Revised Geneva score for pulmonary embolism (also searched with possessive/alternate eponym spelling where applicable, ICD-10: Z03.818) is an objective, evidence-based clinical prediction rule designed to quantify the pretest probability of acute pulmonary embolism in patients presenting with compatible clinical signs and symptoms^{1, 4}. By standardizing the evaluation of historical risk factors, clinical symptoms, and objective physiological parameters such as heart rate and unilateral lower extremity pain, the revised Geneva score stratifies patients into distinct probability categories that guide downstream laboratory testing, such as D-dimer assays, and imaging modalities including computed tomography pulmonary angiography^{3, 6}. Originally developed to eliminate subjective clinician gestalt, the tool assigns specific weighted points to standardized variables to determine whether pulmonary embolism is unlikely or likely, thereby optimizing diagnostic algorithms, preventing unnecessary radiation exposure, and ensuring timely therapeutic intervention^{5, 7}.

Etiology & Risk Factors

• Previous Venous Thromboembolism: A documented prior history of deep vein thrombosis or pulmonary embolism significantly increases the baseline likelihood of recurrence.
• Active Malignancy: Patients with active cancer, ongoing chemotherapy, or palliative treatment within the previous six months experience a hypercoagulable state predisposing to thromboembolism.
• Recent Surgery or Fracture: Major surgery under general anesthesia or lower limb fractures occurring within the preceding month create profound venous stasis and tissue factor release.
• Unilateral Lower Extremity Pain: Clinical manifestation of unilateral calf or thigh swelling, tenderness, or pain strongly suggests an underlying deep vein thrombosis source.
• Haemoptysis: Presenting with coughing up blood indicates pulmonary infarction secondary to acute vascular occlusion.
• Tachycardia: Heart rate exceeding 94 beats per minute reflects physiological compensation for acute hypoxemia and increased right ventricular afterload.
• Pain on lower limb deep venous palpation and unilateral oedema^{1, 3}.

Pathophysiology

The pathophysiological sequence begins with venous stasis, hypercoagulability, or endothelial injury, which promotes thrombus formation predominantly within the deep venous system of the lower extremities¹. Upon dislodgement, the thrombus travels via the inferior vena cava and right cardiac chambers into the pulmonary arterial tree, where it lodges in vessels ranging from the main pulmonary trunk to subsegmental branches. This mechanical obstruction abruptly increases pulmonary vascular resistance, elevating right ventricular afterload and precipitating acute right ventricular dilatation, wall stress, and ischemia. Concurrently, ventilation-perfusion mismatch develops as unperfused alveoli continue to ventilate, increasing alveolar dead space and leading to hypoxemia. The resulting neurohormonal activation and increased right heart strain can ultimately compromise systemic cardiac output, culminating in obstructive shock and cardiovascular collapse if therapeutic intervention is not promptly initiated^{3, 6}.

Clinical Presentation & Classic Clinical Signs

• History & Cardinal Symptoms: Patients frequently present with acute onset dyspnea, pleuritic chest pain exacerbated by inspiration, cough, and occasionally syncope or lightheadedness when central hemodynamics are compromised³.
• Physical Examination & Named Clinical Signs: Examination reveals tachypnea, tachycardia, an accentuated pulmonary component of the second heart sound, jugular venous distention, and unilateral lower extremity swelling, tenderness, or pitting edema indicative of deep vein thrombosis^{1, 3}.

Diagnostic Workup & Interpretation (Laboratory, Imaging & ECG/Pathology)

Staging, Classification & Clinical Scoring Systems

Differential Diagnosis

Management & Treatment Protocol

Initial Stabilization & Resuscitation: Assess airway, breathing, and circulation immediately. Administer supplemental oxygen if oxygen saturation drops below 92%, and provide aggressive fluid resuscitation with caution or vasopressor support (such as norepinephrine infusion titrated from 2 to 20 mcg/min) in patients presenting with hemodynamic instability or obstructive shock⁶.
• First-Line Medical / Pharmacological Therapy (with exact adult dosing): Initiate immediate therapeutic anticoagulation upon suspicion unless contraindicated. Options include low-molecular-weight heparin (e.g., enoxaparin 1 mg/kg subcutaneously every 12 hours or 1.5 mg/kg subcutaneously once daily), unfractionated heparin (initial intravenous bolus of 80 units/kg followed by continuous infusion at 18 units/kg/hour adjusted to maintain a partial thromboplastin time 1.5 to 2.0 times control), or direct oral anticoagulants such as apixaban (10 mg orally twice daily for 7 days, followed by 5 mg orally twice daily) or rivaroxaban (15 mg orally twice daily for 21 days, followed by 20 mg orally once daily)^{3, 6}.
• Surgical / Interventional Indications: Reserve systemic thrombolytic therapy (e.g., alteplase 100 mg intravenous infusion over 2 hours) or catheter-directed mechanical thrombectomy for patients presenting with massive pulmonary embolism accompanied by persistent systemic hypotension, cardiogenic shock, or severe right ventricular dysfunction refractory to medical management⁶.

Complications & Prognosis

• Acute Right Heart Failure: Rapid pressure overload of the right ventricle can precipitate acute cor pulmonale, tricuspid regurgitation, and fatal cardiogenic shock⁶.
• Chronic Thromboembolic Pulmonary Hypertension: Failure of thrombus resolution can lead to progressive pulmonary vascular remodeling, severe pulmonary hypertension, and long-term right ventricular failure⁶.
• Recurrent Venous Thromboembolism: Inadequate duration or intensity of anticoagulation therapy increases the cumulative risk of recurrent thrombotic events. Mortality and morbidity remain directly proportional to the extent of vascular obstruction and baseline cardiopulmonary reserve^{3, 6}.