RECENT UPDATES IN MANAGEMENT OF COMMUNITY ACQUIRED PNEUMONIA

INTRODUCTION   Improving the care of patients with (CAP) has been the focus of many different organizations.   CAP, together with influenza, remains the seventh leading cause of death in the United States.   915,900 episodes of CAP occur in adults 65 years of age each year in the US.

INTRODUCTION   Two of the most widely referenced guidelines for management of CAP are those of the Infectious Diseases Society of America (IDSA) and the American Thoracic Society (ATS)   In response to confusion regarding differences between their respective guidelines, the IDSA and the ATS convened a joint committee to develop a unified CAP guideline document.

INTRODUCTION  Community-acquired pneumonia (CAP) is defined as an acute infection of the pulmonary parenchyma in a patient who has acquired the infection in the community

CLINICAL EVALUATION  cough, fever, pleuritic chest pain, dyspnea and sputum production.  Chest pain occurs in 30 percent of cases, chills in 40 to 50 percent, and rigors in 15 percent.  Other common features are gastrointestinal symptoms (nausea, vomiting, diarrhea), and mental status changes.

CLINICAL EVALUATION  Chest examination reveals audible rales in most patients  one-third have evidence of consolidation  The major blood test abnormality is leukocytosis  Leukopenia can occur

RADIOLOGIC EVALUATION  an infiltrate on plain chest radiograph is considered the gold standard for diagnosing pneumonia  The radiographic appearance of community- acquired pneumonia (CAP) may include lobar consolidation  interstitial infiltrates  cavitation

RADIOLOGIC EVALUATION

Site-of-Care Decisions Hospital admission decision Severity-of-illness scores, such as: - CURB-65 criteria (confusion, uremia, respiratory rate, low blood pressure, age 65 years or greater) - the Pneumonia Severity Index (PSI) can be used to identify patients with CAP who may be candidates for outpatient treatment.

PNEUMONIA SEVERITY INDEX FOR CAP

Site-of-Care Decisions Hospital admission decision PNEUMONIA SEVERITY INDEX FOR CAP PSI riskSite of care I - II Outpatients III Observation unit or with a short hospitalization IV - V Inpatients

Site-of-Care Decisions Hospital admission decision CURB-65 criteria 1- confusion (based on a specific mental test or disorientation to person, place, or time) 2- BUN level > 7 m mol/L (20 mg/dL) 3- respiratory rate > 30 breaths/min 4- low blood pressure (systolic, < 90 mm Hg; or diastolic, < 60 mm Hg) 5- age > 65 years

Site-of-Care Decisions Hospital admission decision CURB-65 score Site of care Outpatients 2 admission (wards) 3 admission (ICU)

Site-of-Care Decisions Hospital admission decision Objective criteria or scores should always be supplemented with physician determination of subjective factors including: - the ability to safely reliably take oral medication - the availability of outpatient support resources.

ICU admission decision Direct admission to an ICU is: required for patients with: - septic shock requiring vasopressors - acute respiratory failure requiring intubation and mechanical ventilation. recommended for patients with: 3 of the minor criteria for severe CAP.

Criteria for severe CAP Minor criteria   Respiratory rate > 30 breaths/min   PaO2/FiO2 ratio < 250   Multilobar infiltrates   Confusion/disorientation   Uremia (BUN level > 20 mg/dL)   Leukopeniac (WBC count, < 4000 cells/mm3)   Thrombocytopenia (platelet count, < 100,000 cells/mm3)   Hypothermia (core temperature, < 36C)   Hypotension requiring aggressive fluid resuscitation Major criteria   Invasive mechanical ventilation   Septic shock with the need for vasopressors PaO2/FiO2 = arterial oxygen pressure/fraction of inspired oxygen

Most common etiologies of CAP OutpatientInpatient (non-ICU)Inpatient (ICU) S. pneumoniae M. pneumoniae Staphylococcus aureus H. influenzaeC. pneumoniaeLegionella species C. pneumoniaeH. influenzaeGram-negative bacilli Respiratory virusesLegionella speciesH. influenzae Aspiration Respiratory viruses

Empirical antimicrobial therapy   the initial treatment for most patients remain empirical   Increasing evidence has strengthened the recommendation for combination empirical therapy for severe CAP.   Only 1 recently released antibiotic has been added to the recommendations: ertapenem, as an acceptable b-lactam alternative for hospitalized patients with risk factors for infection with gram-negative pathogens other than Pseudomonas aeruginosa.

Empirical antimicrobial therapy   Selection of antimicrobial regimens for empirical therapy is based on: prediction of the most likely pathogen(s) 2. 2.knowledge of local susceptibility patterns.   Recommendations are generally for a class of antibiotics rather than a specific drug, unless outcome data clearly favor one drug.

Outpatient treatment 1. Previously healthy and no risk factors for drug-resistant S. pneumoniae (DRSP) infection:   A macrolide (azithromycin, clarithromycin, or erythromycin)   Doxycycline

Outpatient treatment 2. Presence of comorbidities such as chronic heart, lung, liver or renal disease; diabetes mellitus; alcoholism; malignancies; asplenia; immunosuppressing conditions or use of immunosuppressing drugs; or use of antimicrobials within the previous 3 months (in which case an alternative from a different class should be selected):   A respiratory fluoroquinolone (moxifloxacin, gemifloxacin, or levofloxacin [750 mg])   A b-lactam plus a macrolide

Outpatient treatment 3. In regions with a high rate (>25%) of infection with high-level (MIC > 16 mg/mL) macrolide-resistant S.pneumoniae consider the use of alternative agents listed above in (2) for any patient, including those without comorbidities.

Inpatient, non-ICU treatment   A respiratory fluoroquinolone   A b-lactam plus a macrolide

Inpatient, ICU treatment A b-lactam (cefotaxime, ceftriaxone, or ampicillin-sulbactam) plus either azithromycin or a fluoroquinolone (For penicillin-allergic patients, a respiratory fluoroquinolone and aztreonam are recommended.)

Special concerns If Pseudomonas is a consideration   An antipneumococcal, antipseudomonal b-lactam (piperacillintazobactam, cefepime, imipenem, or meropenem) plus either ciprofloxacin or levofloxacin (750 mg) or   The above b-lactam plus an aminoglycoside and azithromycin or   The above b-lactam plus an aminoglycoside and an antipneumococcal Fluoroquinolone (for penicillin-allergic patients, substitute aztreonam for above b-lactam)

Special concerns if CA-MRSA is a consideration add vancomycin or linezolid CA-MRSA = community-acquired methicillin-resistant Staphylococcus aureus

Time to first antibiotic dose For patients admitted through the emergency department (ED), the first antibiotic dose should be administered while still in the ED.

Switch from intravenous to oral therapy   hemo-dynamically stable   improving clinically   able to ingest medications   have a normally functioning gastrointestinal tract.

Switch from intravenous to oral therapy Patients should be discharged as soon as they:   clinically stable   no other active medical problems   have a safe environment for continued care. Inpatient observation while receiving oral therapy is not necessary.

Duration of antibiotic therapy   Patients with CAP should be treated for a minimum of 5 days   before discontinuation of therapy patients should be: - afebrile for 48–72 h - have no more than 1 CAP-associated sign of clinical instability

Criteria for clinical stability Heart rate < 100 beats/min   Respiratory rate < 24 breaths/min   Temperature < 37.8C   Systolic blood pressure > 90 mm Hg   Arterial oxygen saturation > 90% or pO2 > 60 mm Hg on room air   Ability to maintain oral intake   Normal mental status

Deterioration or progression Early (<72 h of treatment)   Severity of illness at presentation   Resistant microorganism - Uncovered pathogen - Inappropriate by sensitivity   Metastatic infection - Empyema/parapneumonic - Endocarditis, meningitis, arthritis   Inaccurate diagnosis - PE, aspiration, ARDS - Vasculitis (e.g., SLE)

Deterioration or progression Delayed   Nosocomial superinfection - Nosocomial pneumonia - Extrapulmonary   Exacerbation of comorbid illness   Intercurrent noninfectious disease - PE - Myocardial infarction - Renal failure