How can I identify sepsis in a patient?

How to Identify Sepsis in Your Patient

Use the NEWS2 scoring system immediately to stratify risk, combining it with clinical assessment for infection and specific danger signs—a NEWS2 score ≥7 indicates high risk, 5-6 moderate risk, and any single parameter score of 3 warrants concern, but always override the score if you see mottled skin, non-blanching rash, or cyanosis. 1

Immediate Bedside Assessment: The NEWS2 Score

Calculate the NEWS2 score using six physiological parameters: 1

• Respiratory rate (per minute)
• Oxygen saturation (SpO₂)
• Systolic blood pressure (mm Hg)
• Pulse (per minute)
• Level of consciousness (Alert vs. CVPU: Confusion [new], Voice response, Pain response, Unresponsive)
• Temperature (°C)

Risk Interpretation:

• NEWS2 ≥7: High risk of severe illness or death from sepsis 1
• NEWS2 5-6: Moderate risk 1
• NEWS2 1-4: Low risk 1
• NEWS2 0: Very low risk 1
• Any single parameter scoring 3: May indicate increased sepsis risk regardless of total score 1

Critical caveat: The NEWS2 score must be interpreted in the context of the patient's underlying physiology, comorbidities, and whether their condition is deteriorating despite interventions. 1 A patient whose NEWS2 is "improving" from 9 to 7 but remains clinically unstable is still high-risk.

Override Criteria: Danger Signs That Trump the Score

Immediately escalate risk assessment if ANY of the following are present, regardless of NEWS2 score: 1

• Mottled or ashen skin appearance
• Non-blanching petechial or purpuric rash
• Cyanosis of skin, lips, or tongue

These findings indicate severe tissue hypoperfusion and should prompt immediate high-risk management. 1

The qSOFA Screening Tool (Alternative Bedside Approach)

For rapid screening in emergency or ward settings, use qSOFA—though it has lower sensitivity (31-50%) and should never delay treatment: 2, 3

qSOFA positive = 2 or more of: 3

• Respiratory rate ≥22/min
• Altered mental status (new confusion or decreased consciousness)
• Systolic blood pressure ≤100 mm Hg

Important limitation: qSOFA is a screening tool, not a diagnostic criterion. 2 A positive qSOFA (≥2 points) should trigger formal SOFA score assessment to diagnose sepsis, defined as infection plus SOFA score increase ≥2 points. 2 However, the American College of Emergency Physicians recommends initiating the Hour-1 Bundle when sepsis is suspected regardless of qSOFA score, as its poor sensitivity can miss patients who need urgent treatment. 2

Recent evidence suggests combining qSOFA with lactate levels (qSOFA-lactate) modestly improves risk stratification (AUROC 0.724 vs. 0.706 for qSOFA alone), providing better net benefit for decision-making at 10-25% risk thresholds. 4

Clinical Markers of Tissue Hypoperfusion

Beyond scoring systems, actively look for these signs of inadequate tissue perfusion: 2, 5

• Altered mental status (confusion, agitation, decreased responsiveness)
• Delayed capillary refill (>3 seconds)
• Mottled skin or cool extremities
• Oliguria (urine output <0.5 mL/kg/hour)
• Tachypnea (respiratory rate ≥22/min)
• Hypotension (systolic BP ≤100 mm Hg or MAP <65 mm Hg)

Laboratory Confirmation

Measure serum lactate immediately when sepsis is suspected: 2, 5

• Lactate ≥2 mmol/L: Indicates tissue hypoperfusion; remeasure every 2-4 hours until normalized 2
• Lactate ≥4 mmol/L: Indicates severe hypoperfusion requiring aggressive 30 mL/kg crystalloid bolus 2, 5

Exception: Do not use lactate to diagnose sepsis during active labor, as it physiologically elevates in laboring patients. 2

Defining Septic Shock

Your patient has septic shock when all three criteria are met: 3, 6

1. Confirmed or suspected infection
2. Persistent hypotension requiring vasopressors to maintain MAP ≥65 mm Hg despite adequate fluid resuscitation
3. Lactate >2 mmol/L despite adequate fluid resuscitation

This combination is associated with hospital mortality rates >40%. 3

Monitoring Frequency Based on Risk

Re-calculate NEWS2 and re-evaluate at these intervals: 1

• High risk (NEWS2 ≥7): Every 30 minutes
• Moderate risk (NEWS2 5-6): Every hour
• Low risk (NEWS2 1-4): Every 4-6 hours
• Very low risk (NEWS2 0): Per standard protocol

Common Pitfalls to Avoid

Do not wait for fever: Sepsis can present with hypothermia (<35°C) or normal temperature, especially in elderly or immunocompromised patients. 1, 7

Do not rely solely on SIRS criteria: The systemic inflammatory response syndrome criteria have excessive focus on inflammation and inadequate specificity/sensitivity for sepsis. 3 They have been replaced by the SOFA-based definition.

Do not dismiss subtle changes: New confusion, cold or clammy skin, and behavioral changes are often early sepsis indicators that precede obvious vital sign derangements. 7

Do not delay intervention for diagnostic certainty: If clinical suspicion is high (history of infection + elevated NEWS2 or qSOFA ≥2), initiate the Hour-1 Bundle immediately—each hour of delay in antibiotic administration increases mortality by approximately 7.6%. 2

History of Infection: What to Look For

Suspect infection based on: 1

• Recent invasive procedures or surgery
• Indwelling devices (urinary catheters, central lines, endotracheal tubes)
• Known infection sources (pneumonia, urinary tract infection, cellulitis, intra-abdominal infection)
• Immunocompromised state (chemotherapy, chronic steroids, HIV, diabetes)
• Recent antibiotic exposure (within 3 months suggests possible resistant organisms) 2

Practical Algorithm for Sepsis Recognition

1. Calculate NEWS2 score on any patient with suspected infection 1
2. Check for danger signs (mottled skin, non-blanching rash, cyanosis)—if present, treat as high-risk immediately 1
3. Measure lactate and assess clinical perfusion markers 2, 5
4. If NEWS2 ≥5 OR qSOFA ≥2 OR lactate ≥2 mmol/L OR any danger sign present: Initiate Hour-1 Bundle (blood cultures, broad-spectrum antibiotics within 1 hour, 30 mL/kg crystalloid if hypotensive or lactate ≥4 mmol/L, vasopressors if hypotension persists) 1, 2
5. Re-assess frequently based on risk category 1