Anesthesiology
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Randomized Controlled Trial Comparative Study Clinical Trial
A single-blind study of combined pulse oximetry and capnography in children.
This single-blind study examined four levels of monitoring in 402 pediatric cases. Patients were randomly assigned to one of four groups: 1) oximeter and capnograph; 2) only oximeter; 3) only capnograph; or 4) neither oximeter nor capnograph data available to the anesthesia team. An anesthesiologist, not involved in patient care, observed all cases and continuously recorded hemoglobin oxygen saturation (Spo2), ECG, expired CO2, and the oximeter plethysmographic output. ⋯ A number of problems fulfilled criteria in multiple categories. Infants less than or equal to 6 months of age had the highest incidence of major desaturation events (18 of 65 [27%]) compared to toddlers 7-24 months of age or children greater than 24 months of age (P less than 0.001). Blinding the oximeter data increased the number of patients (12 vs. 31) experiencing major desaturation events (P = 0.003); blinding the capnograph data altered neither the frequency of desaturation events nor the incidence of major capnograph events.(ABSTRACT TRUNCATED AT 250 WORDS)
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The effects of the new volatile anesthetic desflurane on three indices of left ventricular diastolic function were examined and compared to those produced by equianesthetic concentrations of isoflurane and halothane. Diastolic function has been shown to significantly influence systolic performance, but the effects of volatile anesthetics on diastolic function have not been extensively examined. Since autonomic nervous system function may significantly influence hemodynamic actions of anesthetics in vivo, experiments were performed in the presence of pharmacologic blockade of the autonomic nervous system. ⋯ In addition, no significant changes in myocardial stress-strain relationships as evaluated by nonlinear elastic coefficients, alpha (gain) and beta (myocardial stiffness), were observed with any anesthetic. Although the effects of volatile anesthetics on systolic function could not be entirely excluded from the analysis, the results indicated that desflurane, isoflurane, and halothane produce equivalent degrees of prolongation of isovolumetric relaxation. Halothane also caused a decrease in compliance during passive filling as evaluated by chamber stiffness, but no change in compliance was observed at end diastole as assessed by stress-strain relationships.(ABSTRACT TRUNCATED AT 400 WORDS)
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Randomized Controlled Trial Comparative Study Clinical Trial
Comparison of alfentanil and ketamine infusions in combination with midazolam for outpatient lithotripsy.
Sixty unpremedicated outpatients undergoing elective extracorporeal shock wave lithotripsy using an unmodified Dornier HM-3 lithotriptor were randomly assigned to receive an intravenous infusion of either alfentanil or ketamine as an adjuvant to midazolam for sedation and analgesia. Although both drug regimens allowed the maximal number of shock waves and energy level, the alfentanil group had significantly better calculi fragmentation (78% vs. 50% of patients with fragments less than 2 mm). Ketamine infusion provided superior intraoperative cardiorespiratory stability; however, it was associated with more disruptive movements (22 vs. 5) and dreaming (35% vs. 5%) during the procedure (P less than 0.05). ⋯ The incidence of postoperative nausea was decreased (not significantly) in the alfentanil group (32% vs. 54%). The mean anesthesia time was similar in both groups; however, discharge times (means +/- standard deviations) were shorter in the alfentanil group (142 +/- 42 min vs. 161 +/- 31 min, P = 0.05). These data suggest that although both techniques proved effective for anesthesia in outpatients undergoing immersion lithotripsy, alfentanil is superior to ketamine as part of a sedative-analgesic technique because of the improved recovery profile and calculi fragmentation.