Pneumonia - Hospital-Acquired Management

Evaluation

CURB65 Scoring System for Mortality Risk Assessment  

The CURB65 scoring system may be used as a prognostic baseline for patients diagnosed with hospital-acquired pneumonia.  

Prognostic Features (1 point for each feature present)

• Confusion (abbreviated Mental Test score ≤8 or new disorientation)
• Increased blood urea nitrogen (≥7 mmol/L)
• Increased respiratory rate (≥30 breaths/minute)
• Decreased blood pressure (≤90/60 mmHg)
• ≥65 years old

Stratification

• 0 or 1: Low risk (<3% mortality risk)
• 2: Moderate risk (3-15% mortality risk)
• 3-5: High risk (>15% mortality risk)

Clinical improvement usually becomes apparent within the first 48-72 hours, wherein antibiotics should not be changed unless progressive deterioration is noted.

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Principles of Therapy

Initiation of Empiric Therapy  

Antibiotic therapy should be started within 4 hours after the diagnosis of hospital-acquired pneumonia has been established. Prompt initiation of appropriate initial antibiotic therapy can decrease mortality. When deciding to start empiric therapy, treatment should be microbiologically defined rather than empiric therapy-based. Empiric antibiotic therapy may be started in patients suspected of viral pneumonia if there is clinical evidence of bacterial co-infection. All patients with HAP and VAP should be treated initially with IV therapy, but a switch to oral therapy may be considered in some patients who are responding to therapy.

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Pharmacological therapy

EMPIRIC THERAPY IN PATIENTS WITH NO RISK FACTORS FOR MULTIDRUG-RESISTANT (MDR) PATHOGENS  

Narrow-spectrum antibiotics are recommended for patients with low-risk hospital-acquired pneumonia/ventilator-associated pneumonia.  

Possible Pathogens  

Streptococcus pneumoniae  

Local resistance patterns should be followed because the frequency of Penicillin-resistant and multidrug-resistant S pneumoniae is increasing. An aminopenicillin at appropriate dose remains the treatment of choice for most Penicillin-resistant S pneumoniae with a minimum inhibitory concentration (MIC) of 2 mcg/mL.  

Other potential pathogens

• Haemophilus influenzae, Methicillin-sensitive Staphylococcus aureus (MSSA)
• Gram-negative bacilli (eg Escherichia coli, Klebsiella pneumoniae, Enterobacter sp, Proteus sp, Serratia marcescens)

Hospital-acquired Pneumonia (HAP)/Ventilator-associated Pneumonia (VAP)  

Low-risk patients without risk factors for methicillin-resistant Staphylococcus aureus will likely respond to monotherapy with one of the following agents:

• Beta-lactam/beta-lactamase inhibitor combination (eg Co-amoxiclav, Piperacillin/tazobactam)
• Non-pseudomonal third-generation cephalosporins (eg Ceftriaxone, Cefotaxime)
• Quinolones (eg Levofloxacin or Moxifloxacin)

Consider Doxycycline, Cefalexin or Cotrimoxazole for patients with low-severity HAP. Consider treatment with Ertapenem, Imipenem or Meropenem in patients with increased risk for extended-spectrum beta-lactamase (ESBL)-producing Gram-negative bacillus and with contraindications to Cefepime. If MSSA is confirmed, consider treatment with Oxacillin, Nafcillin, or Cefazolin. Ceftobiprole, a fifth-generation cephalosporin that demonstrated good in vitro activity against Gram-positive and Gram-negative bacteria, may be used especially in cases of high MRSA infection risk.

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• Pseudomonas aeruginosa, K pneumoniae, Acinetobacter sp, and Stenotrophomonas maltophilia
• ESBL Enterobacteriaceae
• MRSA should be considered if MRSA risk factors (eg antibiotic therapy prior to onset of pneumonia, prolonged hospital stay) are present, the presence of severe pneumonia/sepsis and/or if there is high local incidence
• Legionella pneumophila

Hospital-acquired Pneumonia (HAP)  

Monotherapy may be sufficient for patients at high risk but with >90% Gram-negative antibiotic activity. Combination therapy with two different classes of antibiotics is recommended for HAP patients with increased risk for Pseudomonas sp or other Gram-negative infection, patients who received IV antibiotics within the last 90 days, or those at high risk for mortality. 

Recommended therapy for hospital-acquired pneumonia patients at high risk for methicillin-resistant Staphylococcus aureus and Gram-negative pathogens but low risk for mortality:

• Antipseudomonal beta-lactam/beta-lactamase inhibitor (eg Piperacillin/tazobactam, Cefoperazone/sulbactam, Ceftazidime/avibactam, Ceftolozane/tazobactam, Meropenem/vaborbactam)
• Antipseudomonal carbapenems Imipenem or Meropenem
• Antipseudomonal third- and fourth-generation cephalosporins (eg Cefepime, Ceftazidime)
• Antipseudomonal fluoroquinolone (eg Ciprofloxacin, Levofloxacin): In combination with another drug class

Aztreonam may be considered if there is treatment failure with other agents. The use of an aminoglycoside (eg Amikacin, Gentamicin, Tobramycin) in combination with another drug class may be considered in patients who received IV antibiotics within the last 90 days. Addition of Vancomycin, Linezolid or Teicoplanin is recommended for patients at high risk for MRSA (>10-20% MRSA isolates). Telavancin may be considered in patients with MRSA pneumonia when neither Linezolid nor Vancomycin can be used. Tedizolid may be considered in patients who are able to take oral medications. If MSSA is confirmed, consider treatment with Oxacillin, Nafcillin or Cefazolin. Other recently approved agents include Ceftazidime/avibactam, Ceftolozane/tazobactam, Cefiderocol, Imipenem/cilastatin/relebactam and Sulbactam/Durlobactam.

Ventilator-associated Pneumonia (VAP)  

Vancomycin or Linezolid is recommended for patients at high risk for methicillin-resistant Staphylococcus aureus (>10-20% MRSA isolates).  

Two antipseudomonal antibiotics are recommended if with >10% resistance to recommended monotherapy and for ICU patients:

• Antipseudomonal beta-lactam/beta-lactamase inhibitor (eg Piperacillin/tazobactam, Cefoperazone/sulbactam)
• Antipseudomonal carbapenems Imipenem or Meropenem
• Antipseudomonal third- and fourth-generation cephalosporins Cefepime or Ceftazidime
• Aztreonam may be considered if with treatment failure with other agents

If combination therapy is indicated, an aminoglycoside (eg Amikacin, Gentamicin or Tobramycin) or antipseudomonal quinolone (Ciprofloxacin or Levofloxacin) may be considered as secondary agents. Aminoglycoside therapy should be discontinued once susceptibility to beta-lactam therapy is confirmed and if with clinical improvement. The use of polymyxins (eg Colistin, Polymyxin B) instead of an aminoglycoside or quinolone may be considered in ICU patients with Acinetobacter etiology or if a high prevalence of multidrug resistance is present; these should not be used if other Gram-negative antibiotics are available. Telavancin may be considered in patients with MRSA pneumonia when neither Linezolid nor Vancomycin can be used. Other recently approved agents include Ceftazidime/avibactam, Ceftolozane/tazobactam, Cefiderocol, Imipenem/cilastatin/relebactam, and Meropenem/vaborbactam, and Sulbactam/durlobactam.

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Nonpharmacological

Supportive Therapy  

Oxygen (O₂) Therapy  

Indications for Continuous Oxygen Therapy

• Patient with PaO₂ <8 kPa (60 mmHg)
• Hypotension with systolic blood pressure <100 mmHg
• Metabolic acidosis with bicarbonate <18 mmol/L
• Respiratory distress with a respiratory rate >24 breaths/minute

Goal of Oxygen Therapy  

The goal of O₂ therapy is to maintain PaO₂ ≥8 kPa (60 mmHg) or oxygen saturation (SaO₂) ≥92%.

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Prevention

The recommended preventive measures for ventilator-associated pneumonia and/or ventilator-associated events (VAE) by the Society for Healthcare Epidemiology of America (SHEA), the Infectious Diseases Society of America (IDSA) and the Association for Professionals in Infection Control and Epidemiology (APIC) include the following:

• Avoidance of intubation and use of non-invasive positive pressure ventilation (NIPPV) instead
• Reducing the use of sedatives, and assessing the patient's readiness for extubation by interruption of sedation and spontaneous awakening trials
• Physical conditioning and positioning such as early exercise and mobilization and head-of-bed elevation to 30°-45°
• Physical conditioning and positioning such as early exercise and mobilization and head-of-bed elevation to 30°-45°
• Provide early enteral rather than parenteral nutrition
• Ventilation circuit maintenance on as-needed basis only
• Instillation of saline solution before tracheal suctioning

The recommended additional approaches by SHEA, IDSA and APIC for patients with ventilator-associated pneumonia and/or ventilator-associated events are as follows:

• For patients requiring mechanical ventilation, selective oral decontamination with Chlorhexidine or other topical non-absorbable antibiotics may be considered to eliminate potential pathogens from the oropharyngeal tract. A selective digestive decontamination by the application of topical non-absorbable antimicrobial agents to the oropharynx and gastrointestinal tract together with IV antibiotics may also be considered in patients at low risk for antibiotic resistance. 
• Endotracheal tubes with subglottic secretion drainage ports should be used for patients expected to require >48-72 hours of mechanical ventilation
• Consider early tracheostomy
• Post-pyloric feeding should be considered for patients with gastric intolerance or at high risk for aspiration in place of gastric feeding

Recommended preventive measures for non-ventilator-hospital-acquired pneumonia (NV-HAP) by the SHEA, IDSA and APIC include the following:

• Teeth and mouth hygiene: Regular oral care with tooth brushing
• Diagnose and manage dysphagia
• Provide early mobilization

Interventions against viral infections include:

• Screening of patients and healthcare workers for symptoms of viral infection
• All admitted patients to undergo surveillance testing
• Precautions against viral transmission should be placed for patients with suspected and confirmed respiratory viral infections
• Universal masking should be implemented when respiratory viral transmission rates are high in the hospital or community
• Assuring adequate ventilation
• Vaccination of healthcare personnel and patients

The prevention bundle includes heterogeneous combinations of oral hygiene, bed positioning, dysphagia diagnosis and management, mobilizing patients, nasal hygiene, sedation restrictions, incentive spirometry, education for physicians and nurses, and/or electronic order-set bundles. Encourage healthcare workers and at-risk patients to receive influenza and pneumococcal vaccines.