Pneumonia CURB-65 Score

CURB-65 items explained

This risk stratifying tool is addressed to patients diagnosed with community acquired pneumonia and can help clinicians devised the appropriate management strategy, be it in-hospital or as outpatient.

There are five patient factors that are used in the score:

■ Confusion;

■ Blood Nitrogen Urea >19 mg/dL (>7 mmol/L);

■ Respiratory rate equal to or higher than 30/min;

■ Systolic BP <90 mmHg or Diastolic BP ≤60 mmHg;

■ Age equal or higher than 65.

CURB-65 was praised for its specificity in identifying patients with CAP who may require admission to intensive care units.

On the other hand, the score was criticised because it doesn’t account for comorbidities, especially when the score is applied to elderly patients.

Further on, the score has been validated as a clinical prediction rule in several settings and is now recommended by the British Thoracic Society. Another pneumonia addressed scoring system is the PSI.

It is important to note that although the score is an accurate risk stratification tool, clinical judgment prevails.

Score interpretation

CURB-65 not only stratifies the CAP patient in a management group but also offers a prognostic value for 30-day mortality risk.

Each of the five items in the score is awarded 1 point if present during the evaluation, therefore the total result varies from 0 (low risk pneumonia) to 5 (highly severe pneumonia).

Patients who score 0 or 1 can be treated as outpatients and their mortality risk is less than 3%. Patients who score 2 points require more assistance and may be admitted in hospital.

Patients who obtain scores of 3 or above require serious hospitalization, possibly in the intensive care unit.

About the study

The only existent measure for CAP severity before the CURB-65 , the modified British Thoracic Society (mBTS) rule would focus on discovering patient with severe pneumonia but would not stratify the severity of the disease.

In 2003, Lim et al. conducted a multicentre study on a cohort of 1068 patients with the following characteristics: mean age 64 years, 51.5% male, 30-day mortality 9%.

Multiple logistic regression was employed to discover the prognostic variables. The final model was tested against the validation cohort.

CURB-65 was found to be accurate in stratifying patients with CAP into different management groups.

Community acquired pneumonia guidelines

CAP is a common infectious disease with high admission rates. Rapid and accurate diagnosis may help with reducing the associated high morbidity and mortality risks of the condition.

This infection is caused by bacterial pathogens such as Streptococcus pneumonia and Haemophilus influenza, which are inhaled in the lung segments or in the lobes.

Most common symptoms are fever, cough, localized chest pain, mild dyspnea and general malaise.

In severe cases, accompanying comorbidities include cardiopulmonary disease or impaired splenic function.

Original source

Lim W, van der Eerden M, Laing R, Boersma W, Karalus N, Town G, Lewis S, Macfarlane J. Defining community acquired pneumonia severity on presentation to hospital: an international derivation and validation study. Thorax. 2003; 58(5): 377–382.

Validation

1. British Thoracic Society, Myint PK, Kamath AV, Vowler SL, Maisey DN, Harrison BD. Severity assessment criteria recommended by the British Thoracic Society (BTS) for community-acquired pneumonia (CAP) and older patients. Should SOAR (systolic blood pressure, oxygenation, age and respiratory rate) criteria be used in older people? A compilation study of two prospective cohorts. Age Ageing. 2006; 35(3):286-91.

2. Torralba MA, Amores-Arriaga B, Olivera S, Perez-Calvo JI. Validity of Fine and CURB scales in the treatment of community-acquired pneumonia in adults. Med Clin (Barc). 2010; 135(13):624-5.