What is the immediate treatment for a patient with pulmonary infarction?

Immediate Treatment for Pulmonary Infarction

The immediate treatment for pulmonary infarction is anticoagulation therapy with intravenous heparin, which should be initiated as soon as pulmonary embolism is suspected, while the diagnostic workup is ongoing. 1

Initial Assessment and Management

• Perform bedside transthoracic echocardiography (TTE) immediately in patients presenting with hemodynamic instability to differentiate suspected high-risk pulmonary embolism from other acute life-threatening conditions 1
• Assess clinical probability of pulmonary embolism by looking for:
  • Sudden collapse with raised jugular venous pressure
  • Pulmonary hemorrhage syndrome (pleuritic pain and/or hemoptysis)
  • Isolated dyspnea without cough, sputum, or chest pain 1
• Most patients will be breathless and/or tachypneic (respiratory rate >20/min) 1

Immediate Anticoagulation Protocol

Standard Intravenous Heparin Regimen:

• Initial bolus: 5,000-10,000 IU
• Maintenance dose: 1,300 IU/hour
• Alternatively, weight-adjusted dosing:
  • Initial bolus: 80 IU/kg
  • Maintenance: 18 IU/kg/hour 1

APTT Monitoring:

• First check: 4-6 hours after initial bolus
• After dose changes: 6-10 hours later
• When in therapeutic range: Daily
• Target APTT: 1.5-2.5 times control (45-75 seconds) 1

Management Based on Hemodynamic Status

For Hemodynamically Stable Patients:

• Continue anticoagulation with heparin for 7-10 days 2
• Begin oral anticoagulant (warfarin) with target INR 2.0-3.0 3
• Continue heparin until INR reaches at least 2.0 for at least two consecutive days 1

For Hemodynamically Unstable Patients (High-Risk PE):

• Consider thrombolytic therapy immediately for patients with significant hypoxemia or hypotension due to proven pulmonary embolism 4
• Thrombolytic options:
  • rtPA: 100 mg over 2 hours
  • Streptokinase: 250,000 units over 20 minutes, followed by 100,000 units/hour for 24 hours
  • Urokinase: 4,400 IU/kg over 10 minutes, followed by 4,400 IU/kg/hour for 12 hours 1
• Stop heparin before thrombolysis; resume maintenance dose after completion 1

Additional Supportive Measures

• Administer oxygen to maintain adequate saturation 4
• For patients with pulmonary congestion:
  • Consider diuretics (furosemide, torsemide, or bumetanide) if volume overload is present 1
  • Avoid beta-blockers or calcium channel blockers in patients with frank cardiac failure 1
• For hypotensive patients with right ventricular overload:
  • Avoid fluid challenges as they may worsen the condition
  • Consider vasopressors (norepinephrine, isoproterenol, or epinephrine) 4
  • Consider intra-aortic balloon counterpulsation for refractory pulmonary congestion 1

Special Considerations

• In patients with contraindications to anticoagulation, consider inferior vena cava filter placement 1
• For patients with massive PE and hemodynamic instability who have contraindications to thrombolysis or in whom thrombolysis has failed, consider surgical embolectomy 4
• Carefully monitor for complications of pulmonary infarction, including pain, pneumonia, and post-PE syndrome 5

Common Pitfalls to Avoid

• Delaying anticoagulation while waiting for diagnostic confirmation - initiate treatment as soon as PE is suspected 1
• Missing PE diagnosis in elderly patients or those with severe cardiorespiratory disease 1
• Administering fluid challenges to hypotensive patients with right ventricular overload, which can worsen their condition 4
• Discontinuing heparin too early before adequate oral anticoagulation is achieved 1

The management of pulmonary infarction requires prompt recognition and treatment of the underlying pulmonary embolism to prevent significant morbidity and mortality 2, 5.