The journal of physiological sciences : JPS
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Comparative Study
Forearm and calf tissue oxygenation in term neonates measured with near-infrared spectroscopy.
Peripheral tissue oxygenation has been studied with near-infrared spectroscopy (NIRS) on either the forearm or calf with questionable comparability. The aim was to compare forearm and calf tissue oxygenation in healthy term neonates measured with NIRS. Fractional oxygen extraction, tissue oxygenation index, and mixed venous oxygenation were similar in both extremities, whereas oxygen delivery and oxygen consumption of calf tissue were higher.
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A head-down tilt posture, the Trendelenburg position, which could facilitate venous return from the splanchnic organs and lower extremities, is recommended for the treatment of anaphylactic shock. However, few data of animal studies support its effectiveness. We examined the effects of a head-down tilt maneuver on anaphylactic hypotension in BALB/c mice and Sprague-Dawley rats. ⋯ A head-down tilt maneuver in mice substantially attenuated the antigen-induced decrease in Sap throughout the 60 min measurements, though it aggravated slightly, but significantly, only at the late phase of after 25 min in rats. We conclude that a head-down tilt maneuver attenuates anaphylactic hypotension in anesthetized mice and rats. These beneficial effects were smaller in rats than in mice probably because of substantial portal hypertension, which might prevent the head-down tilt-induced increase in venous return from the splanchnic vascular bed.