Anesthesiology
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Clinical studies have reported that body core temperature decreases during prolonged surgery and anesthesia. Although this finding has been attributed primarily to increased heat loss resulting from exposure of body cavities and infusion of cold solutions, it is generally recognized that anesthesia interferes with the thermoregulatory system. The present study examined the effects of mild narcosis induced by 30% N2O on shivering thermogenesis and cutaneous thermoregulatory vasoconstriction in humans, during exposure in a much more intense peripheral thermal stimulus than the ones often used in clinical studies. ⋯ No significant difference was observed in cutaneous thermoregulatory vasoconstriction between the two experimental conditions, as indicated by the Tsk-gr values. The estimated Tes threshold for shivering (estimated from the O2 consumption vs. delta Tes regression) was reduced by 0.95 +/- 0.26 (SE) degrees C during the immersion phase and by 0.39 +/- 0.05 (SE) degrees C during the rewarming phase in the N2O condition compared to the control conditions. Although the thermosensitivity (gain) of shivering appeared preserved during the immersion phase, it was reduced during the N2O rewarming phase.(ABSTRACT TRUNCATED AT 400 WORDS)
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The effects of propofol, etomidate, midazolam, and fentanyl on motor evoked responses to transcranial stimulation (tc-MERs) were studied in five healthy human volunteers. Each subject, in four separate sessions, received intravenous bolus doses of propofol 2 mg.kg-1, etomidate 0.3 mg.kg-1, midazolam 0.05 mg.kg-1, and fentanyl 3 micrograms.kg-1. Electrical tc-MERs (tce-MERs) were elicited with anodal stimuli of 500-700 V. ⋯ Etomidate caused significant but transient depression of tc-MER amplitude. However, there was considerable intersubject variability. Latency did not change significantly after any drug.(ABSTRACT TRUNCATED AT 250 WORDS)
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Human error is believed to contribute to the majority of negative anesthesia outcomes. Because retrospective analysis of critical incidents has several shortcomings and prospective studies are limited by the low frequency of critical incidents, an anesthesia simulator was used to evaluate the management of simulated emergency situations by ten anesthesia residents, ten faculty anesthesiologists, and ten anesthesiologists in private practice in order to identify specific patterns of errors in diagnosis and treatment. The simulator is a computer program that presents the patient, monitors, and management choices in a graphical display on an IBM or compatible personal computer. ⋯ Fixation errors or failure to revise a plan in the presence of inconsistent cues were made by 63% of subjects. The subjects that gathered more information during simulated anaphylaxis made the correct diagnosis more often and made fewer treatment errors. The time since the last ACLS training was found to be an important predictor of correct management of simulated cardiac arrest.(ABSTRACT TRUNCATED AT 250 WORDS)
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Randomized Controlled Trial Comparative Study Clinical Trial
A double-blinded comparison of metoclopramide and droperidol for prevention of emesis following strabismus surgery.
Vomiting in the postoperative period is common in children after strabismus surgery. One hundred ten pediatric patients, ages 8 months to 14 yr, admitted for outpatient strabismus surgery were enrolled in a randomized, double-blinded study to compare droperidol and metoclopramide to placebo for the prevention of postoperative emesis. Each child was prospectively assigned at random to one of four treatment groups: metoclopramide 0.15 mg/kg, metoclopramide 0.25 mg/kg, droperidol 0.075 mg/kg, or saline control. ⋯ Patients receiving droperidol and metoclopramide 0.25 mg/kg also had decreased postoperative stays (metoclopramide 201 min; droperidol 213 min) versus control (258 min, P less than 0.05). No child exhibited extrapyramidal symptoms, excessive drowsiness, or agitation. We conclude that metoclopramide in a dose of 0.25 mg/kg, administered prior to the start of surgery, is at least as effective as droperidol in preventing postoperative emesis and can reduce the time to patient discharge compared to control.
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Randomized Controlled Trial Clinical Trial
Effects of a nighttime opioid infusion with PCA therapy on patient comfort and analgesic requirements after abdominal hysterectomy.
Since pain during the early postoperative period can disrupt a patient's normal sleep pattern, we investigated the influence of a nighttime "basal" infusion of morphine on patient comfort, ability to sleep at night, restfulness, and analgesic requirements following elective abdominal hysterectomy. One hundred fifty-six adult women were randomly assigned to receive either patient-controlled analgesia (PCA) alone or PCA supplemented with a nighttime infusion of morphine 1.0 mg.h-1. The infusion was started in the postanesthesia care unit and continued until the morning after surgery. ⋯ In addition, the number of patient demands and supplemental bolus doses, opioid usage, and recovery parameters were similar in the two treatment groups. The use of a basal infusion resulted in six programming errors, and three patients required discontinuation of the infusion because of hemoglobin oxygen desaturation (i.e., SpO2 less than 85% for greater than 5 min). We concluded that the routine use of a continuous nighttime opioid infusion in combination with a standard PCA regimen failed to improve the management of postoperative pain, sleep patterns, or recovery profiles compared to PCA alone after abdominal hysterectomy.