Anesthesiology
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In the absence of data on the anatomic localization of the cuff of the laryngeal mask airway (LMA) in children, radiologic images were obtained from 50 infants and children (aged 1 month to 15 yr) undergoing diagnostic radiologic procedures during halothane and N2O:O2 anesthesia. In 46 patients, the cuff of the LMA was in the pharynx and covered the laryngeal opening. The upper (proximal) section was adjacent to the base of the tongue at the level of C1 or C2 vertebrae pushing the tongue forward and its lower (distal) end was in the inferior recesses of the hypopharynx at the levels of C4 to T1 vertebrae. ⋯ In four patients, the cuff of the LMA was located in the oropharynx. No correlation was found between the size of the LMA and the position of the epiglottis with respect to end-tidal CO2, respiratory rate, or the leak pressures. The size of the LMA, its anatomic location, and the position of the epiglottis had no significant effect on the respiratory parameters of spontaneously breathing children.
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Sevoflurane previously has been reported to undergo extensive degradation in the presence of soda lime. To more completely characterize the extent and significnce of this reaction, we studied degradation of sevoflurane with and without soda lime, as well as the toxicity and mutagenicity of the degradation products. Two degradation products detected were CF2 = C(CF3)OCH2F (compound A) and CH3OCF2CH(CF3)OCH2F (compound B). ⋯ Exposure of fibroblasts to 7,500 ppm of compound A for 1 h, compound A did not induce structural change. In a study of acute toxicity of compound B, there was no toxicity in Wistar rats after 3 h of exposure at 2,400 ppm. The reverse (Ames) test for compound B was negative at 625-1,250 micrograms/dish.(ABSTRACT TRUNCATED AT 400 WORDS)
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Randomized Controlled Trial Comparative Study Clinical Trial
A comparison of intrathecal, epidural, and intravenous sufentanil for labor analgesia.
A number of recent studies have suggested that the analgesic effects of highly lipid-soluble opioids are similar when these agents are administered either epidurally or intravenously. We sought to test whether the lipid-soluble opioid sufentanil was more effective when administered intrathecally than when administered epidurally or intravenously. Twenty-four women during active labor received sufentanil 10 micrograms either intrathecally (n = 9), epidurally (n = 8), or intravenously (n = 7), using a combined spinal-epidural technique. ⋯ No patient developed post-dural puncture headache. We conclude that sufentanil 10 micrograms intrathecally provides rapid and effective analgesia of 1-2-h duration during labor. Epidural and intravenous use of this dose of sufentanil did not provide evidence of satisfactory analgesia.(ABSTRACT TRUNCATED AT 250 WORDS)