Final answer:
A nurse should expect to find increased hematocrit in a client with diabetes insipidus, as it is associated with dehydration due to the body's inability to conserve water.
Step-by-step explanation:
The nurse assessing a client with diabetes insipidus should expect to find increased hematocrit. Diabetes insipidus is characterized by an inability to conserve water, leading to excessive water loss, dehydration, and consequently a higher concentration of blood cells, which is reflected by the increased hematocrit value. Diabetes insipidus is a condition characterized by excessive thirst and frequent urination. It is caused by a deficiency of antidiuretic hormone (ADH), which regulates the amount of water reabsorbed by the kidneys. As a result, the urine produced by someone with diabetes insipidus will have a high volume and low specific gravity.
The other options are inconsistent with the disease: a decreased heart rate is not typically associated with diabetes insipidus, high urine specific gravity is unlikely because the urine is typically dilute, and a low BUN level is not a characteristic feature of this condition.