The quick Sequential Organ Failure Assessment, or qSOFA, is a clinical tool used at the bedside. Its primary purpose is to help medical staff quickly identify patients who have a suspected infection and are also at a greater risk for poor outcomes. This assessment was developed to be a simple, accessible prompt that can be used outside of the intensive care unit (ICU), such as in an emergency department or general hospital ward. It provides a straightforward method for flagging patients who may be developing life-threatening complications without requiring laboratory tests.
The Three Clinical Criteria
The qSOFA score is determined by evaluating three specific clinical signs. Each component of the assessment points toward potential organ dysfunction, which is a hallmark of the body’s dysregulated response to infection.
One of the core criteria is respiratory rate. A patient’s breathing is counted for one minute, and a rate of 22 breaths per minute or higher is considered a positive sign for the qSOFA assessment. This elevated rate, known as tachypnea, can indicate that the body is working harder to get oxygen, a potential sign of respiratory distress linked to systemic infection.
Altered mental status is the second criterion and refers to a change from a person’s normal level of consciousness. This is not limited to unconsciousness but can include new-onset confusion, agitation, or significant drowsiness. Clinically, this is often assessed using the Glasgow Coma Scale (GCS), where a score lower than the maximum of 15 suggests an alteration.
The final component is systolic blood pressure. This is the “top number” in a blood pressure reading, representing the pressure in the arteries when the heart beats. For the qSOFA score, a systolic blood pressure of 100 millimeters of mercury (mm Hg) or less meets the criterion. This low blood pressure, or hypotension, can signal that the circulatory system is beginning to fail, a dangerous complication of widespread infection.
Scoring and Clinical Significance
The scoring for qSOFA is intentionally simple. A single point is awarded for each of the three criteria that a patient meets: a respiratory rate of 22 or more, any altered mental status, or a systolic blood pressure of 100 mm Hg or less. This results in a total possible score ranging from 0 to 3. The ease of calculation allows for rapid assessment and re-assessment over time.
A score of 2 or more is considered “positive” and acts as a red flag for clinicians. A positive qSOFA score indicates that the patient with a suspected infection has a significantly higher risk of poor outcomes. These outcomes include the likelihood of a prolonged stay in an intensive care unit or even death.
Use as a Sepsis Screening Tool
It is important to understand that the qSOFA score is a screening tool, not a diagnostic one. Its primary function is to rapidly identify patients with infection, particularly outside of the ICU, who are at high risk of developing sepsis and need urgent medical attention. A positive score does not confirm sepsis, but it strongly suggests that the patient’s condition warrants a more thorough evaluation for organ damage.
A patient can have an infection and even be in the early stages of sepsis with a low qSOFA score of 0 or 1. For this reason, updated guidelines caution against using qSOFA as the sole method for sepsis screening. The tool has demonstrated relatively low sensitivity, meaning it can miss some cases, but it has high specificity, so a positive result is a strong indicator of a patient being at higher risk.
The qSOFA score is distinct from the more comprehensive Sequential Organ Failure Assessment (SOFA) score. The full SOFA score is a much more detailed system used to track the degree of organ dysfunction in patients, but it requires laboratory results and is typically used for patients already in the ICU. In contrast, qSOFA serves as an initial alert system, enabling healthcare providers to quickly recognize a potential decline in a patient’s condition before it becomes more severe.