Anesthesiology
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Randomized Controlled Trial Clinical Trial
Evidence that intravenous vasopressors can affect rostral spread of spinal anesthesia in pregnancy.
The authors have previously observed an apparent association between rostral spread of spinal anesthesia and choice of intravenous vasopressor given to maintain maternal systolic arterial pressure during cesarean delivery. This study tested the hypothesis that an intravenous infusion of phenylephrine can reduce rostral spread of spinal anesthesia in pregnancy, compared with ephedrine. ⋯ This study provides evidence that intravenous phenylephrine can decrease rostral spread of spinal anesthesia in pregnancy, compared with intravenous ephedrine. Further work is required to investigate possible mechanisms and to assess its clinical significance.
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Epidurals are effective in relieving labor pain but result in a sympathectomy that may compromise maternal hemodynamic stability and fetal perfusion. Decreases in blood pressure and heart rate can be corrected, but markers of autonomic activity would be useful to predict and prevent such changes. The goal of this study was to find markers describing the changes in autonomic nervous system activity with epidural anesthesia in laboring patients. ⋯ Indices of parasympathetic and sympathetic activity after neuraxial blockade in laboring patients can be obtained by analysis of both heart rate variability and blood pressure variability. The analysis by wavelet transform can discern changes in autonomic activity when values of blood pressure and heart rate do not vary significantly. Whether this technique could be used to predict and prevent hemodynamic compromise after neuraxial blockade merits further studies.
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This study was conducted to investigate the feasibility of using ultrasound as an image tool to locate the sacral hiatus accurately for caudal epidural injections. ⋯ Ultrasound is radiation free, is easy to use, and can provide real-time images in guiding the caudal epidural needle into the caudal epidural space. Ultrasound may therefore be used as an adjuvant tool in caudal needle placement.
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The effect of nitric oxide synthase inhibitor on acute lung injury remains controversial. The current study was designed to examine effects of a newly synthesized and selective inducible nitric oxide synthase inhibitor, ONO1714, on endotoxin-induced lung injury in unanesthetized sheep. ⋯ These findings suggest that nitric oxide release by the inducible nitric oxide synthase pathway partially contributes to the increased permeability of pulmonary edema and decreased oxygenation during endotoxemia in sheep.