Abdominal Trauma - EMT Protocol Management

Overview

• Tintinalli's Emergency Medicine, p. 1793

1. Scene Size-Up and Mechanism of Injury (MOI)

• Motor vehicle collisions (most common cause of blunt abdominal trauma)
• Pedestrians struck by vehicles; motorcycle/bicycle crashes
• Falls (injury proportional to height and impact surface)
• Direct blows (e.g., steering wheel, bicycle handlebars - suspect pancreatic injury)
• Seatbelt sign - classic marker for bowel/mesenteric injury

• Gunshot wounds (GSW): assume abdominal cavity violation with any wound to chest, pelvis, flank, or back
• Stab wounds: trajectory and depth often unknown in the field
• Impalement: never remove the object; stabilize in place

2. Primary Survey (ABCDE) with Abdominal Focus

Airway & Breathing

• Ensure patent airway; apply high-flow O2 for signs of shock or distress
• Be alert for diaphragmatic injury (0.8-5% of thoracoabdominal trauma) - bowel sounds in the chest suggest herniation through a torn diaphragm

Circulation / Hemorrhage Control

• Abdominal bleeding is internal - you cannot directly compress it in the field
• Recognize early shock: tachycardia, anxiety, and rising respiratory rate may precede hypotension
• Hypotension is a late finding - young, healthy patients can compensate until 30-40% blood volume is lost
• Control any external hemorrhage (abdominal wall lacerations, evisceration sites)
• Establish IV access en route if ALS capable; do not delay transport for IV placement at scene

Disability (Neurological)

• GCS assessment - altered consciousness (head injury, intoxication) masks abdominal findings
• Patients with head injury, intoxication, or language barriers are at especially high risk for missed abdominal injury

3. Rapid Physical Assessment

• Abrasions, contusions, lacerations, seatbelt marks ("seatbelt sign")
• Abdominal distension (suggests blood or bowel contents accumulating)
• Evisceration - bowel or omentum outside the abdominal wall
• Impaled objects - note location, do not remove

• Palpate all four quadrants; note tenderness, rigidity, guarding
• Rigid, board-like abdomen with diffuse tenderness = peritonitis = surgical emergency
• Rebound tenderness (pain worse on release than pressure) = peritoneal irritation
• Flanks and back - flank ecchymosis (Grey Turner sign) indicates retroperitoneal hemorrhage (often delayed)
• Periumbilical bruising (Cullen sign) - also retroperitoneal or intraperitoneal blood (often delayed)

• Absent bowel sounds are a late and unreliable finding in the field; do not spend time on this

4. Specific Injury Patterns

• Tintinalli's EM, pp. 1793-1795

5. EMT Field Management by Wound Type

A. Closed/Blunt Abdominal Trauma

1. Position of comfort - usually supine; flex knees slightly if no spinal concern (reduces abdominal wall tension)
2. High-flow O2 - 15 L/min via NRB if signs of shock; titrate to SpO2 ≥ 94%
3. Do not apply pressure to a distended abdomen
4. Nothing by mouth (NPO)
5. Keep the patient warm - prevent hypothermia (worsens coagulopathy)
6. Monitor vitals serially - trend HR, BP, respiratory rate, skin color/temperature
7. Request ALS intercept if hemodynamic instability is present or developing
8. Minimize scene time - rapid transport to appropriate trauma facility is the definitive intervention

B. Open Abdominal Wounds / Evisceration

• Patients with evisceration have an up to 80% incidence of major intraperitoneal injury - Rosen's Emergency Medicine, p. 493
• Do NOT push organs back into the abdomen
• Cover eviscerated organs with a moist sterile dressing (saline-moistened gauze), then a dry dressing over that
• Keep the dressing moist and covered to prevent organ desiccation
• Position the patient supine with knees bent (reduces tension on the wound)
• Transport immediately

C. Penetrating Wounds (Stab/GSW)

• Apply occlusive or pressure dressing to wounds as appropriate
• For impaled objects: stabilize in place with bulky dressings, cut object down to manageable length only if necessary for transport - Tintinalli's EM, p. 1591
• Do NOT remove impaled objects - removal can precipitate catastrophic hemorrhage
• Assume peritoneal violation; treat for shock prophylactically
• Note number and location of all entry/exit wounds for the receiving team

6. Shock Management (Field Level)

• Class I: HR <100, BP normal, skin normal - < 750 mL blood loss
• Class II: HR 100-120, mildly decreased pulse pressure, anxiety - 750-1500 mL loss
• Class III: HR 120-140, hypotension, decreased urine output, confusion - 1500-2000 mL loss
• Class IV: HR >140, profound hypotension, lethargy - >2000 mL loss

• Oxygen supplementation
• Position: supine, legs elevated if no spinal or respiratory concern
• IV access (if AEMT/Paramedic level) - large-bore bilateral
• Fluid resuscitation: current guidance has moved away from aggressive crystalloid toward permissive hypotension in penetrating trauma (target systolic BP ~80-90 mmHg until hemorrhage control) to avoid "popping the clot." This is primarily an ALS/hospital decision, but EMTs should not over-hydrate
• Keep patient warm - hypothermia + acidosis + coagulopathy = lethal triad

7. Special Populations

Pediatric

• 90% of abdominal trauma is blunt
• Spleen is the most commonly injured organ
• 20-30% of children with significant intra-abdominal injuries may have a normal initial physical exam - Tintinalli's EM, p. 809
• Lower threshold for ALS intercept and trauma center transport
• PECARN criteria identify very low-risk patients (no abdominal/thoracic wall trauma, GCS >13, no abdominal pain, normal breath sounds, no vomiting after injury)

Elderly

• Abdominal exam is even more unreliable
• May be on anticoagulants (warfarin, apixaban, rivaroxaban) or beta-blockers that blunt the HR response to shock
• Beta-blockers can mask tachycardia - do not use HR alone to gauge shock severity
• Higher risk of acute kidney injury from any hypotensive episode
• Low-energy mechanisms (minor falls) can cause significant solid organ injury in the elderly

8. Transport Decisions

9. Trauma Notification / Radio Report

• M - Mechanism of injury
• I - Injuries identified or suspected (include wound locations, evisceration, impaled objects)
• V - Vital signs (BP, HR, RR, GCS, SpO2) - include trend (improving or deteriorating)
• ETA - Estimated time of arrival

10. Summary: EMT Priorities at a Glance

1. Scene safety and MOI - mechanism drives suspicion
2. Primary survey - ABC, control external hemorrhage
3. Assess abdomen - inspect, palpate; document findings
4. Treat by wound type - moist dressing for evisceration, stabilize impaled objects, pressure for open wounds
5. Shock management - O2, warmth, positioning, ALS intercept if available
6. Rapid transport - trauma center is the definitive care
7. Serial reassessment - en route, every 5 minutes for unstable patients

Can We Apply a Cervical Collar in Abdominal Trauma?

The Direct Answer

Why This Matters: The Two Independent Decisions

• Abdominal trauma with a cervical collar indication (e.g., high-speed MVC with abdominal contusion + neck pain)
• Abdominal trauma without a cervical collar indication (e.g., isolated stab wound to the abdomen)
• Neither, or both

When to Apply a Cervical Collar (Indications)

Blunt Trauma - Apply collar if ANY of these are present:

1. Neck pain or tenderness along the cervical spine
2. Neurologic symptoms or deficits - numbness, tingling, weakness in extremities
3. Altered level of consciousness (GCS < 15) including intoxication
4. Anatomic deformity of the cervical spine on palpation
5. High-energy mechanism (MVC, fall from height, diving) PLUS one of:
   • Drug or alcohol intoxication
   • Inability to communicate
   • Distracting injury (this is where abdominal trauma becomes relevant)

The "distracting injury" principle: Significant abdominal trauma (or any painful injury) can distract the patient from perceiving or reporting neck pain. In this case, you apply the cervical collar not because of the abdominal injury itself, but because the abdominal pain may be masking an underlying cervical spine injury that you cannot reliably assess. - Roberts and Hedges' Clinical Procedures in Emergency Medicine, p. 1439

Patients NOT Requiring Immobilization (all 5 must be present to withhold):

• Normal level of consciousness (GCS 15)
• No spinal pain or tenderness
• No neurologic findings or complaints
• No distracting injury
• No intoxication
• Roberts and Hedges' Clinical Procedures in Emergency Medicine, pp. 1438-1465

NEXUS Low-Risk Criteria (Validated Decision Rule)

Penetrating Abdominal Trauma - Special Rule

Victims of penetrating trauma to the head, neck, or torso with no evidence of spinal injury should NOT be routinely immobilized. No study has demonstrated worsening neurologic outcomes from lack of prehospital spinal immobilization in penetrating trauma, while delays in definitive care for hemorrhage increase mortality. - Roberts and Hedges', p. 1591

• GSW or stab wound to the abdomen, patient neurologically intact, no neck pain = no cervical collar needed
• Penetrating trauma with focal neurologic deficit or neck complaint = collar is reasonable, but do not let it delay transport

Special Considerations When Collar IS Applied Alongside Abdominal Trauma

1. Airway first - the collar must not compromise a difficult airway; if airway management is needed, remove the front of the collar with manual in-line stabilization maintained
2. Collar placement does not delay treatment of the abdominal injury (wound dressing, hemorrhage control, transport)
3. Vomiting risk - abdominal trauma patients may vomit; with a collar in place, be prepared to log-roll the patient as a unit to prevent aspiration
4. Positioning - for evisceration, you want to flex the knees to relax abdominal wall tension; this is compatible with a cervical collar - just ensure the collar is properly sized and the spine is kept in neutral alignment throughout
5. Penetrating wounds under the collar - document and communicate to the receiving team any wounds near or under the collar; the collar must not obscure active hemorrhage sites

Practical Summary for EMT Decision-Making

ABDOMINAL TRAUMA PATIENT
        |
        v
Is there a HIGH-ENERGY BLUNT mechanism? (MVC, fall, etc.)
        |
       YES                            NO (isolated penetrating)
        |                                      |
Does patient have ANY of:               Any neck pain / neuro deficit?
- Neck pain/tenderness?                        |
- Neuro symptoms?                      YES → Apply collar
- GCS < 15 / intoxicated?             NO  → Do NOT apply collar
- Distracting injury (abdominal pain)?
- Anatomic deformity?
        |
       YES → APPLY CERVICAL COLLAR
       NO  → Do NOT apply collar

Bottom Line

• A cervical collar is applied based on cervical spine indications, not because of the abdominal trauma itself
• Abdominal pain can qualify as a "distracting injury" under NEXUS criteria, which would justify applying a collar in a high-energy mechanism even without obvious neck complaints
• Penetrating abdominal trauma alone is not an indication for a cervical collar unless there are neurologic symptoms or neck complaints
• When both injuries coexist, manage both - the collar does not prevent proper abdominal wound management

Risks of Prolonged Cervical Collar Immobilization in Trauma Patients

1. Pressure Ulcers and Skin Breakdown

• Incidence of skin complications has been reported as high as 38% in patients with severe closed head injuries treated with prolonged collar use
• The highest-risk contact points are: the occiput, angle of the mandible, and sternum
• Even short exposure matters - in one study, 100% of healthy volunteers reported significant pain after only 30 minutes on a long spine board, with occipital headaches and lumbar/sacral pain
• Collars with higher capillary closing pressures at contact points (e.g., Philadelphia, Stifneck) cause more pressure injury than those with better-distributed contact profiles
• Long-term use of the Philadelphia collar has specifically been associated with pressure ulcers of the scalp
• Rockwood and Green's Fractures in Adults, p. 2163; Roberts and Hedges' Clinical Procedures in Emergency Medicine, p. 1921

2. Raised Intracranial Pressure (ICP)

• A rigid cervical collar compresses the jugular veins, impairing venous drainage from the cranium
• This reduces cerebrospinal fluid (CSF) outflow and raises intracranial pressure
• Studies have specifically documented this: "Effect of the cervical collar on cerebrospinal fluid pressure" and "Cervical-cord-induced changes in intracranial pressure" are cited findings
• Do not overtighten the cervical collar on head-injured patients, because jugular venous compression can raise ICP - though the Stifneck® and Miami J® collars perform better than others in this regard
• In TBI patients, any rise in ICP reduces cerebral perfusion pressure (CPP = MAP - ICP) and can worsen neurological outcomes
• Tintinalli's Emergency Medicine, p. 1749 and p. 2839; Roberts and Hedges', p. 1541; Rockwood and Green's, p. 2163

3. Airway Compromise

• A rigid collar can restrict mouth opening and jaw movement, complicating airway assessment and management
• It can mask expanding neck hematomas or soft tissue swelling that could signal impending airway obstruction
• Collars can make direct laryngoscopy and intubation more difficult - human cadaver studies show that manual in-line stabilization provides less cervical motion AND better glottis visualization than a collar during intubation
• In patients needing a surgical airway (cricothyrotomy), the collar must be removed - it cannot remain in place during this procedure
• Immobilizing a combative or postictal patient in a collar can actually worsen airway risks by increasing agitation and muscle exertion
• Roberts and Hedges', p. 1550-1591; Tintinalli's EM, p. 2824

4. Aspiration Risk

• Collars restrict head and neck mobility, making it very difficult to turn the patient's airway if they vomit
• A supine, collared, immobilized trauma patient who vomits is at high risk for aspiration pneumonia or asphyxiation
• This risk is especially notable in geriatric patients, who have reduced airway reflexes and cough strength
• Halo vests (more rigid than collars) have similarly been shown to increase swallowing difficulty and aspiration risk in elderly patients
• Field collars are associated with increased aspiration and delirium risk, which is especially notable in geriatric populations. - Rockwood and Green's, p. 2116; Rockwood and Green's, p. 2163

5. Respiratory Compromise

• Rigid cervical collars, especially when combined with a long backboard and tight strapping, restrict chest wall expansion
• In healthy children aged 6-15 years, forced vital capacity (FVC) decreased by 4% to 59% during spinal immobilization
• In adults, comparison of backboard vs. vacuum mattress immobilization showed average reductions of ~15% across six respiratory function measures (FVC, FVC%, FEV1, FEV1%, peak expiratory flow, forced expiratory flow)
• While tolerable in healthy individuals, this can be clinically significant in patients with chest trauma, rib fractures, pulmonary contusion, or pre-existing respiratory disease
• Roberts and Hedges', pp. 1933-1934

6. Delirium and Agitation

• Prolonged immobilization causes discomfort, pain, and patient agitation, particularly in elderly patients, intoxicated patients, and those with altered mental status
• When a combative patient fights against the collar, the muscular exertion itself can cause movement of fractured cervical spine fragments, potentially worsening spinal cord injury - the very harm the collar was meant to prevent
• Delirium risk is elevated, especially in geriatric populations
• Sedation can address combativeness but introduces its own risks (respiratory depression, hemodynamic effects)
• Roberts and Hedges', p. 1923; Rockwood and Green's, p. 2116

7. Delay in Identifying Injuries Under the Collar

• A cervical collar covers the anterior and lateral neck, the very region where penetrating injuries, expanding hematomas, tracheal deviation, and jugular venous distension are assessed
• In penetrating trauma, a collar can directly obscure active hemorrhage from a neck wound
• This is why the standard recommendation for penetrating trauma to the neck/torso is: do not apply a cervical collar unless there are clear neurological signs
• "Immobilizing the cervical spine in these patients may lead to missed injury under the collar." - Roberts and Hedges', p. 1591

8. Worsening of Specific Injury Patterns

• Atlanto-occipital distraction injuries: A collar placed on a patient with this injury can actually worsen distraction by extending the neck - rigid boards that cause neck flexion via the large occiput and collars that cause extension are both hazardous in this pattern
• Ankylosing spondylitis / kyphosis: Attempts to force the neck into neutral alignment in patients with fixed kyphotic deformity can fracture the already-rigid spine. The collar and board must accommodate the patient's natural (abnormal) anatomy, not force a "normal" neutral position
• Pediatric considerations: Children under 4 years have proportionally large heads; placing them flat on a standard backboard causes involuntary neck flexion - the opposite of neutral alignment
• Tintinalli's EM, p. 1265; Rockwood and Green's, p. 2116

9. Musculoskeletal Pain Mimicking Injury

• Immobilization itself causes musculoskeletal pain - occipital, mandibular, lumbar, and sacral
• This pain can be misinterpreted as injury-related tenderness on examination, leading to unnecessary radiologic investigation (more CT scans, more radiation exposure, more resource use)
• This confounds the clinical assessment that the collar was meant to facilitate
• Tintinalli's EM, p. 1265

10. No Proven Benefit to Counter These Risks

"There is no good evidence that cervical immobilization restricts harmful movement, and the use of c-collars may cause harm." - Roberts and Hedges', p. 1541

"Biomechanical data from cadavers show that cervical collars do not reduce motion in the most unstable cervical spine injury models." - Rockwood and Green's, p. 2116

"No study has demonstrated worsening neurologic outcomes related to a lack of prehospital spinal immobilization." - Roberts and Hedges', p. 1591

Summary Table

Clinical Take-Away