Key Assessment Findings
- Genital Examination: Inspect for ambiguous genitalia in all newborns. In 46, XX infants, this presents as clitoromegaly, fused labia, or a urogenital sinus. In 46, XY infants, the external genitalia may appear normal, but hyperpigmentation of the scrotum can be present.
- Salt-Wasting Signs: Monitor for poor feeding, vomiting, diarrhea, lethargy, and failure to thrive in the first 1 to 3 weeks of life. These symptoms indicate an impending adrenal crisis.
- Vital Signs & Hydration: Assess for tachycardia, hypotension, and signs of dehydration such as sunken fontanelles, dry mucous membranes, and decreased urine output.
- Skin Assessment: Note any generalized hyperpigmentation, especially on the areolae and genitalia, caused by elevated ACTH and melanocyte-stimulating hormone.
Diagnostic Workup
- Newborn Screening: Confirm results from the state-mandated newborn screen measuring 17-hydroxyprogesterone (17-OHP). Elevated levels are the hallmark of 21-hydroxylase deficiency.
- Critical Labs: If CAH is suspected, immediately check serum electrolytes. Expect hyponatremia, hyperkalemia, and metabolic acidosis in the salt-wasting form. Also monitor blood glucose for hypoglycemia due to cortisol deficiency.
- Confirmatory Testing: An ACTH stimulation test with measurement of 17-OHP and other adrenal steroids can definitively diagnose the condition. Karyotype analysis is indicated when genitalia are ambiguous.
Emergency Management of Salt-Wasting Crisis
- Fluid Resuscitation: Administer an intravenous bolus of 0.9% sodium chloride (normal saline) at 20 mL/kg to correct hypovolemia. Follow with D5 0.9% NaCl or D10 0.9% NaCl to prevent hypoglycemia.
- Correct Hyperkalemia: If hyperkalemia is severe or causing ECG changes, initiate emergency treatment with intravenous calcium gluconate, insulin and glucose, or sodium bicarbonate as per protocol.
- Steroid Replacement: Administer an intravenous stress dose of hydrocortisone (an initial bolus of 25-50 mg/m², followed by 50-100 mg/m²/day divided every 6 hours). Hydrocortisone provides both glucocorticoid and mineralocorticoid activity.
- Mineralocorticoid Replacement: Once the patient is stable and tolerating oral intake, start fludrocortisone acetate (typically 0.1 mg daily) to replace aldosterone. Sodium chloride supplementation is often required in infancy.
Nursing Priorities and Family Support
- Frequent Monitoring: Perform strict intake and output monitoring, daily weights, and frequent vital sign checks. Assess for signs of fluid overload or worsening electrolyte imbalance.
- Psychosocial Care: Approach the family with sensitivity regarding the diagnosis of ambiguous genitalia. Use gender-neutral terms like "your baby" until a gender of rearing is determined. Provide clear, non-judgmental education on the genetic and hormonal basis of the condition.
- Discharge Planning: Educate parents on "sick day rules," including doubling or tripling the oral glucocorticoid dose during illness. Ensure they have an emergency injection kit for intramuscular hydrocortisone and a medical alert bracelet for adrenal insufficiency.