When responding to a vehicle accident involving a trapped patient, actions taken before direct access are paramount. These pre-access procedures establish a controlled and safe environment for both the rescuer and the patient. A methodical approach ensures that hazards are identified and mitigated, preventing secondary injuries or complications during extrication. The overriding priority in any rescue scenario is always the safety of the responders, which dictates every subsequent step.
Scene Safety and Hazard Identification
Upon arrival, responders must immediately establish a secure zone by managing surrounding traffic. This involves strategically positioning apparatus to shield the scene and deploying traffic control devices, such as cones or flares, to create a safe working perimeter. Establishing a barrier between traffic flow and the rescue operation minimizes the risk of secondary collisions.
The scene must be rapidly scanned for environmental hazards. Downed power lines present an extreme electrocution risk, requiring immediate isolation and notification of the utility company before any contact is made with the vehicle or ground. Responders must also identify potential fire risks by assessing leaking vehicle fluids (gasoline, diesel, or oil) and preparing fire suppression equipment.
Unstable terrain, such as steep embankments or slick surfaces, can compromise the stability of the vehicle and rescue equipment. Personnel must wear appropriate personal protective equipment (PPE), including helmets, eye protection, and specialized turnout gear, before entering the hot zone. This gear provides defense against sharp metal and hazardous substances.
Only after the scene’s perimeter is secured and immediate external threats are neutralized can responders safely move closer to the vehicle to begin patient assessment.
Initial Assessment and Resource Activation
Once immediate scene hazards are contained, the focus shifts to gathering information about the incident and the occupants’ condition. A quick assessment of the mechanism of injury (MOI) provides insight into the potential severity of patient trauma. High-speed impacts, rollovers, or significant intrusion suggest a high likelihood of severe trauma.
This initial evaluation requires estimating the total number of patients and determining their immediate status (conscious, unresponsive, or visually trapped). The assessment must also note the patient’s position and the extent of entrapment, which informs the complexity and duration of the extrication plan.
Based on this rapid assessment, specialized resources must be activated immediately. If entrapment is complex, requiring heavy cutting tools, specialized extrication teams or fire department units must be called. Emergency medical services (EMS) personnel are required for patient care, and heavy wreckers may be necessary for vehicle stabilization or removal.
If multiple agencies respond, establishing a clear command structure is necessary to coordinate efforts. Designating a single incident commander ensures communication lines remain clear and that all actions follow a unified plan.
Vehicle Stabilization Techniques
Before attempting to access or treat the trapped patient, the vehicle must be secured to prevent unintended movement that could worsen injuries or endanger rescuers. The goal of stabilization is to create a “zero-movement” platform, eliminating rocking or shifting as forces are applied during extrication.
Standard stabilization involves placing step chocks—specialized tiered blocks—under the rocker panels or frame. These chocks fill the space between the vehicle body and the ground, restricting vertical movement. For vehicles resting on their wheels, wheel chocks are placed against the tires to eliminate horizontal movement.
For vehicles resting on their side or roof, stabilization requires a broader base of support. Rescue struts, adjustable high-strength poles, are deployed to create a tripod or quad-pod support system against the vehicle body. These struts are secured with straps or chains to prevent slippage.
Cribbing, constructed from stacked wood blocks, is used to build load-bearing towers to support heavy sections of the vehicle. These techniques ensure the vehicle remains static, protecting the patient and the rescuers working nearby.
Disabling Vehicle Power Systems
Mitigating the dangers posed by the vehicle’s electrical and mechanical systems is the final step before initiating patient access. The primary concern is preventing the inadvertent deployment of undeployed supplemental restraint systems (SRS), commonly known as airbags. Airbag systems contain capacitors that store an electrical charge after the main power is cut, risking late deployment.
To neutralize this risk, the vehicle’s main power source must be disconnected by locating and cutting the battery cables. The negative cable should always be disconnected first to minimize the risk of creating a short circuit. Battery location varies, often found in the engine bay, trunk, or under the rear seats.
After the battery is disconnected, a mandatory waiting period must be observed to allow the SRS capacitors to fully discharge residual electrical energy. This period is typically specified by manufacturers, often ranging from five to ten minutes. Rescuers must respect this time frame before placing tools or personnel near potential airbag deployment zones.
Hybrid and electric vehicles introduce complexity due to their high-voltage systems, which can exceed 600 volts. These vehicles have specialized high-voltage cables, often colored orange, that must never be cut by untrained personnel. Specialized training is required to safely disable the high-voltage cutoff switches unique to these advanced power systems.