ADJUSTMENT OF ELECTROLYTES AND WATER FOLLOWING PREMATURE BIRTH (With Special Reference to Edema)

Abstract

Many premature infants are born with an edema which is probably the expression of a physiologic mechanism common to all and intensified in some. Clinical observation has shown this to be a disabling condition and prejudicial to survival. Measures which assist its removal, if otherwise safe, may be advantageous even to prematures in whom edema is not severe enough to be visible. Conversely, procedures likely to augment an edema already present might tend to produce it in nonedematous babies. This investigation has shown an association between manifest edema, an increased breakdown of body protein, and relatively large amounts of Na and K in the urine. All these changes characterize the phase between birth and feeding. Whether or not edema is present, K is rapidly reaccumulated when feeding is begun, and its replenishment reaches an amount considerably above that present at birth. Disappearance of the edema is accompanied by losses of Na and Cl. These alterations occur whether or not water is administered and are ultimately proportional to the amount of edema originally present. Edema usually clears in a day or two but may occasionally persist for a week or more. The time of its disappearance, like the mechanism of its presence, is governed by unknown, perhaps endocrinologic factors. It could not be "washed out" of the body by an increased water intake in the one infant subjected to that procedure. There is every reason to believe its presence would be increased or prolonged by administration of sodium-containing solutions. On the other hand, since K appears to be present in relative insufficiency at premature birth, we propose to investigate the possible advantages of providing added K in early feedings. The clinical implications of the N balances are not clear. In this clinic, the problem is at present met by allowing no intake whatever for as long as four days after birth, the time being governed by the degree of edema. The excess body water and much of the excess Na are usually removed during this phase. Reduction of body weight by as much as 20% may occur, and the concentration of extracellular fluid becomes significantly increased. On the other hand, danger from aspiration is avoided, and when intake is ultimately begun, the organism is no longer encumbered by edema. Should it be possible in the future to facilitate readjustment of body chemistry by early oral administration of specially designed solutions, the resultant advantages would still have to be weighed against the aspiration hazard.