Potassium and Sodium Homeostasis in the Neonate

Abstract

MANAGEMENT OF FLUIDS AND electrolytes is crucial when caring for the high-risk neonate. Fluid and electrolyte requirements vary with developmental limitations related to gestational age, as well as by the diagnosis or disease process involved. Management is further complicated by the physiologic contraction of extracellular water, and subsequent weight loss, that occurs during the first week after birth. Therefore, fluid and electrolyte balance requires meticulous assessment of both physiologic and clinical data in conjunction with laboratory data. Data to be followed include heart rate, blood pressure, skin turgor, capillary refill, mucus membranes, fullness of the anterior fontanel, daily (or more frequent) weights, intake and output, creatinine levels, and daily (or more frequent) serum electrolyte levels.1,2 Very low birth weight (VLBW) and extremely low birth weight (ELBW) infants may require an assessment of weight as often as three times a day and sampling of serum electrolytes as often as every four to eight hours.1