Anesthesia and analgesia
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Anesthesia and analgesia · Dec 1999
Randomized Controlled Trial Comparative Study Clinical TrialA comparison of two techniques for cervical plexus blockade: evaluation of efficacy and systemic toxicity.
We compared two techniques of cervical plexus blockade (CPB) for carotid endarterectomy. Cervical plexus nerve block was performed with a combination of bupivacaine and lidocaine, with injections at the C2-C3, C3-C4, and C4-C5 transverse processes in 11 patients (classical CPB) or with a single injection after localization of the cervical plexus with a nerve stimulator in 12 patients (interscalene CPB). Pain scores were obtained during block placement and at predetermined phases of the operation. Arterial blood was sampled before and 3, 5, 8, 10, 15, 25, 40, and 60 min after CPB for measurement of bupivacaine and lidocaine concentrations. Interscalene CPB was less painful than classical CPB. The techniques appeared equally effective. Patients in both groups required equivalent supplementation with IV fentanyl and additional local infiltration with lidocaine during the most painful stages of surgery. The maximal concentration of bupivacaine was lower in interscalene CPB compared with classical CPB (1.0 microg/mL versus 1.5 microg/mL, P < 0.01). The time required to reach the maximal concentration of bupivacaine was 15 (10-40) min in interscalene CPB and 10 (5-17) min in classical CPB (P < 0.05). Lidocaine maximal concentration was similar in both groups, however the time required to reach the maximal concentration was longer (P < 0.05) in interscalene CPB (15 [10-60] min) than in classical CPB (10 [8-20] min). We conclude that the interscalene CPB is as effective as the classical CPB as a regional technique for carotid endarterectomy and may be associated with a lower systemic absorption of bupivacaine. ⋯ Cervical plexus blockade for carotid endarterectomy can be effectively performed with a single injection after localization of the cervical plexus with a nerve stimulator. This technique is simple and was associated with less systemic absorption of local anesthetic than the multiple-injection technique.
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Anesthesia and analgesia · Dec 1999
Randomized Controlled Trial Clinical TrialThe ulinastatin-induced effect on neuromuscular block caused by vecuronium.
We examined the effect of ulinastatin, a protease inhibitor purified from human urine, on neuromuscular block caused by vecuronium. Sixty adult patients were randomly divided into four groups of 15 patients each: ulinastatin-posttetanic count (U-PTC), ulinastatin-train-of-four (U-TOF), control-posttetanic count (C-PTC) or control-train-of-four (C-TOF) group. In the U-PTC and U-TOF groups, a bolus dose of ulinastatin 5000 U/kg was administered 2 min before the injection of vecuronium 0.1 mg/kg. In the C-PTC and C-TOF groups, normal saline was administered instead of ulinastatin. The onset of neuromuscular block in the U-PTC and U-TOF groups was significantly slower than in the C-PTC and C-TOF groups (250+/-49 vs 214+/-35 s, mean +/- SD, P < 0.05). The time from the vecuronium injection to the return of PTC in the U-PTC group was significantly shorter than in the C-PTC group (11.0+/-2.8 vs 17.6+/-6.8 min, P < 0.05). Similarly, times to the returns of T1, T2, T3, and T4 (first, second, third, and fourth stimulation of TOF) in the U-TOF group were significantly shorter than in the C-TOF group (18.5+/-5.0 vs 28.0+/-9.1 min for T1, P < 0.05). PTC in the U-PTC group was significantly higher than in the C-PTC Group 10-30 min after the administration of vecuronium (P < 0.05). T1/control twitch height and TOF ratios in the U-TOF group were significantly higher than those in the C-TOF Group 30-70 min and 40-70 min after the administration of vecuronium, respectively (P < 0.05). Ulinastatin delays the onset of neuromuscular block and hastens its recovery caused by vecuronium. ⋯ Ulinastatin delays the onset of neuromuscular block and hastens its recovery caused by vecuronium. This is because ulinastatin may release acetylcholine at the neuromuscular junction and increase hepatic and/or renal clearance of vecuronium.
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Anesthesia and analgesia · Dec 1999
Comparative StudyAnatomical landmarks for femoral nerve block: a comparison of four needle insertion sites.
The site for needle insertion in femoral nerve block varies significantly among various descriptions of the technique. To determine the site with the highest likelihood of needle-femoral nerve contact, femoral nerve block was simulated in a human cadaver model (17 femoral triangles from 9 adult cadavers). Four 20-gauge 50-mm-long styletted catheters were inserted at four frequently suggested insertion sites for femoral nerve block. At the levels of inguinal ligament and the inguinal crease, the catheters were inserted adjacent to the lateral border of the femoral artery and 2 cm lateral to the femoral artery. During anatomical dissection, we studied the number of catheter-nerve contacts for each of the four insertion sites, and relationships between the femoral nerve and other anatomical structures of relevance to femoral nerve block. Insertion of the needle at the level of the inguinal crease, next to the lateral border of the femoral artery resulted in the highest frequency of needle-femoral nerve contacts (71%). Of note, the femoral nerve was significantly wider (14.0 vs 9.8 mm) and closer to the fascia lata (6.8 vs 26.4 mm) at the inguinal crease than at the inguinal ligament level. We conclude that needle insertion at the inguinal crease level immediately adjacent to the femoral artery produced the highest rate of needle-femoral nerve contacts. The main factors influencing this result include the greater width of the femoral nerve and the more predictable femoral artery-femoral nerve relationship at the inguinal crease level, compared with the inguinal ligament level. ⋯ Insertion of a needle at the inguinal crease level and immediately adjacent to the lateral border of the femoral artery results in a high rate of needle-femoral nerve contact.
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Anesthesia and analgesia · Dec 1999
The effect of remifentanil on biliary tract drainage into the duodenum.
Opioids cause spasm of the sphincter of Oddi. Remifentanil is metabolized enzymatically throughout the body. Its context-sensitive half-time is 3-4 min. The effect of remifentanil on the sphincter of Oddi, is unknown. We studied, in six healthy adult volunteers, the effect of remifentanil on the flow of dye from the gall bladder into the duodenum. Control hepatobiliary imaging with 5 mCi of technetium-labeled derivatives of iminodiacetic acid was performed on each volunteer. The time from IV dye (radiopharmaceutical) injection until its appearance in the duodenum was determined by continuous scanning. Two weeks later, each volunteer received remifentanil, 0.1 microg x kg(-1) x min(-1) infused for 30 min IV before the same dose of technetium-labeled derivatives of iminodiacetic acid was injected, and for the time of their control scan plus 10 min after the injection. When the dye appeared in the duodenum, the total time from injection was compared with the control value. The time from stopping the infusion until the dye appeared in the duodenum was the "recovery time." Control scan time was 20.5+/-9.9 min (mean +/- SD; range 10-33 min). Total scan time during and after the remifentanil infusion was 50.3+/-17.3 min (range 30-81 min) (P < 0002). The recovery time was 19.8+/-12.4 min (range 5-40 min). We conclude that remifentanil delays the drainage of dye from the gall bladder into the duodenum, but the delay is shorter than that reported after other studied opioids. ⋯ Radioactive dye was injected IV into healthy volunteers to determine the time it took for the dye to appear in the duodenum. This was repeated under the influence of a short-acting narcotic analgesic, remifentanil. Remifentanil caused a much shorter delay than previously reported after morphine or meperidine.
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Anesthesia and analgesia · Dec 1999
Randomized Controlled Trial Clinical TrialThe hemodynamic and Holter-electrocardiogram changes during halothane and sevoflurane anesthesia for adenoidectomy in children aged one to three years.