1. Disciplina de Pneumologia, Universidade Federal de São Paulo, São Paulo (SP) Brasil. Tissues obtain energy primarily from oxygen. Adequate oxygen levels in the inhaled air and a preserved ventilation/ perfusion ratio (V • /Q) are the major determinants of oxygen supply to the blood. However, peripheral supply depends on effective oxygen transport to the tissue mitochondria, a critical task t...

-----------------Three devices used to measure hemoglobin oxygen saturation in the extracorporeal circuit were studied and compared to a control. The Baxter Bentley OxySat, Oximetrix Accusat, and the Radiometer ABL4 blood gas monitor were compared to a control, the IL 282 CoOximeter. Fifty one sample points were obtained during all phases of cardiopulmonary bypass with results as follows: TABLE...

A laser photolysis technique has been developed to assess the quantitative significance of the delay time of hemoglobin S gelation to the pathophysiology of sickle cell disease. Changes in the saturation of hemoglobin S with carbon monoxide produced by varying the intensity of a photolytic laser beam were used to simulate changes in the saturation of oxyhemoglobin S produced by variations in ox...

Near-infrared spectroscopy (NIRS) is a noninvasive optical technique to monitor cerebral oxygen saturation at the bedside. Despite its applicability, NIRS has had limited clinical use because of concerns about accuracy, noted by intersubject variability in slope and intercept of the line between NIRS- and weighted-average arterial-cerebrovenous saturation (SMO2). This study evaluated transcrani...

T HE RELATIONSHIP between oxygen tension and the sickling phenomenon has been recognized for over 45 years’ and has become central to our thinking about sickle cell disease. It has been emphasized that sickling of red cells depends to a large degree upon the absolute concentration of reduced sickle hemoglobin.2 In the past two decades many therapeutic strategies have been explored in the manage...

www.ajcconline.org • BACKGROUND Pulse oximetry is commonly used to monitor oxygenation in neonates, but cannot detect variations in hemoglobin. Venous and arterial oxygen saturations are rarely monitored. Few data are available to validate measurements of oxygen saturation in neonates (venous, arterial, or pulse oximetric). • PURPOSE To validate oxygen saturation displayed on clinical monitors ...

T HE RELATIONSHIP between oxygen tension and the sickling phenomenon has been recognized for over 45 years’ and has become central to our thinking about sickle cell disease. It has been emphasized that sickling of red cells depends to a large degree upon the absolute concentration of reduced sickle hemoglobin.2 In the past two decades many therapeutic strategies have been explored in the manage...

Gasometric methods for estimating blood oxygen are time-consuming. This consideration often limits the number of observations which can be made in the course of experiments requiring oxygen determinations. In many cases it is an arteriovenous difference which is particularly desired, as in the measurement of cardiac output by the Fick principle, or the estimation of oxygen consumption by human ...

T HE RELATIONSHIP between oxygen tension and the sickling phenomenon has been recognized for over 45 years’ and has become central to our thinking about sickle cell disease. It has been emphasized that sickling of red cells depends to a large degree upon the absolute concentration of reduced sickle hemoglobin.2 In the past two decades many therapeutic strategies have been explored in the manage...

Regional cerebrovascular oxygen saturation, a quantitative measure of hemoglobin saturation in the combined arterial, venous, and microcirculatory compartments of the brain, can be measured noninvasively with near infrared spectroscopy. We assessed the sensitivity of this aggregate saturation to cerebral hypoxia during transient cerebral hypoxic hypoxia in seven human subjects. Regional cerebro...