Estimation of the (pretest) clinical likelihood of pulmonary embolism
| High (> 85% likely) | Otherwise unexplained sudden onset of dyspnoea, tachypnoea, or chest pain and at least 2 of the following: | ||
|---|---|---|---|
| Significant risk factor present (immobility, leg fracture, major surgery) | |||
| Fainting with new signs of right ventricular overload in ECG | |||
| Signs of possible leg DVT (unilateral pain, tenderness, erythema, warmth, or swelling) | |||
| Radiographic signs of infarction, plump hilum, or oligemia | |||
| Intermediate (15-85% likely) | Neither high nor low clinical likelihood | ||
| Low (< 15% likely) | Absence of sudden onset of dyspnoea and tachypnoea and chest pain | ||
| Dyspnoea, tachypnoea, or chest pain present but explainable by another condition | |||
| Risk factors absent | |||
| Radiographic abnormality explainable by another condition | |||
| Adequate anticoagulation (INR > 2 or aPTT > 1.5 times control) during the previous week | |||
INR, international normalised ratio; aPTT, activated partial thromboplastin time