Beyond the Basics: Scene Size-Up

CEU Review Form Scene Size-Up (PDF)Valid until February 1, 2008

     Scene size-up is a vital part of any call, yet one that often doesn't get the attention it deserves. In classroom simulations, students traditionally wave their gloved (or simulated gloved) hands and magnanimously proclaim "Scene safety and BSI!" as if a magic wand could be waved over the scene to make it free of everything from violence to microbes. If only this were possible, or the scene size-up that simple.

     The 1994 DOT EMT-Basic National Standard Curriculum lists five key components of the scene size-up process:

• Number of patients
• Mechanism of injury/nature of illness
• Resource determination (heavy rescue, hazmat, etc.)
• Standard-precautions (BSI) determination
• Scene safety.

     The article will break down each part of the process with a focus on how it affects both our safety and the smooth flow and disposition of the incident.

CASE SCENARIO
     Your ambulance is dispatched mutual-aid for a motor vehicle collision in an adjoining fire district. You arrive to find a small pickup truck has collided with a large dump truck loaded with gravel. Four people are out of the pickup and ambulatory.

     As you approach the patients, you walk by their vehicle. There is considerable intrusion into the front end of the pickup. You notice the rear of the passenger compartment has only side-facing jump seats, and you see the patients are two men and two boys. The local engine company is holding stabilization on one of the men.

     You get an initial report from the firefighters: five people involved. They don't believe the dump truck driver is injured.

     In this real-life scenario, a combination of crossed signals and crossed jurisdictional boundaries caused considerable disorganization--and delay in patient care. The incident commander thought the ambulance crew would handle the request for other ambulances. The ambulance personnel felt they shouldn't call because they were in another district.

     The initial triage really wasn't: The one patient who complained of pain distracted EMTs from the other who was truly injured. The man with internal injuries denied complaints so EMTs would take care of his son.

     After a delay, fortunately brief, priorities were determined and additional ambulances were called to the scene. Four patients were transported to hospitals; one refused. All survived the crash--and the lack of triage.

     The five steps of scene size-up, if followed here, could have prevented the delays and disorganization. To properly size up this scene:

• The first-arriving unit would have assumed command and provided a report on the scene and potential numbers of patients.
• Any hazards with the large truck would have been dealt with by the fire department.
• Arriving EMTs would have more thoroughly considered the mechanism of injury. In this case, the patients' vehicle was an older pickup truck without airbags. The front-seat victims, given the significant mechanism of injury, would have received a higher initial priority until injuries were ruled out.
• EMTs and fire personnel would have worked together to call for enough rigs to handle the number of patients on scene.
• The dump truck driver would have been considered a patient, even if he were a sign-off. Even the sign-off requires an assessment and paperwork.
• A modified triage system would have been utilized to screen all patients for hidden injury.

     To ensure success on your next call, conduct a thoughtful and detailed size-up that includes each of the following five components.

Number of Patients
     We know that multiple-casualty incidents can range from two to hundreds of patients. In fact, the term multiple-casualty incident evolved from mass-casualty incident because the latter seemed to imply a need for numerous patients before invoking incident management principles.

     A motor vehicle collision with three or four patients can stress a small or rural EMS system--or even a large municipal system already operating at capacity. Furthermore, failing to identify the number of patients and other challenges in the scene size-up makes it less likely you'll take the necessary and appropriate actions once you begin patient care. Once that slippery slope begins, time wasted calling for additional resources becomes painfully obvious.

     It also pays to implement the Incident Command System. Simply designating an incident commander and triage officer at smaller scenes is a worthy investment in time and resources.

     Incidents are usually handled based on their numbers of patients. Multiple-casualty incidents are often classified as follows:

     Level 1: 2-10 patients

     Level 2: 11-25 patients

     Level 3: 26 patients or more.

     Are you prepared to handle the small to medium-size incident? Is there an EMS Command vest in the cab of the ambulance? Do you know where your MCI kit is and what's in it? A major incident is not the time to become familiar with its contents.

Mechanism of Injury/Nature of Illness
     Mechanism of injury has sent us a mixed message over the years. While the MOI in a trauma patient helps us decide whether he receives a rapid exam and prompt transport or a slower and more focused exam, experiences over the years can leave us skeptical about the value of such determinations. Many of us have arrived at vehicle rollovers to find occupants who have crawled out of the wreckage and are leaning against it and saying they feel fine.

     Two concepts in mechanism of injury are worth noting. First, it's only one piece in a puzzle. Matching the MOI with trends in vital signs and the patient's apparent injury is necessary. Second, mechanism of injury is a one-way street. Patients with surprisingly unimpressive mechanisms can still be seriously injured. Lack of significant mechanism can't be used to rule out injury.

     Airbags have changed the way we look at mechanism of injury. They reduce serious injury in certain crashes, but can cause trauma themselves. Trauma from the steering wheel and dashboard is still possible from secondary impacts. A thorough MOI determination involves lifting and looking under the airbags for steering wheel or dash damage that indicates trauma.

     The EMT curriculum mentions reconsidering the mechanism of injury during your focused trauma examination. Rechecking the mechanism on the way back to the ambulance with the patient will allow you to match injuries you've found with mechanisms that didn't make sense or were initially missed.

     Nature of illness (NOI) is the red-headed stepchild of mechanism of injury. We don't think about this much, but remember, medical and trauma assessments are different. Medical assessments are largely history-based, while trauma exams are predominantly hands-on. This is how we get the best information for both types of patients. Plus, our first views in the scene size-up give us an indication of how critical the patient is--or may be. This information is filtered directly into the general impression. Patients with obvious chest discomfort, respiratory distress or altered levels of responsiveness become higher priorities for care and transportation.

Resource Determination
     It is best to call for any additional resources as soon as possible--hazmat, extrication, utility companies, wreckers or anything else you need to handle the scene effectively. In order to make these determinations, the scene must be carefully evaluated before patient care begins. Threats such as hazmat and downed wires should be recognized before you set foot outside the ambulance. One clue to downed wires is an asymmetry of telephone poles as you approach the scene.

Standard Precautions (formerly BSI)
     Today decisions about standard precautions are commonly made before any observation of the patient. Precautions are taken in the ambulance or engine and never thought of again.

     The concept of the standard-precautions decision is based on seeing the patient and determining what is necessary. Failing to do this frequently means taking too many precautions (which is acceptable to some) but can sometimes mean not taking enough--and that's dangerous.

     Gloves and eyewear can be kept on a provider's person or immediately accessible in kits, so they can be donned at the patient's side after evaluation of what's needed. Donning gloves before reaching the patient may cause tears and loss of integrity resulting in subsequent exposure to blood or other potentially infectious materials.

     Should a patient suddenly deteriorate and require ventilation and suction, additional precautions will be necessary. Unless providers realize that decisions regarding standard precautions are dynamic and can change throughout the call, protection will not be adequate.

     Finally, although it's heresy to many, precautions aren't necessary on every call. It is conceivable that some calls may not require any protection--even gloves. Break the "Scene safety and BSI!" routine and make your personal protection a thinking process, not a rote one.

Scene Safety
     Before a discussion of traditional scene safety principles--principles which primarily involve protection from violence--a look at how EMS providers die is in order (see Table 1). Over the past three years, per the National EMS Memorial Service, 59 EMS providers have died in the line of duty. Of these, three (5%) were killed by acts of violence.

     Even a small number of deaths from violence is too many. But the point is that, whether by collision or from events set into motion long before the call (such as heart attack), most providers who die on duty don't die on scene. And remember, the Memorial Service only tracks deaths. Each year many more are injured, some seriously, from the causes listed in Table 1.

     While the following material on scene safety is pertinent and important, staying alive in EMS is more than a tactical consideration. Care when responding to calls, in traffic and in choosing a healthy lifestyle is equally important for survival.

OBSERVATION OF SPECIFIC DANGERS
     Much of the scene-safety training EMS providers receive is focused on how to respond to danger. Additional attention must be paid to prevention of danger through observation. Most calls give clues, some subtle, that danger is likely. Observing these and preventing danger is preferable to dealing directly with it.

     The potentials for danger are endless, and observing for anything out of the ordinary at an emergency scene, including unusual silence, is vital. Some providers talk of a "sixth sense" or gut feeling that indicates danger. Experienced providers use these feelings in clinical situations. There is a place for them in safety and survival. Many crime victims report feeling something bad would happen before it did.

     If you get this feeling, listen to it. Depending on your location, the nature of the call and the help available at the scene, your actions may include anything from stopping to investigate to calling for backup to retreating.

     It goes without saying that drugs and alcohol are frequently involved when people do dumb things--including assaulting cops and EMS providers. Remember that intravenous drug users often carry their "works" (needle, tourniquet, etc.) with them. Assess these patients carefully to avoid accidental needlesticks. Many addicts will tell you if they have needles. Ask before you assess.

     Hidden dangers of the drug trade include weapons and money. The money itself isn't dangerous, but the lengths to which people will go to protect it are. It isn't unusual for people to use booby traps to protect their stashes and cash, even in outdoor locations like marijuana fields.

     Drug labs pose another significant hazard. They may be operational, inoperative or dismantled/discarded. Regardless of its condition, each lab is a hazard that should be mitigated by hazmat and law enforcement personnel. Identify labs by chemical odors and trash indicating the presence of chemicals. Inside you may find ventilation devices, heating mantles and burners, and glassware.

     Labs may be anywhere. They require utilities for light, heat and ventilation, and a location that allows trash disposal and ventilation of chemical odors without causing attention. Disassembled labs have been found in abandoned cars, trucks, trailers and storage units.

WHEN FACED WITH DANGER
     Safety is best assured by preventing and avoiding danger, but there are times when this just doesn't happen. In this event, immediate and decisive action will be required to assure your safety.

• Take a position of cover or concealment. Cover protects your body from bullets, while concealment hides it without offering protection.
• Retreating from danger is almost always part of a successful survival strategy. Get distance, plus as many items of cover as possible, between you and danger.
• Distraction will assist with retreat. Throw your first-in bag at an aggressor. Wedge your stretcher in a doorway between you. Close doors behind you as you retreat.
• As soon as it is safe to do so, radio for help. This will ensure you get the assistance you need and prevent others from ending up in the same situation you did.

     It is important to remember that what constitutes danger at a given scene may vary. We talk a lot about knives and guns, but everyday items--and fists--are also weapons capable of causing significant damage. Dangers are evaluated not just by weapons, but by the patient or family's affect (e.g., hostility, aggression), the crowd and external factors such as previous events at the location.

     You will be choosing and executing these tactics and strategies under perhaps the most stress you will ever face--a fight for your life. As important as the tactics you choose is your desire and drive to survive.

CONCLUSION
     The scene size-up usually takes less time than any other part of the assessment process, yet the results have a profound effect on every portion of the call that follows. The five components of the size-up--number of patients, mechanism of injury/nature of illness, resource determination, standard-precautions determination and scene safety--are the steps to a successful run.

CEU Review Form Scene Size-Up (PDF)Valid until February 1, 2008

Daniel D. Limmer, AS, EMT-P, is a paramedic with Kennebunk Fire-Rescue in Kennebunk, ME. He is the author of several EMS textbooks and a nationally recognized lecturer.

Joseph J. Mistovich, Med, NREMT-P, is a professor and chair of the Department of Health Professions at Youngstown (OH) State University, author of several EMS textbooks and a nationally recognized lecturer.

William S. Krost, BSAS, NREMT-P, is an operations manager and flight paramedic with the St. Vincent/Medical University of Ohio/St. Rita's Critical Care Transport Network (Life Flight) in Toledo, OH, and a nationally recognized lecturer.