EMT Trauma: Mechanism, Bleeding, Head, Chest and Spine

In depth

The one-page summary above is what the PDF prints. These sections go further.

Mechanism: motorcycles, child pedestrians and body armor

A 2020 review of motorcycle mechanisms groups crashes as lowside, highside, topside and collision. In a lowside crash the bike falls to the inside of the turn: the leg on that side is often trapped under it and the same-side arm is thrown out to brace, so lower-limb fractures (the tibia most often) and road rash concentrate on that side. In a highside crash the rider is thrown away from the falling bike; in a topside crash the bike slows abruptly and the rider goes over the handlebars, a head-leading impact with skull, facial and brain injury and real concern for the cervical spine. Outstretched arms often break at the distal radius. When the bike stops against an object, the rider's pelvis loads against the fuel tank, causing pelvic ring fractures and bladder injury. The 2021 field triage guideline lists a rider separated from the vehicle with significant impact as a yellow (trauma center) criterion even when the rider is alert.

Waddell triad (StatPearls): a child pedestrian struck by a vehicle may have a femoral shaft fracture and a thoracic or abdominal injury on the impact side and a head injury on the opposite side, and the combination can bleed significantly inside. Classic teaching explains it by height: the bumper strikes a child at the thigh rather than the shin, the hood strikes the torso, and the head strikes the ground. A crying, alert child with one obvious fracture still needs a search for the other two, and children go preferentially to a pediatric-capable trauma center. The 2021 guideline lists a pedestrian thrown, run over or hit with significant impact as a yellow criterion; it dropped the speed threshold used in 2011.

Behind-armor blunt trauma: soft armor stops penetration, but its rapid deformation transfers energy to the body, which Prat (2012) describes as potentially lethal nonpenetrating injury. Carr's 2016 systematic review found skin bruises and lacerations, rib fractures and contusions of the lungs, kidneys and spleen, rarely the heart, and called the threat to life debatable. Reasoning from these, not from a guideline: a tachycardic or tachypneic officer after a center-chest hit has the vest removed, the chest inspected, palpated and auscultated, and is transported for evaluation rather than released to duty.

Bleeding that resists the usual steps

NASEMSO starts with exposing the wound, direct pressure and a pressure dressing, moves to a commercial tourniquet when pressure is ineffective, and reassesses for bleeding without removing the dressing or the packing. Pressure works only if it is continuous: lifting the gauze every few seconds to look pulls the forming clot apart, so the wound seems never to stop. Classic teaching: blood-soaked gauze stays in place and new gauze goes on top. If steady, uninterrupted pressure fails, the tourniquet follows. The full sequence, tourniquet placement and packing are on EMT: Soft-Tissue and Musculoskeletal Trauma.

Varicose vein bleeding: a British Journal of General Practice review says the essential step is raising the foot above the level of the heart, which cuts the blood loss at once, then pressure by hand followed by a pad and a firm bandage. A tourniquet placed above the bleed makes the loss worse and can lead to death. Reported deaths are mostly in people living alone, frail or on anticoagulants, and an Australian report found such bleeding in about 1 in 1,000 autopsies. A patient who stays seated or standing leaves the leg hanging, which is when the bleeding is fastest; lying down with the leg raised avoids that.

Scalp wound over a skull fracture: the scalp bleeds freely and usually stops with firm direct pressure, but NASEMSO limits direct pressure to wounds with no suspected open skull injury and covers a possible open skull wound with a moist sterile dressing. Classic teaching: over a soft or depressed area, press gently around the wound edges, never on the center, and do not pack or wrap tightly, so fragments are not driven into the brain.

Compensated hemorrhagic shock

MSD lists diaphoresis, tachycardia and tachypnea as signs of compensation, with pale, cool, clammy hands and feet, and states that hypotension is common in shock but not required; many patients are normotensive early. A rising respiratory rate with clear, equal breath sounds and a normal SpO2 after a pelvic or femur injury is therefore read as poor perfusion, not anxiety or a lung problem. NASEMSO's Shock guideline (written for medical shock) lists a respiratory rate above 20 among signs of poor perfusion, and its General Trauma guideline starts resuscitation (Paramedic: blood or fluids, TXA within 3 hours) when SBP is below 90 or heart rate above 120. The 2021 field triage guideline makes a heart rate greater than the systolic pressure a red criterion. EMT care: stop visible bleeding, do not rock or spring the pelvis, bind it per protocol, keep the patient warm, call ALS and transport rapidly with scene time under 10 minutes when unstable.

Head injury at EMT scope

NASEMSO Head Injury: maintain cervical stabilization, palpate the skull gently for a depressed or open fracture, check pupils and trend GCS or AVPU. Give high-flow oxygen by non-rebreather as a precaution; if the patient cannot keep the airway open, use an oral airway (a nasal airway is avoided with significant facial injury or a possible basilar skull fracture). Bag-mask ventilation is for oxygenation that a non-rebreather cannot maintain, at 10 breaths a minute for patients 15 or older, 20 for ages 2 to 14 and 25 under 2, with gentle bagging; hyperventilation is avoided. Prevent hypotension rather than wait for it (adult SBP at or above 110). Early signs of deterioration are confusion, agitation, drowsiness, vomiting and severe headache.

Destination: NASEMSO sends patients with GCS 3 to 13, a P or U on AVPU, penetrating head trauma or an open or depressed skull fracture preferentially to the highest level of care, and the 2021 field triage guideline lists skull deformity or suspected skull fracture as a red criterion. Moderate or severe head injury is assumed to include a cervical spine injury.

Flail chest and the low chest wound

Merck defines flail chest as fractures of three or more adjacent ribs, each in at least two places, leaving a segment that moves inward on inspiration and outward on expiration; the force needed usually bruises the lung beneath it (Trauma: Primary and Secondary Survey notes that some texts say two or more ribs). Merck adds that the paradoxical motion does not occur under positive-pressure ventilation, when the segment may instead move outward more than the rest of the chest. A flail segment that stops sinking once bag-mask breaths begin has not healed: the SpO2 gained is the bag's doing, so assisted breaths continue, timed with the patient's own, while the crew watches for tension pneumothorax and gastric inflation. Suspected flail chest is a red field triage criterion.

Merck notes that the diaphragm can rise to the nipple line in exhalation, so a penetrating wound at or below that level can injure abdominal organs. The reverse holds too: a stab wound below the nipple line is still a possible chest wound. When breathing worsens, NASEMSO calls for a semi-occlusive dressing on an open chest wound (a vented chest seal is the usual product) and close watching for tension; the abdomen is reassessed en route. Penetrating torso injury is a red criterion.

Spinal care when the routine fails

Neutral alignment: the Wilderness Medical Society guideline restores neutral alignment unless the move meets resistance, increased pain or a new or worsening neurologic deficit, and otherwise supports the neck in a position of comfort. NASEMSO notes that patients in pain self-limit movement and that forcing immobilization adds discomfort; for patients who cannot wear a collar (it names severe kyphosis and ankylosing spondylitis) it uses towel rolls or sandbags in a position of comfort. So the EMT stops, holds the head where it is and pads it in place, then moves the patient as a unit.

Small children: the University of Washington pediatric trauma course says a collar must let the chin sit snugly without pushing the jaw backward, which can obstruct the airway, and that towel rolls or IV fluid bags on both sides of the head may be used instead for small children and infants. Shoulder padding and chest and pelvis straps are on Spinal Motion Restriction.

Helmets: NASEMSO gives guidance only for football helmets and says evidence is lacking for other types. The two-rescuer method from the American College of Surgeons Committee on Trauma pamphlet holds in-line support from above, transfers it to the second rescuer below at the jaw and occiput, eases the helmet over the ears and nose, and re-establishes support from above once it is off. A full-face helmet comes off when it keeps the crew from the airway, as with vomiting; the who-holds-what detail is classic teaching and local protocol governs.

Long boards: NASEMSO says not to transport on a rigid long board unless the situation warrants it, for example to immobilize multiple extremity injuries or when removing the board from an unstable patient would delay transport; the board is then padded or a vacuum mattress is added. Tight straps limit chest excursion and cause hypoventilation, and long board time causes pressure injury. The 2025 NAEMSP review recommends limiting boards and full-body vacuum splints to active extrication, so keeping the board is the exception, not the routine.

Dog bites and rabies

ACIP (2008) calls for prompt, thorough wound cleansing and irrigation, consideration of a tetanus booster and avoiding sutures when possible; antibiotics and closure are individual decisions made later. A healthy dog, cat or ferret that bites a person is confined and observed for 10 days, because an animal still well after 10 days was not shedding virus at the bite. Postexposure prophylaxis is a medical urgency, not an emergency, and every possible exposure needs a risk assessment with public health. CDC (2026) tells clinicians to contact the health department immediately for that assessment; prophylaxis is wound washing, human rabies immune globulin and a four-dose vaccine series. The 2010 ACIP update set that four-dose schedule (days 0, 3, 7 and 14, with immune globulin on day 0 for a previously unvaccinated patient) and starts every course with immediate thorough cleansing of the wound with soap and water.

EMT role: control bleeding and dress the wound, do not close punctures, and explain that the danger is infection and rabies exposure rather than the bleeding. A capable adult may decline transport after that explanation, with same-day evaluation urged, the refusal documented and the bite passed to the health department as local rules require. Snakebites are on EMT By-Complaint Quick Pages.

Exam pearls

• Read the crash type: laid down hurts the down side; over the bars hits the head; the tank hits the pelvis
• Child pedestrian with a broken femur: look for the torso and head injuries too
• Intact vest does not mean no injury
• Keep pressure on; do not peek
• Varicose bleed: leg up, finger on it; never a band above it
• Depressed skull: press around, not on
• Fast breathing with clear lungs after a pelvic crush is shock
• Flail that stops moving paradoxically on the bag still needs the bag
• Neutral alignment is never forced
• Dog bite: dressing, rabies risk assessment, health department