Certified Emergency Nurse (CEN) Practice Test 2025 - Free CEN Practice Questions and Study Guide

In the context of myxedema coma, the elevated lab value is TSH (thyroid-stimulating hormone). Myxedema coma is a severe form of hypothyroidism characterized by significantly reduced thyroid hormone levels. When the thyroid gland is not producing enough hormones, the pituitary gland compensates by producing more TSH in an attempt to stimulate the thyroid to release more thyroid hormones. Consequently, in patients experiencing myxedema coma, it is common to see increased levels of TSH in the laboratory results.

In contrast, other lab values such as serum insulin, blood glucose, and serum cortisol do not have the same direct relationship with hypothyroid states. Serum insulin may be normal or reduced due to decreased metabolic activity, blood glucose levels may vary, and serum cortisol may be elevated due to stress responses in severe illness. Therefore, TSH is the key lab value that reflects the body's compensatory response in a state of profound hypothyroidism like that seen in myxedema coma.