Hypokalsemian

Hypokalsemian is a rarely used term that refers to a state of abnormally low calcium levels in the blood. In modern medical literature, the condition is typically called hypocalcemia (or hypocalcæmia in some British sources). Hypokalsemian is generally considered nonstandard or obsolete, and formal discussion should use hypocalcemia to avoid confusion.

Pathophysiology involves the regulation of serum calcium by parathyroid hormone, vitamin D, calcitonin, and kidney function. When calcium falls, there is increased neuromuscular excitability, which can lead to tingling, cramps, muscle stiffness, tetany, and, in severe cases, seizures or cardiac conduction abnormalities.

Clinical features vary and may include perioral numbness, paresthesias of the hands and feet, muscle cramps, carpopedal spasm, laryngospasm, seizures, and arrhythmias. Physical signs such as Chvostek’s sign or Trousseau’s sign may be present in some patients. Symptoms often correlate with the severity and the level of ionized calcium.

Common etiologies include hypoparathyroidism (often post-surgical), vitamin D deficiency or resistance, chronic kidney disease, magnesium deficiency, pancreatitis, inadequate intake, and certain medications (for example, loop diuretics, bisphosphonates). Transfusion of citrated blood can also acutely lower serum calcium.

Diagnosis relies on measuring total and/or ionized serum calcium, with correction for albumin when using total calcium. Additional tests typically include phosphate, magnesium, parathyroid hormone, and 25-hydroxy vitamin D. Electrocardiography may show QT prolongation in significant cases.

Management depends on severity. Acute symptomatic hypocalcemia is treated with intravenous calcium (often calcium gluconate) with monitoring. Chronic management involves oral calcium supplementation, vitamin D or its active analogs, and correcting contributing factors such as magnesium deficiency. With appropriate treatment, prognosis is generally favorable, though ongoing monitoring is important to prevent recurrence.