Oddly enough, the very same thing that can stop the heart is capable of coaxing it into beating again. Only 50mA of current needs to run through a person's body to shut down its most vital organ, yet a similar shock applied to the chest by means of a machine no larger than a laptop computer can flip a virtual switch to turn it back on. In fact, a defibrillator — that two-paddle instrument that when grasped has a tendency to cause TV doctors to melodramatically shout “Clear!” — is the only tool that can restart the heart. In the time it takes an ambulance to arrive with such an advanced medical care device, though, a shock victim can die if witnesses fail to administer the one technique that many people have a vague idea of how to perform yet often lack the confidence or formal training to use. Cardiopulmonary resuscitation (CPR) won't reverse cardiac arrest, but it will prevent it from becoming a permanent condition.
“When you're doing CPR, you're more concerned with keeping the victim oxygenated until help arrives than you are in restarting the heart,” says Dr. Michael Morse, an associate professor of electrical engineering at the University of San Diego and an expert witness in more than 100 electrical shock cases from Portland, Ore. to Orlando, Fla. Unlike what many movies and television shows may lead you to believe, the chest compressions associated with CPR won't force the heart to start beating again. Instead, they do the heart's job while it's temporarily sidelined, pushing blood to the brain and keeping it alive until trained medical personnel can shock the heart back into its standard electrical rhythm with a defibrillator.
The ability of an electric shock to cause damage to the human body is a function of skin resistance, voltage, the path the current travels, and to a lesser extent the frequency of the electricity. As it turns out, the type of electricity that most people come into contact with daily, albeit safely, can be the deadliest given the right circumstances. The Table above explains how much voltage, skin resistance, and resultant current is necessary to hurt the human body. Given enough moisture on the skin, a 120V, 15A 60-Hz jolt that travels through the chest cavity is sufficient to send the heart's lower chambers into a rapid unsynchronized fluttering called ventricular fibrillation, or v-fib, that renders it unable to pump blood to the rest of the body. With its usual form of transportation shut down, oxygen fails to reach the body's cells — most importantly, those that constitute the brain — and they begin to die. The medical community's best estimates offer an electrical shock victim whose heart has entered v-fib four minutes before death in the absence of medical attention.
Ironically, excessively high currents are less likely to do catastrophic damage to the heart. Such currents will cause the heart to tighten like a clenched fist — a condition called ventricular seizure — and if the victim is knocked clear of the power source, the heart can actually restart itself.
It's at that point on an imaginary risk chart where the lines representing resistance, voltage, current path, and frequency converge — coincidentally the same recipe of electricity most electrical workers are exposed to — where electricity can be the deadliest. And in those brief moments after ventricular fibrillation that are book-ended by life and death, the simple act of applying pressure to the chest in short, timed thrusts with the palms of your hands can give an otherwise helpless victim a chance at survival.
Unpredictable at best.
Electricity's behavior is bound by Kirkhoff's and Ohm's laws, but its effect on the body can never be predicted with any level of certainty. In some cases, it's possible for a worker to receive a lethal shock and appear fine for several minutes before suddenly suffering a heart attack and dying. Such instances are rare, but Morse stresses that this unpredictability is all the more reason to take any electrocution seriously and seek medical assistance even if the victim appears to be fine. “That may be the overly cautious view, but considering the fact that the only other option is death, it's a lot better to make the mistake of going to the hospital or calling an ambulance than to watch a shock victim keel over and die before help arrives.”
The most common scenario, however, is instant defibrillation and collapse. Because the effects of electric shock are so similar to that of a heart attack, it can be difficult to identify what caused the victim to collapse. But because the treatment is the same in either case, it isn't necessary to worry about making such a distinction. “The heart fibrillates, the body de-oxygenates, the person collapses, and within 15 seconds they're unconscious,” Morse says. “To a person who walks into the room five seconds after the shock, it appears to be a heart attack.”
Electric shock may not make the victim's hair stand on end or cause them to light up and then smolder as cartoons often depict, but neither is there a special form of CPR required for treating the condition. A collapsed worker near electrical equipment is, however, an indication of shock, and in such cases the priority of the person responding to the situation should be to make sure that either the offending power source has been shut down or the victim is clear of it.
Running blindly into an energized environment to save a co-worker can only serve to double the body count, so Morse stresses caution in such situations. “The mere fact that someone has received a shock says that there is a presence of electricity,” he says. “There may well be current flowing, putting you at great risk of suffering the same fate as the person who's been injured.”
In the time it takes to pop a bag of popcorn, a witness to electric shock must find the victim, call 9-1-1 or instruct someone else to, determine whether it's safe to proceed with CPR, and begin chest compressions to have any chance of saving the victim. In the absence of any CPR, the American Heart Association estimates that the victim's chances of survival drop by 7% to 10% each minute, further demonstrating the importance of beginning chest compressions immediately.
Even more sobering are the statistics involving the survival rate of cardiac arrest victims. A mere 5% of people in the United States whose hearts stop beating are ever revived. Those numbers aren't narrowed to show how many incidences of electric shock end in death, but as Morse points out, the prognosis isn't good. “Even if people can get to you in a timely fashion, the probability is not in your favor,” he says. “All the time I see cases involving people who have been hit by an electrical jolt, fibrillated, CPR was immediately rendered, and an ambulance was called and got there within five or 10 minutes, and the person still died.”
Despite such empirical and anecdotal evidence that suggests otherwise, the rule of thumb with CPR is that it can only help. In fact, even “bad” CPR from someone who has never been formally trained can be better than standing by and doing nothing. Laura Jackson, CPR and First Aid Program Manager for the Kansas City Red Cross, says inaction can be the death knell for electric shock victims. “We try to tell people to not be afraid and to react because it's better to do something,” she says. “Maybe it won't be the perfect textbook technique, but the fact that they did something may make the difference.”
It used to be that short of driving the victim to the hospital yourself, you could do little more than continue chest compressions and wait for the ambulance to arrive. In recent years, however, advances in automatic heart rhythm analysis and design efficiency have made it possible to put defibrillators on the jobsite and in the hands of electrical workers who have little experience with medical devices. A smaller automated version of the defibrillators that emergency room doctors use to revive trauma patients, automatic external defibrillators (AED) serve the same function and eliminate the decision process necessary to safely shock the victim.
In lieu of the handheld paddles that emergency room defibrillators use for administering the shock, AEDs employ square adhesive electrodes connected by leads to the base unit that are applied directly to the chest of the victim. A series of prompts on the laptop computer-sized base unit will walk the user through the process that begins with testing the victim's heart to determine if it's in v-fib. If it fails to detect a cardiac rhythm that requires shock, the AED won't discharge. If the victim is in v-fib, it will administer a series of three pulses and then give the user time to reassess the victim's condition, taking user analysis out of the equation altogether. “The AED isn't like the paddles you see on TV or at a hospital that trained doctors use to determine the level of shock the person needs,” Jackson says. “It has one level of electricity — 120 joules — and that's the shock that it would give every time.” The shock delivered by the device actually stops the heart momentarily and gives it a chance to reset itself — in effect giving it a hard slap and yelling, “Snap out of it!”
Despite the obvious advantages of such devices, their infiltration into the workplace has been slow. An AED can cost as much as $3,000, a price that many contractors can't justify, especially if they've yet to lose a crew member to electrocution. Steps are being taken, however, to make AEDs easier to obtain. The Community Access to Emergency Defibrillation Act of 2001 became a law in June of 2002, setting aside $30 million in funding to establish public access defibrillation programs.
A lesson from a peer.
It's been 16 months since an employee of SKC Electric has missed a day of work due to a work-related injury. After three years as the director of education and safety for the independent Lenexa, Kan.-based firm, Del Cook has helped management realign the safety priorities of the firm's 200 employees. “Productivity is important, but it's not as important as getting the job done safely,” he says. “We have a service to sell, and that's our electricians. If they're not working, what do we have?”
Under Cook's tenure at SKC, an electrician has yet to receive a shock of any kind, thanks in large part to the firm's strict policy against working on energized systems, yet he still insists that every employee be certified in CPR. All apprentices must have CPR training before achieving journeyman status, and in order to be considered for promotions, they must keep up their certification.
To accommodate the constantly shifting CPR certification needs of the 200 employees in his charge, Cook says he has to schedule at least one training session per month, with either the American Heart Association or the American Red Cross. The typical class size can range from 15 to 20 electricians.
Whether they're receiving their training in Kansas City or in Dayton, Ohio, where Sharon Browning, safety director for IBEW Local 82, recently updated her chapter's safety program to include CPR and AED training, the instruction that participants in the class will receive is the same. Contractors can send their employees to the local branch of the American Red Cross or American Heart Association, which both get their curriculum from the Emergency Cardiac Care Council, or pay to have an instructor certified for third-party training, as Browning and Local 82 chose to do. The Cleveland chapter has trained 140 apprentices in CPR — a requirement, just as it is for open shop electrical workers — and another 63 journeymen have taken the training this year.
Participants in an American Red Cross class will spend about six and a half hours watching videos, listening to the instructor cover things like the principles of “Check, Call, Care,” which is the Red Cross' recommended process for addressing a victim of cardiac arrest, and practicing what they've learned on a mannequin. The Red Cross will travel to a work site to accommodate a class' worth of employees from one company. “We actually have a traveling classroom, so we're able to bring in equipment and offer training almost anywhere,” she says.
Despite her admission that even sub-par CPR is better than nothing, Jackson is quick to point out that it's a skill that must be kept up and should be taken seriously. “If you don't take it often and neglect your training, you will forget it,” she says. “There's research to indicate that you lose a lot of the knowledge you gain in a class within six months.” Red Cross CPR certifications are good for one year.
Talk of requirements or Saturdays spent cooped up in a classroom blowing into the mouth of a plastic, armless mannequin is usually enough to cause most people to invent excuses like “Saturdays are when I have brunch with my mother-in-law,” but Cook says most of his guys will not only eventually appreciate the class but realize they're taking it so they can keep their co-workers safe. “They may complain a little about having to come in for training on a Saturday, but when it comes down to it and they actually do it, they end up appreciating it,” he says. “They're bright individuals, and they want to take care of each other.”
Browning has also found that although they may enroll in the class because they have to, many of the members of Local 82 realize they're learning a skill they can use outside the workplace as well. Her staff of instructors will add training in child CPR for those who want the additional instruction. “Most of these guys are young and have kids, so they're willing to sit there for an extra few hours if it means learning how to save an infant or small child.”
The simple fact is that a heart stopped by an electrical current is unlikely to restart, a sobering thought for members of a trade who deal with energized equipment on a daily basis. “The human body just doesn't respond well to electricity,” says Dr. Morse. For those instances when the heart can be restarted and the victim revived, which are just as hard to predict as the effects of a shock itself, the knowledge that you can keep your co-worker alive should make all of those hours spent pushing on that plastic mannequin's chest seem worthwhile afterall.