Anesthesia and analgesia
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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 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
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)
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Anesthesia and analgesia · Sep 1995
Comparative StudyComparison of needle deviation during regional anesthetic techniques in a laboratory model.
Although many characteristics of needles used for spinal and epidural anesthesia have been studied extensively, the amount that a needle deviates from a straight path while passing through tissue has been relatively ignored. A laboratory model was used to determine the amount of needle deviation produced when different types of new spinal needles and epidural needles were passed through porcine tissue. ⋯ Needles commonly used for epidural anesthesia (Tuohy, Hustead, Crawford) exhibited increased deviation (range 1.73-3.54 mm/50 mm tissue), although the largest amount was seen with beveled spinal needles (Quincke, Atraucan) (range 4.42-5.90 mm/50 mm tissue). The possible clinical significance of needle deviation during the performance of a regional anesthetic is discussed.
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Anesthesia and analgesia · Sep 1995
Effects of extracorporeal circulation on renal function in coronary surgical patients.
We prospectively studied perioperative changes of renal function in 12 previously normal patients (plasma creatinine < 1.5 mg/dL) scheduled for elective coronary surgery. Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were measured with inulin and 125I-hippuran clearances before induction of anesthesia, before cardiopulmonary bypass (CPB), during hypo- and normothermic CPB, after sternal closure, and 1 h postoperatively. Renal and systemic vascular resistances were calculated. ⋯ Urine NAG, creatinine, and free water clearances were normal in all patients both pre- and postoperatively. Osmolal clearance and fractional excretion of sodium increased postoperatively from 1.54 +/- 0.06 to 12.47 4/- 11.37 mL/min, and from 0.44 +/- 0.3 to 6.07 +/- 6.27, respectively. We conclude that renal function does not seem to be adversely affected by CPB.(ABSTRACT TRUNCATED AT 250 WORDS)