What is the diagnostic approach and treatment for suspected sepsis in high-risk populations, such as the elderly, immunocompromised individuals, and those with chronic medical conditions?

Sepsis Diagnosis and Management in High-Risk Populations

Use the NEWS2 scoring system to risk-stratify all patients aged 16 and over with suspected infection, then tailor antibiotic timing and monitoring intensity based on their risk category, with particular attention to high-risk populations (elderly, immunocompromised, chronic disease) who may present atypically and require more aggressive evaluation. 1

Initial Risk Stratification Using NEWS2

Calculate a NEWS2 score immediately upon suspicion of sepsis in any patient with confirmed or suspected infection. 1

The NEWS2 tool assigns points based on seven physiological parameters:

• Respiratory rate, oxygen saturation, supplemental oxygen use, systolic blood pressure, heart rate, level of consciousness (CVPU), and temperature 1

Risk Category 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: Increased risk regardless of total score 1

Critical Clinical Overrides:

Immediately escalate risk assessment if any of these signs are present, regardless of NEWS2 score: 1

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

Special Considerations for High-Risk Populations

Elderly Patients:

Interpret NEWS2 scores in the context of baseline physiology, as elderly patients are at significantly higher risk for sepsis and may present with atypical vital signs. 1, 2

• Age itself is a major risk factor for sepsis development 1, 2
• Elderly patients may not mount typical fever responses 2

Immunocompromised Patients:

Obtain detailed immunosuppression history including neutropenia, HIV/AIDS, splenectomy, chronic steroid use, chemotherapy, transplant status, or congenital/acquired immunodeficiencies, as these patients are predisposed to atypical and resistant pathogens including Candida species. 2

Consider upgrading the risk category if the patient has: 2

• Underlying malignancy
• Diabetes
• Liver disease
• Renal failure
• Any form of immunosuppression

Patients with Chronic Medical Conditions:

Factor in chronic organ failures when interpreting NEWS2 scores, as these conditions increase infection susceptibility and affect antimicrobial choices. 2

Essential Historical Elements

While gathering history, do NOT delay antibiotic administration—obtain history simultaneously with initial treatment. 2

Critical History to Extract:

• Identify the infection source (respiratory, abdominal, urinary, skin/soft tissue) to determine pathogen profile 2
• Distinguish between community-acquired, healthcare-associated, or hospital-acquired infection, as this dramatically affects likely pathogens and resistance patterns 2
• Document antimicrobial use within the previous 3 months—this is critical for predicting resistance patterns 2
• Identify prior hospitalization within the past 90 days as a risk factor for resistant pathogens 2
• Note prolonged hospitalization or chronic facility stay, which increases exposure to resistant organisms 2

Diagnostic Imaging Approach

For Respiratory Symptoms (Cough, Dyspnea, Chest Pain):

Order CT chest with IV contrast as the primary imaging modality for suspected sepsis with respiratory symptoms. 1

• CT chest with IV contrast has 81.82% positive predictive value for identifying septic foci and leads to management changes in 45% of cases 1, 3
• Pneumonia is the most common septic focus, identified in 38.6% of emergency department patients with suspected sepsis 1, 3
• Among patients undergoing chest CT for suspected infection, a pathologic infectious source is found in the chest in 72% of cases 1, 3
• Initial chest radiography has only 58% sensitivity (though 91% specificity) for pneumonia in septic patients 3

Risk-Stratified Antibiotic Timing

Administer antibiotics according to NEWS2 risk category, with each timeframe representing a maximum time until prescription, not a target: 1

• High risk (NEWS2 ≥7): Give antibiotics within 1 hour 1
• Moderate risk (NEWS2 5-6): Give antibiotics within 3 hours 1
• Low risk (NEWS2 1-4): Give antibiotics within 6 hours 1

This risk-stratified approach reduces antibiotic-related harm while promoting antimicrobial stewardship, but use clinical judgment to escalate urgency when indicated. 1

Monitoring Frequency Based on Risk

Re-calculate NEWS2 scores at the following intervals: 1

• Every 30 minutes for high-risk patients 1
• Every hour for moderate-risk patients 1
• Every 4-6 hours for low-risk patients 1

Upgrade risk assessment if the patient's condition deteriorates or fails to improve despite interventions. 1

Antibiotic Selection and De-escalation

When microbiological results become available, review antibiotic choice within 1 hour and change to narrower spectrum agents according to results. 1

In high-risk populations, consider broader initial coverage accounting for: 2

• Recent antibiotic exposure (within 3 months)
• Healthcare-associated or hospital-acquired infection status
• Immunosuppression status
• Local resistance patterns

Common Pitfalls to Avoid

Do not delay antimicrobial administration to obtain a complete history—the first dose should be given within the risk-appropriate timeframe while simultaneously gathering historical information. 2

Do not overlook recent antibiotic exposure, as this is one of the most critical historical elements predicting resistance patterns and necessitating broader coverage or alternative agents. 2

Do not rely solely on NEWS2 scores in immunocompromised or elderly patients—these populations may not mount typical physiological responses and require clinical judgment to upgrade risk assessment. 1, 2

Do not use chest radiography alone to exclude pneumonia in septic patients—CT chest with IV contrast has superior sensitivity and frequently changes management. 1, 3