What is a positive Trousseau's sign an indication of?

A positive Trousseau's sign is considered an indication of hypocalcemia. This sign is elicited by inflating a blood pressure cuff around the upper arm, which temporarily occludes the brachial artery and can lead to muscle spasms or twitching of the hand and forearm. This response occurs due to low levels of calcium in the blood, which affects the excitability of nerves and muscles.

In the context of hypocalcemia, the decreased levels of calcium disrupt normal neuromuscular function, leading to hyperexcitability. This might further manifest as muscle cramps, spasms, or tetany. Trousseau's sign, along with Chvostek’s sign (tapping the facial nerve leading to contraction of facial muscles), serves as a clinical test indicating the presence of hypocalcemia and helps clinicians identify patients at risk for complications.

Other electrolyte imbalances, such as hypokalemia, hypophosphatemia, and hyponatremia, do not specifically result in the characteristic muscle contractions seen in a positive Trousseau's sign. Each of those conditions has its own clinical manifestations but does not directly correspond to the symptoms or tests associated with hypocalcemia.