ISSN:0003-3022    

出版商:OVID    

年代:2003

数据来源: OVID

ISSN:0003-3022    

出版商:OVID    

年代:2003

数据来源: OVID

ISSN:0003-3022    

出版商:OVID    

年代:2003

数据来源: OVID

ISSN:0003-3022    

出版商:OVID    

年代:2003

数据来源: OVID

ISSN:0003-3022    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

BackgroundThe authors reappraised the conventional wisdom that the intubating dose of succinylcholine must be 1.0 mg/kg and attempted to define the lower range of succinylcholine doses that provide acceptable intubation conditions in 95% of patients within 60 s.MethodsThis prospective, randomized, double-blind study involved 200 patients. Anesthesia was induced with 2 &mgr;g/kg fentanyl and 2 mg/kg propofol. After loss of consciousness, patients were randomly allocated to receive 0.3, 0.5, or 1.0 mg/kg succinylcholine or saline (control group). Tracheal intubation was performed 60 s later. A blinded investigator performed all laryngoscopies and also graded intubating conditions.ResultsIntubating conditions were acceptable (excellent plus good grade combined) in 30%, 92%, 94%, and 98% of patients after 0.0, 0.3, 0.5, and 1.0 mg/kg succinylcholine, respectively. The incidence of acceptable intubating conditions was significantly greater (P< 0.05) in patients receiving succinylcholine compared with those in the control group but was not different among the different succinylcholine dose groups. The calculated doses of succinylcholine (and their 95% confidence intervals) that were required to achieve acceptable intubating conditions in 90% and 95% of patients at 60 s were 0.24 (0.19–0.31) mg/kg and 0.56 (0.43–0.73) mg/kg, respectively.ConclusionsThe use of 1.0 mg/kg of succinylcholine may be excessive if the goal is to achieve acceptable intubating conditions within 60 s. Comparable intubating conditions were achieved after 0.3, 0.5, or 1.0 mg/kg succinylcholine. In a rapid-sequence induction, 95% of patients with normal airway anatomy anesthetized with 2 &mgr;g/kg fentanyl and 2 mg/kg propofol should have acceptable intubating conditions at 60 s after 0.56 mg/kg succinylcholine. Reducing the dose of succinylcholine should allow a more rapid return of spontaneous respiration and airway reflexes.

ISSN:0003-3022    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

BackgroundThe usually cited “intubation dose” of succinylcholine is 1.0 mg/kg. In the majority of patients, this dose will produce apnea of sufficient duration that significant hemoglobin desaturation may occur before neuromuscular recovery takes place in those whose ventilation is not assisted. This study was undertaken to examine the extent to which reducing this dose would decrease the duration of action of succinylcholine.MethodsDuring stable desflurane/oxygen/opioid anesthesia and after adequate twitch stabilization, neuromuscular function was recorded with an acceleromyographic monitor. Supramaximal stimuli were delivered at 0.10 Hz. Patients received 0.40, 0.60, or 1.0 mg/kg succinylcholine, and twitch height was monitored for at least 20 min thereafter.ResultsThe onset times to maximal effect were 105 ± 23 s, 81 ± 19 s, and 71 ± 22 s, respectively. The lowest dose (0.40 mg/kg) did not reliably produce 100% twitch depression. The times to 90% twitch recovery at the adductor pollicis in the three groups were 6.6 ± 1.5 min, 7.6 ± 1.6 min, and 9.3 ± 1.2 min, respectively.ConclusionsReducing the dose of succinylcholine from 1.0 mg/kg to 0.60 mg/kg shortens the duration of effect at the adductor pollicis by more than 90 s. The authors believe that even this modest decrease in the duration of drug-induced paralysis is often worth pursuing.

ISSN:0003-3022    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

BackgroundInhalational induction with sevoflurane and nitrous oxide is frequently used forLaryngeal Mask Airway™ (LMA™; Laryngeal Mask Company, Henley-on-Thames, United Kingdom) insertion in children. The authors determined the influence of nitrous oxide on the minimum alveolar concentration (MAC) of sevoflurane forLMA™ insertion.MethodsOne hundred twenty unpremedicated children (age, 1–9 yr; American Society of Anesthesiologists physical status I) were randomly assigned to receive 1 of 15 end-tidal concentrations of nitrous oxide and sevoflurane for inhalational inductionviaa facemask: 0% nitrous oxide with 1.2, 1.4, 1.6, 1.8, or 2.0% sevoflurane; 33% nitrous oxide with 0.8, 1.0, 1.2, 1.4, or 1.6% sevoflurane; or 67% nitrous oxide with 0.4, 0.6, 0.8, 1.0, or 1.2% sevoflurane. TheLMA™ was inserted after steady state end-tidal anesthetic concentrations had been maintained for 15 min. The response to insertion was recorded by three independent blinded observers. The interaction between nitrous oxide and sevoflurane was determined using logistic regression analysis.ResultsThe MAC of sevoflurane forLMA™ insertion (95% confidence limit) was 1.57% (1.42–1.72%), and the concentration of sevoflurane required to prevent movement in 95% of children was 1.99% (1.81–2.57%). The addition of 33% and 67% nitrous oxide linearly decreased the MAC of sevoflurane forLMA™ insertion by 22% and 49%, respectively (P< 0.001). The interaction coefficient between nitrous oxide and sevoflurane did not differ from zero (P= 0.7843), indicating that the relation was additive.ConclusionsNitrous oxide and sevoflurane suppress the responses toLMA™ insertion in a linear and additive fashion in children.

ISSN:0003-3022    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

BackgroundA recent report finds that elderly Japanese women given xenon have a significantly smaller (26% less) MAC (minimum alveolar concentration required to eliminate movement in response to surgical incision in 50% of patients) than Japanese men of the same age. The authors assessed whether this finding applied to other/all anesthetics.MethodsThe authors reviewed data obtained previously for 258 patients (127 women and 131 men) anesthetized with desflurane, diethyl ether, halothane, methoxyflurane, sevoflurane, or xenon. Data were normalized to the MAC for the anesthetic as determined by logistic regression (i.e., MAC would equal a value of 1.000.)ResultsThe MAC for the normalized combined (all) data for women (1.013 ± 0.017; mean ± SEM) did not differ significantly from the normalized combined data for men (1.005 ± 0.009), and neither differed significantly from 1.000. However, a significantly smaller MAC value was found for women in two studies of sevoflurane (subsets of the above studies) given to Japanese patients: 12% in one study and 16% in the other.ConclusionsOverall, no difference in MAC was found for womenversusmen. Whether women (particularly older Japanese women) have a smaller MAC than men remains to be confirmed by prospective studies.

ISSN:0003-3022    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

BackgroundWomen generally report greater sensitivity to pain than do men, and healthy young women require 20% more anesthetic than healthy age-matched men to prevent movement in response to noxious electrical stimulation. In contrast, minimum alveolar concentration (MAC) for xenon is 26% less in elderly Japanese women than in elderly Japanese men. Whether anesthetic requirement is similar in men and women thus remains in dispute. The authors therefore tested the hypothesis that the desflurane concentration required to prevent movement in response to skin incision (MAC) differs between men and women.MethodsUsing the Dixon “up and down” method, the authors determined MAC for desflurane in 15 female and 15 male patients (18–40 yr old) undergoing surgery.ResultsMAC was 6.2 ± 0.4% desflurane for womenversus6.0 ± 0.3% for men (P= 0.31), a difference of only 3%. These data provide 90% power to detect a 9% difference between the groups.ConclusionsThe MAC of desflurane did not differ between young men and women undergoing surgery with a true surgical incision. Although pain sensitivity may differ in womenversusmen, MAC of desflurane does not.

ISSN:0003-3022    

出版商:OVID    

年代:2003

数据来源: OVID