A patient with a closed head injury secondary to a motorcycle accident has a urine output of 6 to 8 L/day and electrolytes are within normal limits.The nurse draws a serum ADH level and conducts a water deprivation test.With no intake for 4 hours,there is no change in the patient's polyuria.The serum ADH level is low.These are an indication of:

Question

Quizplus · Accepted Answer

The patient's low serum ADH level and lack of response to the water deprivation test suggest neurogenic diabetes insipidus, which is caused by a lack of ADH secretion or a lack of response to ADH. Syndrome of inappropriate antidiuretic hormone (SIADH) would have high levels of ADH, whereas psychogenic polydipsia and osmotically induced diuresis would not present with the same set of symptoms.

A Patient with a Closed Head Injury Secondary to a Motorcycle