Pulmonary Embolus

Definition/Etiology:

Obstruction (air, fat, bone, amniotic fluid, or clotted blood) lodges in branch of pulmonary artery causing partial or total occlusion and potential infarct

Risk factors:

• Previous DVT
• Surgery within the past 4 weeks
• Current estrogen use
• Active or metastatic cancer
• Recent travel with relative immobility
• IV drug use
• Advanced age
• Smoking
• Hypercoagulable state

Pathophysiology:

No blood supply to the affected area of the lung causes bronchoconstriction and pulmonary vasoconstriction resulting in alveolar hypoventilation.

• Blood clot migrates from another part of the body, usually the right side of the heart, the pelvis, or from a deep vein thrombosis (DVT) in the legs
• Fat embolism can occur 24–48 hours after a long bone fracture – petechiae of the chest and axilla
• Amniotic fluid embolism shows up shortly after delivery
• Air – inadvertent injection of air in an IV; dive injuries

Tools:

• PE Rule-out
• PERC – Pulmonary Embolism Rule-out Criteria

None of the following present:

• hormone use
• Age >50
• DVT/PE history
• coughing blood
• lower extremity swelling unilaterally
• SpO2 less than 95%
• HR >99
• surgery/trauma within past 28 days

Wells Score:

• Symptoms of DVT (+3)
• pulmonary embolism most likely (+3)
• HR greater than 100 beats/min (+1.5)
• immobilization of 3 days or surgery in previous 28 days (+1.5)
• previous PE/DVT (+1.5)
• hemoptysis (+1)
• malignancy with treatment in past 6 months or palliative (+1)

Score of less than or equal to 4 qualifies to rule out with D-dimer

Clinical Presentation:

• Sudden shortness of breath
• Tachypnea, tachycardia
• Cough with possible hemoptysis
• Diaphoresis
• Syncope
• Fever
• Crackles upon auscultation
• Accentuated S2 heart sound
• Jugular vein distention (JVD)
• Hypotension
• Elevated ESR, D-dimer
• New onset RBBB, peaked P waves, depressed T waves

Collaborative Management:

• Labs: D-dimer, BNP
  • D-dimer best if low index of suspicion
• EKG
• Chest X-ray, CT/MRI/V/Q scan, echocardiogram
  • V/Q scanning – sufficient to confirm PE

Interventions:

• Maintain ABCs
• Supplemental O2
• Cardiac and pulse oximetry monitoring

Meds:

• Anticoagulants: heparin, low-molecular-weight heparin
• Fibrinolytics

Evaluation | Patient Monitoring | Education:

• Hemodynamic status
• Level of consciousness
• Cardiac rate and rhythm
• Breath sounds and pulse oximetry
• Pain relief

Linchpins: (Key Points)

• Lungs perform activity (gas exchange)
• Activity requires energy
• Energy comes from blood supply
• Blocked blood supply
• Decreased activity (gas exchange)