Sample Health Care Scenario: Cerebral Embolism

Tom is a 21 year-old who had a congenital heart valve defect that required replacement of a defective valve that he had received when he was 13 years-old. He had lived a relatively normal life, having participated in sports throughout high school and college. He had the valve replacement yesterday, but had bled slowly through the night and had to return to the operating room this morning because the bleeding continued despite multiple doses of protamine (used to reverse the effects of heparin, an anticoagulant) and multiple units of fresh frozen plasma.

When I came on duty in the large surgical intensive care unit of a Midwestern metropolitan, teaching medical center, I was assigned to the room where Tom would be admitted following his second surgery. A procedure that normally should take less than an hour, had taken nearly 3 hours and he had to go back on cardiopulmonary bypass for about 40 minutes -- clearly this was not to be the normal "routine" re-op case.

Approximately 1 hour after the beginning of the shift, Tom was returned to the ICU. As per routine for this unit, his anesthesia had not been reversed, which meant that he was still pharmacologically paralyzed and unresponsive, and thus he remained intubated and ventilated (on a ventilator). My assessment revealed that Tom was slightly hypothermic (about 95 degrees), pulses were palpable but weak in four extremities, his lungs were clear, and there were no bowel sounds. His blood pressure and pulmonary artery pressures were in acceptable ranges, his urine output seemed adequate and his chest tube output was considerably less than it had been the previous evening. His pupils were about 1.5 mm and sluggish to light. Something about Tom bothered me. I couldn't put my finger on it at the time, but he fit into a category that nurses use, called 'just doesn't look right.' So, I decided to keep a close watch on him. Fifteen minutes after his admission, as I began my re-assessment, I decided to look at his pupils again (something that would not be routine). As I said, I was bothered by something. I was shocked to see that his right pupil was completely dilated and nonreactive to light. This is an ominous sign because it indicates there has been an increase in intracranial pressure. I stat-paged the cardiovascular surgical fellow, who came immediately and was as shocked as I was -- so much so that he really didn't know how to intervene. I suggested an infusion of Mannitol (an osmotic diuretic) to reduce intracerebral pressure, which we infused quickly and noted a reduction in the size of the pupil. However, Tom continued to deteriorate and show signs of progressive cerebral damage. Two days after this episode, he was declared brain dead and the family had him removed from the ventilator.

Autopsy revealed that Tom had sustained multiple emboli (blood clots) to his brain. The development of emboli is always a risk after this surgery, but even more so with increased 'pump' time. It was probably this factor, and the unusual course of his surgical course that gave me the uneasy feeling that something was (potentially) wrong.