Trial Clinical TrialThoracic epidural anesthesia increases tissue oxygenation during major abdominal surgery.
Intraoperative surgical stress may markedly increase adrenergic nerve activity and plasma catecholamine concentrations, which causes peripheral vasoconstriction and decreased tissue oxygen partial pressure possibly leading to tissue hypoxia. Tissue hypoxia is associated with an increased incidence of surgical wound infections. Thoracic epidural anesthesia blocks afferent neural stimuli and inhibits efferent sympathetic outflow in response to painful stimuli. Consequently, we tested the hypothesis that supplemental thoracic epidural anesthesia during major abdominal surgery improves tissue perfusion and subcutaneous oxygen tension. Thirty patients were randomly assigned to two groups: general (n = 15) or combined general and epidural anesthesia (n = 15). Anesthesia technique and fluid management were standardized. Subcutaneous tissue oxygen tension was measured continuously in the upper arm with a Clark type electrode. Data were compared with unpaired, two-tailed t-tests, Wilcoxon's ranked sum test, or repeated-measures analysis of variance and Scheffé F tests as appropriate; P < 0.05 was considered statistically significant. After 60 min, intraoperative tissue oxygen tension was significantly larger during combined anesthesia than during general anesthesia (54.3 +/- 7.4 mm Hg versus 42.1 +/- 8.6 mm Hg; P = 0.0002). Subcutaneous tissue oxygen tension remained significantly higher in the combined general/epidural anesthesia group throughout the observation period. Hemodynamic responses and global oxygen variables were similar in the groups. Thoracic epidural anesthesia improved intraoperative tissue oxygen tension outside the area of the epidural block. Thus, our results give evidence that supplemental neural nociceptive block blunts generalized vasoconstriction caused by surgical stress and adrenergic responses. ⋯ Thoracic epidural anesthesia blunts the decrease of subcutaneous tissue oxygen tension caused by surgical stress and adrenergic vasoconstriction during major abdominal surgery. Consequently, combined general and epidural anesthesia helps to provide sufficient tissue oxygenation.