Anesthesia and analgesia
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Anesthesia and analgesia · Feb 1997
Randomized Controlled Trial Clinical TrialThe effect of timing of ondansetron administration in outpatients undergoing otolaryngologic surgery.
A randomized, double-blind, placebo-controlled study was designed to compare the relative efficacy of prophylactic ondansetron, 4 mg intravenously (IV), when administered before induction of anesthesia or at the end of surgery to an outpatient population at high risk of developing postoperative nausea and vomiting (PONV). Patients undergoing otolaryngologic surgery were randomly assigned to one of three different treatment groups: Group 1 (placebo) received saline 5 mL prior to induction of anesthesia and again at the end of surgery; Group II received ondansetron 4 mg in 5 mL prior to induction of anesthesia and saline 5 mL at the end of surgery; and Group III received saline 5 mL prior to induction of anesthesia and ondansetron 4 mg at the end of surgery. All patients received the same general anesthetic technique. ⋯ After discharge from the ambulatory surgery unit, the incidence of nausea, vomiting, and the need for rescue antiemetic drugs were similar in all three treatment groups. In conclusion, ondansetron (4 mg IV) was more effective in reducing the need for rescue antiemetics in the recovery room when administered at the end versus prior to the start of otolaryngologic surgery. Therefore, when ondansetron is used for antiemetic prophylaxis in outpatients undergoing otolaryngologic procedures, it should be administered at the end of the operation rather than prior to induction of anesthesia.
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Anesthesia and analgesia · Feb 1997
Randomized Controlled Trial Comparative Study Clinical TrialHands-up positioning during asymmetric sternal retraction for internal mammary artery harvest: a possible method to reduce brachial plexus injury.
This study compares the hands-up (HU) with the arms at side (AAS) position to determine whether one is beneficial in reducing brachial plexus stress during asymmetric sternal retraction. Eighty patients undergoing cardiac surgery were assigned to either Group 1 (AAS) or Group 2 (HU). Perioperative neurologic evaluations of the brachial plexus were performed and somatosensory evoked potentials (SSEPs) were collected during internal mammary artery harvest using asymmetric sternal retraction. ⋯ During asymmetric sternal retraction, HU positioning offered minimal benefit in reducing brachial plexus stress as measured by SSEP. Three of the seven AAS patients who reported brachial plexus symptoms had an ulnar nerve distribution of injury. However, none of the four patients with plexus symptoms in the HU group had ulnar nerve problems, suggesting that the higher incidence of postoperative symptoms observed with AAS positioning may occur from ulnar nerve compression.
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Anesthesia and analgesia · Feb 1997
Randomized Controlled Trial Clinical TrialThe direction of the Whitacre needle aperture affects the extent and duration of isobaric spinal anesthesia.
The use of Whitacre spinal needles results in directional flow out of the needle aperture, diverting local anesthetic from the longitudinal axis of the needle. Thus, a change in orientation of the needle aperture would be expected to result in a different local anesthetic distribution in the subarachnoid space. We studied 40 outpatients undergoing elective knee arthroscopy under spinal anesthesia with 60 mg plain lidocaine 2% in a prospective, double-blinded manner. ⋯ Group I had significantly shorter duration of lumbar sensory anesthesia (149.2 +/- 30.6 min vs 177.8 +/- 23.5 min, P < 0.01) and motor blockade (117.6 +/- 26.1 min vs 150.0 +/- 22.8 min, P < 0.001). Mean time to outpatient discharge was approximately 32 min shorter in Group I. The orientation of the Whitacre needle aperture exerts a major influence on sensory level, as well as the duration of isobaric lidocaine spinal anesthesia.
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Anesthesia and analgesia · Feb 1997
Immediate tracheal extubation after liver transplantation: experience of two transplant centers.
Early tracheal extubation has been safely performed after large operative procedures, questioning the need for routine postoperative ventilation. Because immediate postoperative tracheal extubation of liver transplantation patients has not been previously reported, we performed preliminary studies at two institutions to evaluate potential risk and cost benefit. At the University of Colorado (UC), extubation criteria were derived from the retrospective analysis of patients who were ventilated less than 8 h and experienced an intensive care unit stay less than 48 h in 1994. ⋯ Wider limits on age and severity of illness did not preclude successful extubation. Cost analysis at UC showed a significant reduction in intensive care unit services and associated cost for extubated patients. We conclude that immediate postoperative tracheal extubation of selected liver transplantation patients is safe and cost effective.
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Anesthesia and analgesia · Feb 1997
A common epineural sheath for the nerves in the popliteal fossa and its possible implications for sciatic nerve block.
Sciatic nerve block in the popliteal fossa is associated with a highly variable success rate. Frequently, anesthesia is profound in the distribution of both the tibial (TN) and common peroneal nerves (CPN), although the response to nerve stimulation or paresthesia is obtained in the distribution of one division of the nerve. However, anesthesia in the distribution of only one division of the nerve is also a common occurrence under apparently identical clinical circumstances. ⋯ In a majority of the legs, the dye reached the division of the sciatic nerve in the popliteal fossa, bathing both the TN and CPN. Gross inspection and histologic examination of the sciatic nerve specimens revealed a common epineural sheath enveloping the TN and CPN. The presence of the common epineural sheath and its characteristics may have important clinical implications for sciatic nerve blockade in the popliteal fossa.