Blog | Friday, November 13, 2015

Hyponatremia, and he fell--a case study

A 78-year-old man was admitted after a fall with no fractures.

His labs on admission:

125, 89, 33, 128

5.2, 22, 2.1

He has a history of B-cell lymphoma.

His serum osm was 273 and urine osm was 263.

Clinically he is euvolemic (i.e., not orthostatic). He is bradycardic (we stopped his beta blocker given for previous CABG).

He is new to our hospital, we do not know his previous renal function.

Your question: What further tests do you want? Can you speculate on his diagnosis?

One doctor had the proper instincts. The patient had a random cortisol of ~4 (normal 8 or greater). His stimulation test had a peak cortisol of 8. His ACTH was significantly elevated.

A CT scan showed bilateral adrenal involvement.

Hydrocortisone (25 b.i.d) and fludrocortisone (0.1mg) led to a dramatic improvement in his energy level and his laboratory data.

This is a classic presentation of adrenal insufficiency secondary to a tumor destroying glandular tissue.

db is the nickname for Robert M. Centor, MD, FACP. db stands both for Dr. Bob and da boss. He is an academic general internist at the University of Alabama School of Medicine, and is the Regional Associate Dean for the Huntsville Regional Medical Campus of UASOM. He still makes inpatient rounds over 100 days each year. This post originally appeared at his blog, db's Medical Rants.