Clinical Scores

The Modified Wells Score for Pulmonary Embolism

The Wells score is used in the prediction that a patient has a pulmonary embolism. There are multiple versions and the newest should be used (given below).

1. Suspected DVT: 3 points
2. An alternative diagnosis is less likely than a PE: 3 points
3. Heart rate > 100 bpm: 1.5 points
4. Immobilization or surgery in the previous 4 weeks: 1.5 points
5. Previous DVT or PE: 1.5 points
6. Haemoptysis: 1 point
7. Malignancy: 1 point

Interpretation

• Score > 6: High risk (59%)
• Score 2-6: Moderate risk (29%)
• Score < 2: Low risk (15%)

TIMI (Thrombolysis in myocardial Infarction) Score

This score predicts the chance of mortality, probability of MI, or severe recurrent ischaemia immediately after a non-ST-elevation MI (up to 14 days). It helps in the decision of whether to proceed to urgent angiogram and thrombolysis. All factors are worth 1 point:

1. Age > 65 years
2. Over 3 risk factors for IHD (family history, hypertension, hypercholesterolemia, diabetes, smoker)
3. Known IHD
4. Aspirin use in the past 7 days
5. 2 episodes of severe angina in 24 hours
6. ST changes > 0.5 mm
7. Positive Troponin T

Interpretation

Note that with a 7/7 score the risk is still just 41% of one of the 3 events listed in the introduction. Nevertheless it is widely used for decision making in hospitals.

The Glasgow Coma Scale

1. Best motor response (out of 6):
   • No motor response
   • Extension to pain
   • Withdrawel from pain
   • Localizes pain
   • Obeys commands
2. Best eye response (out of 5):
   • No eye opening
   • Eye opening to pain
   • Eye opening to verbal command
   • Eyes opening spontaneously
3. Best verbal response (out of 4):
   • No verbal response
   • Incomprehensible sounds
   • Inappropriate words
   • Confused words
   • Orientated

Interpretation

Note that confusingly the lowest score that can be achieved is 3 (i.e. dead people achieve this score). The score can be used to follow a trend - if it keeps dropping then this is worring.

The CHADS2 score for AF

Atrial fibrillation increases the risk of stroke in patients, but it is not the only risk factor. This score predicts stroke for patients with AF and is often used in the decision regarding which antithrombotic to use (i.e. aspirin and warfarin, or just aspirin). "CHADS" is a mnemonic for the first letter of the 6-point score. The "2" indicates that prior stroke/TIA is worth 2 points rather than 1.

1. Congestive heart failure: 1 point
2. Hypertension 1 point
3. Age > 75: 1 point
4. Diabetes: 1 point
5. Stroke or TIA in the past: 2 points

The Ransom criteria for Pancreatitis

This is used in predicting the severity of pancreatitis. One point is given for each criteria.

1. On Admission:
   • Age > 55?
   • WBC > 16 on admission?
   • Glucose > 200 (US) > 10 (SI) son admission?
   • LDH > 350 on admission?
   • AST > 250 on admission?
2. At 48 hours After Admission:
   • Hct drop > 10% within 48h of admission?
   • BUN increase > 5 US (> 1.79 SI) within 48h of admission?
   • Ca < 8 (US) < 2 (SI) within 48h of admission?
   • Arterial pO2 < 60 within 48h of admission?
   • Base deficit (24 - HCO3) < 4 within 48h of admission?
   • Fluid needs > 6L within 48h of admission?

Interpretation

3 or more points indicates that severe pancreatitis is likely.

References

• Wells PS, Anderson DR, Rodger M, Ginsberg JS, Kearon C, Gent M, et al. Derivation of a simple clinical model to categorize patients probability of pulmonary embolism: increasing the models utility with the SimpliRED d-dimer. Thromb Haemost 2000;83:416-20
• Antman EM, Cohen M, Bernink PJ, McCabe CH, Horacek T, Papuchis G, Mautner B, Corbalan R, Radley D, Braunwald E. The TIMI risk score for unstable angina/non-ST elevation MI: A method for prognostication and therapeutic decision making. JAMA. 2000 Aug 16;284(7):835-42.
• Gage BF, Waterman AD, Shannon W, Boechler M, Rich MW, Radford MJ. Validation of clinical classification schemes for predicting stroke: results from the National Registry of Atrial Fibrillation. JAMA. 2001 Jun 13;285(22):2864-70
• Ranson JH, Rifkind KM, Roses DF, Fink SD, Eng K, Spencer FC. Prognostic signs and the role of operative management in acute pancreatitis". Surgery, gynecology & obstetrics. 1974. 139(1):69-81