Anesthesia and analgesia
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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.
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Anesthesia and analgesia · Mar 1991
Randomized Controlled Trial Clinical TrialEffects of succinylcholine on the pharmacodynamics of pipecuronium and pancuronium.
To study the effects of succinylcholine on subsequent pharmacodynamics of nondepolarizing muscle relaxants, a comparative pharmacodynamic study was carried out in patients having balanced anesthesia (thiopental, fentanyl, nitrous oxide/oxygen) in whom equipotent doses of pipecuronium (80 micrograms/kg) and pancuronium (100 micrograms/kg) were given with or without prior administration of succinylcholine (1 mg/kg). Fifty-two patients were randomly assigned to one of the following four groups: 1, pancuronium (100 micrograms/kg); 2, pipecuronium (80 micrograms/kg); 3, succinylcholine (1 mg/kg) plus pancuronium (100 micrograms/kg); and 4, succinylcholine (1 mg/kg) plus pipecuronium (80 micrograms/kg). In groups 3 and 4, the nondepolarizing relaxant was given after succinylcholine when the twitch height recovered to 75% of its control value. ⋯ Mean onset times for pancuronium (group 1) and pipecuronium (group 2) given without succinylcholine were (mean +/- SEM) 2.5 +/- 0.3 and 2.8 +/- 0.2 min, respectively. Mean onset times (times to maximum twitch depression) of the two drugs given after succinylcholine (groups 3 and 4) were significantly shorter (1.4 +/- 0.4 and 1.6 +/- 0.1 min, respectively). Clinical durations (i.e., until 25% twitch recovery of pancuronium and pipecuronium) were not significantly different among the four groups, varying from 81.1 +/- 5.4 (group 4) to 107.0 +/- 17.0 (group 2) min.(ABSTRACT TRUNCATED AT 250 WORDS)
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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
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
Comparative StudyComparison of kinetics of sevoflurane and isoflurane in humans.
The low solubility of sevoflurane in blood suggests that this agent should enter and leave the body more rapidly than isoflurane. However, the closeness of sevoflurane and isoflurane tissue/blood partition coefficients suggests that the rates of equilibration with and elimination from tissues should be similar. We tested both predictions, comparing sevoflurane with isoflurane and nitrous oxide in seven volunteers. ⋯ FA/FA0 (FA0 = the last FA during administration) values after 5 min of elimination were as follows: sevoflurane, 0.157 +/- 0.020; isoflurane, 0.223 +/- 0.024. Recovery (volume of anesthetic recovered during elimination/volume taken up) of sevoflurane (101% +/- 7%) equaled recovery of isoflurane (101% +/- 6%). Time constants for a five-compartment mammillary model for sevoflurane were smaller than those for isoflurane for the lungs but were not different from isoflurane for the other compartments.(ABSTRACT TRUNCATED AT 250 WORDS)