What is the most appropriate next step in management for a patient with suspected pulmonary embolism (PE) and acute onset of shortness of breath, tachycardia, and hypoxemia?

Heparin Therapy is the Most Appropriate Next Step in Management for Suspected Pulmonary Embolism

Heparin therapy is the most appropriate next step in management for this patient with suspected pulmonary embolism following hip fracture surgery. 1

Clinical Presentation Analysis

This 62-year-old woman presents with classic signs and symptoms of pulmonary embolism (PE):

• Acute onset shortness of breath 3 days after hip fracture surgery
• Hemoptysis (blood-tinged sputum)
• Tachycardia (pulse 110/min)
• Tachypnea (respirations 24/min)
• Hypoxemia (PO₂ 70 mmHg on 40% oxygen)
• Ventilation-perfusion lung scans showing multiple segmental areas of mismatch

These findings strongly indicate intermediate-risk (non-high-risk) PE in a patient with a major risk factor (recent hip fracture surgery with immobilization).

Management Algorithm

1. Risk Stratification:

   • Patient is hemodynamically stable (BP 110/70 mmHg)
   • No signs of cardiogenic shock
   • Multiple segmental V/Q mismatches indicate PE
   • Classification: Intermediate-risk (non-high-risk) PE

2. Immediate Management:

   • Anticoagulation with heparin should be initiated without delay 1
   • Oxygen therapy should be continued for hypoxemia 1

3. Treatment Options Analysis:

   Option	Appropriateness	Rationale
   Heparin therapy	Most appropriate	First-line treatment for confirmed non-high-risk PE 1
   Pulmonary angiography	Not needed initially	Diagnosis already established with V/Q scan showing multiple mismatches
   Dopamine therapy	Not indicated	Patient is normotensive; vasopressors only needed for hypotension 1
   Urokinase therapy	Not indicated	Thrombolysis not recommended for non-high-risk PE without hemodynamic compromise 1
   Intubation	Not indicated	Patient maintaining adequate oxygenation on supplemental oxygen

Evidence-Based Recommendation

The European Society of Cardiology (ESC) guidelines clearly state that "anticoagulation should be initiated without delay in patients with high or intermediate clinical probability of PE while diagnostic workup is still ongoing" 1. The British Thoracic Society (BTS) guidelines similarly recommend that "heparin should be given to patients with intermediate or high clinical probability before imaging" 1.

For this patient with confirmed PE on V/Q scan and stable hemodynamics, heparin therapy is the cornerstone of initial management. Either unfractionated heparin (UFH) or low molecular weight heparin (LMWH) can be used, with LMWH generally preferred due to equal efficacy, better safety profile, and easier administration 1.

Important Considerations

• Timing: Anticoagulation should be started immediately without further delay
• Type of heparin: LMWH is generally preferred over UFH except in cases of severe renal dysfunction or high bleeding risk 1
• Duration: Heparin should be continued for at least 5 days and overlapped with oral anticoagulation (vitamin K antagonist) until target INR is achieved for at least 2 consecutive days 1

Pitfalls to Avoid

1. Delaying anticoagulation while pursuing additional diagnostic testing can increase mortality risk
2. Unnecessary thrombolysis (urokinase) in non-high-risk PE increases bleeding risk without improving outcomes 1
3. Overuse of pulmonary angiography when diagnosis is already established by V/Q scan
4. Premature discontinuation of anticoagulation therapy before adequate oral anticoagulation is established

The patient should be monitored closely for clinical improvement, with consideration of extended anticoagulation therapy given the post-surgical context of her PE.