Anyone who has watched a medical drama has seen desperate but handsome doctors tending to a person in cardiac arrest yell, “Clear,” before administering a jolt of electricity to the patient’s lifeless body. Although using an AED in real life is more dramatic, but less staged, there are three reasons why doctors and rescuers yell, “Clear” before using a defibrillator.
1. Electricity Travels to Ground
Electricity is always looking for a ground. Defibrillators use large amounts of electricity to restore the human heart to a normal rhythm. At its highest setting, a defibrillator sends 360 joules through a person’s body. To give you some perspective, 360 joules translates to about 54 amps at 3,000 volts for a millisecond. 60 amps of electricity powers an average house. Even though the shock is only a millisecond long, anyone who is touching the victim when they receive an electrical shock will experience a portion of that electricity as it travels to the ground. This is also why doctors who are in the process of defibrillating do so while standing clear of the bed where the patient is laying.
2. Multiple People are Performing Multiple Tasks
In a hospital setting, the doctor who is defibrillating the patient is not the only one at work. Nurses and other doctors are simultaneously drawing blood, monitoring vital signs, starting IVs, and administering medications. Yelling, “Clear,” and then giving all of the people working on the patient an opportunity to move away protects everyone involved, including the patient.
3. It Gives Everyone a Chance to Reset
One particular study on college students showed that short-term stress can positively impact concentration making you more effective in what you are doing. However, as time passes and the more stress you are under, the more you need to concentrate to be effective at your task. In essence, your brain is fighting against itself to get the job done the more stress it is under. Aside from the danger presented by using large amounts of electricity on a human body, yelling, “Clear” and then waiting for the brief seconds, it takes to defibrillate a patient gives everyone a chance to take a second and reset their position. A deep breath may give a nurse a new eye for the vein they are trying to access. A pause may enable a doctor to ask for a new medication to help the patient. Even in a case where a layperson is using an AED to defibrillate a victim in a grocery store, yelling “Clear” can offer a brief, and much-needed respite from the intensity of the situation.
While using a defibrillator to resuscitate a patient, it is important to ensure the safety of bystanders and medical personnel. Even if yelling the word, “Clear,” conjures up images of TV emergency rooms and doctors with perfect hair, it is important to remember that electricity is involved, other people are performing other tasks and taking a second to reset may mean the difference between life and death.