What is the pathophysiology, treatment, and management of common conditions in emergency medicine for paramedics, including cardiac arrest, acute coronary syndrome, severe trauma, and stroke?

Paramedic Cheat Sheet: Pathophysiology, Treatment, and Management of Common Emergency Conditions

Paramedics should follow standardized, evidence-based protocols for managing common emergency conditions, with primary focus on interventions that reduce morbidity and mortality through rapid assessment and targeted treatment. 1

Cardiac Arrest

Pathophysiology

• Cessation of effective cardiac output leading to tissue hypoperfusion and hypoxia
• Common causes: ACS (most frequent), pulmonary embolism, tamponade, hypovolemia, hypoxia, acidosis, tension pneumothorax 1
• Brain damage begins within 4-6 minutes without intervention

Assessment

• Check responsiveness, breathing, and pulse (≤10 seconds)
• Identify shockable (VF/pulseless VT) vs. non-shockable rhythms (asystole/PEA)
• Consider reversible causes (H's and T's)

Management

1. High-quality CPR

   • Rate: 100-120 compressions/min
   • Depth: 5-6 cm
   • Complete chest recoil
   • Minimize interruptions (<10 seconds)
   • Rotate compressors every 2 minutes

2. Defibrillation

   • For VF/pulseless VT: immediate defibrillation
   • Resume CPR immediately after shock
   • Minimize pre-shock and post-shock pauses

3. Airway Management

   • Initial BVM ventilation with airway adjuncts
   • Advanced airway when feasible without interrupting compressions
   • Avoid hyperventilation (10 breaths/min)

4. Medications

   • Epinephrine 1mg IV/IO every 3-5 minutes
   • Amiodarone 300mg IV/IO for refractory VF/VT after 3rd shock

5. Post-ROSC Care 1

   • Maintain SBP >90 mmHg
   • Avoid hypoxemia and hyperoxemia (target SpO2 94-98%)
   • Obtain 12-lead ECG
   • Consider targeted temperature management
   • Transport to appropriate facility (PCI-capable if suspected cardiac etiology)

Acute Coronary Syndrome (ACS)

Pathophysiology

• Coronary plaque rupture → thrombosis → myocardial ischemia/infarction
• STEMI: Complete occlusion with transmural ischemia
• NSTEMI: Partial occlusion or transient occlusion
• Unstable angina: Ischemia without myocardial necrosis

Assessment

• Chest pain/discomfort (may radiate to arm, jaw, back)
• Associated symptoms: dyspnea, diaphoresis, nausea, lightheadedness
• 12-lead ECG within 10 minutes of first medical contact 1
• Vital signs, oxygen saturation, cardiac monitoring

Management 1

1. Position - Semi-recumbent, comfortable position

2. Oxygen

   • Only if SpO2 <94% or respiratory distress
   • Target SpO2 94-98%

3. Medications

   • Aspirin 160-325mg chewed (unless true allergy)
   • Nitroglycerin 0.4mg SL every 3-5 minutes (up to 3 doses)
     • Contraindicated if SBP <90mmHg, HR <50 or >100bpm, right ventricular infarct, or PDE5 inhibitor use
   • Consider morphine 2-4mg IV for pain unrelieved by nitrates

4. 12-lead ECG

   • Obtain within 10 minutes of patient contact
   • Transmit to receiving facility when possible
   • Serial ECGs for evolving symptoms

5. STEMI Management

   • Early notification to receiving hospital
   • Rapid transport to PCI-capable facility (goal: first medical contact to device time ≤90 minutes) 1
   • Consider prehospital activation of cardiac catheterization team

Severe Trauma

Pathophysiology

• Primary injury: direct tissue damage from traumatic force
• Secondary injury: hypoxia, hypoperfusion, inflammation
• Hemorrhagic shock: inadequate tissue perfusion due to blood loss

Assessment

• Primary survey: ABCDE (Airway, Breathing, Circulation, Disability, Exposure)
• Secondary survey: head-to-toe examination
• Mechanism of injury, vital signs, GCS
• High-risk features: altered mental status, abnormal vital signs, significant mechanism

Management

1. Airway

   • Maintain patent airway with C-spine precautions
   • Advanced airway if GCS ≤8 or unable to protect airway

2. Breathing

   • High-flow oxygen
   • Decompress tension pneumothorax if present
   • Seal open chest wounds with occlusive dressing

3. Circulation

   • Control external hemorrhage (direct pressure, tourniquets, hemostatic agents)
   • Establish large-bore IV access (2 lines)
   • Fluid resuscitation: balanced crystalloids
   • Permissive hypotension (SBP 80-90mmHg) in penetrating trauma without TBI

4. Disability

   • Rapid neurological assessment (GCS, pupils, motor function)
   • Immobilize spine if indicated

5. Exposure/Environment

   • Fully expose patient
   • Prevent hypothermia

6. Transport

   • Rapid transport to appropriate trauma center
   • Minimize scene time (<10 minutes if possible)
   • Early notification to receiving facility

Stroke

Pathophysiology

• Ischemic (87%): vessel occlusion → brain tissue hypoperfusion
• Hemorrhagic (13%): vessel rupture → increased intracranial pressure
• "Time is brain" - 1.9 million neurons lost per minute of untreated stroke

Assessment

• Use validated stroke scale (e.g., FAST, Cincinnati, Los Angeles)
• Determine last known well time (critical for treatment decisions)
• Blood glucose, vital signs
• Exclude stroke mimics (hypoglycemia, seizure, migraine)

Management

1. Airway and Breathing

   • Maintain patent airway
   • Supplemental oxygen only if hypoxemic (SpO2 <94%)
   • Position head elevated 30° if no trauma

2. Circulation

   • Establish IV access
   • Manage blood pressure (avoid treatment unless extreme hypertension)

3. Disability

   • Serial neurological assessments
   • Protect paralyzed extremities

4. Transport

   • Rapid transport to stroke-capable center
   • Pre-notification to activate stroke team
   • Consider direct transport to comprehensive stroke center for large vessel occlusion

5. Additional Considerations

   • Keep NPO
   • Manage blood glucose (treat if <60mg/dL)
   • Document accurate last known well time
   • Obtain family contact information for consent purposes

Respiratory Distress

Pathophysiology

• Asthma: Bronchospasm, inflammation, mucus production
• COPD: Airflow limitation, air trapping, V/Q mismatch
• Pulmonary edema: Fluid accumulation in alveoli from cardiac dysfunction
• Pneumonia: Inflammatory response to infection in lung parenchyma

Assessment

• Work of breathing: accessory muscle use, retractions, tripod positioning
• Breath sounds: wheezing, crackles, diminished
• Vital signs: tachypnea, tachycardia, SpO2
• Signs of fatigue or impending respiratory failure

Management

1. Positioning

   • Upright position to maximize respiratory mechanics

2. Oxygen

   • Titrate to SpO2 94-98% (88-92% in COPD)

3. Medication by Condition

   • Asthma/COPD:

     • Albuterol 2.5-5mg nebulized (may repeat)
     • Consider ipratropium 0.5mg nebulized
     • Consider methylprednisolone 125mg IV for severe cases

   • Pulmonary Edema:

     • Nitroglycerin 0.4mg SL (if SBP >100mmHg)
     • Consider CPAP if available
     • Furosemide 40mg IV (if evidence of fluid overload)

4. Advanced Interventions

   • CPAP/BiPAP if available and indicated
   • Advanced airway management if respiratory failure

Key Pitfalls to Avoid

1. Delayed recognition of time-sensitive conditions

   • Obtain 12-lead ECG within 10 minutes for suspected ACS 1
   • Document last known well time for stroke patients

2. Inadequate assessment

   • Complete primary and secondary surveys
   • Serial reassessments for changing conditions

3. Inappropriate oxygen administration

   • Avoid hyperoxia in cardiac arrest and post-ROSC patients 1
   • Target appropriate SpO2 ranges based on condition

4. Ineffective CPR

   • Ensure adequate depth, rate, and minimal interruptions
   • Rotate compressors to prevent fatigue

5. Delayed transport

   • Minimize on-scene time for time-critical conditions
   • Early notification to receiving facilities

Remember: Early recognition, appropriate intervention, and rapid transport to the right facility are the cornerstones of effective emergency care.