Anesthesiology
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Randomized Controlled Trial Comparative Study Clinical Trial
Onset of action of mivacurium chloride. A comparison of neuromuscular blockade monitoring at the adductor pollicis and the orbicularis oculi.
The optimal site for monitoring neuromuscular blockade for intubations facilitated with mivacurium chloride has not been established. The primary purpose of this evaluation was to determine the difference in onset of neuromuscular blockade between the orbicularis oculi and adductor pollicis in patients administered mivacurium chloride. We also evaluated intubating conditions when intubation was timed to maximal neuromuscular blockade at either the orbicularis oculi or the adductor pollicis. The results for patients administered mivacurium chloride were compared with those for a control group administered succinylcholine. ⋯ When monitoring 95% twitch height depression of the orbicularis oculi muscle, intubation can be accomplished in approximately 2 min after administration of mivacurium chloride (0.15 mg.kg-1). Because intubating conditions were comparable to the patients administered succinylcholine or intubated during monitoring of the twitch height depression of the adductor pollicis, we believe that optimal site for monitoring during intubation using mivacurium chloride is the orbicularis oculi muscle.
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Comparative Study Clinical Trial Controlled Clinical Trial
What is the best way to determine oropharyngeal classification and mandibular space length to predict difficult laryngoscopy?
Previous studies have suggested that the degree of visibility of oropharyngeal structures (OP class) and mandibular space (MS) length can predict difficult laryngoscopy. However, those studies were either inconsistent or omit description of how to perform these tests with regard to body, head and tongue position, and the use of phonation, hyoid versus thyroid cartilage and inside versus outside of the mentum. The purpose of this investigation was to determine which method of testing best predicts difficult laryngoscopy. ⋯ Based on the above ROC areas and ease of performing the test for the patient, we recommend that these tests be performed with patients in the sitting position, with the head in full extension, the tongue out, and with phonation, and with distance measured from the thyroid cartilage to inside of the mentum. Nevertheless, it is clear that these two tests, either used alone or in combination, will fail to predict a few difficult laryngoscopies and that they will predict difficult laryngoscopy in a significant number of patients in whom the trachea is easy to intubate.
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Comparative Study
Lower-extremity motor neuropathy associated with surgery performed on patients in a lithotomy position.
Motor neuropathy of a lower extremity is well-recognized as a potential complication of procedures performed on patients in a lithotomy position. Most of this awareness is based on anecdotal reports, however, and the incidence and risk factors for this complication have not been reported. ⋯ These data suggest that prolonged duration in lithotomy and patient risk factors, including very thin body habitus and smoking in the preoperative period, are associated with the development of a lower-extremity neuropathy after procedures performed on patients in a lithotomy position. A reduction of time in the lithotomy position may be particularly worthwhile for patients with these risk factors.
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Comparative Study Clinical Trial
Bedside assessment of intravascular volume status in patients undergoing coronary bypass surgery.
Management of intravascular volume is crucial in patients after cardiopulmonary bypass as myocardial dysfunction is common. The purpose of this study was to validate a novel bedside technique for real-time assessment of intravascular volumes. ⋯ This study shows that bedside determinations of intravascular blood volumes are feasible and that these measurements are more indicative of intravascular volume status than are either pulmonary capillary wedge or central venous pressures in the post-cardiopulmonary bypass period. Our data also demonstrate that despite a normal central blood volume both circulating and total blood volume are significantly increased in the immediate post-cardiopulmonary bypass period.
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Comparative Study
Inhibition of volatile sevoflurane degradation product formation in an anesthesia circuit by a reduction in soda lime temperature.
Sevoflurane reacts with carbon dioxide absorbents, such as soda lime, to release the volatile products compounds A and B. These two products, which have been detected in anesthesia circuits, are among five formed when sevoflurane is degraded by soda lime at increased temperature; the others, compounds C, D, and E, have been detected only in heated sealed systems. The current study attempted to determine the influence of soda lime temperature on compounds A and B generation in an anesthesia circuit and whether a decrease in soda lime temperature could eliminate product formation in the circulating gases. ⋯ This study demonstrates that the release of volatile sevoflurane degradation products in an anesthesia circuit is highly dependent on soda lime temperatures. A reduction of the temperature of soda lime may be a feasible method of preventing the release of significant levels of sevoflurane degradation products without interfering with carbon dioxide absorption or altering the sevoflurane concentration.