Hypotension in septic shock is a reflection of unregulated nitric oxide (NO) production and vascular smooth muscle guanylyl cyclase activation. We examined the effect of methylene blue on lipopolysaccharide (LPS)-induced shock in anesthetized rabbits. Shock was induced with 150 micrograms/kg LPS after measurement of mean arterial pressure, platelet cGMP, and total plasma NO (nitrogen monoxide+S...

OBJECTIVE Chemoreceptors play an important role in the autonomic modulation of circulatory and ventilatory responses to changes in arterial O(2) and/or CO(2). However, studies evaluating hemodynamic responses to hypoxia and hypercapnia in rats have shown inconsistent results. Our aim was to evaluate hemodynamic and respiratory responses to different levels of hypoxia and hypercapnia in consciou...

OBJECTIVE To determine the accuracy of peripheral (radial) arterial access as compared to central (femoral) arterial access for measurement of invasive blood pressure (IBP) in critically ill patients after cardiopulmonary bypass. METHODS Sixty patients (60) who required high inotropic/vasopressor support on weaning from cardio-pulmonary bypass and weaned off in 2nd attempt were included in th...

We developed a preparation in which the mean arterial pressure of the newborn lamb is varied with little change in left ventricular preload. Seven lambs underwent balloon atrial septostomy and were instrumented with vascular catheters, an electromagnetic flow transducer on the aorta, and a balloon occluder on the aorta. Four different preload conditions were established by volume infusion or wi...

BACKGROUND AND PURPOSE The effect of antihypertensive drugs on autonomic neural control of the cerebral circulation remains unclear. This study was designed to compare middle cerebral artery mean blood velocity responses to acute hypotension with and without alpha(1)-adrenoreceptor blockade (Prazosin) in young, healthy humans. METHODS Acute hypotension was induced nonpharmacologically in 6 he...

To elucidate the role of arterial baroreceptors in the acute regulation of arterial pressure in the conscious animal, arterial pressure was lowered and raised in intact, conscious dogs, and in dogs after bilateral section of both carotid sinus and aortic nerves (total arterial baroreceptor denervation, TABD). Pressure was altered by intravenous bolus injections and continuous infusions of nitro...

BACKGROUND True arterial blood samples are essential in making clinical decisions for respiratory patients. Previous studies using only the Portex Pro-Vent arterial sampler have shown a significant difference between arterial and venous filling times. The goal of this study was to determine whether there is a statistically significant difference between sampler filling times measured at a norma...

Conscious normotensive and two-kidney, one-clip Goldblatt hypertensive rabbits were studied to determine the sensitivity of the arterial baroreflex control of renal sympathetic nerve activity (RSNA) and heart rate. The relations of the mean arterial pressure-RSNA and mean arterial pressure-heart rate were examined over a wide range of blood pressures produced by infusions of phenylephrine and n...