Pneumonia Diagnosis and Treatment

• Pneumonia is an integrated sequence course, PHIDD 1607, taught by Dr. Denise Kolanczyk, PharmD, BCPS, Associate Professor of Pharmacy Practice, occuring during the winter of 2024-2025.
• Contact information for Dr. Kolanczyk include 630-515-6204 for office phone, Alumni Hall - 391 for office, and [email protected] for email.

Pneumonia Readings

• Lower Respiratory Tract Infections, in DiPiro's Pharmacotherapy: A Pathophysiologic Approach, 12th Edition, McGraw Hill; 2023, Accessed on January 14, 2025.

Pneumonia Guidlines

• Diagnosis and treatment of adults with community-acquired pneumonia, American Journal of Respiratory and Critical Care Medicine. 2019;200(7):e45-e67.
• Management of adults with hospital-acquired and ventilator-associated pneumonia: 2016 clinical practice guidelines by the Infectious Disease Society of America and the American Thoracic Society. CID. 2016;1-51.

Defenitions

• Pneumonia (PNA) is identified as a lung infiltrate, clinical evidence of infectious origin, new fever onset, purulent sputum, leukocytosis, and a decline in oxygenation.
• Community-acquired pneumonia (CAP) develops outside the hospital or within 48 hours of admission.
• Hospital-acquired pneumonia (HAP) has an onset of over 48 hours after admission in non-ventilated patients.
• Ventilator-associated pneumonia (VAP) develops in patients mechanically ventilated, or endotracheal intubation for over 48 hours.
• Aspiration pneumonia results from the aspiration of oropharyngeal or gastrointestinal contents.

Pathogenesis

• Pneumonia occurs throughout all seasons.
• Microorganisms access the lower respiratory tract through inhalation, hematogenous spread, or aspiration.
• Viral lung infections may increase susceptibility to secondary bacterial pneumonia through immune suppression.

Etiology: The "Bugs"

Common bacterial pathogens

• Streptococcus pneumoniae
• Haemophilus influenzae
• Mycoplasma pneumoniae
• Legionella species
• Chlamydia pneumoniae

Less common bacterial pathogens

• Staphylococcus aureus

• Escherichia coli

• Klebsiella pneumoniae

• M. tuberculosis

• Fungal

• Viral pathogens are the most common cause of CAP in adults.

Hospital-Aquired and Ventilator-Associated Pneumonias

• Pseudomonas aeruginosa

• Acinetobacter baumanii

• Staphylococcus aureus

• Klebsiella pneumoniae

• Escherichia coli

• Enterobacter Species

• The bacteriology of aspiration pneumonia is similar to CAP or HAP.

Diagnosis

• It is recommended adult patients suspected of pneumonia undergo diagnosis.
• Routine follow-up of chest imaging is not recommended for pneumonia.

Clinical Presentation

Signs and Symptoms

• Abrupt onset of fever, chills
• Dyspnea
• Productive cough
• Sputum production (+/- hemoptysis)
• Pleuritic chest pain

Physical examination findings

• Tachypnea and tachycardia
• Chest wall retractions and grunting respirations
• Dullness to percussion
• Diminished breath sounds
• Inspiratory crackles during lung expansion
• Increased tactile fremitus, whisper pectoriloquy, or egophony

Cultures and Laboratory Data

Recommended Cultures

• Blood cultures
• Rapid diagnostic tests for viruses
• Respiratory tract cultures are not routinely recommended for outpatient CAP and are recommended prior to starting treatment for severe CAP, HAP, or VAP.
• Urinary antigen tests for S. pneumonia and L. pneumophila are not routinely obtained, unless patients meet severe CAP criteria.

Laboratory tests

• Complete blood count (CBC) is usually present.
• Low oxygen saturation on arterial blood gas or pulse oximetry.
• Serum procalcitonin is not recommended to determine initial need for antibiotic therapy per the 2019 IDSA/ATS Guideline, utilized in practice as an adjunct to clinical judgement for guiding antibiotic therapy decisions.

Goals of Therapy

• It is important to eradicate the offending organism through using appropriate antibiotics.
• It is important to achieve a complete clinical cure.
• It is important to minimizing adverse drug effects and toxicity.
• It is important to minimize morbidity and mortality.
• It is also important to use cost effective antimicrobials.

Community-Aquired Pneumonia

Risk factors for the development of CAP

• Increasing age
• Asplenia
• Diabetes mellitus
• Chronic cardiovascular, pulmonary, kidney and/or liver disease
• Smoking and/or alcohol abuse

Site of Care Decision

• Pneumonia Severity Index (PSI) can be used.

Demographics

• Age is 1 point per year.
• Male
• Female Yr - 10
• Nursing Home Resident: + 10

Co-Morbidities

• Neoplasia +30
• Liver disease +20
• Heart failure +10
• CVA +10
• Kidney disease +10

Physical Exam/Vitals

• Altered mental status +20
• Respiratory rate ≥ 30/min +20
• SBP < 90 mmHg +20
• Temperature < 35 °C or ≥ 40 °C +15
• Pulse ≥ 125 bpm +10

Laboratory/ Imaging

• Arterial pH < 7.35 +30
• BUN ≥ 30 mg/dL +20
• Sodium < 130 mmol/L +20
• Glucose ≥ 250 mg/dL +10
• Hematocrit < 30% +10
• Oxygen saturation < 90% (or pulse oximetry < 60 mmHg) + 10
• Pleural effusion +10

Criteria for Severe CAP

• 1 or more defines severe CAP
  • Septic shock requiring vasopressors
  • Respiratory failure requiring mechanical ventilation
• 3 or more defines severe CAP
  • Respiratory rate ≥ 30 breaths/min
  • PaO2/FiO2 ratio ≤ 250
  • Multilobar infiltrates
  • Confusion/disorientation
  • Uremia (BUN ≥ 20 mg/dL)
  • WBC < 4000 cells/mm3
  • Platelets < 100,000 cells/mm³
  • Hypothermia (core temperature < 36 °C)
    • Hypotension requiring aggressive fluid resuscitation

Respiratory versus Non-Respiratory Fluoroquinolones (FQs)

• All FQs can penetrate the lungs and maintain adequate concentrations
• "Respiratory” FQs (levofloxacin and moxifloxacin) implies good coverage towards Streptococcus pneumoniae.
• “Non-respiratory” FQs such as ciprofloxacin has poor coverage towards Streptococcus pneumoniae.

Empiric Outpatient CAP Standard Regimens

• Previously healthy, no antibiotics or hospitalizations within last 90 days, and no recent of MRSA or Pseudomonas aeruginosa include: Amoxicillin 1 gm TID, Doxycycline 100 mg BID, or macrolide (if local pneumococcal resistance <25%).
• Comorbidities include respiratory fluoroquinolone.
• Immunocompromised or immunosuppressant includes B-lactam, high dose amoxicillin/clavulanate or cephalosporin.

Empiric Inpatient CAP Standard Regimens

• Nonsevere CAP with no risk factors for MRSA or Pseudomonas aeruginosa includes B-lactam and macrolide or respiratory fluoroquinolone.
• Severe CAP no risk factors for MRSA or Peudomonas aeruginosa includes Prefered Regimen of B-lactam and macrolide. However can alternate with B-lactam and respiratory fluoroquinolone.

Treatments for Inpatients with CAP and Risk for Drug Resistance

• In nonsevere inpatient CAP, obtain cultures. Add MRSA coverage if culture or nasal PCR returns positive.
• In severe inpatient CAP, add MRSA coverage and de-escalate or continue, based on culture PCR. Add P. aeruginosa coverage if culture returns positive. Add P. aeruginosa coverage and de-escalate or continue, therapy based on culture.

Hospital-Aquired Pneumonia

• Lungs are the most frequent site of infection acquired in hospitals.
• HAP has a higher mortality rate.
• Length of stay in increased by 7-9 days.
• 50% of patients get serious complications (respiratory failure, pleural effusions, septic shock, renal failure, empyema).

Risk Factors for the Development of HAP

• Age > 60 years
• Witnessed aspiration
• COPD, acute respiratory distress syndrome (ARDS)
• Medications: antacids, H2 blockers, PPIs
• Reintubation, tracheostomy, or patient transport
• Head trauma, ICP monitoring
• Coma
• Supine patient position
• Enteral feeding, nasogastric tubes
• MDR risk if IV antibiotic use within 90 days

Symptoms of HAP

• Presence of new infiltrate on CXR
• Fever
• Worsening respiratory status
• Thick, neutrophil-laden respiratory secretions

Approaching Empiric Management of HAP

• All empiric regimens should cover MSSA, Pseudomonas aeruginosa, and other gram-negative bacilli
• Assess risk factors for MDR gram-negative bacilli and MRSA.

Risk Factors for Multidrug-Resistant (MDR) Pathogens in HAP

• Risk Factors for MDR Gram-Negative Bacilli (including MDR Pseudomonas)
  • Prior intravenous antibiotic use within 90 days
  • Structural lung disease (i.e., bronchiectasis, cystic fibrosis)
  • High risk for mortality

Risk Factors for MRSA

• Prior intravenous antibiotic use within 90 days
• Hospitalization in unit where >20% of S. aureus isolates are methicillin resistant
• Prevalence of MRSA not known in hospital unit
• High risk for mortality

Empiric Abx Therapy for HAP

• Choose one of the following for no risk factors present: Piperacillin-tazobactam, cefepime, imipenem-cilastatin, meropenem, or levofloxacin Choose one B-lactam-Based Agent and one non B-lactam-Based agent for risk factors present for MDR Gram-Negative Bacilli. If ANY risk factors present for MRSA, ADD vancomycin OR linezolid. If patient has severe PCN allergy and aztreonam is to be used, include coverage for MSSA

Ventilator-Associated Pneumonia (VAP)

• Risk for developing VAP increases 6-21x after intubation
• All-cause mortality: 20-50%
• Prolongation of mechanical ventilation by 7-11 days and hospital stay by 11-13 days

Pathophysiology of VAP

• Bypassing natural airway defenses allows migration of upper respiratory tract organisms to lower tract.
• May be exacerbated by acid-reducing drugs (H2 blockers, PPIs)
• Increasing pH of gastric secretions may promote proliferation of microorganisms in the upper GI tract
• Subclinical microaspirations routinely occur in intubated patients; which results in inoculation of bacteria-contaminated gastric contents into lung

Risk Factors for the Development of VAP

• Same risk factors as HAP plus septic shock, ARDS preceding VAP, acute renal replacement therapy preceding VAP, and 5+ days of hospitlaization preceding vap.

When VAP is Suspected/Diagnosed

• There is no gold standard method
• When there are new or persistent infiltrates found on CXR plus ≥ 2 of the following:
  • Purulent tracheal secretions
  • Leukocytosis or leucopenia
  • Body temperature > 38.3

Approaching Empiric Management of VAP

• Includes S. aureus, Pseudomonas aeruginosa, and other gram-negative bacilli - Assess if risk factors are present for MDR gram-negative bacilli and MRSA

Risk Factors for Multidrug-Resistant (MDR) Pathogens in VAP

• Prior intravenous antibiotic use within 90 days
• Septic shock at time of VAP
• ARDS preceding VAP
• ≥ 5 days of hospitalization prior to occurrence of VAP
• Acute renal replacement therapy prior to VAP onset
• Hospitalization in unit where >10% of gram-negative isolates are resistant
• Antimicrobial susceptibilities for gram-negative isolates not available/unknown
• Structural lung disease (ie, bronchiectasis, cystic fibrosis)

Empiric abx therapy for VAP

• Choose one of the following for no risk factors present: Piperacillin-tazobactam, cefepime, imipenem-cilastatin, meropenem, or levofloxacin
• Choose one b-lactam based agent and one non b-lactam based agen for risk factors present for MDR gram-negative bacilli.
• If any risk factors are present for MRSA, ADD vancomycin OR linezolid
• If patient has severe PCN allergy and aztreonam used, include coverage for MSSA

Directed Therapy and Non-Responders

• Antibiotic therapy should be de-escalated when possible. If empiric antibiotics should be modified once culture results are available, de-escalate or narrow coverage of anticipated organism if the organism turns out not as dangerous. Modification may also be necessary if organism is resistant to antibiotic. If organism is unknown, the oral regimen should be equivalent to the IV regimen that the patient is transitioned from

Factors to Consider When Transitioning to Oral Antibiotic Therapy

• Bioavailability of the agent.
• Functioning GI tract is crucial.
• Adequate PO intake.
• Switch from IV to oral therapy when clinical stability is achieved:
• Temperature ≤ 37.8
  • Heart rate ≤ 100 beats/min
  • Respiratory rate ≤ 24 breaths/min
  • Systolic blood pressure ≥ 90 mmHg
  • Oxygen saturation ≥ 90% or pulse oximetry ≥ 60 mmHg on room air
  • Ability to maintain oral intake
  • Normal mental status

Duration of Therapy - CAP

• A minimum 5-day course is recommended. The patient should be afebrile for 48-72 hours before discontinuation of therapy, having no more than one sign of clinical instability.
• If CAP was due to suspected or proven MRSA or Pseudomonas aeruginosa, recommended duration of therapy is 7 days.

HAP/VAP

• 7-day antimicrobial of antibiotic therapy is recommended. Studies have shown no difference in mortality, recurrent pneumonia, treatment failure, hospital length of stay, or duration of mechanical ventilation when compared to long courses of medications.

Prevention

• Available vaccines for the two leading bacterial causes of pneumonia:
  • Haemophilus b conjugate vaccine
  • Pneumococcal conjugate vaccine (15-valent)
  • Pneumococcal conjugate vaccine (20-valent)
  • Pneumococcal conjugate vaccine (21-valent)
  • Pneumococcal polysaccharide vaccine (23-valent)

Adult Recommendations for the Pneumococcal Vaccine

• Adults > 50 years: PCV20, PCV21.
• Adults Aged 19-49 w/ underlying medical conds. or immunocompromising conditions: PCV15, PCV23, PCV20, PCV21
• Special note: If patients previously. received PCV7, PCV13 and/or PPSV23, refer to the current Adult Immunization Schedule for recommendations on how to proceed

This quiz covers key aspects of diagnosing and treating pneumonia, including differentiating between hospital-acquired and community-acquired pneumonia. It addresses identifying appropriate empiric antibiotic therapy, determining when to switch from IV to oral antibiotics, and understanding the duration of treatment.