Anesthesia and analgesia
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Anesthesia and analgesia · Jul 2002
Clinical TrialElectro-acupuncture at the Zusanli, Yanglingquan, and Kunlun points does not reduce anesthetic requirement.
We tested the hypothesis that electro-acupuncture at the Zusanli, Yanglingquan, and Kunlun acupuncture points on the legs decreases anesthetic requirement. Fourteen young, healthy volunteers were anesthetized with desflurane on two separate days. Needle electrodes were positioned at the three acupuncture points thought to produce a generalized sedative and analgesic effect. Needles were percutaneously placed on treatment days; on control days, they were insulated and taped near the insertion points. The electrodes were stimulated on the treatment day. Stimulation consisted of 2-Hz and 100-Hz currents alternated at 2-s intervals. When the end-tidal desflurane concentration of 5.5% was stable for 15 min, noxious electrical stimuli were administered via 25-gauge needles on both thighs (70 mA at 100 Hz for 10 s). Desflurane concentration was increased 0.5% when movement occurred and decreased 0.5% when it did not. An investigator, blinded to treatment, determined movement. These up-and-down sequences were continued until volunteers crossed from movement to no movement four times. A logistic regression determined the partial pressure of desflurane that produced a 50% likelihood of movement in response to noxious stimulation and consequently identified the minimum alveolar anesthetic concentration equivalent for desflurane. There was no significant difference in minimum alveolar anesthetic concentration equivalents between the electro-acupuncture (4.6% +/- 0.6%, mean +/- SD) and control (4.6% +/- 0.8%) days (P = 0.8). These data provided an 80% power for detecting a difference of 0.35 volume-percent between the groups. ⋯ Electro-stimulation of three general acupuncture points on the leg did not reduce desflurane requirements. This type of acupuncture is thus unlikely to facilitate general anesthesia or decrease the need for anesthetic drugs.
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Anesthesia and analgesia · Jul 2002
Randomized Controlled Trial Comparative Study Clinical TrialIntrathecal versus intravenous fentanyl for supplementation of subarachnoid block during cesarean delivery.
Forty-eight healthy parturients scheduled for elective cesarean delivery were randomly allocated to receive intrathecally either 12 mg of hyperbaric bupivacaine plus 12.5 microg of fentanyl (n = 23) or bupivacaine alone (n = 25). In the latter group, IV 12.5 microg of fentanyl was administered immediately after spinal anesthesia. We compared the amount of IV fentanyl required for supplementation of the spinal anesthesia during surgery, the intraoperative visual analog scale, the time to the first request for postoperative analgesia, and the incidence of adverse effects. Additional IV fentanyl supplementation amounting to a mean of 32 +/- 35 microg was required in the IV Fentanyl group, whereas no supple- mentation was required in the Intrathecal Fentanyl group (P = 0.009). The time to the first request for postoperative analgesia was significantly longer in the Intrathecal Fentanyl group than in the IV Fentanyl group (159 +/- 39 min versus 119 +/- 44 min; P = 0.003). The incidence of systolic blood pressure <90 mm Hg and the ephedrine requirements were significantly higher in the IV Fentanyl group as compared with the Intrathecal Fentanyl group (P = 0.01). Also, intraoperative nausea and vomiting occurred less frequently in the Intrathecal Fentanyl group compared with the IV Fentanyl group (8 of 23 vs 17 of 25; P = 0.02). ⋯ Supplementation of spinal bupivacaine anesthesia for cesarean delivery with intrathecal fentanyl provides a better quality of anesthesia and is associated with a decreased incidence of side effects as compared with supplementation with the same dose of IV fentanyl.
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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
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.