Anesthesia and analgesia
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Anesthesia and analgesia · Sep 1979
Nitrous oxide: effect on accumulation rate and uptake of bowel gases.
Breathing 79% nitrous oxide (N2O) in oxygen increased the rate of accumulation of bowel gas during intraluminal bowel segment infusions of hydrogen, methane (CH4), air, or carbon dioxide (CO2) in four pentobarbital-anesthetized dogs more than did breathing 100% oxygen. A N2O-associated increase in the volume of naturally produced intestinal gas in five halothane-anesthetized ponies corroborated the findings in the dog studies. In a second group of four dogs a bolus of CH4 or CO2 was injected into the bowel lumen. ⋯ Breathing N2O increased the volume of the segments containing CH4 while the CO2 segments decreased less rapidly than during O2 breathing. Breathing O2 after 30 minutes of N2O breathing caused little change in the rate of decrease in CO2 segment volumes. However, the CH4 segment volume ceased to increase and eventually returned toward control volumes.
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Anesthesia and analgesia · Sep 1979
Comparative StudyCumulative dose-response curves for gallamine: effect of altered resting thumb tension and mode of stimulation.
Neuromuscular blockade studies often use the thumb adductor twitch response to ulna nerve stimulation. Two factors that may influence the results are the resting muscle tension (initial fiber length) and the pattern of the stimulus wave form. This study was undertaken to improve understanding of the effect of these factors and lead to better controlled study conditions and more consistent data. ⋯ The muscle response to biphasic stimulation during a non-depolarizing blockade was not affected by the average muscle refractory period. Because of the significantly lower developed tension at resting tension settings of 50 to 100 g, a practical consideration during neuromuscular function studies would be to have the resting thumb tension adjusted and rechecked for each patient and kept within the 200-300-g range to ensure maximum uniform developed tension. The type of stimulus wave form selected will not affect results as long as it is used consistently throughout the study.