American Association of Critical-Care Nurses (AACN) Certification Practice Test

Which factor is NOT included in the SOFA score assessment?

1. PaO2/FiO2 ratio

2. Heart rate

3. Bilirubin level

4. Platelet count

The correct answer is: Heart rate

In the SOFA (Sequential Organ Failure Assessment) score, various physiological parameters are evaluated to assess the extent of organ dysfunction. The parameters included in the SOFA score specifically focus on six organ systems: respiratory, coagulation, liver, cardiovascular, central nervous system, and renal function. The PaO2/FiO2 ratio is a key component of the respiratory system assessment in the SOFA score, as it reflects the degree of hypoxemia and respiratory failure. Similarly, bilirubin level is included in the liver function assessment, indicating liver impairment, and the platelet count evaluates the coagulation status, which is essential for gauging the degree of coagulopathy. In contrast, heart rate is not directly included in the SOFA score assessment; the cardiovascular system is evaluated through the mean arterial pressure or the use of vasopressors rather than heart rate itself. Therefore, identifying heart rate as not being part of the SOFA scoring criteria highlights its distinction from the other listed parameters that are integral to the overall assessment of organ function in critically ill patients.