🚨 Massive Pulmonary Embolism

A life-threatening condition caused by a large blood clot obstructing a major pulmonary artery, leading to acute right heart failure and cardiovascular collapse. It presents with sudden onset dyspnoea, chest pain, and haemodynamic instability. Prompt diagnosis and treatment are critical to survival.

Sudden onset of severe dyspnoea, pleuritic chest pain, syncope, or pre-syncope. Clinical signs include hypotension, tachycardia, tachypnoea, and signs of right heart strain (elevated JVP, tricuspid regurgitation murmur). Cyanosis may be present. Risk factors for VTE are often present.

Assess airway and breathing, noting respiratory rate, oxygen saturation, and signs of respiratory distress. Evaluate circulation for heart rate, blood pressure, capillary refill time, and signs of shock. Assess disability (GCS) and expose to look for DVT signs or cyanosis.

Persistent hypotension (systolic BP <90 mmHg or drop >40 mmHg from baseline), persistent tachycardia, deteriorating oxygen saturation, altered mental status, or signs of cardiogenic shock. Recurrent syncope is a major red flag.

ECG is crucial, often showing sinus tachycardia, right axis deviation, or new RBBB; S1Q3T3 pattern is classic but uncommon. ABG will show hypoxia and often respiratory alkalosis. Bedside echocardiography can show right ventricular strain. CT Pulmonary Angiogram (CTPA) is the gold standard for diagnosis but may be delayed in unstable patients. D-dimer is useful to rule out PE in low-risk patients, but not in suspected massive PE.

Administer high-flow oxygen to maintain saturations. Provide intravenous fluid resuscitation cautiously if hypotensive, but avoid fluid overload in right heart failure. Consider vasopressors to support blood pressure. Urgent thrombolysis is indicated for haemodynamically unstable patients. Anticoagulation should be initiated promptly.

Any haemodynamic instability (hypotension, cardiogenic shock) in suspected PE warrants immediate senior medical and cardiology/respiratory consultant review. Consider ICU for close monitoring and potential advanced therapies like thrombolysis or embolectomy.

Massive PE is defined by haemodynamic instability, not clot size. Thrombolysis is the mainstay of treatment for massive PE. Remember the ECG findings, especially S1Q3T3, though it's not always present. Always consider PE in patients with sudden unexplained dyspnoea and hypotension.