The jangle of a phone. Breaching a deep, delicious sleep, I reach out and palm the receiver. Jeff's voice: "I need some help." No point quizzing he's my best resident. My eyelids shut against hot pokers of light. It's 3:30 a.m.
In the emergency room, a young Chinese man crouches on a stretcher, bellowing in pain. He springs forward, pushing Jeff and Jackie, the nurse, aside. "Aaahhh,"
he wails. His upper body writhes, as if he's trying to dislodge a sword wedged between his shoulder blades. Anguished, his wife and brother stand by.
"Tell him he must sit back," I say to them. "We must examine him."
The brother, who speaks some English, relays the message. I try to push the man back, only to bounce off his rubbery, muscled body.
"Story?" I ask Jeff.
"Robert Chen, 36, woke up in the middle of the night with sudden severe back pain. History of hypertension. Doesn't always take his meds."
I press on Chen's back in search of a muscle spasm or ligament pull. Every nerve in his body seems to hum with pain. Somehow, Jackie has managed to slip an IV into his arm and attach a blood pressure cuff. It reads 200/120. High. "You should pinpoint the cause of pain before you suppress it," I tell Jeff.
"But the heck with that." I turn to Jackie. "How about 5 milligrams of morphine?"
Ten minutes later, Chen gingerly sits back on the stretcher. His physical exam is normal. We study his chest X ray.
"Mediastinum looks wide, doesn't it?" Jeff says.
On chest X rays, normal lungs appear black. The denser central structures--heart, spinal column, and great vessels--look white. I agree with Jeff. The mediastinum--the space between the lungs--seems wide at the level of the aortic arch.
"He's dissecting," I say, suddenly sure.
"Isn't he a little young?" Jeff exclaims.
Jeff's right. Most cases of aortic dissection arise between ages 50 and 70. Under 40 is rare--but not unheard of.
"Remember Jonathan Larson, the Rent
playwright?" I ask.
"He was 35. Discharged from two emergency rooms before he died."
"One CAT scan, coming up," says Jeff.
The term aortic dissection
originated with René-Théophile-Hyacinthe Laënnec, the French physician who invented the stethoscope in 1819. The aorta, the largest artery in the body, is shaped like a cane, its handle fused to the exit port of the left ventricle. Strong and elastic--absorbing 2.5 billion pulses of blood over a lifetime--the aorta consists of three layers of tissue, just like any other blood vessel. And therein lies its flaw. If the intima--the innermost layer--frays, jets of blood can force their way between the layers. The blood can advance in a corkscrew fashion, or backward and forward at once, choking off any aortic branch in its path. If it closes down a carotid artery, you have a stroke; if it closes a spinal cord artery, you're a paraplegic.
A young woman once came to the emergency room after passing out with a sudden headache. The doctor said he knew a hysteria-enhanced migraine when he saw one. He gave her painkillers. An hour later she said her right leg was hurting. More analgesics. A nurse found that the pulse in the right foot was weak, but the doctor ignored her: What could a headache have to do with leg pain? The patient's aorta had dissected from high in the chest, at the arch, to the iliac artery feeding the right leg. She died on her way to the operating room.
The range of presentations for aortic dissection defies belief. The classic story starts with a sudden tearing pain between the shoulder blades. But there are reports of painless dissections causing "unexplained" cardiovascular collapse. Most devilish of all, an aortic dissection can impersonate a heart attack. Not only does it trigger left-side chest pain, but it can cause the electrocardiogram changes that make doctors reach for clot-busting drugs. Whether the EKG abnormalities stem from the adrenaline surge of life-threatening stress, or from occlusion of a coronary artery, is not always clear. What is clear, however, is that thrombolytics, which open plugged coronary arteries, will wipe out the body's clotting--and will prove lethal in a patient with an aortic dissection.
A dozen conditions may predispose to dissection, but high blood pressure leads the pack, causing 70 to 90 percent of cases. Other triggers include Marfan's syndrome, cocaine use, and even pregnancy, but a disquieting number of the 15,000 to 30,000 cases in the United States each year arise in young people with no risk factors.
Up in the CAT scan suite, Mr. Chen's morphine is wearing off. We are about to inject intravenous dye to light up his aorta; if he moves, the scan will be botched. But he won't lie down on the scanning platform. More morphine: 5, then 10 milligrams. Finally, he is quiet.
As the scan whirs and the images come up on the screen, Jeff whistles.
"Look at that flap," he says.
Mr. Chen's aorta appears as a bright unchanging disk amid the successive cuts of chest and abdominal organs. Coursing down its center is a shadow as wispy as a hair on a camera lens. This is the intima, peeled off the outer aortic wall. It now, almost literally, flaps in the breeze. The peel-away extends from the aortic arch past the renal arteries, from collarbones to belly button.
Dissections kill in one of three ways: by closing off vital arteries, by back-flooding into the sac around the heart and choking off the heartbeat, or by rupturing the outer aortic wall. Bizarrely, the advancing column of blood can find its way back into the main aorta, effectively fixing itself. This waxing and waning of dissections means they can smolder and shift for days. Odd as it sounds, there's nothing inherently lethal about a double-barreled aorta. But most patients succumb within days; many by two weeks.
Jeff and I hurry Mr. Chen back to the emergency room. Mercifully, he is asleep.
Treatment is straightforward: Slam down blood pressure to dampen the shearing forces on the aorta. And surgery. Pioneered in 1955, the definitive treatment of most dissections of the aorta is to cut out the diseased segment, replace it with a synthetic graft, and painstakingly reconnect all its tributaries.
Jeff calls the vascular surgeons uptown while Jackie starts a nitroglycerin drip, which will dilate Mr. Chen's clenched arteries and lower his blood pressure. I give him labetalol, a drug that blocks both the adrenaline beta receptors that drive the heart, and the alpha receptors that constrict the arteries.
Jeff calls over, "Vascular says they can't take him. We have to call cardiology first."
Cardiology doesn't respond. The transfer ambulance will take 45 minutes. Minutes before the ambulance's estimated arrival, I reach for the phone, but it rings first. It's the vascular surgery fellow.
"We'll accept him," he declares, as if this were an option.
"Good," I say, "because he's on his way."
A few weeks later, I run into the head vascular surgeon. "You guys are getting fast down there with the dissections." He smiles. "Two-hour turnaround time. Not bad."
I say nothing about sluggish underlings.
"And Mr. Chen?"
"Big dissection," he replies, "stem to stern. He's having a little trouble with his kidneys and has some fluid retention. Otherwise doing nicely. But he really shouldn't be so young."
That's what the textbooks say, but cases like Mr. Chen's mean you can never let down your guard.
For an overview on aortic dissections, visit the on-line journal E medicine: www.emedicine.com/emerg/topic28.htm