Anesthesia and analgesia
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Anesthesia and analgesia · Mar 1991
Comparative StudyRole of experience in the response to simulated critical incidents.
Eight experienced anesthesiologists (faculty or private practitioners) were presented with the same simulated critical incidents that had previously been presented to 19 anesthesia trainees. The detection and correction times for these incidents were measured, as was compliance with Advanced Cardiac Life Support (ACLS) guidelines during cardiac arrest, and the occurrence of unplanned incidents. Experienced personnel tended to react more rapidly than did trainees, but differences between second-year anesthesia residents (CA2) and experienced anesthesiologists were not statistically significant. ⋯ The response to incidents during anesthesia is a complex process that involves multiple levels of cognitive activity and is vulnerable to error regardless of experience. Most trainees seemed to acquire adequate response routines by the end of the CA2 year. Formal reasoning appeared to play a minor role in responding to intraoperative events, but the exact nature of the anesthesiologist's cognition remains to be thoroughly investigated.
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Anesthesia and analgesia · Mar 1991
Continuous postoperative regional analgesia by nerve sheath block for amputation surgery--a pilot study.
A pilot study of continuous postoperative regional analgesia by nerve sheath block for lower limb amputation is presented. At the time of exposure of sciatic or posterior tibial nerve trunks during above- or below-knee amputations in 11 patients with ASA physical status III or IV, a catheter was introduced directly into the transected nerve sheath for continuous infusion of 0.25% bupivacaine at a rate of 10 mL/h for 72 h. ⋯ No complications related to the technique were observed. A follow-up of the group receiving continuous postoperative regional analgesia for up to 12 mo showed a total absence of phantom pain despite the presence of preoperative limb pain.
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Anesthesia and analgesia · Mar 1991
Effect of fentanyl and nitrous oxide on the desflurane anesthetic requirement.
The minimum alveolar anesthetic concentration (MAC) of desflurane (I-653) was determined when administered with 60% nitrous oxide (N2O) in oxygen after a standardized induction sequence consisting of 0, 3, 6, or 9 micrograms/kg intravenous (IV) fentanyl followed by 3-6 mg/kg IV thiopental and 1.5 mg/kg IV succinylcholine. For comparison, we also determined the isoflurane MAC with 60% N2O in oxygen after an induction dose of 3 micrograms/kg IV fentanyl and similar doses of thiopental and succinylcholine. All patients were undergoing elective surgical procedures. ⋯ The minimum alveolar anesthetic concentration of desflurane with 60% N2O plus 0, 3, 6, and 9 micrograms/kg IV fentanyl was 3.7%, 3.0%, 1.2%, and 0.1%, respectively. Thus, the MAC-lowering effect of 3 micrograms/kg IV fentanyl appears to be similar with both isoflurane and desflurane. Fentanyl, 3-9 micrograms/kg IV, produces dose-dependent decreases in the MAC of desflurane.
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Anesthesia and analgesia · Mar 1991
Should you cancel the operation when a child has an upper respiratory tract infection?
Cancelling an operation when a child has an upper respiratory tract infection (URI) is not always feasible or practical. Yet we know very little about the additional risk posed by a URI occurring in a child undergoing anesthesia and surgery. Using a large prospectively collected pediatric anesthesia database, we studied 1283 children with a preoperative URI and 20,876 children without a URI. ⋯ The elevation in risk after URI as compared with children without a URI was not explained by differences in age, physical status scores, surgical site, and emergency or elective status. However, if a child had a URI and had endotracheal anesthesia, the risk of a respiratory complication increased 11-fold (95% confidence intervals 6.8, 18.1). We conclude that the administration of general anesthesia to children with a URI is not benign and that these children require more observation/management in all perioperative phases of their surgical procedure.
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Anesthesia and analgesia · Mar 1991
Randomized Controlled Trial Clinical TrialPatient-controlled sedation during epidural anesthesia.
The purpose of this study was to evaluate the feasibility and advantages or disadvantages, if any, of patient-controlled sedation compared with sedation administered by the anesthesiologist during surgical epidural anesthesia. Forty patients were divided at random into two groups with 20 patients in each group. Patients in group 1 received 0.5-1.0 mg intravenous midazolam and 25-50 micrograms intravenous fentanyl in increments administered by the anesthesiologist to achieve intraoperative sedation; patients in group 2 self-administered a mixture of midazolam (0.5 mg) and fentanyl (25 micrograms) in increments using an Abbott Lifecare PCA infuser to achieve sedation. ⋯ This could have been due to a positive psychological effect produced by allowing patient to feel that they have some control over their situation. The findings of this study indicate that patient-controlled sedation using a combination of midazolam and fentanyl is a safe and effective technique that provides intraoperative sedation ranked better by patients than that provided by anesthesiologists using the same drugs. More studies are, however, needed to determine the best choice of drug(s), the doses, the lock-out intervals, and the possible use of continuous infusion with patient-controlled sedation.