Diagnosis
Perform blood tests including FBC, U&Es, LFTs, clotting screen and d-dimer. Where oxygen saturations are low, arterial blood sampling can confirm hypoxaemia and hypocapnia.
In PE, the ECG may show sinus tachycardia, T wave inversion V1-4, atrial fibrillation, nonspecific ST segment changes or may be normal. The classic textbook right heart strain pattern of S1Q3T3 is seen in 20% of cases and is neither sensitive nor specific for PE.
The utility of d-dimer is described below. Where DVT or PE is suspected, a 2-level Wells’ score should be performed (see Tables 1 and 2).
Table 1. Two-level DVT Wells’ score
| Clinical feature | Points |
|---|---|
| Active cancer (treatment ongoing, within 6 months or palliative) | 1 |
| Paralysis, paresis or recent plaster immobilisation of lower extremities | 1 |
| Recently bedridden for 3 days or more, or major surgery within 12 weeks requiring general or regional anaesthesia | 1 |
| Localised tenderness along the distribution of deep venous system | 1 |
| Entire leg swollen | 1 |
| Calf swelling at least 3 cm larger than asymptomatic side | 1 |
| Collateral superficial veins (non-varicose) | 1 |
| Previously documented DVT | 1 |
| An alternative diagnosis is at least as likely as DVT | -2 |
| Clinical probability simplified score | Points |
| DVT likely | >/= 2 points |
| DVT unlikely | </= 1 point |
Management of suspected DVT based on DVT Well’s score (recommendations by NICE)


Table 2. 2 level PE Wells’ score
| Clinical features | Points |
|---|---|
| Clinical features and symptoms of DVT (minimum of leg swelling and pain with palpation of the deep veins) | 3 |
| An alternative diagnosis is less likely than PE | 3 |
| Heart rate more than 100/min | 1.5 |
| Immobilisation for more than 3 days or surgery in the previous 4 weeks | 1.5 |
| Previous DVT/ PE | 1.5 |
| Haemoptysis | 1 |
| Active cancer (on treatment, treated in the last 6 months, or palliative) | 1 |
| Clinical probability simplified score | Points |
| PE likely | >4 points |
| PE unlikely | </= 4 points |
Management of suspected PE based on Well’s score (recommendations by NICE)

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