CPR

Predictive elements and scoring system

Three‐level Wells score

The predictive elements of this CPR are: clinical signs and symptoms of DVT (3 points), alternative diagnosis less likely than PE (3 points), heart rate > 100 beats per minute (1.5 points), immobilisation for more than 3 days or recent (< 4 weeks) surgery (1.5 points), previous VTE (1.5 points), haemoptysis (1 point), cancer treatment in the previous 6 months or palliative care (1 point).

Low probability ‐ less than 2; intermediate probability ‐ 2 to 6; high probability ‐ more than 6.

Two‐level Wells score

The predictive elements of the two‐level Wells score are the same as the three‐level Wells score but patients are categorised into two as opposed to three categories, PE likely or PE unlikely based on a score of more than 4 or 4 or less points respectively.

The simplified Wells score

The same predictive elements as the three‐level Wells score are used but the points scoring has been simplified ‐ each item now scores 1 point. Patients are regarded as low risk if they have 1 point or less, and high risk if they score more than 1.

The Geneva score

The predictive elements of the Geneva score are: recent surgery (3 points), previous history of PE or DVT (2 points), heart rate > 100 beats per minute (1 point), 60‐79 years old (1 point), 80 or more years old (2 points), chest radiograph showing atelectasis (1 point), chest radiograph showing elevated hemidiaphragm (1 point), partial pressure of oxygen (PaO₂) < 49 mm Hg (4 points), PaO₂ 49‐59 mm Hg (3 points), PaO₂ 60‐71 mm Hg (2 points), PaO₂ 72‐82 mm Hg (1 point), and partial pressure of carbon dioxide (PaCO₂) < 36 mm Hg (2 points), PaCO₂ 36‐38.9 mm Hg (1 point).

Risk of PE is scored low (0 ‐ 4 points), intermediate (5 ‐ 8 points), or high (9 or more points).

The revised Geneva score

The predictive elements of the revised Geneva score are: age > 65 years old (1 point), previous history of PE or DVT (3 points), surgery with general anaesthesia or fracture within one month of the symptoms arising (2 points), active malignancy (2 points), heart rate 75‐94 beats per minute (3 points), heart rate > 94 beats per minute (5 points), pain on leg venous palpation and unilateral oedema (4 points), haemoptysis (2 points), and unilateral leg pain (3 points).

This CPR is scored low risk (0 ‐ 3 points), intermediate (4 ‐ 10 points), or high risk (11 or more points).

The simplified revised Geneva score

The same predictive elements are used as in the revised score Geneva score but the points scoring has been simplified. Each item now scores 1 point.

The risk of PE is scored low (0 ‐ 1 point), intermediate (2 ‐ 4 points), or high (5 or more points).

The Charlotte rule

The elements of the Charlotte rule are: > 50 years old, heart rate higher than the systolic blood pressure, unexplained hypoxaemia (O₂ < 95%), recent surgery (previous four weeks), haemoptysis, and unilateral leg swelling.

The risk score from the Charlotte rule is classified as either safe (all of the predictive elements absent), or unsafe (any of the predictive elements present).