The Sequential Organ Failure Assessment (SOFA) score has been widely used for its simplicity and applicability, but now it may require an update to keep pace with the evolution of medicine

Published in the journal Critical Care, an article featuring contributions from the Instituto D’Or de Pesquisa e Ensino (IDOR) and various international centers suggests important updates to this scoring system, which is widely used in intensive care medicine. The discussion takes into account aspects of the system that should be preserved, as well as features that are outdated compared to contemporary therapeutic technologies and diagnostics.

What is the Sequential Organ Failure Assessment (SOFA)?

Developed in 1994, the SOFA score still plays a crucial role in assessing organ dysfunction in critically ill patients. Its primary objective is to objectively describe dysfunction across various organ systems, including cardiovascular, respiratory, renal, hepatic, neurological, and coagulation, without predicting disease outcomes. However, as intensive care medicine has significantly evolved in the 30 years since its conception, the need for an update has become evident to better reflect current clinical practices.

Why is SOFA Still Widely Used?

The article, authored by several physicians and researchers with extensive experience in intensive care medicine, highlights several aspects of the SOFA score that remain relevant, such as its expression of the dynamic nature of organ dysfunction, which requires regular assessment to capture the temporal course of organ damage. The authors believe that the fundamental principles of simplicity and objectivity are essential and should remain a key consideration during the update. They also suggest that implementing a limited number of objective variables that are easily obtained across all healthcare institutions would be ideal for what could be considered a “SOFA 2.0.” Some systems, such as cardiovascular and respiratory, may require more considerable changes to the score.

Perspectives on Updating SOFA

According to the article, keeping bilirubin as a marker for assessing liver function in the SOFA score remains a relevant decision for clinical practice, as it is a reliable and widely available measure in many clinical contexts. The variables chosen to assess cardiovascular function should also remain independent of the administered therapies. However, given advances in cardiovascular therapy, the SOFA update should consider including new vasopressors and inotropic agents. It would also be relevant to incorporate advanced cardiovascular support techniques, such as venoarterial extracorporeal membrane oxygenation (VA-ECMO), cardiac assist devices, or other support systems.

Respecting SOFA’s core principles, the authors emphasize that the inclusion of these new elements should occur without making the score excessively complex. Additionally, they suggest the inclusion of additional biomarkers, such as blood lactate concentration. Monitoring lactate can be an effective way to assess the response to initial treatment, although its inclusion would require a prospective evaluation of its utility.

The authors comment that modernizing the SOFA score in the pulmonary context should balance tradition and innovation, maintaining its essential simplicity while incorporating elements that accurately reflect contemporary practices in respiratory intensive care. Less invasive monitoring could be achieved by replacing the PaO2 measured from blood gas analysis with SpO2 obtained through pulse oximetry. However, it is crucial to recognize that SpO2 may be subject to bias and require additional mathematical considerations to be included as an alternative for assessing oxygenation, which could affect its applicability.

The inclusion of new respiratory support methods, such as high-flow oxygen therapy (HFOT), non-invasive mechanical ventilation, and venovenous extracorporeal membrane oxygenation (VV-ECMO), may also be of interest, as well as expanding the criteria used to assess respiratory dysfunction.

Given the complexity of interpreting the Glasgow Coma Scale (GCS) in sedated patients, it may be necessary to consider alternative approaches, such as using the assumed GCS, taking into account the sedation status. However, this should be weighed against the limitations and the increasing automation of data collection.

Conclusions

While the article considers the inclusion of other organ systems, such as gastrointestinal, metabolic, or immune, the authors recognize the simplicity of the SOFA score as a key characteristic that remains relevant in the objective description of patterns of organ dysfunction. However, the evolving landscape of intensive care demands a reassessment, leading to the proposal of a SOFA 2.0 that modernizes the score. The article points out that before any replacement of the original SOFA score can be considered, there is still a need for data-driven exploration, consensus-building, and validation of these changes, while maintaining the commitment to ensuring the score’s simplicity while reflecting contemporary practices in intensive care settings.

Written by Maria Eduarda Ledo de Abreu.