Anesthesia and analgesia
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Anesthesia and analgesia · May 1997
Randomized Controlled Trial Multicenter Study Comparative Study Clinical TrialA randomized multicenter study of remifentanil compared with alfentanil, isoflurane, or propofol in anesthetized pediatric patients undergoing elective strabismus surgery.
Remifentanil hydrochloride is a new, ultrashort-acting opioid metabolized by nonspecific plasma and tissue esterases. We conducted this multicenter study to examine the hemodynamic response and recovery profile of premedicated children undergoing strabismus repair who were randomly assigned to receive one of four treatment drugs (remifentanil, alfentanil, isoflurane, or propofol) along with nitrous oxide and oxygen for maintenance of anesthesia. Induction of anesthesia was by nitrous oxide, oxygen, and halothane or nitrous oxide, oxygen, and propofol. ⋯ Its hemodynamic and recovery profile appear similar to other comparable drugs. Based on previous pharmacokinetic studies, the 1.0 microgram.kg-1.min-1 infusion may be twice the 50% effective dose observed in adults. In this study, the relative "overdose" of remifentanil was well tolerated and did not prolong recovery.
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Anesthesia and analgesia · May 1997
Clinical Trial Controlled Clinical TrialHemodynamic effects of anesthesia in patients with ischemic heart failure chronically treated with angiotensin-converting enzyme inhibitors.
Anesthesia may induce hemodynamic instability in patients treated with angiotensin-converting enzyme inhibitors (ACEIs). To assess the hemodynamic effects of anesthesia in patients treated (n = 9) or not treated (n = 9) with ACEIs for ischemic left ventricle dysfunction after myocardial infarction, we studied 18 patients scheduled for elective coronary artery bypass graft surgery. Induction of anesthesia with fentanyl (5 micrograms/kg), flunitrazepam (30 micrograms/kg), and pancuronium (100 micrograms/kg) was followed by a significant decrease in mean arterial blood pressure in both groups (-18.6% +/- 8.1% in controls and -25.7% +/- 7.8% in ACEI-treated patients, P = 0.01). ⋯ In ACEI-treated patients, cardiac index decreased significantly (-27.3% +/- 11.6%, P = 0.01 from baseline and P = 0.03 when compared with controls), and systemic vascular resistance was unchanged (1.0% +/- 18.7%, NS from baseline and P = 0.04 when compared with controls). Two patients from each group experienced a transient severe hypotensive episode. ACEI treatment in patients with infarction-induced myocardial dysfunction does not increase the incidence of severe hypotension after induction of anesthesia.
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Anesthesia and analgesia · May 1997
The threshold for thermoregulatory vasoconstriction during nitrous oxide/sevoflurane anesthesia is reduced in the elderly.
Elderly patients become more hypothermic during surgery, shiver less postoperatively, and take longer to rewarm than younger patients. Similarly, the vasoconstriction threshold (triggering core temperature) is reduced approximately 1 degree C in elderly patients during nitrous oxide/isoflurane anesthesia. Accordingly, we tested the hypothesis that the vasoconstriction threshold in the elderly is also reduced approximately 1 degree C during nitrous oxide and sevoflurane anesthesia. ⋯ The data from five patients who did not vasoconstrict at minimum core temperatures of 33-34 degrees C were eliminated, leaving 10 patients in each group. The vasoconstriction threshold was significantly less in the elderly (35.0 +/- 0.8 degrees C) than in younger patients (35.8 +/- 0.3 degrees C), despite similar mean skin temperatures (mean +/- SD, P < 0.01, Student's t-test). Age dependence of thermoregulatory vasoconstriction during nitrous oxide/sevoflurane anesthesia is similar to that previously observed during nitrous oxide/isoflurane anesthesia.
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Anesthesia and analgesia · May 1997
Randomized Controlled Trial Clinical TrialEffect on postoperative analgesia of small-dose lysine acetylsalicylate added to prilocaine during intravenous regional anesthesia.
Nonsteroidal antiinflammatory drugs act largely peripherally by blocking the local synthesis of prostaglandins. The aim of this study was to evaluate whether the addition of a small dose of lysine acetylsalicylate (LA) to the prilocaine used for intravenous regional anesthesia (IVRA) would improve the quality of postoperative analgesia. Sixty patients undergoing lower extremity IVRA for foot or ankle surgery were randomly assigned to three double-blind groups: LA-IVRA where 90 mg of LA was mixed with prilocaine 0.5% for IVRA and 1 mL of 0.9% NaCl administered intravenously (IV) through the forearm catheter after tourniquet inflation; LA-IV where 1 mL of 0.9% NaCl was mixed with prilocaine and 90 mg of LA administered IV; and placebo where 1 mL of 0.9% NaCl was administered both with prilocaine for the IVRA and IV. ⋯ Analgesic requirements remained significantly lower in LA-IVRA when compared with placebo only during the first six postoperative hours, LA-IV being in an intermediate position. Pain scores were significantly lower in LA-IVRA during the first postoperative hour when compared with LA-IV and during the first 3 postoperative hours when compared with placebo. We conclude that 90 mg of LA (corresponding to 50 mg of acetylsalicylic acid) added to prilocaine 0.5% during IVRA improves the quality of postoperative analgesia in the early postoperative period.