A 24-year-old man is brought to the emergency department because of a 4-day history of fever and profuse, watery diarrhea. He appears lethargic. Blood pressure is 124/82 mm Hg while supine and 100/70 on standing; pulse is 98/min. Examination shows dry mucous membranes. The abdomen is soft and nontender. Laboratory results are as follows: Which of the following changes are most likely to be seen in this patient?

Question

A 24-year-old man is brought to the emergency department because of a 4-day history of fever and profuse, watery diarrhea. He appears lethargic. Blood pressure is 124/82 mm Hg while supine and 100/70 on standing; pulse is 98/min.  Examination shows dry mucous membranes.  The abdomen is soft and nontender.  Laboratory results are as follows:  Which of the following changes are most likely to be seen in this patient?

Quizplus · Accepted Answer

Eductional Objective: Hypovolemia triggers a variety of compensatory mechanisms to improve tissue perfusion.  These include activation of the renin-angiotensin-aldosterone system (resulting in increased aldosterone and endothelin release), increased vasopressin release, and increased sympathetic tone.

A 24-Year-Old Man Is Brought to the Emergency Department Because