Anesthesia and analgesia
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Anesthesia and analgesia · Aug 1994
Review Case ReportsBronchospasm after intravenous adenosine administration.
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Anesthesia and analgesia · Aug 1994
Experimental hypothermia: effects of core cooling and rewarming on hemodynamics, coronary blood flow, and myocardial metabolism in dogs.
Conflicting results have been reported as to the extent that cardiovascular function can be reestablished after rewarming from hypothermia. We measured hemodynamic function, myocardial metabolism and tissue water content in dogs core-cooled to 25 degrees C and later rewarmed. At 25 degrees C left ventricular (LV) systolic pressure (LVSP) was 54% +/- 4%, maximum rate of LV pressure rise (LV dP/dtmax) 44% +/- 5%, aortic pressure (AOP) 50% +/- 6%, heart rate (HR) 40% +/- 0%, cardiac output (CO) 37% +/- 5%, myocardial blood flow (MBF) 34% +/- 5%, and myocardial oxygen consumption (MVO2) 8% +/- 1%, compared to precooling. ⋯ Increased myocardial contents of creatine phosphate and water were found during both hypothermia and rewarming. The present study demonstrates a persistent depression of cardiac function after hypothermia and rewarming in spite of adequate energy stores. Thus, a direct influence on myocardial contractile function by the cooling and rewarming process is suggested.
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The effect of mivacurium after atracurium was evaluated in 36 children anesthetized with halothane-nitrous oxide-oxygen by measuring the force of contraction of the adductor pollicis during train-of-four stimulation at 0.1 Hz. The children were evaluated in two main groups. In Group 1 the effect of bolus doses of mivacurium after equipotent repeat doses of atracurium were evaluated. ⋯ The infusion requirement increased gradually (P < 0.0001) until, at 90 min of infusion, it was 7.4 +/- 0.8 micrograms.kg-1.min-1. In Group 2 the recovery indices were similar to those seen when mivacurium is the sole relaxant given. When mivacurium is given after atracurium, evidence of the residual neuromuscular effects of the atracurium are detected beyond the usual recovery range.
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Anesthesia and analgesia · Aug 1994
Previous wet tap does not reduce success rate of labor epidural analgesia.
Whether unintentional dural puncture (wet tap) during a previous labor epidural increases the failure rate of epidural analgesia for later deliveries is controversial. In this study, charts of 47 women with a previous wet tap who received epidural analgesia for labor were compared to those of 500 consecutive women receiving epidural analgesia in 1991 and, separately, to 44 women matched for month of delivery, previous epidural without a wet tap, and the same anesthesiologist. In comparison to the 500 consecutive control patients, women with a previous wet tap had a lower incidence of epidural catheter manipulation for inadequate block (9% vs 20%), but a similar incidence of catheter removal for failed block (4% vs 6.7%). ⋯ Epidural analgesia was considered successful in 93% of cases and 89% of matched control subjects by chart review. Two women (4%) with previous wet tap experienced a second wet tap during attempted epidural catheterization, compared to 0% in 500 consecutive patients (P < 0.001). These data suggest that there is no decrease in the success rate of epidural analgesia in women with a previous wet tap, although the chance for a repeated wet tap may be increased.
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Anesthesia and analgesia · Aug 1994
Determination of end-tidal sevoflurane concentration for tracheal intubation and minimum alveolar anesthetic concentration in adults.
The purpose of this study was to determine both the concentration of sevoflurane required for tracheal intubation (MACEI) and its minimum alveolar anesthetic concentration (MAC) in adults. The study group consisted of 86 elective surgical patients, ASA physical status I or II, aged 16-59 yr. There was no premedication administered. ⋯ The MAC of sevoflurane was 1.58% (95% confidence limits, 1.14%-1.98%), and the AD95 (anesthetic ED95) was 2.96%. The MACEI/MAC ratio was 2.86 (95% confidence limits, 2.63-3.43). Anesthesia induction followed by tracheal intubation can be accomplished in adults when sevoflurane is administered as a sole anesthetic, but in excess of 8% end-tidal concentration.