Anesthesiology
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Clinical Trial
Pharmacokinetics of bupivacaine during postoperative epidural infusion: enantioselectivity and role of protein binding.
Changing plasma protein concentrations may affect the protein binding and pharmacokinetics of drugs in the postoperative period. This study examined the effect of postoperative increases (in response to surgery) in plasma alpha1-acid-glycoprotein (AAG) concentrations on the plasma concentrations of the enantiomers of bupivacaine during continuous epidural infusion of racemic bupivacaine for postoperative pain relief. ⋯ The study confirmed that the pharmacokinetics of bupivacaine are enantioselective. During postoperative epidural infusion, changing plasma AAG concentrations affect the protein binding of both enantiomers of bupivacaine. Consequently, total plasma concentrations of the enantiomers increase with time, whereas unbound concentrations reach a plateau.
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The authors determined the influence of cuff volume and anatomic location on pharyngeal, esophageal, and tracheal mucosal pressures for the esophageal tracheal combitube. ⋯ We conclude that mucosal pressures for the esophageal tracheal combitube increase with cuff volume, are highest where the cuff is adjacent to rigid anatomic structures, and potentially exceed mucosal perfusion pressure even when cuff volumes are limited to achieving an oropharyngeal seal of 30 cm H2O.
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Task analysis may be useful for assessing how anesthesiologists alter their behavior in response to different clinical situations. In this study, the authors examined the intraobserver and interobserver reliability of an established task analysis methodology. ⋯ A task analysis technique used in anesthesia research for several decades showed good intrarater reliability. Off-line analysis of videotapes is a viable alternative to real-time data collection. Acceptable interrater reliability requires the use of strict task definitions, sophisticated software, and rigorous observer training. New techniques must be developed to more accurately capture multitasking. Substantial effort is required to conduct task analyses that will have sufficient reliability for purposes of research or clinical evaluation.
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Comment Letter Comparative Study
Do sevoflurane and desflurane differ in upper airway reactivity?