Journal of anesthesia
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Journal of anesthesia · Mar 1996
RETRACTED ARTICLE: Dobutamine increases contractility of fatigued diaphragm in dogs: The relationship between dose and diaphragmatic contractility.
The dose-related effects of dobutamine (DOB) on the contractility of fatigued diaphragm were studied in 16 anesthetized, mechanically ventilated dogs. The animals were divided into two groups of eight: the control (group C) and the DOB (group D). Diaphragmatic fatigue was induced by intermittent supramaximal electrophrenic stimulation at a frequency of 20 Hz applied for 30 min. ⋯ In group C, the speed of Pdi recovery at 20-Hz stimulation was relatively slower. The integrated diaphragmatic electric activity (Edi) in each group did not change at any frequency of stimulation throughout the study. It is concluded that DOB increases the contractility of fatigued diaphragm in a dose-dependent manner.
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Journal of anesthesia · Mar 1996
A comparison of sympathetic adrenal nerve responses to intravenous high-dose morphine and fentanyl administration in rats.
We compared the effects of intravenous morphine (5 mg·kg(-1)) and fentanyl, (50μg·kg(-1)) on systolic blood pressure (SBP), heart rate (HR), and efferent sympathetic adrenal nerve action potentials (SANA) in rats. We also determined the extent of the reflex responses of these parameters of 9% carbon dioxide (CO2) challenge during the above narcotic anesthesia. In the morphine group, SBP was elevated and the elevated levels were maintained, while changes in SBP in the fentanyl group were not significant. ⋯ CO2 challenge induced only very small changes in SBP and HR, suggesting that during high-dose narcotic anesthesia the hypercapnic stimulus may not be reflected in circulatory parameters. In both groups, hypercapnia increased SANA to 30% of the baseline values from the pre-challenge level. However, these values were only 91% and 56% of the baseline value in the morphine and the fentanyl, groups, respectively.
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Journal of anesthesia · Mar 1996
Evaluation of Mapleson systems for administration of inhaled nitric oxide.
To assess the safety of nitric oxide (NO) inhalation during manual-controlled ventilation using Mapleson A, D, and F systems, we examined nitrogen dioxide (NO2) production using a chemiluminescence analyzer. The NO concentration was changed from 0 to 19 parts per million (ppm), and at each level of NO the oxygen (O2) concentration was changed from 21% to 100%. ⋯ The NO2 concentrations of the Mapleson A system were significantly higher than those of either the Mapleson D or F system at 4, 8, and 12 ppm NO and 100% O2, and than that of the Mapleson D system at 19 ppm NO and 100% O2. From the viewpoint of NO2 production, we suggest that the Mapleson D and F systems are safer than the Mapleson A system when manual-controlled ventilation is required.