Main concern

• Salt-wasting congenital adrenal hyperplasia (CAH), usually 21-hydroxylase deficiency
• Primary adrenal insufficiency or adrenal hemorrhage
• Pseudohypoaldosteronism: aldosterone resistance, either genetic or secondary to urinary tract infection/obstruction
• Less commonly: aldosterone-synthesis defects, renal failure, or medication/exogenous potassium effect

What to do now in a clinical setting

1. Repeat urgently from a non-hemolyzed venous/plasma sample. Heel-prick hemolysis can falsely elevate potassium.
2. Put the infant on continuous ECG/cardiac monitoring and obtain a 12-lead ECG.
3. Assess for shock/dehydration, weight loss, poor feeding, vomiting, lethargy, pigmentation, ambiguous genitalia, urine output, and hypoglycemia.
4. Obtain critical samples, if this does not delay resuscitation:
   • Blood gas, glucose, urea/creatinine, bicarbonate
   • Serum cortisol and ACTH
   • 17-hydroxyprogesterone, androstenedione
   • Plasma renin and aldosterone
   • Urine sodium/potassium, urinalysis and culture
   • Renal/bladder ultrasound if pseudohypoaldosteronism/obstruction is possible
5. In an unwell infant or if adrenal crisis is plausible, give stress-dose hydrocortisone promptly after samples, plus isotonic saline with dextrose as needed, under neonatology/pediatric endocrinology direction.
6. Treat hyperkalemia urgently according to neonatal protocol if severe or if ECG changes are present. The CAH emergency guidance recommends cardiac monitoring and immediate treatment of ECG-associated hyperkalemia. Endotext emergency management

How to interpret the hypercalcemia

• Sampling/laboratory issue
• Excess calcium or vitamin D exposure
• Hyperparathyroidism, including neonatal severe hyperparathyroidism
• Subcutaneous fat necrosis
• Renal dysfunction

Practical diagnostic distinction

• CAH/adrenal crisis remains a major concern because hyponatremia plus hyperkalemia is the more dangerous and specific pattern. Classic cortisol deficiency more often causes hypoglycemia, not hyperglycemia.
• One hyperglycemic value may reflect dextrose-containing IV fluids/TPN, stress illness, sepsis, dehydration, medication exposure, or sampling issues.
• It should raise concern for neonatal diabetes only if hyperglycemia is persistent, especially with glucosuria, dehydration, poor weight gain, or low/absent insulin/C-peptide. Persistent hyperglycemia before 6 months is the usual setting for neonatal diabetes; genetic causes account for most such cases. Tietz Textbook of Laboratory Medicine, 7th ed., Monogenic Diabetes Mellitus section.

Immediate implications

1. Check the glucose infusion rate and all IV fluids, including line flushes and TPN. Iatrogenic glucose delivery is a common neonatal cause.
2. Confirm with a laboratory plasma glucose, not only a bedside capillary test.
3. Repeat glucose at short intervals and test urine glucose and ketones.
4. Obtain blood gas, bicarbonate, lactate, renal function, serum/urine osmolality if indicated, and sepsis evaluation based on clinical state.
5. If glucose remains >180-200 mg/dL on repeated checks, especially with glucosuria, discuss treatment with the NICU/endocrine team. Neonatal hyperglycemia management generally starts with reviewing and reducing excessive IV glucose delivery; insulin is reserved for persistent/significant cases with close monitoring. Neonatal hyperglycemia review

Integrating all four values

• True hyperkalemia with salt-wasting: CAH/adrenal insufficiency or pseudohypoaldosteronism
• Dehydration/renal impairment, which can concentrate calcium and contribute to potassium and glucose abnormalities
• Sepsis/critical illness, causing stress hyperglycemia and renal/tubular dysfunction
• Iatrogenic factors, particularly potassium-containing fluids, dextrose infusion, TPN, or blood-product effects
• Laboratory artifact, especially hemolyzed potassium, and potentially misleading total calcium if albumin is abnormal

• Hyponatremia
• Hyperkalemia
• Hypocalcemia
• One glucose of 213 mg/dL on day 2

1. Salt-wasting congenital adrenal hyperplasia, usually 21-hydroxylase deficiency
2. Primary adrenal insufficiency, including adrenal hypoplasia or hemorrhage
3. Pseudohypoaldosteronism, due to renal tubular aldosterone resistance, sometimes associated with urinary infection or urinary tract obstruction
4. Renal dysfunction, severe illness/sepsis, or drug/IV-fluid related disturbance

Meaning of hypocalcemia

• Prematurity, growth restriction, perinatal stress/asphyxia
• Sepsis
• Maternal diabetes
• High phosphate intake or phosphate load
• Low magnesium, which can impair PTH secretion/action
• Renal impairment
• Hypoparathyroidism, including syndromic causes such as 22q11.2 deletion if there are relevant cardiac/facial/thymic findings
• Citrated blood-product transfusion, if applicable

How the hyperglycemia fits

• Dextrose-containing IV fluids, TPN, or a glucose-containing line flush
• Stress response from dehydration, sepsis, respiratory illness, or other critical illness
• Sampling from or near an infusion line

Immediate practical workup

• Repeat non-hemolyzed venous electrolytes, ionized Ca, glucose, magnesium, phosphate, renal function, and blood gas
• ECG and continuous monitoring for hyperkalemia and hypocalcemia
• Glucose-infusion/TPN review
• Cortisol, ACTH, 17-hydroxyprogesterone, renin, aldosterone, urine sodium/potassium
• Sepsis screen and urine culture as clinically indicated
• Renal/bladder ultrasound if pseudohypoaldosteronism or obstruction is possible