A 56-Year-Old Man Is Admitted to the Intensive Care Unit

question 88

Multiple Choice

A 56-year-old man is admitted to the intensive care unit due to septic shock from pneumonia and is treated with intravenous fluids, antibiotics, and vasopressors.  Four days later, the patient's hemodynamic and respiratory status has improved, but he has worsening anemia with positive stool occult blood.  He has had no abdominal pain, nausea, vomiting, hematemesis, diarrhea, or hematochezia.  Medical history includes hypertension but no prior gastrointestinal disorders.  The patient is a smoker with a 40-pack-year history.  Medications are intravenous ceftriaxone and azithromycin.  Temperature is 37.2 C (99 F) , blood pressure is 110/66 mm Hg, and pulse is 84/min.  Physical examination reveals right lung crackles and no abdominal tenderness.  Hemoglobin is 10.2 g/dL (12.6 g/dL at admission) , platelets are 180,000/mm³, and leukocytes are 12,000/mm³.  Which of the following is the most likely cause of this patient's anemia?

• A)Acute colonic ischemia
• B)Acute infectious colitis
• C)Diverticular bleeding
• D)Peptic ulcer disease
• E)Stress-induced ulcer

---

Definitions:

Diencephalon

is a division of the forebrain, located between the cerebral hemispheres and above the brainstem, including the thalamus and hypothalamus.

Brain Stem

The part of the brain connecting the spinal cord with the forebrain and cerebrum, responsible for basic life functions such as breathing and heartbeat.

Choroid Plexus

A network of blood vessels in each ventricle of the brain, responsible for the production of cerebrospinal fluid (CSF).

Cerebellum

A part of the brain located at the back of the skull that coordinates voluntary movements and maintains balance.