Anesthesia and analgesia
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Anesthesia and analgesia · Sep 1995
Randomized Controlled Trial Comparative Study Clinical TrialIntravenous regional anesthesia with meperidine.
Forty-five ASA physical status I volunteers, divided in three groups of 15 each, received intravenous regional anesthesia (IVRA) of the upper limb with 40 mL meperidine 0.25%, lidocaine 0.5%, or 0.9% sodium chloride (isolated ischemia) by random allocation. Using a double-blind method, the onset and recovery of sensory block was tested at six sites of the forearm and hand. The onset of complete motor block was also assessed. ⋯ In the meperidine group, motor block developed concomitantly or prior to sensory block. There was a significant increase in the incidence of dizziness, nausea, and pain at the injection site in the meperidine group in comparison with the lidocaine group. We conclude that meperidine has local anesthetic action on the peripheral nerve in vivo, but that its single use for IVRA should be a second choice for patients allergic to local anesthetics.
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Anesthesia and analgesia · Sep 1995
Randomized Controlled Trial Comparative Study Clinical TrialRenal function and serum fluoride concentrations in patients with stable renal insufficiency after anesthesia with sevoflurane or enflurane.
Sevoflurane is metabolized to hexa-fluoro-isopropanol and inorganic fluoride by the human liver. Its use as an anesthetic may lead to peak plasma fluoride concentrations exceeding those seen after enflurane. Although there is no nephrotoxicity after sevoflurane anesthesia in humans with normal kidneys, those with chronically impaired renal function might be at increased risk because of increased fluoride load due to prolonged elimination half-life. ⋯ No patient suffered a permanent deterioration of preexisting renal insufficiency and none required dialysis. Thus, neither sevoflurane nor enflurane deteriorated postoperative renal function in these patients with preexisting renal insufficiency. There is no evidence that fluoride released by metabolism of sevoflurane metabolism worsened renal function in these patients with stable, permanent serum creatinine concentrations more than 1.5 mg/dL.(ABSTRACT TRUNCATED AT 250 WORDS)
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Anesthesia and analgesia · Sep 1995
Randomized Controlled Trial Comparative Study Clinical TrialAnalgesia after bilateral myringotomy and placement of pressure equalization tubes in children: acetaminophen versus acetaminophen with codeine.
Despite the brief nature of the procedure with limited tissue trauma, some form of analgesia is required in most children after bilateral myringotomy and placement of pressure equalization (PE) tubes. Previous studies have demonstrated the relative inefficacy of acetaminophen and nonsteroidal antiinflammatory drugs (NSAIDs), with 30%-55% of patients requiring supplemental postoperative analgesia. We undertook a prospective study evaluating the efficacy of the preoperative administration of oral acetaminophen (15 mg/kg) versus acetaminophen (10 mg/kg) and codeine (1 mg/kg). ⋯ None of the 25 patients who received acetaminophen with codeine required supplemental analgesics compared with 12 of 25 who received acetaminophen. No adverse effects were noted in either group. We conclude that the preoperative administration of acetaminophen with codeine provides superior analgesia after bilateral myringotomy and placement of PE tubes.
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Anesthesia and analgesia · Sep 1995
Randomized Controlled Trial Comparative Study Clinical TrialComparison of propofol administration techniques for sedation during monitored anesthesia care.
Sixty-three outpatients undergoing breast biopsy procedures with local anesthesia were randomly assigned to receive propofol by intermittent bolus injections (n = 21), a conventional syringe infusion pump (n = 21), or a target-controlled infusion (TCI) device (n = 21) for intraoperative sedation. In the first two groups, an initial intravenous (IV) bolus of propofol (0.3 mg/kg) was administered and an attempt was made to maintain the sedation level at an Observer's Assessment of Alertness/Sedation (OAA/S) score of 3 or 4 with either intermittent bolus injections of propofol (10 mg) or a variable-rate infusion (25-100 micrograms.kg-1.min-1). In the TCI group, the initial target concentration of propofol was set at 2 micrograms/mL and the target concentration was adjusted between 1 and 4 micrograms/mL in an attempt to maintain an OAA/S score of 3 or 4. ⋯ The anesthesiologist had to intervene more frequently in the intermittent bolus injection group than in the two infusion groups. We conclude that the use of an infusion technique may allow the anesthesiologist more time for monitoring the patient by decreasing the number of interventions necessary to administer supplemental doses of the sedative medication during the operation. However, the cost of the IV drug delivery system may become an increasingly important factor in the future.
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Anesthesia and analgesia · Sep 1995
Isoflurane and sevoflurane produce a dose-dependent reduction in the shivering threshold in rabbits.
All general anesthetics markedly impair thermoregulatory responses; nonetheless, sufficient hyperthermia or hypothermia will trigger most protective reflexes. Shivering, however, remains an exception among thermo-regulatory responses: it is common during postanesthetic recovery, but is rare at typical anesthetic concentrations. This observation suggests that general anesthesia impairs shivering far more than other thermoregulatory defenses. ⋯ Four of the six rabbits given 0.3 MAC isoflurane shivered at a mean core temperature of 36.2 +/- 0.6 degrees C, and two of these rabbits failed to shiver at a minimum core temperature of 35.0 degrees C. However, no rabbit given 0.4 MAC isoflurane shivered, even at minimum core temperatures of 35.0 degrees C. All of the rabbits given 0.2 MAC sevoflurane shivered at a mean core temperature of 36.6 +/- 0.7 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)