What are they doing to Linda Blair or why doctors love a good arterial shunt
For me, the most flinch inducing scene in William Friedkin’s film of The Exorcist is the one where Linda Blair, strapped down and swathed with sterile paper blankets, has a giant needle inserted into her neck by doctors performing the primitive 70’s version of a CT scan. Blood shoots out the exposed end of the needle in rhythmic spurts, keeping time with her heartbeat, spattering her feet until counter-pressure is added in the form of a tube of saline. For me, nothing else even comes close. Not the soup spewing, not even the seriously misused crucifix. After all, none of those other things ever happened to me.
The procedure described above is called a cardiac shunt, and I’ve had a couple. Mercifully, mine were done while I was unconscious, and I never knew what the installation looked like until seeing it in Friedkin’s movie. Basically, a shunt is a direct line into a major artery. Normally, an IV (short for intravenous) goes into a medium-sized vein, where the blood is kept moving only by the regular squeezing of the veins themselves. Arterial blood is pumped much more forcefully by the heart, hence the long-distance spatter when a shunt is installed. Cutting into a major artery is obviously a dangerous business, but both doctors and nurses just love a good shunt.
A shunt is essentially blood on tap. Need to order extra lab work? No problem. Just hook a collection vial to the shunt, twist the tap, and wait a couple of heartbeats. No need to waste time hunting for those annoying little veins. In my early days, a fresh sample of arterial blood was the only way to measure oxygen saturation levels, and a shunt was the only way to get those samples regularly. These days, a bead-shaped probe taped to a fingernail does the same job less intrusively, but shunts still have their uses.
Shunts hardly ever collapse or “blow” the way IVs regularly do, so they’re good for long term patients. Better still, anything forced into a shunt, from drugs to radioactive dye, hits the body all at once. No waiting around for whatever it is to work its way through the system. And since this is a major artery, a large volume of fluid can be pumped in at one time. This is still the ideal set-up for CT scans, where techs often need a highball’s worth of dye delivered within a span of ten seconds. A shunt is still considered mandatory for scans of the brain, the heart, or the lungs.
Recently, shunts have moved away from the neck and over to the major arteries of the arm. I know this because a nurse tried to install one in the upper part of my right arm the last time I was hospitalized. As I have grown older, and the various access points to my circulatory system have become more scarred, it’s gotten more difficult to get a decent picture of my heart. My doctors really wanted one this time, and I had already lost several perfectly good veins in attempts at a CT scans. Finally, they called in the shunt nurse. Time was, shunts were the exclusive province of cardiac surgeons, but now all major hospitals have at least one shunt nurse, a person whose job consists solely of installing and maintaining shunts. To be fair, they are nurse practitioners, all of whom have been through nearly as much education as a medical doctor.
The attempt took place in my hospital room, not a surgical suite. I say attempt because the entire process was a disaster, doomed to failure from the start. The first casualty was pain control. The arteries in the arm are deep, closer to the bones than to the skin. Topical anesthetics like lidocaine are of little use. Normally, the arm is numbed with an electrical stimulator, but this was out of question because of my pacemaker. So began thirty of the most excruciating minutes of my life. The nurse tried no less than three points of entry, pushing and wiggling the needle as the arteries squirmed and rolled. The first one she managed to pin was too small. The needle itself blocked the flow of blood. The last one actually blew, covering my upper arm with a horrible, crimson bruise. At this point, in pain and thoroughly irritated, I called a halt to the proceedings. The bruise took months to fade.
It occurs to me that I have one up on Linda Blair. My shunts were real while hers was a special effect. Then again, I have no idea what her medical history is like. She may very well have had one. Imagine being that shunt nurse. You push your cart of instruments into the hospital room, pull back the pastel curtain, and sitting in the bed is Linda Blair.
Dave Hurwitz
