Anesthesia and analgesia
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Anesthesia and analgesia · Aug 2001
Randomized Controlled Trial Clinical TrialThoracic epidural bupivacaine attenuates supraventricular tachyarrhythmias after pulmonary resection.
Supraventricular tachyarrhythmias after pulmonary surgery are well described. Some investigators suggest that tachyarrhythmias after thoracic operations may result from the relative sympathotonic status produced by injury to the cardiac parasympathetic nerves. We examined whether postoperative thoracic sympathetic blockade by thoracic epidural bupivacaine might reduce the tachyarrhythmias after pulmonary resection. Fifty patients with lung cancer were randomized to receive epidural bupivacaine (Group B) or epidural morphine (Group M). Patients in Group B were given 6 to 10 mL of 0.25% bupivacaine epidurally, followed by epidural infusion at 3 to 5 mL/h for 3 days, and patients in Group M were given 2 to 3 mg morphine epidurally, followed by morphine infusion at a rate of 0.2 mg/h. Tachyarrhythmias were diagnosed by using the continuous heart rate trend and arrhythmia trend with a central monitoring system. Postoperative analgesia was not statistically different between groups. However, the incidence of postoperative tachyarrhythmias in Group B was significantly less than in Group M (1 of 23 vs 7 of 25, P = 0.0497, Fisher's exact test). The continuous infusion of thoracic epidural bupivacaine can reduce supraventricular tachyarrhythmias compared with epidural morphine infusion, presumably because of attenuation of the sympathotonic status after pulmonary resection. ⋯ We examined whether postoperative thoracic sympathetic blockade by thoracic epidural bupivacaine after pulmonary resection might reduce the tachyarrhythmias that may result from the relative sympathotonic status produced by injury to the cardiac parasympathetic nerves. The continuous infusion of thoracic epidural bupivacaine was shown to reduce supraventricular tachyarrhythmias.
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Anesthesia and analgesia · Aug 2001
Randomized Controlled Trial Clinical TrialThe analgesic efficacy of patient-controlled bupivacaine wound instillation after total abdominal hysterectomy with bilateral salpingo-oophorectomy.
To assess the effect of local anesthetic wound instillation on visceral and somatic pain, we studied 36 patients undergoing total abdominal hysterectomy and bilateral salpingo-oophorectomy. A standard general anesthetic was administered. On completion of the operation, a multiorifice 20-gauge epidural catheter was placed above the superficial abdominal fascia such that the tip was at the midpoint of the surgical wound. After surgery, either bupivacaine 0.25% (Bupivacaine group) or sterile water (Control group) was administered via a patient-controlled analgesia device programmed to deliver 9.0 mL with a 60-min lockout interval. During the first 6 h after surgery, rescue IV morphine (2 mg) was administered every 10 min until a visual analog scale score of <30 mm was achieved. Thereafter, on patient request, rescue meperidine 1 mg/kg IM was administered. When compared with the Control group, significantly (P < 0.001) less rescue analgesia was administered to patients in the Bupivacaine group. Rescue morphine administered during the first 6 h after surgery was 6 +/- 4 mg versus 12 +/- 6 mg (P < 0.001) for the Bupivacaine and Control groups, respectively. Rescue meperidine administered was 29 +/- 37 mg versus 95 +/- 36 mg (P < 0.001) for the Bupivacaine and Control groups, respectively. Nausea and antiemetic drug administration was significantly (P = 0.003) less in the Bupivacaine group. Pain scores were similar between the groups. Patient satisfaction was significantly (P = 0.04) more in the Bupivacaine group. We conclude that bupivacaine wound instillation decreases opioid requirements and nausea in the first 24 h after total abdominal hysterectomy with bilateral salpingo-oophorectomy. ⋯ Bupivacaine instillation via an electronic patient-controlled analgesia device provides effective analgesia after total abdominal hysterectomy with bilateral salpingo-oophorectomy.
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Anesthesia and analgesia · Aug 2001
Randomized Controlled Trial Clinical TrialClonidine prevents sevoflurane-induced agitation in children.
In a double-blinded trial, 40 male children (age 2-7 yr) undergoing circumcision were randomly assigned to receive clonidine 2 microg/kg IV or placebo after anesthetic induction. For induction and maintenance of anesthesia, we used sevoflurane as the sole anesthetic. For pain treatment, a penile block was performed before surgery. After surgery the incidence and severity of agitation was measured during an observation period of 2 h. Severe agitation was treated with midazolam. In 16 placebo and 2 clonidine-treated patients agitation was observed (P < 0.001). In 6 patients of the Placebo group, agitation was graded as severe, whereas none of the patients in the Clonidine group developed severe agitation (P = 0.02). During the postoperative period heart rate and blood pressure were significantly decreased in clonidine treated patients (P < 0.05). We conclude that clonidine effectively prevents agitation after sevoflurane anesthesia. ⋯ The recovery from sevoflurane anesthesia may be complicated by the presence of agitation in pediatric patients. Clonidine 2 microg/kg IV after anesthetic induction effectively reduces the incidence of agitation without resulting in clinically relevant bradycardia and hypotension.
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Anesthesia and analgesia · Aug 2001
Randomized Controlled Trial Comparative Study Clinical TrialA comparison of minidose lidocaine-fentanyl spinal anesthesia and local anesthesia/propofol infusion for outpatient knee arthroscopy.
Traditional methods of spinal anesthesia have proven problematic in the outpatient setting. Minidose lidocaine-fentanyl spinal anesthesia (SAB(MLF)) may be the adaptation necessary to reestablish spinal anesthesia in this venue. One hundred patients scheduled for outpatient knee arthroscopy were randomized to receive either local anesthesia plus a titrated IV propofol infusion (LA/PI) or SAB(MLF) using 20 mg lidocaine 0.5% + 20 microg fentanyl. Patients received midazolam 0.02-0.03 mg/kg IV and fentanyl 0.75-1.0 microg/kg IV upon arrival in the operating room before lumbar puncture or propofol infusion. The propofol infusion was begun at 50-75 microg. kg(-)(1). min(-)(1) and titrated to maintain patient comfort. Boluses (200-400 microg/kg) were given as needed. Local anesthesia included 30 mL lidocaine 1% with epinephrine 1:200,000 intraarticularly plus 10 mL at the portal sites. Three patients (6%) in the LA/PI group versus none in the SAB(MLF) group required general anesthesia. Airway support was required in 54% of the LA/PI patients and in none of the SAB(MLF) patients. Total operating room time (43 vs 45 min), time to home readiness (43 vs 45 min), actual discharge times (73.5 min in both groups), and the incidence of discharge >90 min (22% vs 24%) were the same for both LA/PI and SAB(MLF) groups. LA/PI and SAB(MLF) groups differed in terms of postoperative pruritus (8% vs 68%), pain (44% vs 20%), nausea (8% vs 22%), and ability to void before discharge (56% vs 32%). One patient in each group had mild difficulty initiating voiding at home, but neither required medical attention. In both groups, 90% of patients were either "satisfied" or "very satisfied" with their anesthetic. The two techniques provided comparable patient satisfaction and efficiencies both intraoperatively and in postoperative recovery and discharge. The efficiencies of these techniques were not dependent on special provisions of the physical plant or the practice model. ⋯ Both local anesthesia supplemented by a titrated IV propofol infusion and minidose lidocaine-fentanyl spinal anesthesia for outpatient knee arthroscopy provide high patient satisfaction with equally rapid recovery and discharge.
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Anesthesia and analgesia · Aug 2001
Randomized Controlled Trial Clinical TrialMore epidural than intravenous sufentanil is required to provide comparable postoperative pain relief.
The extent to which epidurally administered sufentanil acts directly on spinal opioid receptors remains controversial. We tested the hypothesis that small-dose boluses of sufentanil, given epidurally or IV, provide comparable analgesia at similar plasma sufentanil concentrations. The lipophilicity of sufentanil makes it likely to be absorbed into fat surrounding the epidural space. We therefore also tested the hypothesis that more epidural than IV sufentanil is required to produce comparable analgesia. Analgesia and plasma sufentanil concentrations were evaluated in 20 postoperative patients randomly assigned to patient-controlled epidural or IV sufentanil. Pain was evaluated with visual analog scales by blinded observers. Sufentanil doses and plasma concentrations were measured. Analgesia was similar with epidural and IV sufentanil administration. Plasma sufentanil concentrations were virtually identical in the two groups. However, significantly larger sufentanil doses were required with epidural administration: 238 +/- 50 microg vs 160 +/- 32 microg (P < 0.01). The primary mechanism by which small-dose boluses of epidurally-administered sufentanil produce analgesia seems to be systemic absorption of the drug with subsequent recirculation to the supraspinal opioid receptors. This study demonstrates that the cumulative dose of sufentanil, when administered as a small epidural bolus, is approximately 50% more than that administered IV to provide comparable analgesia. This indicates that the bioavailability of epidurally-administered sufentanil is reduced and suggests that a large proportion of the drug may be absorbed into the epidural fat. ⋯ More epidural than IV sufentanil was required to provide comparable postoperative pain relief and similar plasma sufentanil concentrations. These data suggest that when sufentanil is administered in small-dose boluses, much of the drug is absorbed into the epidural fat and that the primary mechanism by which epidurally administered sufentanil produces analgesia is via systemic absorption.