Electrical Safety: Medical Aspects of Electrical Trauma (part 2)

<< cont. from part 1

Survivor experience

As suggested in Table 6, an electrical event may unfold in fractions of a second. In electrical scenarios, a full second is a "long time," suggesting a 60-cycle event. Compare this to the investigation of an electrical incident, which may take weeks to months. The litigation accompanying such an event typically takes years. Note that the logistics of work do not permit a site to go "on hold" while these activities are under way.

Obviously, survivors experience an electrical event on a different time frame than their workplace. Practically, within a few work shifts, an electrical accident site may be operating routinely. In contrast, the survivor experience may unfold from the moment of the electrical event through minutes of triage to years of rehabilitation.

Worker reflexes

At the scene of an electrical event, survivors rely on their reflexes and senses. As discussed in Section 12, to see, think, and then respond to a scenario demanding a choice requires at least 1.5 seconds. Physical responses to an unfolding electrical event in a shorter amount of time occur with reflexes, such as eye blinks in response to flash, or quick hand withdrawal from a hot surface.

Sometimes the injured survivor can "walk away" from the electrical event. However, this immediate postincident behavior may be deceptive, given the possible medical consequences of electrical trauma.

Instead of walking away, a person may collapse with the loss of regular heart function if a nonfatal electrical contact is made. As the heart's pumping action becomes inefficient, the blood supply to the lungs and brain can be severely limited, reducing the delivery of oxygen and glucose (the body's fuel). When oxygen and glucose are not available because of circulation failure, a survivor cannot breathe or remain upright or awake. Survivors may later recall this experience as "near death" or "out of body." In this time, successful cardio pulmonary resuscitation (CPR) is essential to rescue the affected individual, as discussed in Section 8. Anyone who needs CPR should then be sent to the hospital without exception for further evaluation and treatment.

Once help arrives at the scene, an alert electrical incident survivor is routinely questioned.

As first responders, emergency medical technicians, or paramedics become involved, survivors are expected to tell these clinicians a "history" of their difficulties.

Even while survivors need to explain how they were injured to first responder and emergency medical providers, it may be difficult for employees to respond if their thinking ability is clouded by the event or if the electrical accident has occurred quickly. For example, a 30-cycle event in a 60-Hz electrical power system occurs in 0.5 second. A scenario that takes a half second to complete is faster than most people can even recognize, much less remember in detail.

Triage and Medical Evacuation

Medical triage, evacuation, and treatment require minutes, hours, and longer, as discussed in the following sections. In the emergency or first response period, American Burn Association (ABA) Advanced Burn Life Support guidelines outline triage, initial resuscitation, and emergency transport protocols. On admission to the emergency medical services, physical examination, laboratory studies, and diagnostic radiology evaluation are prioritized, depending on the patient's clinical situation.

When the survivor cannot remember accident details, little information is available to clinicians for rigorous decision making about the exposure circumstances, possible mechanisms of injury, and need to obtain extensive laboratory studies or diagnostic imaging.

If in a coma or heavily medicated, the survivor may not be able to coherently answer questions like the following:

• What happened in terms of the energy, such as volts, amps, and cycles?

• Was there a blast or an explosion?

• Was the space small or confined?

• Did you fall or lose consciousness?

• Were you wearing protection?

• Did you need CPR?

• Was anyone else hurt or killed at the scene?

Further confusion between a survivor who becomes a patient and clinicians may arise when the circumstances around the injury event simply cannot be immediately known. For example, when an electrical accident occurs in a work situation believed to be "safely de energized," engineers may investigate over weeks to months to establish the "root causes" and available energy to the fault. During that investigation time, electrical incident survivors may be repeatedly asked by clinicians, "What happened? Why didn't you turn off the power?" From the survivors' perspective, each episode of questioning by clinicians is an opportunity for self-doubt about their accident recollection.

Commonly, survivors report they were doing a manual task or handling equipment when caught in an electrical event. Upper extremities-the body from the fingertips to the shoulders-are involved most often in electrical trauma. However, depending on the employee's body position at the time of the electrical fault, contact wounds from electrical shock may be found in more than one body location. Current flow in the body may follow a path as short as the distance between two fingers, or as long as the length from the employee's arm span or height in a standing position.

From a clinician's viewpoint, knowledge of the electrical event's voltage conditions alone is of limited helpfulness because the extent of a survivor's electrical injury is a function of the power frequency energy transfer due to a combination of the current density in the tissue and the contact duration. The geometry of the body influences the current density.

Similarly, from a medical perspective, the heat, radiation, and pressure damage to the body are predicated on the efficiency of the electromechanical and electrochemical coupling between the hazardous source, the event space, and the body. This information is not usually available to the medical team and may only come to light after months of investigation.

Physically, when an extremity is exposed to electrical current, the skeletal muscle in the current path through the extremity can be significantly injured from the electrical effect, extreme heat, and damage to proteins. At the electrical accident site, first responders may see minimal skin wounds, or they might notice profound charring and vaporization of tissue.

Even in the absence of impressive wounds, the survivor's risk of amputation can be high.

After a severe electrical contact injury, a survivor's injured muscles can swell massively, resulting in a condition referred to as "compartment syndrome." In compartment syndrome, the blood supply to local muscle is literally squeezed by swelling. With this swelling, oxygen supply to the muscle can be "choked." Without oxygen from the blood supply, muscle tissue dies. If muscle tissue dies, proteins are lost as waste and filtered by the kidneys. These proteins can block the kidneys and result in kidney or renal failure.

Other significant features of severe electrical exposure include disturbances in the survivor's heart electrical pattern, called refractory cardiac arrhythmias, discussed in Sections. 1 and 8. Further serious problems may include the following:

• Neck and back fractures from the electrical current exposure, falls, or blast

• Disruption in the blood serum's balance of sodium, potassium, and chloride

• Transient lifeless signs, including a condition referred to as keraunoparalysis

• Shock lung, perforated eardrums, and ruptured gastrointestinal organs subsequent to blast trauma

In high-voltage electrical incidents, current passing through a limb across opposite sides of a joint can set up large skin or "transdermal" potentials, resulting in burns called "kissing" wounds. The most frequent sites of this trauma include

• the armpit or axilla, with injury between the limb and skin of the chest.

• the leg by the space in back of the knee, where the skin of the upper and lower leg can meet when the survivor is caught in a crouched position.

Other skin burns may result in the following ways:

• With ohmic or joule heating at the electrical contact points between the survivor and the electrical hazard

• From the ignition of clothing burning in place against the survivor's skin

• At unprotected skin exposed in the extremes of heat generated by and radiating from electrical arcing

Stabilization and initial evaluation

Severely electrically injured victims are difficult to resuscitate, and the early phase of medical management can be very complex. Survivors are best served by admission to a burn trauma center where staffing is experienced in the management of patients with massive loss of tissue from electrical current damage and burns.

From the survivor's perspective, after a severely traumatic accident, a breathing tube, intravenous fluids, and massive pain control medicines obliterate awareness of all that happens in the early treatment period.

Because nerves are very sensitive to electrical forces, even minor electrical exposures may cause temporary nerve dysfunction in the affected limbs or body areas. Pain may dominate. Nerve symptoms called by the medical terms anesthesia (no feeling), paresthesia (some feelings), or dysesthesia (prickly, pin-prick, or knifelike feelings) may occur. With a less severe hand electrical contact, the survivor may experience loss of feeling or "funny" feelings in the contact areas referred to as "stunning," which can hamper how effective hand grip is in terms of strength, endurance, and reliability. Stunning usually completely resolves within hours or days.

Although less common, electrical contacts may also lead to a nerve problem called temporary autonomic nervous system dysfunction, which may show up in the patient as specifically reflex sympathetic dystrophy (RSD), and hypertension or high blood pressure.

Less quickly resolved for a survivor are the classic complaints of burning pain and exquisite sensitivity, which may develop within hours after an electrical injury. Swelling (called edema) and excessive sweats may then manifest during the next three to six months.

This may be followed in six to 12 months with loss of muscle mass, nails, and hair.

Osteoporosis may develop in the limb. To evaluate this problem, clinicians conduct diagnostic nerve tests and treat with injections of medication near the nerves to produce a "nerve blockade."

Medical and surgical intervention

For a survivor with a severe electrical exposure, polytrauma can require more intensive medical and surgical care. Polytrauma refers to the injury of two or more body parts or systems that leads to physical, cognitive, psychological, or psychosocial impairments. An initial goal of medical and surgical intervention is to completely diagnose the extent of injury. To distinguish central nervous system damage from peripheral nerve injury, testing includes key steps summarized in Table 7. The diagnostic evaluation of muscle and nerve injury unfolds while the patient's clinical condition is being stabilized and treated.

Even when an employee's injury at the scene of the electrical event may appear less severe to coworkers or witnesses, diagnostic testing in a hospital is still necessary because the health changes resulting from electrical exposure may not be obvious for hours. An employee who "walks away" from an electrical event may not want to draw more attention to the accident by seeking or attending a medical evaluation. Yet because the body damage may not be detectable by the eye, an exposed employee should always be required to have a medical checkup.

Hospitalization experience

Employees surviving a serious occupational electrical event are often hospitalized. During days or weeks of hospitalization, the uncertainty in answering a clinician's questions (e.g., "What happened?" "Why did this happen?" "How were you hurt?") Can impact their medical treatment and amplify their distress at their injury.

Clinicians may not be aware of the extended time required to complete engineering root cause analyses of the factors contributing to an electrical event. Employer representatives may be cautious, limiting their statements to the employee about their investigation findings due to medical concerns for the employee or risk management considerations.

Therefore, minimal information may flow to the affected employee and the employee's family or caregiver regarding the electrical accident.

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Table 7 Determination of Muscle and peripheral Nerve Injury

[ Determination of the exposure circumstances

Documentation of the physical findings

Radiology studies

Electro-physiology studies

]

[ Determination of the electrical current exposure circumstances is fundamental to understanding the survivor's pattern of injury.

Exposures may involve direct mechanical contact with an energized surface by an unprotected body part, or may occur through electrical arc current flow. Personal protection equipment such as industrial garments and gloves, face shields, safety glasses, and arc enclosures may moderate the intensity of the incidental exposure. For example, safety gloves may minimize skin wounds; or safety glasses may protect the eyes from the ultraviolet radiation released by an electrical arc. The duration of the electrical current flow, release of multiple forms of energy at time of the current flow, and geographic location of the event may increase the potential severity of the patient's trauma.

Physical findings may include open wounds, traumatic amputation, fracture dislocations, impaired neuromuscular function, or edema.

Physical examination supported by laboratory studies for the serum markers of muscle damage (e.g., serum enzymes and urine myoglobin) provides correlative information for radiology and electro-physiology diagnostic studies. When external wounds are not observed, a high degree of clinical suspicion of occult neurologic injury is advised.

Radiographic and nuclear medicine examination can evaluate nervous system structural damage and confirm fractures, local tissue edema, and focal areas of inflammation. For example, in the acute period, the localization of tissue edema in an upper extremity is an early sign of muscle injury.

Electro-physiology studies are guided by the patient's history and physical examination. Muscle weakness, easy fatigue, loss of endurance, paralysis, or pain are indications for electromyography and peripheral nerve conduction studies (sensory and motor). Further evaluation may be needed with peripheral nerve refractory period spectroscopy and magnetic resonance spectroscopy. Neurophysiologic evaluation may also be indicated by additional complaints.

For example, history of loss of consciousness or seizures, central nervous system complaints such as headache, impaired memory, attentional problems, personality changes or cognitive changes suggests electroencephalography (EEG) and electrocardiography (EKG). A history of temporary or persistent loss of hearing, ringing in the ears, or change in memory to verbal communication are indications for auditory evoked potentials (AEP). A change in visual acuity or visual disturbance are indications for visual evoked potentials (VEP). Cardiac rhythm disturbances, syncope, chest pain, and easy fatigue are indications for electrocardiography (EKG).

]

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As a consequence, experienced, knowledgeable, and competent employees can be made to feel ignorant, uninformative, manipulative, or uncooperative-as if they don't have the "right answer." After surviving a workplace electrical accident, the hospitalized employee essentially moves from the occupational environment, where he may be considered "a good worker" or an "expert at his job," to the health care environment and the medical care delivery system, where the survivor may be known only by reference to a medical record number, a date of admission, and a treating physician's name. Concurrently, for family or coworkers who have not been hurt, the hospitalization experience can be alienating and frightening.

Outpatient care

Even without a visible physical injury like burns or electrical contact wounds requiring hospitalization, electrical injury survivors may report medical complaints. These com plaints may seem unrelated to the electrical event sometimes because they show up hours, days, or weeks after the occurrence, or because they seem more or less severe than the event itself.

This situation can go from bad to worse when the facts of the injury scenario do emerge and survivors learn that they have experienced a near-fatal situation. Hearing comments like "You are lucky to be alive!" can disintegrate workers' belief in their professional competence. Employees who work around electricity don't survive on luck. Moreover, having a near-death accident doesn't "feel" lucky to most.

In particular, electrical professionals especially hold to an occupational identity and set of beliefs that suggest workplace policies, procedures, planning, and personal protection can provide for safe occupational activity. When an employee's identity or beliefs are threatened, anxiety, adjustment reactions, or more serious psychiatric issues should be expected. If the facts of the injury scenario emerge as attributing blame for an electrical incident on the survivor, then personal and professional guilt are added to the list of issues the worker may need to confront.

Besides difficulty in remembering details because of how quickly the event occurred, the employee who does not have an easily observable physical injury may still have problems that suggest a brain or nerve injury. These problems directly affect employability and may be described as weakness, pain, headache, memory changes, disorientation, slowing of mental processes, agitation, or confusion. Personality changes such as irritability, moodiness, nightmares, difficulty sleeping, or feelings of depression or post-traumatic stress may also occur. These changes can interfere with personal and workplace relationships, straining a worker's support network.

Rehabilitation focus and return to work planning

Rehabilitation and return to work (RTW) planning starts at the time of hospital admission and may extend months after hospital discharge. With massive trauma, years may be necessary to return a survivor to active employment. Retraining to allow for change of professions may be required.

Successful rehabilitation often does not lead to the return of patients to their pre-injury job. The disability for electrical incident survivors is disproportionate to the incidence of this preventable condition. This means that for relatively few injuries, there is a relatively high frequency of permanent disability. With the typical youth of those injured in electrical accidents and the loss of potential productivity in economic terms, the health effects of electrical incidents carry significant costs for victims, their families, and their employers.

Reentry to employment settings

When workers have difficulty in the use of their limbs after an electrical incident, their security in completing tasks (like exerting a forceful grip, climbing a ladder, using their hands to lift a load, and assisting a coworker in a hazardous activity) may be unacceptably compromised. This difficulty can drastically reduce employment options. Workers may wish to return to their job but face resistance in this step from their family because of concerns for reinjury. When the electrical incident is deemed to be the victim's "fault," coworkers may harbor undisclosed resentments, acting as a roadblock to reentry to employment.

Plateau in recovery

The complexities of electrical injury rehabilitation are often underappreciated by the medical community. As a general guide, three elements are essential to successful recovery following an electrical incident: team, time, and talk. The involvement of an experienced occupational rehabilitation team is needed to avoid the catastrophe of repeated failure to return to work, depression, and loss of self-respect that may evolve when injured workers fear for their livelihood. Time is necessary for the survivor to go through the healing stages following repeated surgeries, possible amputation, and long hospitalizations. Talk, or excel lent communication, is critical to maintaining the employee's relationships with family, friends, coworkers, and caregivers.

Research suggests electrical trauma survival is associated with significant functional impairment. The scope of impairments has been detailed in a limited number of scientific reports.

In a landmark retrospective study of employees of a national electrical energy company, Gourbiere and colleagues reviewed the electrical trauma survival experience of a workforce of between 100,000 and 120,000 people during the period from 1970 to 1989. Electrical burns affected 2080 workers. Of these, 515 patients, or 25 percent, were noted to haven postinjury problems that included the following:

• 63 percent burn related, with amputations in 5 percent

• 18 percent neuropsychiatric

• 12 percent sensory

• 5 percent orthopedic

• 1 percent cardiovascular

Sense organ problems were also noted, including the following:

• Vision-related changes due to conjunctivitis, keratitis, and cataracts

• Auditory late effects, with conductive or sensor-ineural hearing loss, tinnitus, and vertigo

• Anosmia, or loss of the sense of smell In 59 of the 515 patients, disability was considered serious, with impairment rating 31 to 100 percent.

Neuropsychological changes after an electrical injury may be categorized as post-traumatic stress syndrome or be assigned diagnoses such as depression or anxiety subsequent to electrical contacts that do not appear to have an electrical path through the brain. In one study, all patients had peripheral electrical contacts, with no evidence on history or examination of direct mechanical electrical contact with the head. Forty-four patients were injured on the job and nine were injured during nonvocational activities. At the time of follow-up study interviews, 30 (56.6 percent) patients were working again, 18 (44.0 percent) patients were unemployed or retired, one patient was deceased, and four patients could not be contacted.

Electrical trauma patients meet with varying degrees of success in their return to work.

While some electrical trauma patients are able to return to their preinjury activities without functional impairment, others are not. Both survivors who are "owner operators" of their business as well as employees of larger organizations see postinjury job loss. While their postinjury medical care may not interfere with their company's core business, survivors may find after their accident that their job may not exist due to competition from other vendors, contract completion, restaffing, or workforce reductions.

If survivors wish to return to work, and their preinjury job is not available, the clinician can be influential in assisting placement into new work. To limit the potentially destructive effect of financial uncertainty on survivors and their personal or family situation, when a clinician is advising on placement in new work, a vocational evaluation is recommended as soon as possible to establish the local employment area's market for the survivor's skills set, occupational abilities, and training.

For example, driving is a common requirement in service jobs where travel is necessary to deliver tasks to client sites, like construction locations, factories, or customer businesses.

Under U.S. Department of Transportation (DOT) rules, individuals cannot be medically certified for a commercial driver's license if they have a recent history of loss of consciousness, vision less than 40/40 in each eye and both eyes, and certain cardiac conditions, and if they are on certain medications.

Individuals with amputations must demonstrate performance in driving in a vehicle that may fall under DOT rules. When the patient cannot drive a DOT-regulated vehicle, designed work support is necessary to allow access to job sites and equipment.

Another aspect of return to commercial and industrial work is the need for bimanual secure grip. To climb a ladder, lift a load, or handle a heavy tool, secure, forceful bimanual grip that can be reliably and repeatedly used is an essential function of the job. When finger or hand amputation is a consequence of electrical trauma, supported work to offset the limitation of secure bimanual grip is needed.

At a certain point after an electrical trauma, survivors reach a plateau in their recovery.

With consideration for numerous surgeries, retraining for employment, and mental health care, plateaus are assessed on an individual basis. Nevertheless, a common characteristic is that survivors rarely go "back" to the life they had before their incident. A survivor typically goes "forward" by living differently. The differences can be small, as with an attitude change, or dramatic, as with a job change. The bottom line for the survivor is that after electrical trauma, life may never be the same.