Journal of anesthesia
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Journal of anesthesia · Dec 1996
Changes in respiratory system resistance and reactance following acute respiratory and metabolic alkalosis in dogs.
To differentiate between the effects of respiratory and metabolic alkalosis on respiratory mechanics, respiratory system resistance (Rrs) and reactance (Xrs) were examined in anesthetized, paralyzed, and mechanically hyperventilated dogs. Rrs and Xrs were measured by the forced oscillation method with a random noise input of 0-25 Hz. ⋯ A significant decrease in Rrs (-16.3±2.5%) following vagotomy or atropine administration was no longer affected by CO2 inhalation. These results suggest that (1) the vagus nerve appears to play a role in maintaining the resting tension of airway smooth muscle, (2) systemic hypocapnia decreases Rrs presumably due to the central airway dilation, and (3) this response is associated with a change in systemic partial pressure of carbon dioxide (PCO 2) rather than that in pH.
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To determine the optimum priming dose of vecuronium, we divided 173 surgical patients into five groups according to priming dose (0, 2.5, 5.0, 7.5, and 10 μg·kg-1). For endotracheal intubation, we administered a priming dose of vecuronium, and then after 4 min, the remainder was injected for a total dosage of 0.15 mg·kg-1. Onset time was determined by a 95% depression of twitch height as shown by electromyography (EMG) of the hypothenar muscles. ⋯ A priming dose of 10 μg·kg-1 showed a decrease of TOF ratio to 95% or less in 1 out of 25 cases. Although one-third of the patients in the 5 and 7.5 μg·kg-1 groups complained of clinical symptoms such as ptosis, this was clinically allowable. We conclude that the optimum priming dose of vecuronium is 7.5 μg·kg-1; however, in obese patients, a smaller dosage would be recommended.
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Journal of anesthesia · Dec 1996
Complications in the use of intravenous catheters for major surgery: A clinical study.
Two groups of patients received one of two intravenous catheters, a 20-gauge (ga) Criticon (C group;n=96) or a 20-gauge (ga) Vitaflon Plus (V group;n=100). Each catheter was inserted under identical cannulation conditions. Fluids and drugs used pre- and postoperatively were comparable in both groups. ⋯ The period from catheter insertion to the clinical onset of phlebitis was prolonged in both groups if antiphlebitogenous fluids were used. The incidence of late complications (phlebitis, displacement of the cannulae, etc.) and damage to the catheters was more frequent in the C group. The authors discuss the clinical relevance of these findings.