November 25, 2004
Hunting the Pulmonary Embolus ; My Emotional Reaction to This Killer is Excessive and Beyond the Reach of Reason.
A 32-year-old woman is short of breath, but the clinical picture is unusual.
It's about 8 p.m. in the hospital, and I'm admitting this person with what is supposedly just asthma. But she has had severe respiratory distress, and the chest X-ray is negative, and she's otherwise healthy and has never had asthma before.
She's a little nervous, surrounded by her family, breathing OK now because she just got an inhaled treatment. And she's on birth control pills.
While evaluating this patient I learned something about myself: Like Captain Ahab's monomaniacal obsession with the elusive whale Moby Dick, I am obsessed with finding the pulmonary embolus (PE).
My emotional reaction to this killer is excessive and beyond the reach of reason. It infuriates me that there is a diagnosis out there that is consistently killing people under the radar screen.
The birth control pills put this woman at higher risk for PE, so I ordered a CT scan of her chest.
The CT was negative, but I found myself still angry -- somehow remembering, I think, all my patients who have died suddenly and without explanation. All those people whose chests we have crunched down 60 times a minute, sometimes breaking the frail ribs in the process -- all those people we have pumped drugs into in the last few minutes of their lives as their eyes fade. How many of them died of a PE? We never know because nobody lets us do autopsies any more.
In a pulmonary embolus, a blood clot travels from somewhere in the body through the veins, ending up where all the veins end up: in the right side of the heart. From there it is pumped at high speed right into the lungs, where it lodges across some or all of the arteries leading into the lungs.
When a severe embolus occurs, it hurts, and creates mind- squeezing anxiety, and cuts off oxygen to the body, and sometimes kills people, and sometimes the death is instantaneous.
I find it difficult to express my hatred for this illness without descending into vulgar language.
The sad thing about it is that most cases of this disease go undetected. Over the past five decades or so, autopsy studies show that most pulmonary emboli are not even suspected prior to death. The percentage of missed PEs has remained stable over time; we're not doing any better.
The so called "classic signs" -- shortness of breath, chest pain and coughing up blood -- are rarely present. The disease can present in all kinds of ways: back pain, shoulder pain, abdominal pain, passing out, dizziness, wheezing, irregular heart beat, seizure, hiccoughs, cough, or even no symptoms at all.
Probably a more useful way to think about the disease is in terms of its risk factors -- things that predispose one to getting it. The three main classes are blood stagnation, hypercoagulability and injury to the veins.
Normally, blood in the veins is pumped back to the heart through the motion of the body and pressure from muscles contracting. When one is laying in bed for a long period of time, such as during a hospitalization, the blood pools in the veins and is prone to clotting.
Various medical conditions predispose to clotting: cancer is the most common one, along with being on hormone replacement therapy, being pregnant, and a number of blood disorders.
And any inflammation or irritation of the veins can cause clotting: varicose veins, catheters, or an infection in the area are examples.
Whenever these conditions are present, and when the clinical picture is not explained by what is known, you have to suspect pulmonary embolus.
Diagnosing a PE has been difficult in the past -- that's one of the reasons it's been so tricky. Classically you would use a "V/Q" scan, which involves injecting and inhaling trace amounts of radiopharmaceuticals, or an angiogram.
However, recently physicians have started using the new high- resolution CT scans to detect pulmonary emboli, and this seems to work quite well.
Somehow this disease has tapped into my mind's archetypal conception of evil. Looking at it across the abyss of uncertainty, sometimes I feel I can say, with Ahab:
"Towards thee I roll, thou all-destroying but unconquering whale; to the last I grapple with thee; from hell's heart I stab at thee; for hate's sake I spit my last breath at thee."