Mechanism documentation (Document **role** (restrained passenger, unrestrained, pedestrian, cyclist) · vehicle speed estimate · intrusion/deformity · ejection · death in same vehicle · LOC at scene · child restraint type and appropriateness (ATLS pediatric, NHTSA child passenger safety, AAP))
Low-energy criteria (examples) (Low-speed (<40 km/h / <25 mph) · no passenger compartment intrusion · restrained in appropriate car seat/booster · no ejection · no death in vehicle · no LOC >1 min · ambulatory at scene · no high-risk complaints — still requires structured exam and shared decision-making (ATLS pediatric, pediatric MVC guidelines))
First-line therapy
ABCDE + targeted exam + observation • procedure
Duration: ED / observation · Full primary survey · focused secondary exam · apply head-injury rules if head impact · c-spine assessment per mechanism · observe 4–6 h if any concern · discharge only if low-risk mechanism + normal exams + reliable follow-up (ATLS pediatric, AAP)
• **Red flags despite 'minor' mechanism:** death in same vehicle · ejection · rollover · high-speed (>65 km/h / 40 mph) · significant intrusion · unrestrained · pedestrian/bicycle struck at >30 km/h · LOC · vomiting · chest/abdominal pain/tenderness · seatbelt sign · extremity deformity (ATLS pediatric, trauma activation criteria).
• **Head injury:** if head struck — PECARN/CATCH/CHALICE; minor MVC with isolated low-risk head bump may observe without CT if rule-negative (AAP, PECARN).
• **C-spine:** clinical clearance in cooperative child if low-risk mechanism AND no midline tenderness, no neuro deficit, GCS 15, no intoxication — per ATLS pediatric NEXUS-style criteria adapted for children; immobilize if any doubt.
• **Chest/abdomen:** auscultate, palpate, observe for seatbelt sign, handlebar injury equivalent; delayed solid-organ injury possible — admit if tenderness, tachycardia disproportionate to exam, or mechanism concern (see **chest_trauma**, **abdominal_trauma**).
• **Discharge criteria:** GCS 15 throughout · no red flags · normal repeat exams · reliable caregivers · written return precautions · car seat re-check before next ride (AAP, NHTSA).
Admission for observation • procedure
Duration: As indicated · Admit 12–24 h if intermediate mechanism, unreliable exam (young infant), evolving symptoms, social concerns, or abnormal vitals — CT/selective imaging per clinical findings (ATLS, AAP)
• **Admit:** persistent vomiting, headache, abdominal/chest tenderness, tachycardia, mechanism with intrusion/ejection even if currently well, infant/toddler with unreliable exam (ATLS, AAP).
• **Imaging:** CT head per head-injury rules; CXR if respiratory symptoms; FAST if abdominal tenderness or mechanism concern — not routine for all minor MVC (ATLS pediatric).
• **Child passenger safety:** document restraint use; educate on appropriate car seat/booster; refer for seat inspection if misused (NHTSA, AAP).
• **Safeguarding:** unrestrained child, intentional crash, neglect of safety devices — assess and refer per local policy (AAP).
• **Escalate to high-energy variant** if hemodynamic instability, GCS <15, open wounds, or multi-system injury identified.
Clinical notes
• Mechanism drives risk: document speed, restraint, intrusion, ejection, pedestrian role, LOC — low-speed restrained passenger with normal exams may observe; red flags mandate escalation (ATLS pediatric, NHTSA).
• ABCDE + head-injury rules for any head impact; c-spine selective clearance in low-risk cooperative children per ATLS pediatric criteria.
• Chest/abdomen: seatbelt sign, tenderness, tachycardia — admit and image selectively; delayed solid-organ bleeding possible 12–24 h (see **chest_trauma**, **abdominal_trauma**).
• Discharge: GCS 15, no red flags, normal serial exams, return precautions, car seat safety education (AAP, NHTSA).
• Cross-links: focal injuries → **head_trauma**, **chest_trauma**, **abdominal_trauma**; high-energy mechanism → escalate to severe MVC variant.
• ATLS — Pediatric trauma mechanism and c-spine clearance (2024)
