Journal of clinical monitoring and computing
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J Clin Monit Comput · Jun 2004
Increased tidal volume variability in children is a better marker of opioid-induced respiratory depression than decreased respiratory rate.
During opioid administration, decreasing respiratory rate is typically used as a predictor of respiratory depression. Prior to opioid-induced apnea, progressively irregular breathing patterns have been noticed. We hypothesize that opioid administration to children will increase tidal volume variability (TV(var)) and that this will be a better predictor of respiratory depression than a decrease in respiratory rate. ⋯ TV(var) increases as children approach opioid-induced respiratory depression. This is a more useful predictor of respiratory depression than a fall in respiratory rate because the TV(var) increase is 10 times the drop in respiratory rate. A TV(var) increase also correctly predicts respiratory depression twice as often as decreased respiratory rate and is independent of age-related alterations in physiologic respiratory rates.
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Direct-current injuries have occurred to anesthetized patients connected to battery-operated medical devices. This study was designed to document the effects of direct current applied to two electrodes on a tissue surrogate (round steak) at room temperature. Direct current from a 9 V source was applied to a pair of stainless steel electrodes (1.6 cm diameter) spaced 4.3 cm center-to-center. ⋯ At the end of each experiment the electrodes were different in appearance. The negative electrode retained its original shiny appearance but the positive electrode was pitted and dull in appearance, reflecting the different chemical reactions at each site. The lesions under the negative electrodes were more severe, indicating that alkali is more damaging than the acid environment that was produced electrolytically.