Matthew T. Huberty, MSIV, Mayo Medical School, Rochester, MNIf you've worked an ED shift lately, perhaps you've noticed how physics plays an important role in emergency medicine; but more likely, you have not.
While you probably aren't routinely reflecting on it during a busy day, physics actually plays a very overt role in emergency medicine. Think about a baseball's blunt Newtonian force when it causes an orbital wall fracture. Sometimes, though, science is subtler. After all, you can calculate the rate at which to run a patient's infusion without giving much direct thought to Poiseuille's law and the principles of fluid mechanics governing the flow of medication in the patient's IV line. But beyond even the basic principles of physics, it is striking that even advanced physical theory applies to emergency medicine.
Einstein — famous for his theory of relativity, among other scientific contributions — was the first to report on his observation that the motion of an object in space occurs relative to a frame of reference, such as the motion of some other reference object in space.1 For example, to a person standing on a train platform, a baseball thrown in the direction of the train's travel by someone standing on top of a moving train car will appear to move faster than it will to the person atop the car who threw it. In this case, the thrower's frame of reference is the train car, and the viewer's frame of reference is the fixed train platform.
Last year, as part of my third-year pediatrics clerkship, I worked several shifts in the pediatric side of our ED, and I was struck by how quickly the time seemed to pass each shift. Receiving sign-out from everyone covering the previous shift seemed to only just begin before I was already presenting the last patient of my shift to the attending. The passage of time — like the motion of the baseball — is relative as well. In a typical shift, you move speedily between patient rooms, deliver quick-fire presentations, make phone calls, document, and provide patient education, among many other things. All of these activities require mental focus as you switch from task to task. However, an eight-hour shift, for example, lasts the same eight clock hours as would physically tick by if you spent them all watching paint dry. Hours spent in the ED seem to dissolve to mere minutes relative to most of the other things on which time in life is spent. Psychologist Mihály Csíkszentmihályi has termed this experience of accelerated time “flow.”2
It is important to remember, though, that time might not seem to pass by so quickly for everyone in the ED. Patients lying atop their stretchers might wait with their eyes glued to the clock, watching the seconds slowly tick by as they await their lab results. Time goes slowly as they wonder if they're suffering from something benign and can go home, or if that anxious, gnawing feeling in their stomach means that something very bad is at hand. Patients' family members pace the waiting room, repeatedly checking their watches and wondering how soon they will be allowed back to see a loved one; sometimes, they're wondering if their loved one is even alive. For patients and families, this frame of reference is different.
As an expression of how fundamental time is to the specialty, the American Board of Emergency Medicine created a logo depicting an hourglass filling with sand.3 Perhaps it is Einstein's relativity theory that makes time relevant to both the physicians and the patients in emergency medicine. Like a baseball thrown on a train, time may appear to go faster for us; but for those we are serving, time may be slowly ticking by. It is important to remember both perspectives and to quickly intervene on behalf of our patients. We may not notice, but they're counting the clock — and they're counting on us.