Anesthesia and analgesia
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Anesthesia and analgesia · Apr 1991
Comparative Study Clinical Trial Controlled Clinical TrialSensory and motor blockade during epidural analgesia with 1%, 0.75%, and 0.5% ropivacaine--a double-blind study.
Levels of sensory (pinprick) and somatic motor blockade were measured in a double-blind study of 30 volunteers given single epidural injections of 1%, 0.75%, and 0.5% ropivacaine. Onset of analgesia was rapid with all concentrations (7-10 min). Maximal levels of analgesia were established 60 min after injection, with no significant differences in the maximal median cephalad spread. ⋯ Motor blockade described by the Bromage scale showed only the first part of the regression phase. Full recovery of muscle strength (Bromage scale = 0) was attained 1.5-2.5 h earlier than assessed by the quantitative method. No adverse effects were registered.
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Anesthesia and analgesia · Apr 1991
Randomized Controlled Trial Comparative Study Clinical TrialWhich drug prevents tachycardia and hypertension associated with tracheal intubation: lidocaine, fentanyl, or esmolol?
Eighty patients, ASA physical status II-IV, scheduled for noncardiac surgery, were randomly assigned in a double-blind, placebo-controlled manner to receive a preintubation dose of either placebo, 200 mg lidocaine, 200 micrograms fentanyl, or 150 mg esmolol. Induction of anesthesia was accomplished with 4-6 mg/kg thiopental IV followed immediately by the study drug; 1-1.5 mg/kg succinylcholine was given at minute 1. Laryngoscopy and intubation were performed at minute 2 with anesthesia thereafter maintained with 1 MAC (+/- 10%) isoflurane in 60% nitrous oxide in oxygen at a 5 L/min flow for 10 min. ⋯ Maximum percent increases in heart rate (mean +/- SE) during and after intubation were similar in the placebo (44% +/- 6%), lidocaine (51% +/- 10%), and fentanyl (37% +/- 5%) groups, but lower in the esmolol (18% +/- 5%) group (P less than 0.05). Maximum systolic blood pressure percent increases were lower in the lidocaine (20% +/- 6%), fentanyl (12% +/- 3%), and esmolol (19% +/- 4%) groups than in the placebo (36% +/- 5%) group (P less than 0.05), but not different from each other (P greater than 0.05). Only esmolol provided consistent and reliable protection against increases in both heart rate and systolic blood pressure accompanying laryngoscopy and intubation.
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Anesthesia and analgesia · Apr 1991
Potentiation of atracurium neuromuscular blockade by enflurane: time-course of effect.
This study was designed to determine the time required for potentiation of atracurium neuromuscular blockade after the introduction of enflurane. Ten ASA physical status I and II adults anesthetized with thiopental, nitrous oxide, and alfentanil were given 0.4 mg/kg atracurium besylate. The force of contraction of the adductor pollicis muscle in response to train-of-four stimulation of the ulnar nerve was recorded. ⋯ During the first 30 min, no significant decrease in plasma levels occurred; but at 45 min, concentrations were only 67% +/- 8% of their initial value (P less than 0.01) and 48% +/- 2% at 120 min (P less than 0.01). This suggests that the interaction between enflurane and atracurium is time-dependent. Clinically, the interaction between atracurium and enflurane is negligible during procedures of less than 45 min.
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Anesthesia and analgesia · Apr 1991
One hundred percent incidence of hemidiaphragmatic paresis associated with interscalene brachial plexus anesthesia as diagnosed by ultrasonography.
Interscalene brachial plexus anesthesia for shoulder surgery routinely includes sensory anesthesia of the fourth and fifth cervical nerves. The authors reasoned that some degree of diaphragm paralysis should result from interscalene blocks that produce surgical C3-C5 sensory anesthesia. In this investigation, ultrasonography was used to study the incidence of ipsilateral hemidiaphragmatic paresis during routine interscalene block, as it is a practical, sensitive, and low-risk method for diagnosing hemidiaphragmatic function without radiation exposure. ⋯ Changes from normal to paradoxical motion of the ipsilateral hemidiaphragm were seen in all 13 patients during sniff and Mueller maneuvers within 5 min (in 11 of 13 patients at 2 min). Diaphragmatic motion returned to normal in 10 of 11 patients between 3 and 4 h after injection and in the remaining patient by the fifth hour after injection. Diaphragmatic paresis appears to be an inevitable consequence of interscalene brachial plexus block when providing anesthesia sufficient for shoulder surgery.
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Anesthesia and analgesia · Apr 1991
Comparative StudyBenefits of a glucose-containing priming solution for cardiopulmonary bypass.
Benefits from the use of glucose-containing intravenous and priming solutions during coronary artery bypass operation have not been documented, but an increased risk of postoperative neurologic deficit by hyperglycemia has been suggested. To determine benefits, 107 patients undergoing coronary artery bypass operation were managed identically except that one group (n = 54) received 5% dextrose in lactated Ringer's solution (D5LR) as the sole intravenous and priming solution during operation and a second group (n = 53) received the same solution without glucose (LR). During cardiopulmonary bypass, the D5LR group required significantly less additional crystalloid to maintain safe oxygenator levels and flow (1.8 +/- 3.3 vs 15.8 +/- 20.9 mL.kg-1.h-1) and produced more urine (3.5 +/- 3.2 vs 1.2 +/- 1.4 mL.kg-1.h-1). ⋯ Five days after operation, the D5LR group weighed less than preoperatively (-0.8 +/- 2.6 kg), whereas the LR group gained weight (+1.0 +/- 2.8 kg). We conclude that use of glucose-containing solutions during coronary artery bypass operation benefits patients by decreasing perioperative fluid requirements and postoperative fluid retention. Because embolism is the cause of most postoperative neurologic deficits, any increased risk by hyperglycemia is small.