ACEM Fellowship Learning Objective 3.13 - Special Cases in Trauma
## Overview: Why Special Populations Matter in Trauma
Standard ATLS-derived trauma principles provide the framework for all major trauma patients, but several populations require deliberate adaptation of those principles. The emergency physician must recognise both the physiological and sociological factors that alter injury patterns, clinical presentation, resuscitation targets, and disposition. Failure to adapt to these populations is a recurring source of preventable harm and medicolegal exposure.
Paediatric Trauma and Non-Accidental Injury (NAI)
Physiological Adaptations in Paediatric Trauma
| Parameter | Adaptation Required |
|---|---|
| Airway | Smaller calibre, more anterior/cephalad larynx, large occiput causes flexion - use shoulder roll |
| Breathing | Higher respiratory rate, smaller FRC, rapid desaturation |
| Circulation | Compensated shock - HR and vasoconstriction maintained until late; SBP drops are pre-arrest signs |
| Disability | GCS modified for age; fontanelle assessment in infants |
| Exposure | High surface area:mass ratio - rapid hypothermia risk |
Fluid resuscitation: initial bolus 10 mL/kg crystalloid (not 20 mL/kg in haemorrhagic shock - risk of dilution coagulopathy). Transition early to massive transfusion protocol (MTP) with 1:1:1 pRBC:FFP:platelets. Permissive hypotension targets are less well-validated in children; maintain age-appropriate SBP.
$$\text{Estimated Blood Volume (EBV)} = 80 \text{ mL/kg (child)}$$
Non-Accidental Injury (NAI): Recognition and Management
NAI requires a high index of suspicion; the ED presentation is often the only opportunity for detection.
Red flag patterns in history: - Inconsistent or evolving mechanism - Developmental mismatch (injury not possible given age/development) - Delayed presentation - Multiple ED visits for "accidents" - Injuries attributed to sibling or self
Injury patterns raising concern for NAI:
| Injury | Significance |
|---|---|
| Posterior rib fractures | High specificity for inflicted trauma (squeezing force) |
| Metaphyseal "bucket handle" fractures | Classic for shaking/traction forces |
| Subdural haematoma | Especially bilateral, or with thin film appearance |
| Retinal haemorrhages | Seen in abusive head trauma (shaken baby) |
| Burns with clear demarcation | Immersion burns, glove/stocking distribution |
| Bruising in non-mobile child | Any bruise in pre-mobile infant is suspicious |
| Multiple fractures of different ages |
Management priorities: 1. Resuscitate and stabilise as per standard trauma principles 2. Document injuries meticulously (photographic documentation where available/consented) 3. Full skeletal survey (not just targeted x-rays) for children < 2 years 4. Ophthalmology review for retinal haemorrhages 5. Coagulation screen (exclude bleeding diathesis) 6. Mandatory reporting obligations - notify child protection services; escalate to social work and senior ED staff 7. Safe disposition - do not discharge to the alleged perpetrator; admission or place of safety required 8. Multidisciplinary team involvement: paediatrics, social work, police (as appropriate) 9. Documentation must be objective, not interpretive - describe injuries, not conclusions
Obstetric Trauma
Anatomical and Physiological Changes
| System | Change | Clinical Impact |
|---|---|---|
| Blood volume | Increases ~50% by term | Haemorrhage masked; 1500-2000 mL blood loss before haemodynamic change |
| Cardiac output | Increases 40-50% | Higher baseline HR (tachycardia less specific) |
| Uterus | Enlarges out of pelvis at 12 wks | Vulnerable to penetrating/blunt injury after 1st trimester |
| Aortocaval compression | IVC compression in supine position | 15° left lateral tilt or manual uterine displacement |
| Diaphragm elevation | Rises ~4 cm | Chest drain insertion one space higher |
| Gastric emptying | Delayed | Rapid sequence intubation always required |
| GFR/creatinine | GFR rises; creatinine falls | Normal creatinine ~45 µmol/L at term; "normal" lab value may represent impairment |
Primary survey is for the mother first. Foetal survival is best served by optimal maternal resuscitation. Do not let foetal monitoring distract from maternal primary survey.
Perimortem Caesarean Section (PMCS)
- If maternal cardiac arrest occurs from 20 weeks gestation: commence PMCS by 4 minutes, deliver by 5 minutes (the "4-minute rule")
- Goal is to relieve aortocaval compression and improve maternal CPR effectiveness, not solely foetal salvage
- Prepare for PMCS simultaneously with resuscitation - do not wait for obstetric team
- Neonatal resuscitation team required
Foetal Assessment
- Cardiotocography (CTG) after any significant trauma from 24 weeks
- Minimum monitoring: 4 hours; 24 hours if any abnormality
- Kleihauer-Betke test (or flow cytometry) to detect foetomaternal haemorrhage - guides anti-D administration in Rh-negative mothers
- Anti-D 300 mcg IM for Rh-negative mothers after any trauma (first trimester: 250 mcg)
Elderly Trauma Population
Why Elderly Trauma is Under-Triaged
- Attenuated physiological response: beta-blockade (iatrogenic), reduced cardiac reserve, autonomic dysfunction
- "Normal" vital signs may represent significant physiological stress
- Premorbid conditions amplify injury severity: osteoporosis, anticoagulation, cognitive impairment
- Age >55 is an independent predictor of mortality in trauma
Injury Patterns
| Pattern | Mechanism |
|---|---|
| Rib fractures | Low energy - high morbidity (2% mortality per rib, cumulative) |
| Subdural haematoma | Cerebral atrophy increases bridging vein tension; trivial mechanism |
| Cervical spine injury | Degenerative changes narrow canal; central cord syndrome from hyperextension |
| Hip fracture | Often precipitating event (fracture then fall) |
| Solid organ injury | Reduced physiological reserve for non-operative management |
Resuscitation targets: More aggressive early resuscitation warranted; permissive hypotension less appropriate given reduced physiological reserve and risk of end-organ ischaemia. Cardiac monitoring essential - rate control, ischaemia detection.
Anticoagulation reversal: A significant proportion of elderly trauma patients are on anticoagulants. Know reversal strategies rapidly:
| Agent | Reversal |
|---|---|
| Warfarin | Vitamin K + 4F-PCC (Prothrombinex 25-50 IU/kg); FFP if PCC unavailable |
| Dabigatran | Idarucizumab 5 g IV |
| Rivaroxaban/Apixaban | Andexanet alfa (or 4F-PCC 50 IU/kg empirically) |
| Aspirin/Clopidogrel | Platelets if active neurosurgical bleeding; desmopressin 0.3 mcg/kg |
Disposition: lower threshold for admission, ICU monitoring, early orthogeriatric involvement for fractures.
Bariatric Patients
- Altered drug pharmacokinetics: volume of distribution expanded, protein binding altered
- Airway challenge: positioning critical - ramped position (ear to sternal notch) essential; videolaryngoscopy as first-line
- Ventilation: increased chest wall compliance challenge; higher PEEP requirements post-intubation
- Imaging: CT scanner weight limits must be confirmed in advance; standard equipment may be inadequate
- Intravenous access: ultrasound guidance routinely required
- Logistical challenges: adequate personnel, bariatric trolleys and equipment
- C-spine immobilisation: standard collars may not fit; improvise with sandbags and tape
- Drug dosing: ideal body weight (IBW) for most drugs; total body weight (TBW) for lipophilic agents
$$\text{IBW (male)} = 50 + 2.3 \times (\text{height in inches} - 60)$$
$$\text{IBW (female)} = 45.5 + 2.3 \times (\text{height in inches} - 60)$$
Multiple Casualties / Mass Casualty Incidents (MCI)
Triage Systems
The purpose of triage in MCI is to do the greatest good for the greatest number - this represents a fundamental ethical shift from individual-focused care.
| Category | Colour | Priority | Description |
|---|---|---|---|
| Immediate | Red | P1 | Life-threatening but salvageable |
| Delayed | Yellow | P2 | Serious but can wait 4-6 hours |
| Minimal | Green | P3 | Walking wounded |
| Expectant | Blue/Black | P4 | Unsurvivable or consumes excessive resources |
| Dead | Black | P0 | No signs of life |
START triage: Respirations → Perfusion → Mental status (RPM) - Respirations >30/min or absent (after airway opening) → Red or Black - Radial pulse absent or capillary refill >2 sec → Red - Cannot follow commands → Red
ED and System Response
- Declare early, escalate through hospital incident command system
- Designate triage officer, team roles explicitly assigned
- Surge capacity: clear department early, activate internal escalation
- Communication: clear, closed-loop; avoid radio silence; incident commander role
- Documentation: triage tags, log keeping for medicolegal purposes
- Media, family management: centralise family liaison, not in clinical areas
- Debrief: structured post-incident review mandatory
Patients on Multiple Medications
Beyond anticoagulants, several drug classes significantly alter the trauma response:
| Drug Class | Effect on Trauma Response | Action |
|---|---|---|
| Beta-blockers | Mask tachycardia in haemorrhage; bradycardic shock possible | Treat with glucagon 5-10 mg IV, calcium |
| ACE inhibitors/ARBs | Refractory vasodilatory shock | Vasopressin as preferred vasopressor |
| Immunosuppressants | Blunted inflammatory response; occult infection post-trauma | Low threshold for infectious workup |
| Insulin/OHA | Hypoglycaemia after physiological stress | Frequent glucose monitoring |
| Lithium | Narrow therapeutic index; altered by resuscitation fluids | Check levels; avoid aggressive sodium shifts |
| Antiepileptics | Drug interactions; seizure threshold altered | Continue where possible; IV formulation if NBM |
| Corticosteroids | Adrenal suppression; relative adrenal insufficiency post-trauma | Stress dosing: hydrocortisone 100 mg Q8h |
Vulnerable Patients Post-Assault
Physical Assessment
- Full body examination: clothing removed, patient draped appropriately with same-gender clinician if possible
- Document ALL injuries with body diagram and photography
- Strangulation: external marks absent in up to 50% of cases with significant internal injury - CT angiography neck if any hoarseness, dysphagia, or neurological symptoms
- Patterned injuries may indicate object used
- Sexual assault: forensic examination within 72 hours for most meaningful evidence
Trauma-Informed Care
- Explain all procedures before performing them; obtain explicit consent
- Patient-directed approach: patient controls pace of examination
- Minimise number of staff; preserve dignity
- Avoid re-traumatising language; do not express disbelief
- Same-gender clinician if requested
Forensic Considerations
- Chain of evidence: label samples with patient ID, date/time, collector's name, seal appropriately
- Do not clean wounds before photography
- Retain clothing in paper bags (not plastic)
- Toxicology (drug-facilitated assault): urine within 72 hours, blood within 24 hours
- Sexual assault evidence kit: use standardised state/territory kit; do not improvise
Mandatory Reporting and Safeguarding
- Domestic violence: mandatory reporting obligations vary by jurisdiction - know your local law
- Safety planning: do not discharge into the presence of the alleged perpetrator without safety assessment
- Social work, DVSA (Domestic Violence Safety Assessment), culturally appropriate support
- For Aboriginal and Torres Strait Islander, CALD, and LGBTQ+ patients: culturally safe and appropriate referrals
## ACEM Fellowship Implications
Written Examination
Expect structured questions requiring you to adapt standard trauma management to one or more special populations simultaneously (e.g., elderly patient on warfarin with rib fractures, or pregnant patient after motor vehicle crash). Key themes include: - Recognising when standard parameters are misleading (e.g., "normal" HR in elderly on beta-blocker, "normal" BP in pregnant patient with 30% blood loss) - NAI recognition - the exam will test both clinical signs and the mandatory reporting/safeguarding response, not just medical management - PMCS - indications, timing, and the rationale for 4-minute decision - MCI triage - START algorithm, ethical framework, incident command structure
OSCE Stations
These populations commonly appear in communication stations: - Explaining to a parent that NAI is suspected - remain non-accusatory, explain mandatory reporting clearly - Safety planning conversation with a domestic violence victim - trauma-informed, non-judgemental - Briefing nursing staff during an MCI declaration - clear role assignment, closed-loop communication
Disposition Pitfalls
- Never discharge a child with suspected NAI without child protection notification and senior review
- Never discharge an obstetric trauma patient <24 weeks with uterine irritability or foetal heart rate abnormality without obstetric review
- Elderly rib fractures: ≥3 ribs, any age >65 - consider HDU/ICU admission; pain management plan essential (regional anaesthesia, PCA, respiratory physiotherapy)
- Post-assault patients: discharge safety planning is a mandatory component of the disposition - not optional
System and Governance
- Know your institution's MTP activation criteria and MCI plan
- Know your jurisdictional mandatory reporting obligations for both child abuse and domestic violence
- Document your reasoning in special populations - medicolegal exposure is highest when the clinical picture is ambiguous and management deviated from standard pathways