Acute Renal Failure Management in the Neonate

Abstract

After completing this article, readers should be able to: 1. Define the types and delineate the causes of acute renal failure (ARF) in neonates. 2. Describe the laboratory tests and imaging studies used to diagnose ARF. 3. Explain the roles of fluid balance, diuretics, dopamine, and nutrition in the management of neonatal ARF. 4. Describe the approaches to treating hyponatremia, hyperkalemia, calcium-phosphorus perturbations, acidosis, and hypertension in ARF. 5. Review the outcome and prognosis for ARF in neonates. Acute renal failure (ARF) is a very common problem in the neonatal intensive care unit. The newborn kidney has a very low glomerular filtration rate (GFR) that is maintained by a delicate balance between vasoconstrictor and vasodilatory forces. (1) Although sufficient for growth and development under normal conditions, the low GFR of the newborn kidney limits postnatal renal functional adaptation to endogenous and exogenous stresses. (2) This limited response predisposes the newborn to the development of ARF and is even more pronounced in the low birthweight infant (ie, <2,500 g due to preterm birth or intrauterine growth restriction). (3) Given this predisposition, early identification of ARF in the neonate is essential to preserving renal function. The true incidence of neonatal ARF is difficult to ascertain, but studies have reported that 8% to 24% of newborns admitted to the neonatal intensive care unit present with ARF. These percentages are likely an underestimation because many cases of nonoliguric neonatal ARF, which occurs commonly in sick neonates, are excluded. (1) ARF is defined as a sudden decrease in GFR that results in the progressive retention of creatinine and nitrogenous waste products and the inability to regulate fluid and electrolyte homeostasis. The definition of ARF in neonates is less precise because the serum creatinine shortly after birth is a reflection of maternal renal function, usually less than 1.0 mg/dL (88.4 …