Prehospital Management of Suspected Acute Aortic Dissection
In suspected aortic dissection, prehospital treatment must be strictly limited to pain relief and blood pressure control, with mandatory withholding of all antithrombotic therapy, followed by immediate transport to a center with 24/7 cardiac surgery and aortic imaging capabilities. 1
Diagnostic Approach
Risk Stratification
- Use the ADD (Aortic Dissection Detection) score in the prehospital setting to identify high-risk patients 1
- Patients with ADD score ≥1 have very high probability of dissection and require immediate surgical center transport
- FoCUS (focused cardiac ultrasound) echocardiography may be considered if expertise is available to support the diagnosis 1
Critical Pitfall
The diagnosis is frequently missed in the prehospital setting—only 17% of EMS clinicians correctly suspected aortic dissection, with most cases misdiagnosed as chest pain or angina 2. Maintain high clinical suspicion in any patient with severe chest pain, particularly if described as tearing or ripping.
Medical Management
Blood Pressure and Heart Rate Control
Start beta-blockers BEFORE other antihypertensive agents 1. This is highly recommended because beta-blockers prevent reflex tachycardia that can worsen dissection propagation.
Target parameters:
- Heart rate: <60 beats/min
- Systolic blood pressure: 100-120 mmHg
- These targets apply in the absence of neurological complications 1
Antihypertensive options (after beta-blockade):
- Intravenous beta-blockers (first-line)
- Nitrates
- Sodium nitroprusside
- Calcium channel blockers 1
Pain Management
- Provide adequate analgesia with narcotic analgesics
- Critical gap in current practice: Only 47% of patients transported by EMS receive narcotic analgesics despite 89% having intensive or very intensive pain, and only 12% are pain-free on hospital arrival 2
- Inadequate pain control contributes to hypertension and tachycardia, worsening outcomes
Mandatory Contraindication
Withholding antithrombotic therapy is MANDATORY 1. This includes:
- No aspirin
- No clopidogrel or other antiplatelet agents
- No anticoagulation
- This is the opposite of acute coronary syndrome management—a critical distinction
Transport Strategy
Destination Selection
Patients with ADD score ≥1 must be transported directly to a center with:
- 24/7 available aortic imaging (CT angiography capability)
- Cardiac surgery on-site 1
Alternative if surgical center unavailable:
- Transfer to non-surgical center for imaging, then immediate secondary transfer to facility with cardiac surgery 1
Pre-arrival Activation
Consider activating aortic imaging and cardiac surgery teams en route, with direct admission to radiology before proceeding to the operating theater 1
Common Pitfalls in Current Practice
Inadequate Hemodynamic Management
Research demonstrates that pretransport hemodynamic therapy is frequently omitted or inadequate 3:
- In patients with SBP <120 mmHg upon EMS arrival, antihypertensives had been given in only 55% of cases
- In 19 cases where pretransport SBP was <120 mmHg with no antihypertensive therapy, median pretransport SBP was 158 mmHg (range 122-212)
- This represents a significant missed opportunity for intervention
Misdiagnosis Risk
The most common preliminary diagnoses by dispatch centers (31%) and EMS clinicians (52%) were chest pain or angina pectoris 2, leading to potential inappropriate treatment with antithrombotics that are contraindicated in dissection.
Management Algorithm
- Suspect dissection in severe chest pain (especially tearing quality)
- Calculate ADD score immediately
- Withhold all antithrombotics (aspirin, anticoagulants)
- Start IV beta-blocker to achieve HR <60
- Add additional antihypertensives to achieve SBP 100-120 mmHg
- Provide adequate narcotic analgesia
- Transport to cardiac surgery center (ADD ≥1)
- Activate receiving team en route if high suspicion
This approach prioritizes mortality reduction through prevention of dissection propagation and rupture while ensuring timely definitive surgical intervention.