I peeked into the emergency room cubicle as our nurse manager filled me in. “Fifty-two-year-old. Sudden nausea and weakness. Blood pressure’s low: 66 over 40. Only history is obesity surgery four years ago.” Vincent, my fellow attending, stood at the bedside. Mr. Dexter, the patient, was alert and uncomplaining.
“Can’t be too sick. Probably vasovagal,” I thought, walking on. The vasovagal reaction is a catchall term for a transient condition involving fear or pain, such as gastrointestinal upset, that causes low blood pressure, slow heart rate, and in some cases fainting. Patients who have had gastric bypass surgery, a treatment for obesity that dramatically reduces the size of the stomach, often experience such upset. The condition usually passes quickly.
An hour later, Vincent buttonholed me. “Could you help me look at his heart?” he asked. “We’ve given three liters of saline, plus dopamine [a blood pressure booster]. Blood pressure won’t come up. EKG shows no heart attack. No fever, headache, chest pain, or abdominal pain,” he added. “Maybe the ventricle wall isn’t contracting right. EKGs don’t always pick up heart attacks.”
The numbers on the monitor jolted me: still 66 over 40. So much for my snap diagnosis.
I wheeled the ultrasound machine over.
“What does that do, doctor?”
“We’re going to look at your heart,” I told Mr. Dexter. “No chest pain, right?”
“That’s correct, doctor.”
“Tell me again what happened.”
“I was sitting at my desk,” he related. “A wave of weakness hit me, then I got short
of breath. Nausea, too.”
“No pain anywhere?”
“Not that I can recall.”
His heart looked fine. He didn’t have fever, vomiting, or diarrhea.
In medical parlance, a drop in blood pressure is known as shock. It has nothing to do with emotional upset and everything to do with hydraulics. When blood pressure suddenly dips, there are three main possible causes: pump failure (as in a heart attack), leaky blood vessels (an immune response to an overwhelming infection), or fluid loss (bleeding or dehydration). A systolic pressure of 66 meant Mr. Dexter had lost about two quarts of blood. So where was it? The GI tract—the most common source of spontaneous hemorrhage—was clean.
I placed the ultrasound probe on Mr. Dexter’s right flank, where the kidney and liver meet. Anatomists call this spot Morison’s pouch. Luckily for emergency room doctors, it’s easy to find and happens to be where free fluid in the abdomen accumulates. Immediately a broad black stripe showed up between the grayish-looking liver and the right kidney.
“Lots of free fluid in there,” I announced. An ultrasound cannot distinguish between blood and other fluids, but there was no reason for Mr. Dexter to have ascites, the accumulation of fluid in the belly that can come with cirrhosis of the liver.
