What is the recommended management approach for Lower Respiratory Tract Infections (LRTI) in vulnerable populations, including the elderly, young children, and those with underlying health conditions such as Chronic Obstructive Pulmonary Disease (COPD) or asthma?

Management of Lower Respiratory Tract Infections in Vulnerable Populations

Initial Risk Stratification and Severity Assessment

In vulnerable populations including elderly (>65 years), young children, and those with COPD or asthma, immediate risk stratification determines whether outpatient management is safe or hospital referral is required. 1

High-Risk Features Requiring Hospital Referral

Patients should be referred to hospital if they meet any of the following criteria:

Vital Sign Abnormalities:

• Temperature <35°C or ≥40°C 1, 2
• Heart rate ≥125 beats/min 1, 2
• Respiratory rate ≥30 breaths/min 1
• Blood pressure <90/60 mmHg 1
• Confusion or diminished consciousness 1

Laboratory Criteria:

• White blood cell count <4,000 or >20,000 cells/mm³ 1, 2
• Oxygen saturation concerns or PaO₂ <60 mmHg 1, 2

Clinical Features:

• Suspected pleural effusion or cavitation 1
• Failure to respond to first-line antibiotics within 3 days 1, 3

Vulnerable Population-Specific Risk Factors

For elderly patients (>65 years), the following increase complication risk and warrant careful monitoring with low threshold for hospital referral: 1

• COPD, diabetes, or heart failure 1
• Previous hospitalization in past year 1
• Current oral glucocorticoid use 1
• Antibiotic use in previous month 1
• General malaise with absence of upper respiratory symptoms 1

For patients with underlying COPD or asthma:

• Moderate to severe COPD increases risk substantially 1, 2
• Asthma may be a risk factor for complications in patients under 65 1

Diagnostic Approach in Primary Care

Differentiating Pneumonia from Other LRTI

Use C-reactive protein (CRP) testing to guide pneumonia diagnosis: 1

• CRP <20 mg/L with symptoms >24 hours makes pneumonia highly unlikely 1
• CRP >100 mg/L makes pneumonia likely 1
• If doubt persists after CRP testing, obtain chest X-ray 1

Clinical features suggesting pneumonia (any one present): 1

• New focal chest signs 1
• Dyspnoea 1
• Tachypnoea 1
• Pulse rate >100 1
• Fever >4 days 1

Microbiological Testing

Do not perform routine microbiological tests (cultures, gram stains) or biomarkers for bacterial pathogens in primary care settings. 1 These tests are not recommended for outpatient management and do not alter treatment decisions. 1

Antibiotic Treatment Strategy

First-Line Antibiotic Selection

Amoxicillin or tetracycline should be used as first-choice antibiotics for LRTI in primary care. 1, 4 These agents are recommended based on least chance of harm and extensive clinical experience. 1

Dosing for amoxicillin: 4

• Adults: 500 mg every 12 hours or 250 mg every 8 hours for mild/moderate infections 4
• Adults: 875 mg every 12 hours or 500 mg every 8 hours for severe infections or lower respiratory tract involvement 4
• Pediatric patients >3 months and <40 kg: 25 mg/kg/day divided every 12 hours or 20 mg/kg/day divided every 8 hours for mild/moderate infections 4
• Pediatric patients >3 months and <40 kg: 45 mg/kg/day divided every 12 hours or 40 mg/kg/day divided every 8 hours for severe infections 4

Alternative Antibiotics

In patients with penicillin hypersensitivity: 1

• Use tetracycline or macrolide (azithromycin, clarithromycin, erythromycin, roxithromycin) in countries with low pneumococcal macrolide resistance 1
• Consider national/local resistance rates when selecting antibiotics 1

When bacterial resistance rates are clinically relevant against all first-choice agents:

• Consider levofloxacin or moxifloxacin 1
• Use high-dose levofloxacin (750 mg once daily) for suspected Pseudomonas or Klebsiella 1

Special Consideration: COPD Exacerbations

Antibiotics should be given in COPD exacerbations only when patients have all three of the following symptoms: 1

• Increased dyspnoea 1
• Increased sputum volume 1
• Increased sputum purulence 1

Additionally, consider antibiotics for exacerbations in patients with severe COPD. 1

Symptomatic Treatment

Do not prescribe cough suppressants, expectorants, mucolytics, antihistamines, inhaled corticosteroids, or bronchodilators for acute LRTI in primary care. 1 These agents have not demonstrated benefit and should be avoided. 1

Monitoring and Follow-Up

Patients should be instructed to contact their physician if: 1

• Clinical improvement is not noticeable within 3 days of starting antibiotics 1, 3
• Symptoms persist longer than 3 weeks 1

Seriously ill patients (suspected pneumonia, elderly with relevant comorbidity) require follow-up within 2 days of initial visit. 1

If no improvement occurs within 72 hours of antibiotic change, consider alternative diagnoses: 3

• Pulmonary embolism 3
• Malignancy 3
• Heart failure exacerbation 3
• Pleural effusion or empyema requiring drainage 3

Prevention Strategies

Vaccination Recommendations

Influenza vaccination should be given yearly to: 1

• All persons >65 years 1
• Institutionalized individuals 1
• Patients with chronic cardiac diseases, chronic pulmonary diseases, diabetes mellitus, chronic renal diseases, or haemoglobinopathies 1
• Women in second or third trimester of pregnancy during influenza season 1
• Healthcare personnel, especially those caring for elderly or high-risk groups 1

Use inactivated (not live attenuated) vaccine in adults. 1

Pneumococcal vaccination (23-valent polysaccharide) should be given to all adults at risk for pneumococcal disease. 1 Risk factors include age >65 years, institutionalization, dementia, seizure disorders, congestive heart failure, cerebrovascular disease, COPD, history of previous pneumonia, chronic liver disease, diabetes mellitus, functional or anatomic asplenia, and chronic cerebrospinal fluid leakage. 1

Revaccination once (not earlier than 5 years after primary vaccination) should be performed in asplenic patients and can be considered in elderly and other high-risk groups. 1

Important Caveats

Inhaled steroids in COPD patients may actually increase the risk of LRTI/CAP, despite potentially decreasing acute exacerbation risk. 1 This is a critical consideration when managing COPD patients. 1

Statins and/or ACE inhibitors might decrease the risk of CAP or CAP-related death in the general population, though evidence is stronger for statins than ACE inhibitors. 1