The Fluid Shift from the Vascular Compartment Immediately after Birth

Abstract

In an earlier paper (Gairdner, Marks and Roscoe, 1952) we drew attention to the fact that the haemoglobin (Hb) level during the first day of life is generally much higher than at birth. We questioned the adequacy of the current explanation, that any rise in the Hb level after birth is the result of transfer of placental blood, and suggested that the effect merited study. We now present further observations comparing the composition of cord blood at birth with venous blood taken from a few minutes to a few hours after birth. Hb, packed cell volume, (PCV), plasma protein and plasma sodium have been measured. From these comparisons we conclude that after birth there is usually a shift of fluid, mainly whole plasma, from the circulation. The volume of the plasma shift may be large, amounting to an appreciable fraction of the initial plasma volume, and the effect may consequently prove to be of some clinical importance. MaterialNinety-two infants were studied, of whom 73 were delivered vaginally and 19 by caesarean section. The mother's permission for blood sampling was obtained. Most of the subjects were normal, but a few of the mothers had toxaemia or diabetes; the results in these were similar to those of the normals and have not been separately analysed. MethodsThe cord was always clamped as soon as conveniently possible, both in vaginal and caesarean deliveries. A blood sample was taken by puncture of the umbilical vein between placenta and clamp. Subsequent specimens were taken from an external jugular, internal jugular or femoral vein, or from the ductus venosus (i.e. the continuation of the umbilical vein). The ductus venosus was used particularly for samples within a few minutes of birth. We have found that the ductus venosus can often be catheterized conveniently by inserting a widebore trocar into the terminal part of the umbilical vein in the cord, and threading a polythene catheter through it.Samples were taken into heparinized tubes. Hb and PCV were estimated as described previously (Marks, Gairdner and Roscoe, 1955), Hb being estimated in duplicate in most cases. Plasma protein was estimated by the biuret method, using 0-2 ml. plasma. Plasma sodium was estimated by flame photometer. These four estimations required about 2 5 ml. of blood. Results(i) Change in Hb Level a Few Hours After Birth. In 92 infants samples were taken one to eight hours after birth and compared with cord blood. These included 19 caesarean deliveries, all but two of which were elective, and thus performed before the onset of labour. Results are shown in Fig. 1. Twenty-two cases showed a negligible change (less than ± 5 %) in Hb level after birth; in two cases there was a fall exceeding 5%, while the remaining 68 (74% of the sample) showed a rise exceeding 5 %. This rise amounted to 6-15% in 24 cases, to 16-25% in 23 cases, and to 26 % or over in 21 cases. In five cases the rise exceeded 40 %, the most extreme example being that of an infant born with an abnormally low haemoglobin level of 10i5 g./100 ml. which six hours after birt...

Blood volume and haematocrit studies in respiratory distress syndrome of the newborn.

“…Gairdner, Marks, Roscoe, and Brettell (1958) and Clark and Gairdner (1960) have suggested that there is a diminution in the blood volume in the first 2 hours of life due to an outward shift of plasma fluid. On the other hand, Sisson and Whalen (1960) have demonstrated an increase in the blood volumes which they suggest is derived from blood in a storage space such as the liver.…”

Plasma Osmolality in the Early and Late Neonatal Period with Particular Reference to Low Birth Weight Infants

“…Earlier {Gairdner et al, 1958.Steele, 1962 and recent (Oh and Lind, 1966) examinations suggest that the fluid leaving the vascular space represents in fact plasma whose magnitude of transcapillary loss, and, hence, the resulting hemoconcentration is directly correlated to the blood or plasma volume at birth. In view of the plasma shift it is understandable why plasma osmolality remains stable during the early neonatal period in spite of the abrupt and marked redis tribution of fluids between intra-and extravascular compartment.…”

“…To our knowledge no systematic studies on body fluid osmolality are available which could form a basis for investigations of the developmental changes of osmolal homeostasis in the newborn infant and for the quantitative assessment of iatrogenic hyper-and hypoosmolality induced by various intravenous therapeutic procedures at dif ferent postnatal ages. While earlier (Pincus et al, 1956;Gairdner et al, 1958) and recent investigation provided data on plasma sodium concentration in cord blood and infant's blood within a few hours, or days of birth, much less attention was paid to measurement of total plasma osmolality. Since, however, plasma sodium content is a useful practical indicator of osmotic concentration, the observations on sodium level can be used as rough approximations of os molality of body fluids.…”

The Effect of Blood Volume Expansion on Gastrointestinal Oxygenation in Piglets

“…In the human neonate, placental transfusion results in hypervolemia, followed by compensatory plasma transudation and restoration of normovolemia (3,22). Thus, the circulatory consequences of placental transfusion include both intravascular hypemolemia and subsequent expansion of the extravascular space.…”

“…Placental transfusion during parturition produces rapid intravascular volume expansion in the neonate, followed by plasma transudation and a shift of the volume load to the extravascular, or interstitial space (3,19). These circulatory events are clinically expressed in several ways, including alterations in neonatal renal (1 8) and respiratory ( 19) function.…”