Neonatal hypocalcemia | causes, symptoms, diagnosis, treatment & pathology

Neonatal hypocalcemia is a metabolic disorder defined as a total serum calcium level below 8.0 mg/dL (2.0 mmol/L) in term infants, or below 7.0 mg/dL (1.75 mmol/L) in preterm infants, or an ionized calcium level below 4.4 mg/dL (1.1 mmol/L). Calcium is critical for neuromuscular excitability, cardiac contractility, bone mineralization, and blood coagulation. Pathophysiology & Classification Early-Onset Hypocalcemia (First 72 Hours of Life): An exaggeration of the normal physiological drop in calcium after delivery, caused by the sudden interruption of the maternal-fetal calcium transfer via the placenta. Risk Factors: Prematurity, intrauterine growth restriction (IUGR), maternal diabetes, and perinatal asphyxia (which increases calcitonin release and delays parathyroid hormone responsiveness). Late-Onset Hypocalcemia (After 72 Hours / 1 to 2 Weeks of Life): Typically caused by exogenous mineral loads or hormonal imbalances. Causes: High-phosphate infant formulas, maternal vitamin D deficiency, neonatal hypoparathyroidism (congenital or transient), hypomagnesemia (which impairs parathyroid hormone secretion), or renal tubular disease. Clinical Presentation Hypocalcemia increases neuromuscular irritability. While some infants are asymptomatic, symptomatic infants often present with non-specific neurological or cardiac signs: Neuromuscular: Jitteriness, exaggerated startle response, tremors, hypertonia, muscular twitching, high-pitched cry, and focal or generalized tonic-clonic seizures. Respiratory: Apnea, tachypnea, laryngospasm, or stridor. Autonomic & Cardiac: Poor feeding, vomiting, lethargy, prolonged QT interval on electrocardiogram (ECG), decreased cardiac contractility, or hypotension. Diagnostic Evaluation Laboratory Testing: Total and ionized serum calcium, serum magnesium, phosphate, alkaline phosphatase, parathyroid hormone (PTH), and 25-hydroxyvitamin D levels. Electrocardiogram (ECG): Demonstrates a prolonged QTc interval (typically greater than 0.40 seconds in infants), reflecting delayed ventricular repolarization. Management & Treatment #viral #viralvideo #mbbs #mcq #bestmedicalcollegeinindia #neet #biology #mbbsabroad #mcqsseries