Anesthesia and analgesia
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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.
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Anesthesia and analgesia · May 1997
Randomized Controlled Trial Comparative Study Clinical TrialPreemptive ketamine decreases postoperative narcotic requirements in patients undergoing abdominal surgery.
The aim of this study was to determine if preemptive administration of systemic ketamine decreases postoperative pain when compared with postwound closure administration of ketamine. Patients undergoing abdominal procedures were randomized into a preemptive or postwound closure ketamine administration group. Before surgical incision, patients in the preemptive group (n = 20) were given 0.5 mg/kg ketamine followed by a ketamine infusion of 10 micrograms.kg-1.min-1, which was discontinued at abdominal closure. ⋯ Patients in the preemptive group had significantly lower morphine consumption on postoperative Days 1 and 2. No significant intergroup differences were seen in the pain scores throughout the study period. Preemptive ketamine decreased postoperative opioid requirements, which was observed long after the normal expected duration of ketamine.
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Anesthesia and analgesia · May 1997
Randomized Controlled Trial Clinical TrialHemodynamic effects of intravenous isoproterenol versus saline in the parturient.
The use of epinephrine as a test dose for epidural analgesia in obstetrics remains controversial. Isoproterenol as a test dose may be efficacious in the parturient. However, the effects of isoproterenol on the uterine blood flow (UBF) and umbilical blood flow (UMB) in the parturient are unknown. ⋯ UMB did not change. Other hemodynamic variables did not change. We conclude that isoproterenol, 5 micrograms, may be a suitable test dose for epidural analgesia in obstetrics.