Anesthesia and analgesia
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Anesthesia and analgesia · Jul 2002
Randomized Controlled Trial Clinical TrialNew landmarks for the anterior approach to the sciatic nerve block: imaging and clinical study.
In this study, we assessed the reliability of the inguinal crease and femoral artery as anatomic landmarks for the anterior approach to the sciatic nerve and determined the optimal position of the leg during this approach. An imaging study was conducted before the clinical study. The sciatic nerve was located twice in 20 patients undergoing ankle or foot surgery, once with the leg in the neutral position and once with the leg in the externally rotated position. The patient was lying supine. A 22-gauge, 150-mm insulated b-beveled needle connected to a nerve stimulator was inserted 2.5 cm distal to the inguinal crease and 2.5 cm medial to the femoral artery and was directed posteriorly and laterally with a 10 degrees -15 degrees angle relative to the vertical plane. The sciatic nerve was located in all patients at a depth of 10.6 +/- 1.8 cm when the leg was in the neutral position and 10.4 +/- 1.5 cm when the leg was in the externally rotated position (not significant). In the neutral position and in the externally rotated position, the time needed to identify anatomic landmarks was 28 +/- 15 s and 26 +/- 14 s, respectively (not significant), and the time needed to locate the sciatic nerve was 79 +/- 53 s and 46 +/- 25 s (P < 0.006), respectively. We conclude that the inguinal crease and femoral artery are reliable and effective anatomic landmarks for the anterior approach to the sciatic nerve and that the optimal position of the leg is the externally rotated position. ⋯ This new anterior approach to the sciatic nerve using the inguinal crease and femoral artery as landmarks is an easy and reliable technique.
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Anesthesia and analgesia · Jul 2002
Meta AnalysisThe efficacy and safety of transdermal scopolamine for the prevention of postoperative nausea and vomiting: a quantitative systematic review.
The role of scopolamine administered via transdermal therapeutic systems in the prevention of postoperative vomiting, nausea, and nausea and vomiting is unclear. We performed a systematic search for full reports of randomized comparisons of transdermal scopolamine with inactive control. Dichotomous data were extracted. In the meta-analysis, relative risks and numbers-needed-to-treat/harm were calculated with 95% confidence intervals (CI). In 23 trials, 979 patients received transdermal scopolamine, and 984 patients received placebo. Sensitivity analyses were performed using restricted data for truncated control event rates (40%-80%) and for large trials. With these data, the relative risks for postoperative vomiting (five reports), nausea (five reports), nausea and vomiting (eight reports), and rescue treatment (three reports) were 0.69 (95% CI, 0.58-0.82), 0.69 (95% CI, 0.54-0.87), 0.76 (95% CI, 0.66-0.88), and 0.68 (95% CI, 0.54-0.85), respectively. This means that of 100 patients who receive transdermal scopolamine, approximately 17 will not experience postoperative vomiting who would have done so had they all received a placebo. However, 18 of 100 patients will have visual disturbances, eight will report dry mouth, two will report dizziness, one will be classified as being agitated, and 1-13 patients who are prescribed transdermal scopolamine will not use it correctly. The timing of application does not alter efficacy. ⋯ Of 100 patients who receive transdermal scopolamine, approximately 17 will not vomit in the postoperative period who would have done so had they all received a placebo. However, 18 of 100 patients will have visual disturbances, and eight will report dry mouth. Incorrect use further limits its efficacy.
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Anesthesia and analgesia · Jul 2002
Randomized Controlled Trial Comparative Study Clinical TrialSmall-dose dexamethasone reduces nausea and vomiting after laparoscopic cholecystectomy: a comparison of tropisetron with saline.
Dexamethasone is an effective antiemetic drug, but the efficacy of small-dose dexamethasone 5 mg on the prophylaxis of postoperative nausea and vomiting (PONV) in patients undergoing laparoscopic cholecystectomy has not been evaluated. We, therefore, evaluated the prophylactic effect of small-dose dexamethasone (5 mg) on PONV in patients undergoing laparoscopic cholecystectomy. Tropisetron and saline served as controls. One-hundred-twenty patients scheduled for laparoscopic cholecystectomy were enrolled in a randomized, double-blinded, placebo-controlled study. At the induction of anesthesia, the Dexamethasone group received IV dexamethasone 5 mg, the Tropisetron group received IV tropisetron 2 mg, and the Placebo group received IV saline. We found that both dexamethasone and tropisetron significantly decreased the following variables: the total incidence of PONV (P < 0.01), more than four vomiting episodes (P < 0.05), and the proportions of patients requiring rescue antiemetics (P < 0.05). The differences between the Dexamethasone and Tropisetron groups were not significant. We conclude that prophylactic IV dexamethasone 5 mg significantly reduces the incidence of PONV in patients undergoing laparoscopic cholecystectomy. At this dose, dexamethasone is as effective as tropisetron 2 mg and is more effective than placebo. ⋯ We evaluated the prophylactic effect of small-dose dexamethasone (5 mg) on postoperative nausea and vomiting (PONV) in patients undergoing laparoscopic cholecystectomy. Tropisetron (2 mg) and saline served as controls. We found that dexamethasone 5 mg (IV) significantly reduced the incidence of PONV in these patients, and, at this dose, dexamethasone was as effective as tropisetron and was more effective than placebo.
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Anesthesia and analgesia · Jul 2002
Review Comparative StudyThe analgesic effects of intraperitoneal and incisional bupivacaine with epinephrine after total abdominal hysterectomy.
The objective of our study was to see if incisional and intraperitoneal bupivacaine with epinephrine produces analgesia after total abdominal hysterectomy. Forty-six ASA physical status I and II patients received a standardized anesthetic, patient-controlled analgesia (PCA) morphine, and rectal paracetamol 1 g every 6 h. Patients were randomized to receive 50 mL of bupivacaine 0.25% with epinephrine 5 microg/mL or 50 mL of normal saline. Thirty milliliters and 20 mL of treatment solution were administered into the peritoneum and incision, respectively, before wound closure. Seventeen and 16 patients in the Placebo and Bupivacaine groups, respectively, completed the study. The reasons for withdrawal were PCA malfunction, PCA discontinued too early, nausea, chest infection, intraabdominal drain insertion, and protocol violation. There were no significant differences between the Bupivacaine and Placebo groups in age, height, weight, or duration of surgery. Pain on movement was significantly more intense in the Placebo group than in the Bupivacaine group on awakening. Morphine consumption (interquartile range) over 24 h was 62 mg (53-85 mg) in the Placebo group compared with 44 mg (33-56 mg) in the Bupivacaine group (P < 0.01). This significant difference was attributable to the larger morphine consumption in the Placebo group in the first 4 postoperative h. We conclude that a combination of intraperitoneal and incisional bupivacaine with epinephrine provides significant morphine-sparing analgesia for 4 h after total abdominal hysterectomy. ⋯ A combination of intraperitoneal and incisional bupivacaine with epinephrine may be recommended because it provides significant morphine-sparing analgesia for 4 h after total abdominal hysterectomy.
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Anesthesia and analgesia · Jul 2002
Randomized Controlled Trial Clinical TrialRapid deflation of the bronchial cuff of the double-lumen tube after decreasing the concentration of inspired nitrous oxide.
Deflationary phenomena of the endotracheal tube cuff may occur after inspired nitrous oxide (N(2)O) concentrations are reduced, but deflationary phenomena of the double-lumen tube (DLT) cuff have not been investigated. In this study, tracheal and bronchial cuffs of left-sided Mallinckrodt (Athlone, Ireland) DLTs were inflated with air, 40% N(2)O, or 67% N(2)O (Air, N40, or N67 groups, respectively) in 24 patients undergoing thoracic surgery; 40 min later, O(2) was substituted for N(2)O in some of the patients in the N40 group (N40-c group). Intracuff gas volumes, N(2)O concentrations, and cuff compliance were also measured. Both tracheal and bronchial cuff pressures significantly increased in the Air group but decreased in the N67 group. Neither pressure significantly changed in the N40 group, but both decreased in the N40-c group after terminating N(2)O anesthesia; the time required for bronchial cuff pressures to decrease by half (12.0 +/- 5.5 min) was less than that for tracheal cuff pressures (31.2 +/- 11.0 min, P < 0.01). The volume change in the N40-c group was not significantly different between the tracheal and bronchial cuffs, but tracheal cuff compliance was significantly higher than bronchial compliance. Therefore, filling DLT cuffs with 40% N(2)O stabilizes cuff pressure during anesthesia with 67% N(2)O, but bronchial cuffs deflate more quickly than tracheal cuffs after cessation of N(2)O administration through smaller compliance. ⋯ We demonstrated that after cessation of nitrous oxide (N(2)O) administration, bronchial N(2)O-filled cuffs of the double-lumen tube deflate more rapidly than tracheal cuffs. To avoid insufficient separation of the lungs by the bronchial cuff, a frequent check of the cuff pressure is recommended after the inspired N(2)O concentration is decreased.