qSOFA Score Calculator

Acute heart failure, cardiogenic shock, and massive myocardial infarction can present with hypotension, tachypnoea, and altered mentation — all three qSOFA criteria. Key distinguishing features include an elevated jugular venous pressure, pulmonary oedema on chest radiograph, an S3 gallop, and a history of cardiac disease.

Point-of-care echocardiography is valuable: a severely reduced ejection fraction or significant regional wall motion abnormalities suggest a primary cardiac aetiology. Troponin and BNP/NT-proBNP can help differentiate, though these may also be elevated in severe sepsis.

Massive or submassive pulmonary embolism frequently presents with acute tachypnoea, hypotension, and syncope or altered consciousness. These patients may score ≥ 2 on qSOFA while having no infection whatsoever. Risk factors include recent surgery, immobilisation, malignancy, and oral contraceptive use.

The key diagnostic clues are acute-onset pleuritic chest pain, unilateral leg swelling, and hypoxia disproportionate to the chest radiograph findings. CT pulmonary angiography is the definitive investigation. D-dimer may help exclude PE in low-risk patients but is non-specific and often elevated in sepsis as well.

Acute blood loss — from gastrointestinal haemorrhage, trauma, ruptured aortic aneurysm, or ectopic pregnancy — causes hypotension and tachycardia with compensatory tachypnoea and, when severe, altered mentation. All three qSOFA criteria can be met in the absence of infection.

Serial haemoglobin monitoring, a focused history for blood loss, and FAST ultrasound in the emergency department can help identify a haemorrhagic source. In patients with both haemorrhage and infection (e.g., perforated viscus), both processes must be addressed simultaneously.

Diabetic ketoacidosis (DKA) classically produces Kussmaul breathing (deep, rapid respirations), which can score on the respiratory rate criterion. Hypotension from dehydration and altered mentation from cerebral oedema or acidosis may fulfil all three qSOFA criteria. Check blood glucose, ketones, and a venous blood gas.

Drug overdoses — particularly opioids, benzodiazepines, tricyclic antidepressants, and sympathomimetics — can produce altered consciousness, respiratory depression or tachypnoea, and haemodynamic instability. A thorough medication and substance use history is essential. Salicylate toxicity specifically causes a mixed respiratory alkalosis and metabolic acidosis with tachypnoea.

Stroke — both ischaemic and haemorrhagic — can cause altered mentation (GCS < 15) and may produce autonomic instability with hypotension or hypertension. Subarachnoid haemorrhage in particular can present with a reduced GCS, tachypnoea, and neurogenic stunned myocardium causing hypotension.

Status epilepticus, meningoencephalitis, and intracranial mass lesions with raised intracranial pressure all cause altered mentation and potentially Cushing’s response (hypertension, bradycardia, irregular respiration) — although the last of these may be misread as tachypnoea if respiration is irregular. Always perform a focused neurological examination.

Anaphylaxis produces distributive shock with hypotension, tachypnoea (from bronchospasm or laryngeal oedema), and altered mentation from cerebral hypoperfusion — potentially meeting qSOFA ≥ 2. The hallmark features are urticaria, angioedema, wheezing, and a clear temporal relationship to allergen exposure.

Adrenal crisis is another form of distributive shock: profound hypotension, altered mentation, and compensatory tachypnoea in a patient with known adrenal insufficiency or chronic steroid use. Random cortisol and ACTH levels are diagnostic. Neurogenic shock from spinal cord injury presents with hypotension and bradycardia — the bradycardia helps distinguish it from other shock states.

The most frequent misunderstanding is equating qSOFA ≥ 2 with a diagnosis of sepsis. The Sepsis-3 definition of sepsis requires life-threatening organ dysfunction caused by a dysregulated host response to infection, assessed by a SOFA score increase of ≥ 2. qSOFA is a prompt to investigate further — not a diagnostic endpoint.

This distinction matters clinically: a patient with qSOFA of 2 due to pneumonia may have sepsis, but a patient with qSOFA of 2 due to acute heart failure exacerbation does not. The full SOFA score, combined with clinical suspicion of infection and source identification, is needed to confirm sepsis.

A qSOFA of 0 or 1 does not exclude sepsis. Several studies — including Churpek et al. (2017) — have shown that the sensitivity of qSOFA for predicting in-hospital mortality is lower than SIRS or the Modified Early Warning Score (MEWS), particularly in the emergency department. Patients with early or compensated sepsis may have a normal blood pressure, preserved mentation, and only mild tachypnoea.

If clinical suspicion for infection is high — based on history, examination, or inflammatory markers — the clinician should proceed with a full sepsis workup regardless of the qSOFA result. The score should never override clinical judgement.

The qSOFA is typically calculated once at presentation. However, sepsis is a dynamic process, and vital signs can deteriorate rapidly. A patient with qSOFA 1 at triage may progress to qSOFA 3 within hours. Serial reassessment is important, particularly in patients with suspected but unconfirmed infection.

Incorporating qSOFA into nursing early warning score documentation — or reassessing at set intervals (e.g., every 2–4 hours) — can improve its utility as a monitoring tool rather than a one-off screening test.

Patients with chronic conditions may meet qSOFA criteria at their baseline. A patient with COPD may chronically have a respiratory rate of 22–24. A patient with chronic kidney disease on antihypertensives may have a baseline systolic BP of 95 mmHg. Patients with dementia often have a GCS below 15.

In these populations, the qSOFA should be interpreted relative to the patient’s known baseline, not absolute thresholds. A change from baseline — rather than an absolute value — is more clinically meaningful. Unfortunately, the binary nature of the qSOFA criteria does not accommodate this nuance, and clinician judgement must compensate.

Multiple external validation studies have demonstrated that while qSOFA has reasonable specificity for predicting mortality, its sensitivity is lower than alternative screening tools. Freund et al. (2017) found that qSOFA had a sensitivity of approximately 70% for in-hospital mortality compared with 90% for SIRS in ED patients with suspected infection.

The National Early Warning Score (NEWS/NEWS2) may outperform qSOFA for early identification of deterioration in ward patients. Many institutions use NEWS as the primary screening tool and reserve qSOFA or SOFA for targeted sepsis assessment. The optimal approach depends on institutional protocols and clinical setting.