Renal and Metabolic Disorders
Core concepts
Understand neonatal fluid and electrolyte management, including insensible losses in preterm infants and the risk of hyperkalemia and hyponatremia. Know hypoglycemia - risk factors (infant of diabetic mother, preterm, small or large for gestational age, sepsis), symptoms (jitteriness, lethargy, poor feeding, apnea), and treatment thresholds and recheck intervals. Understand hypocalcemia, including the early and late forms and the association with maternal diabetes and prematurity. Recognize acute kidney injury in the newborn, oliguria, and the significance of a single umbilical artery or renal anomalies. Know maternal diabetes effects on the fetus: macrosomia, hypoglycemia, RDS, and congenital anomalies.
Traps
Questions often test that asymptomatic hypoglycemia may be treated with feeding while symptomatic or severely low glucose requires IV dextrose. Another trap: forgetting that the infant of a diabetic mother has hyperinsulinism and is at risk for hypoglycemia after delivery. Also beware assuming a single low glucose value requires no follow-up.
Worked example
An infant of a diabetic mother has jitteriness at 2 hours of life with glucose 30 mg/dL. Rule of thumb: symptomatic hypoglycemia requires IV dextrose; asymptomatic low glucose may be treated with feeding and recheck in 30 minutes per protocol.
Study focus
Link maternal metabolic disease to neonatal risk and know treatment thresholds.