By Dr. Ken Lavelle, MD, NREMT-P
You are standing by at a small to moderate sized dwelling fire. The bulk of the fire has been knocked down, and a second crew is completing rehab on the first-in companies. You see four firefighters walk out of the building and confer with a chief, and then they walk over to your staging area. They appear to be in no distress.
"We were inside doing overhaul when all four of us came in contact with an electrical cord and were shocked. Chief said we have to come see you. Do we have to go to the hospital?"
Surprisingly, the answer to this question may be no. EMS providers usually do not make decisions like this, but with proper protocols and training, and in consultation with an on-line medical command physician, it may be reasonable to evaluate them on scene and avoid an ambulance transport.
Some may believe this is risky. Why not just take them to the hospital "to be sure?" In rural areas, the hospital may be quite far away. The number of ambulances and EMS personnel on scene may be limited, as well as the availability of firefighters. Taking four firefighters off the scene, and transporting them all to the hospital may not just be expensive, it may compromise the safety of the remaining staff on scene. Fortunately, there are some fairly clear guidelines that can be followed to assist with this decision. First, let's briefly look at the nature of electrical injury and electrical burns for those victims that do have injuries.
Electricity represents the flow of electrons through a conductor. Voltage is the term used to describe the force that causes these electrons to flow. The voltage of electricity can be divided into low voltage (less than 600 volts) and high voltage (over 600 volts). In our homes the voltage is typically low, at 120 to 240 volts. Higher voltage may occur in industry and in the transmission of electricity.
The current or flow of electrons can be AC (alternating current) or DC (direct current). In AC, the electrons flow back and forth in a cyclic fashion, typically 60 times per second. AC is more efficient to generate and distribute than DC, in which the electrons flow in one direction. These two types of current can cause different effects upon contact with a victim. AC causes muscle contraction, so the victim may grip the source and not let go, resulting in an extended contact, and more injury. DC often causes a single muscle contraction, and the victim may possibly be thrown clear.
Electrical injury can occur in three different ways:
• Direct damage to tissues by the current
• Conversion of electrical energy to thermal injury, resulting in typical burns
• Indirect damage such as severe muscle contractions causing fractures
Direct damage to various structures of the body will change even at the same voltage. This is because the actual current will change based on the resistance of the tissue. Nerves, blood and muscle have the least resistance, so the current will be greatest. Bones, fat and tendons have the highest, and skin is intermediate. The current can travel and cause internal injuries based on this resistance.
Thermal injury from electricity is unique in that the internal damage may be much worse than is apparent from the external appearance. Do not be deceived into thinking your patient has no injuries if they do not have marks on the skin or pain out of proportion to the apparent injury.
Finally, be concerned about both extremity fractures and spinal cord injury. The muscle contractions caused by the current can be strong enough to cause significant trauma. Immobilize the cervical spine of any patient that has been thrown or has simply come in contact with a significant electrical current. Treat these patients in the usual manner, and transport to a trauma and/or burn center, based on your local protocols.
Now, what about those firefighters with no complaints and no injuries? Emergency medicine docs like clear-cut protocols on how to manage patients. Usually these are rare, but not in this case. After looking at thousands of individuals, a number of guidelines have been published.
At the hospital, if a person has received a low voltage electrical contact, has had no loss of consciousness and has a normal 12-lead EKG, they can be discharged from the emergency department. They also need to have no other need for admission to the hospital, such as burn injury or chest pain. But does this help us in the field? Can a paramedic evaluate an individual that has been shocked and obtain and interpret a 12-lead EKG, and then determine that the individual does not need to go to the hospital?
This will once again fall back to local protocol, but I think it is reasonable that a paramedic, with direct contact and assistance from a medical command physician, and a progressive and active medical director, can make this determination. One concern is that a firefighter may not be completely honest with any complaints that they have, out of a desire to not go to the hospital. Once they are at the hospital and are speaking with the ED doc, they may be more open with any complaints. This is possible, and can be mitigated by having a paramedic (or medical director) know the firefighter well, and by having the firefighter actually speak to the on-line medical command physician — kind of an assessment over the phone.
So, while we do not want to blow off every contact with electricity, we also do not need to have a knee-jerk reaction and transport every individual to a burn center. Consider your local area and talk to your medical director. Perhaps this is an area where we can limit the inconvenience and cost without jeopardizing the safety of our firefighters.