What should a nurse suspect in a client admitting with symptoms of numbness in their lips and hands, carpopedal spasms, and prolonged QT interval?

The symptoms presented in this scenario—numbness in the lips and hands, carpopedal spasms, and a prolonged QT interval—strongly align with hypocalcemia. Low levels of calcium in the body can lead to neuromuscular irritability, which is characterized by tingling or numbness, especially in the extremities and around the mouth, as well as muscle spasms like carpopedal spasms.

A prolonged QT interval is another cardiac manifestation of low calcium levels, increasing the risk for serious arrhythmias. These clinical findings suggest that the client is likely experiencing the effects of inadequate calcium, as seen in conditions leading to hypoparathyroidism or other causes of low calcium levels.

In contrast to hypoparathyroidism, which would indeed lead to low calcium levels, the symptoms and their presentation are more closely linked to hypocalcemia specifically, as it reflects the direct impact of low calcium on neuromuscular function and cardiac conduction. Thus, the combination of clinical signs and the prolonged QT interval support the diagnosis of hypocalcemia.