A 72-year-old man with a history of diverticulitis is admitted to the intensive care unit with chills, fever, malaise, and confusion. He resides in a nursing home, and has been complaining of severe abdominal pain. His temperature is 40°C (104°F), his blood pressure is 84/58 mm Hg, his pulse is 111/min, and respirations are 22/min. He remains hypotensive despite aggressive hydration. Physical examination shows rebound tenderness and guarding of his abdomen. A CT of the abdomen to shows pneumoperitoneum as well as bilateral adrenal hemorrhage. Laboratory studies show:
Sodium 130 mEq/L
Potassium 5.1 mEq/L
Glucose 70 mg/dL
Which of the following laboratory findings is most likely present in this patient?
Elevated renin activity
Reduced adrenocorticotropic hormone
Reduced corticotropin-releasing hormone
C!! The correct answer is C. Lab findings indicative of low aldosterone must mean renin is elevated. This patient is suffering from septic shock. The pneumoperitoneum on CT indicates that bowel perforation occurred, from a ruptured diverticulum, for example.
Severe septic shock can lead to destruction of the adrenal cortex, which causes loss of mineralocorticoids as well as glucocorticoids (i.e., Waterhouse-Friderichsen syndrome). The adrenal gland receives a rich blood supply from the aorta and the inferior phrenic and renal arteries, which form a subcapsular plexus. Adrenal necrosis and hemorrhage may occur during hypotension and stress, resulting in vascular engorgement and stasis.