THE INFLUENCE OF AGE ON THE HAeMOGLOBIN LEVEL IN CONGENITAL HEART DISEASE

Abstract

The haemoglobin content of the blood is a convenient out-patient test, and it has some value in the assessment of cyanotic heart cases both before and after operation (Campbell and Deuchar, 1953 and Campbell, Deuchar, andBrock, 1954). However, the theoretical background to variations of the hemoglobin level in congenital heart disease is not well understood.When the oxygen tension of arterial blood is reduced by altitude, it is comparatively easy to demonstrate an inverse relationship between oxygen tension and hxmoglobin level (Fitzgerald, 1913;Hurtado et al., 1945), but in congenital heart disease the relationship is less obvious. This has variously been attributed to the presence of a severe associated disease (Talbot et al., 1941), to a relative deficiency of iron (Brinton, 1951), and to the complicating effect of possible changes in circulatory flow (Holling, 1952). Little attention has so far been focused on the effect of age of the patient, although it is clear that most high altitude studies have been conducted on homogeneous populations of adults, while the congenital heart series have always included a large and rather varied proportion of children. It was therefore thought of interest to examine data from a large group of congenital heart patients, acyanotic as well as cyanotic, in order to determine the influence of age. METHODSCollection of Blood Samples. The sampling errors introduced by prolonged venous or capillary stasis have been discussed by Peterson et al. (1943). For the present purpose, blood samples were collected directly from the right side of the heart and from the femoral artery during the course of cardiac catheterization. Samples were kept in syringes at 0°C. for a maximum of 2-3 hours. The syringes were lubricated with silicone and contained a trace of heparin and one drop of mercury. Prior to analysis the syringes were shaken for 1-2 minutes to allow mixing and warming to room temperature, and then the contents were transferred anaerobically to Ostwald pipettes. Five or six independent samples were obtained from each subject.Method ofAnalysis. The percentage saturation and total oxygen capacity of the samples were estimated by the Haldane blood gas analysis apparatus (Douglas and Priestley, 1948). The repeatability of measurements by this technique is quite good, the oxygen uptake in any one estimate usually differing by no more than 0-001 ml. from the mean value, and the oxygen capacity rarely differing by more than 0 005 ml. from the mean value (Ernsting and Shephard, 1951). The original technique, using bicarbonate buffers, gave values for oxygen capacity that were 5-7 per cent lower than those obtained by the Van Slyke apparatus (Bierring et al., 1937), this error arising largely from oxidation of the lipoid fraction of the plasma (Litarczek, 1928). However, it has now been shown that if borate buffer of pH1O be used in place of the bicarbonate buffer, there is no systematic difference between the Haldane and Van Slyke methods (Courtice and Douglas, 1947).The Subjects. The p...

Increasing obstruction to the outflow tract in Fallot's tetralogy.

“…Brinton (1951) also showed that hiemoglobin concentration was not related directly to the arterial oxygen saturation and that the packed cell volume and absolute red cell counts were more valuable. Shephard (1956), too, confirmed that the hiemoglobin increased with age in patients with cyanotic heart disease, though his subjects were over 3 years of age. In another group of patients (unpublished observations) we have observed that infants with cyanotic heart disease show evidence of iron deficiency.…”