The Sting of the Assassin (Cont.)

Outside Magazine October 2001

Page:

The Sting of the Assassin (Cont.)

NO ONE KNOWS exactly what's in the venom ofChironex fleckeri that makes it so potent. Research has been stymied in part because the venom is susceptible to heat, making it difficult to analyze without chemically altering it. Scientists believe that the venom, made up of proteinlike substances, contains three major toxins: one that damages skin, one that affects the blood, and another that works, sometimes fatally, on the heart and other organs. The incredible skin pain, some have speculated, could be due in part to a compound called 5-hydroxytryptamine, found in the tentacles of many types of jellyfish as well as in bees and stinging nettles. It has been estimated that Chironex venom enters the circulatory system of a healthy person within 20 seconds of the sting, as the tiny tubules inject thousands of doses of venom directly into the capillaries just beneath the skin. This is unlike snakebite, in which the snake's fangs leave a few large deposits of venom that take hours to be absorbed into the tissue.

Mary's "fight or flight" response—which might be useful if she were fending off a shark attack—had sent surges of adrenaline through her body, boosting her heart rate from 80 beats per minute to its maximum exertional rate of 180. Her rapidly contracting muscle tissues, which demanded oxygen, triggered a rush of blood from her heart and lungs to her limbs and back again. The needs of her muscles, induced by her panic, helped carry the venom from the capillaries beneath her skin straight to her heart.

The venom quickly did its work. Something in the venom—a cardiotoxin, as it's known—began to wreak havoc on her heart's electrical system, causing a big upsurge in the number of positively charged calcium ions entering the cardiac muscle cells. An excess of calcium ions inside these cells causes spasms in the carefully timed contractions of the heart, a bit like throwing a jug of water onto the circuitry of an electric motor.

Mary's heart abruptly lost its rhythm. The ventricles, the heart's two high-pressure pumping chambers, normally contract smoothly from the bottom up, squeezing blood out the top. But theChironex venom triggered chaotic contractions originating somewhere in the middle of the ventricular walls and firing at an arrhythmic pace of 240 beats per minute. Instead of a powerful, coordinated stroke pushing out three ounces of blood with every beat, her heart dribbled less than a twentieth of that amount. Her blood pressure plummeted. The blood flow to her brain slowed to a trickle. The bright circle of sunlight and seawater and pain faded to a twilight pool.

Her head dropped in the water, bobbed up, dropped again. She wasn't screaming now, though her lesioned arms still waved vaguely, keeping her afloat.

"Mary! Mary!" Gil shouted.

She gave no indication that she heard him.

Gil had never seen anyone die before, but it was perfectly clear to him that she was almost dead. He knew he'd replay this moment for the rest of his life: Mary floating face down, arms stirring dully, hair gently fanning out on the water, while he stood frozen and simply... watched.

He moved one foot forward across the sandy bottom. Then the other. Suddenly he was churning through the water toward her, no longer caring what happened to him, as long as he acted. Thigh-deep...waist-deep...chest-deep. She lay floating only ten feet away. He shuffled two steps closer. He stretched out his right arm, reaching up over the surface of the water, above any stray tentacles. He touched her left hand, feeling the sticky softness of the strands that were wrapped around it. He pulled away. Oddly, he felt no stinging. Were they somehow spent?

They were not. He felt no sting because the tiny venom-filled tubes launched by the nematocysts didn't have enough power to penetrate the thick skin of his palm. The hair on the back of his hand also acted as a barrier to their penetration. Women and children, who have less hair, smaller bodies, and more tender skin than men, are therefore more susceptible toChironex stings. Even a thin layer of nylon can repel stings, as discovered by Australian surfers and lifeguards, who pull pantyhose over their legs and torsos when swimming in jellyfish-infested waters.

Gil reached out again and gripped her left wrist, between tentacles. Adrenaline pumping, he dragged her 122 pounds through the shallow water and pulled her up onto the beach.

He dropped to his knees beside her. Strands of tentacle clung to her torso, etching purplish-brown weals on her skin. If she survived, the tissue could die, and she might be scarred for life with the whorled markings, as if tattooed by a heap of rope.

Gil remembered the sign posted at the beach near town: "Flood sting with vinegar." Dousing tentacles with vinegar prevents the nematocysts from firing. Gil had noticed the jugs placed at regular intervals along that beach, but there was no vinegar here. He grabbed his towel and wrapped it around his right hand, plucking the tentacle fragments from Mary's skin.

The severity of aChironex sting depends largely on how much tentacle has made contact with the victim; about six feet is considered the minimum for a lethal dose in an adult human. By some estimates, a full-grownChironex contains enough venom in all of its tentacles to kill up to 60 people.

About 15 feet of tentacle had made contact with Mary's skin. Gil rolled her over. He watched her sand-covered abdomen for the rise and fall of breathing. Nothing.

Years earlier Gil had taken a course in CPR and then later, a refresher course before their trip to the Bahamas. He pinched Mary's nostrils, placed his open mouth over hers, and exhaled once. Her chest rose slightly as the air went in, then fell. But what about her heart? He felt for a pulse in her neck, holding his trembling fingers as still as he could. Nothing. Her heart was still in wild spasms, pumping at over 200 beats per minute, but her blood pressure was too low to register a pulse.

Gil had to become both her heart and her lungs, at least long enough for her body to recover from the venom's shock and regain some of its equilibrium. This was not a simple task for one person to perform. He'd have to work quickly. Laying his hands on top of her breastbone, he compressed her sternum, then released and shoved again. After the first 15 thrusts he gave her two more quick breaths, followed by another set of 15 compressions. His rapid, steady thrusts kept blood moving up her carotid arteries and into her brain at one-third its normal flow—not a lot, but enough to deliver the crucial supply of oxygen to the brain's starving tissues.

Thirty seconds passed. A minute. The pumping action he forced on her heart began to wash away the poisoned blood, dispersing it throughout her body.

Another 40 seconds passed. Sweat flew from Gil's face and arms. He didn't know how long he could keep this up.

Embedded in the roof of the right atrium is the heart's own pacemaker, a bundle of muscle fibers called the sinoatrial node that generates its own electrical charges. As it fired, it tried to send impulses through Mary's heart like a wave, ordering contractions of the exact proper muscle tissue in the exact proper sequence. But tiny holes in her cell membranes remained opened from the venom's effect, and the calcium ions passed too easily into the cells, keeping the muscle in spasms. For her heart to resume its normal rhythm through CPR, Gil would have to keep up the chest compressions long enough for the venom to degrade, 30 to 40 minutes.

The second minute passed. Gil stopped again to probe for a pulse. He felt something. But what? He placed his hands on her sternum and resumed the frenzied pace of chest compressions punctuated by breathing. Another minute. He was panting so hard now he had to pause to catch his breath. It seemed that he'd been working over her for a very long time. Was this futile? He felt again for her pulse, trying to understand what he sensed in his fingertips. Then he heard a small gasp. He looked at her chest. Another gasp. He saw her rib cage fall slightly.

He thrust his ear to her chest. He could hear something. Was it thelub-dub of his own thumping heart or the sound of her heart valves opening and closing as they should?

"Keep going, Mary!" he shouted.

He lifted his head from her chest. Now her breath came in small gasps.

"That's right, breathe, Mary,breathe!"

Her limbs stirred, brushing against the sand as if she remembered, deep in her subconscious, that she was supposed to swim. Her head lolled back and forth. Her eyes were still closed. Gil knew he'd have to pick her up in his arms and haul her to the car, then jounce over the rutted beach road to the highway to town. They'd arrive in 20 minutes, and the hospital would surely have a ready supply of the box jellyfish antivenin. Quickly administered, the antivenin (made from the blood of a sheep that's been immunized to the venom) does much to ameliorate the jellyfish's sting. She could relapse—Chironex fleckeri victims sometimes show a brief improvement and rising blood pressure before suddenly expiring—though Gil didn't know this. They'd put her on a respirator if she needed it, and give her medicine for the pain that would return once she woke up.

What would happen then? he wondered. What would they say to each other? Would she in some way be a different person, not pushing him always? And would he be different, not hanging back? Could a brush against this tentacled creature that had no brain, no sense of good and evil, change a life, two lives, a marriage?

He jumped up. He ran to the pile of clothes they'd shed on the beach and grabbed his daypack with the car keys in it. He knelt beside her again.

"Come on, Mary, come on!"

He allowed himself to wish now, to hope. Gil knew that he'd done everything for her that was humanly possible, far more than he would have ever guessed he could do. As her chest continued to rise and fall, tears began to fill his eyes.

Page: