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Biomedical subjects

S Hellerstein

Publications and source records attributed to S Hellerstein.

At least 91 records · Page 5Linked to original sources
PubMed1977

The effects of single infusion of hypertonic sodium bicarbonate on body composition in neonates with acidosis.

Acid-base equilibrium and plasma and red blood cell water and solute were evaluated in a group of asphyxiated, acidotic neonates prior to and following infusion of hypertonic NaHCO3. The dose was calculated to correct the deficit of base in a bicarbonate space of 400 ml/kg and was given at a rate of 0.3 mM NaHCO3/kg/minute. All of the infants with RDS and two of the five with other forms of asphyxia received ventilatory assistance during the infusion. The quantity of base infused was sufficient to alter acid-base balance and shift whole blood and red blood cell pH values toward normal. The changes in body composition 3 minutes following the infusion indicate that the osmotic load imposed by the hypertonic NaHCO3 caused a shift of solute-free water into the interstitial and intravascular fluids. During the period from 3 to 30 minutes following the infusion there was redistribution of extracellular water and solute so that plasma volume and [Na]PL decreased. Since there was no evidence of an intracellular shift of solute, we hypothesize that the changes in body composition between 3 and 30 minutes postinfusion were in part the consequence of gradual penetration of transcellular fluids by Na. Osmotic inactivation of ECF Na by sequestration with connective tissue polyelectrolytes may also play a role. These studies' do not provide an answer to the clinical problem of whether the beneficial effects of prompt correction metabolic acidosis outweigh the potenially harmful effect of the osmotic alterations that accompany rapid infusion of hypertonic NaHCO3.

Acid-Base Equilibrium↗
PubMed1976

Effect of time and temperature on blood P50 and 2,3-diphosphoglycerate measurements.

The oxygen affinity of hemoglobin is affected by various factors, including blood pH and erythrocyte 2,3-diphosphoglycerate. The latter and blood P50 values are unchanged when aliquots of blood from normal individuals are permitted to stand at room temperature for as long as 7 h. Our data also show that equilibration in a 37 degrees C tonometer for times ranging from 0.5 to 1.5 h causes no detectable alterations in P50 values.

Adult↗