Potassium has long been known to be almost completely confined to the intracellular compartment, and the neutral fat present in muscle has been shown to have a low chloride content (1). It seemed probable, therefore, that the error associated with predictions of total exchangeable electrolyte from total body weight would diminish if the variable of depot fat was eliminated by the use of lean body mass as a reference standard. A close correlation of lean body mass with red cell mass (2) and urinary creatinine (3) has previously been shown. Accordingly, measurements of total exchangeable chloride and potassium have been correlated with lean body mass, red cell mass and creatinine excretion in a series of normal subjects.
MATERIALS AND METHODSSixteen normal males and fourteen normal females were studied, their ages ranging from 18 to 81 years and their body weights from 44.5 to 100.2 Kg. They were selected to include both lean and obese subjects, the range of body fat being 5 to 50.8 per cent of total body weight.Total exchangeable potassium (K.) measurements were carried out according to the method of Corsa, Olney, Steenburg, Ball, and Moore (4), four spot urine specimes being collected between twenty-two and twenty-six hours after injection. The urinary potassium concentration was estimated by flume photometry. Siice the short half-life of C1 precluded its use, Br' wag
The observation that a raised venous pressure appears to be of benefit to newborn babies with respiratory distress (Bonham Carter, Bound, and Smellie, 1956) led Bound, Harvey, and Bagshaw (1962) to assess the effect of delayed clamping of the umbilical cord of premature babies. In that investigation it was concluded that the placental transfusion was responsible for the lower incidence of respiratory distress in those premature babies where clamping of the cord was delayed. It occurred to us that these observations might have a common basis in some abnormality of the blood volume in those babies who develop the respiratory distress syndrome (RDS). While we were studying a therapeutic approach to RDS (Hutchison, Kerr, Douglas, Inall, and Crosbie, 1964), we took the opportunity to measure the blood volumes of 17 babies. A group of 20 normal premature babies was also studied by the same technique. This paper describes the results of these studies.The criteria previously described for the diagnosis of severe idiopathic respiratory distress (Hutchison et al., 1964) were common to all cases. These were (1) respiratory grunting; (2) tachypnoea over 60 per minute after the first hour; (3) marked and persistent sternal, subcostal, and intercostal recession during inspiration; (4) cyanosis when breathing air; and (5) characteristic radiographic changes, i.e. diffuse reticulogranular mottling in the lung fields and an 'air bronchogram'.
Material and MethodsThe blood volumes were measured at times varying from 2j to 9 hours after birth. 13 within 9 hours of birth. Although the time of cord clamping was not accurately recorded, the policy in the hospital was such that few, if any, of the babies that were studied would have had the cord clamping delayed.Haematocrits.-These were determined in a microhaematocrit centrifuge (Hawksley Ltd., London). Preparation of RIHSA for Injection.-The RIHSA was diluted with sterile water so that the final solution contained 0 -5 ,uc 1311/ml.; 1% stable HSA was added as carrier.Measurement of Quantity Injected.-The quantity administered was determined by counting the syringe before and after the injection. For this purpose, the syringe was placed into a plastic adapter, thus achieving a constant spatial relation between radioactivity and detector (Fig. 1).Since the blood samples were diluted to 3 ml. with water and counted in a plastic vial, it was necessary to derive the factor relating the activity of 1 ml. RISHA in the syringe adapter to 1 ml. diluted to 3 ml. and counted in a plastic vial. This factor was determined experimentally and used throughout the investigation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.