Anesthesiology
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The authors determined the efficacy of four postoperative warming devices by measuring cutaneous and tympanic membrane temperatures, and heat loss/gain using 11 thermocouples and ten thermal flux transducers in five healthy, unanesthetized volunteers. Overall thermal comfort was evaluated at 5-10 min intervals using a 10-cm visual analog scale. The warming devices were: 1) a pair of 250-W infrared heating lamps mounted 71 cm above the abdomen; 2) the Thermal Ceiling MTC XI UL (500 W) set on "high" and mounted 56 cm above the volunteer; 3) a 54-by-145-cm circulating-water blanket set to 40 degrees C placed over the volunteer; and 4) the Bair Hugger forced air warmer with an adult-sized cover set on "low" (approximately 33 degrees C), "medium" (approximately 38 degrees C), and "high" (approximately 43 degrees C). ⋯ Set on "high," the Bair Hugger increased skin-surface temperature more than the circulating-water blanket. The Bair Hugger (all settings) and the water blanket raised skin temperature more than the radiant heaters. The circulating-water blanket was the most effective device for heating an optimally placed transducer on the chest (directly under and parallel to the radiant heat sources, and touching the water and Bair Hugger blankets).(ABSTRACT TRUNCATED AT 250 WORDS)
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Randomized Controlled Trial Clinical Trial
Herpes labialis in parturients receiving epidural morphine following cesarean section.
A significant association exists between the use of epidural morphine (EM), reactivation of herpes labialis (HL) commonly known as coldsores, and pruritus in the obstetric population. A randomized prospective study was designed to eliminate previously identified confounding variables. Immediately following delivery, parturients having undergone cesarean section with epidural anesthesia with carbonated lidocaine (Xylocaine CO2, Astra, Mississauga, Ontario, Canada) with 1:200,000 epinephrine were sequentially randomized to receive either EM or im opioids for postoperative analgesia. ⋯ The incidence of oral viral shedding was low. Surgical stress, the local anesthetic solution, and epinephrine addition to the local anesthetic were eliminated as confounders. Stepwise logistic regression analysis revealed that EM and a history of herpes labialis in these patients were predictive for reactivating oral HSV.
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Clinical Trial Controlled Clinical Trial
Dexmedetomidine, an alpha 2-adrenoceptor agonist, reduces anesthetic requirements for patients undergoing minor gynecologic surgery.
The effects of dexmedetomidine, an alpha 2-adrenoceptor agonist, on vigilance, thiopental anesthetic requirements, and the hemodynamic, catecholamine, and hormonal responses to surgery were investigated in healthy (ASA physical status 1) women scheduled for dilatation and curettage (D & C) of the uterus. Fifteen minutes before induction they received single iv doses of either dexmedetomidine (0.5 micrograms/kg; n = 19) or saline (n = 20) in a double-blind fashion. Anesthesia was induced with thiopental and maintained with N2O/O2 (70/30%) and thiopental. ⋯ Systolic and diastolic blood pressure were moderately reduced after dexmedetomidine administration. The authors conclude that dexmedetomidine preanesthetic medication decreases thiopental anesthetic requirements and improves the recuperation from anesthesia with no serious hemodynamic or other adverse effects. Further studies in patients undergoing more stressful surgery are indicated.
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A combined pharmacokinetic and pharmacodynamic model of methohexital was used to establish and evaluate feedback control of methohexital delivery during total intravenous anesthesia with fentanyl in 11 surgical patients. The median frequency of the EEG power spectrum served as the pharmacodynamic variable constituting feedback. Based on previous investigations a median frequency from 2-3 Hz was chosen as the desired EEG set point. ⋯ The decrease of median EEG frequency to 2-3 Hz was primarily induced by an increase in fractional power in the 0.5-2- Hz frequency band to 46 +/- 4%. The average requirement of methohexital during the first 2 h was 675 +/- 250 mg. The authors conclude that model-based feedback control of intravenous methohexital delivery can help establish and quantitate methohexital requirements during total intravenous anesthesia with fentanyl.