What is the purpose and application of the Baux score in burn patients?

The Baux Score in Burn Patients: Purpose and Application

The Baux score is a prognostic tool used to predict mortality risk in burn patients, with the revised version (rBaux) being the most accurate and current standard for clinical decision-making in burn management. 1, 2

What is the Baux Score?

• The original Baux score is calculated as the sum of patient's age in years plus the percentage of total body surface area burned (TBSA%) 1
• The revised Baux score (rBaux) adds 17 points if inhalation injury is present: Age + TBSA% + 17*(inhalation injury, 1=yes, 0=no) 1
• The revised version was developed to address the overly pessimistic predictions of the original score and to account for advances in burn care 1

Clinical Application and Purpose

• Primary purpose: To predict mortality risk in burn patients, helping clinicians make informed treatment and triage decisions 2
• The rBaux score demonstrates excellent predictive value with area under the curve (AUC) values ranging from 0.682 to 0.99, with a summary AUC of 0.93 across multiple studies 2
• Helps determine the need for transfer to specialized burn centers by objectively quantifying injury severity 3, 4
• Assists in patient counseling and family discussions regarding prognosis 5
• Facilitates resource allocation in mass casualty incidents involving burn victims 4

Advantages of the Revised Baux Score

• Simple enough for mental calculation in emergency settings, making it practical for frontline providers 1
• More accurate than other quick assessment tools like qSOFA for predicting mortality in burn patients (AUC 0.99 vs 0.68) 6
• Incorporates the three most significant risk factors for burn mortality: age, TBSA%, and inhalation injury 1, 5
• Helps standardize communication between healthcare providers regarding burn severity 4

Clinical Interpretation

• A revised Baux score >140 indicates very high mortality risk (nearly 100% specificity) 6
• An optimal cutoff of 85 on the revised Baux score yields 100% sensitivity and 94% specificity for predicting mortality 6
• The score should be calculated after accurate TBSA assessment using the Lund-Browder chart, which is the most accurate method for TBSA quantification 3
• When combined with the Updated Charlson Comorbidity Index (CCI), the predictive value increases further, emphasizing the importance of considering pre-existing conditions 5

Limitations and Considerations

• The rBaux score has diminished predictive ability at extremes of age (very young or very elderly patients) 2
• May not account for deaths from causes unrelated to burns, which can affect its sensitivity 7
• When patients die with Baux scores <100, the cause is often unrelated to the burn itself (such as cerebrovascular disease), which affects the score's sensitivity 7
• Should be used alongside clinical judgment, not as the sole determinant of care decisions 4, 5

Integration with Burn Management

• Should be calculated after accurate TBSA assessment using the Lund-Browder chart rather than the Wallace rule of nines, which tends to overestimate TBSA 3, 8
• Helps determine which patients require specialist consultation and potential transfer to burn centers 4
• Can guide fluid resuscitation requirements, which are based on TBSA calculations 8
• Should be recalculated as needed during initial management as burn appearance may evolve 8