Community Acquired Pneumonia

Definitions Community acquired pneumonia (CAP) – Infection of the lung parenchyma in a person who is not hospitalized or living in a long-term care facility for ≥ 2 weeks Hospital-acquired pneumonia (HAP) – Occurs 48 hours or more after admission, which was not incubating at the time of admission Healthcare-associated pneumonia (HCAP) is defined as pneumonia that occurs in a non-hospitalized patient with extensive healthcare contact, as defined by one or more of the following: – Intravenous therapy, wound care, or intravenous chemotherapy within the prior 30 days. – Residence in a nursing home or other long-term care facility – Hospitalization in an acute care hospital for two or more days within the prior 90 days – Attendance at a hemodialysis clinic within the prior 30 days Ventilator-associated pneumonia (VAP) – Arises more than hours after endotracheal intubation

Initial Evaluation of Suspected Pneumonia Common clinical features – Cough – Fever/Chills – Pleuritic chest pain – Dyspnea – Sputum production – Some may have GI symptoms including nausea, vomiting and diarrhea Physical Exam – Fever – Respiratory Rate >24 – Tachycardia – Chest examination may reveal audible rales

Initial Evaluation of Suspected Pneumonia A chest radiograph should be obtained in patients with suspected pneumonia when possible; a demonstrable infiltrate by chest radiograph or other imaging technique is required for the diagnosis of pneumonia, according to the 2007 consensus guidelines from the Infectious Diseases Society of America and the American Thoracic Society (IDSA/ATS) The radiographic appearance of Pneumonia may include lobar consolidation, interstitial infiltrates, and/or cavitation.

Initial Evaluation of Suspected Pneumonia The 2007 IDSA/ATS consensus guidelines recommend for diagnostic testing: – For outpatients with CAP routine diagnostic tests are optional. – Hospitalized patients should have CBC w/ diff, blood cultures and sputum Gram stain and culture – Patients with severe CAP requiring ICU admission should have blood cultures, urinary antigen tests, and sputum culture (either expectorated or endotracheal aspirate)

Hospital Admission There are a Severity-of-illness scores that can help guide whether to admit or not but should not be used over clinical judgment of the patient and situation CURB-65 criteria (>2, more-intensive treatment) – Confusion – Urea 7 mmol/L (20 mg/dL) – Increased respiratory rate >30 – low blood pressure (SBP <90 or DBP <60) Pneumonia Severity Index (PSI) – uses demographics, the coexistence of co-morbid illnesses findings on physical examination, vital signs and essential laboratory findings

ICU Admission Minor criteria (need 3) – Respiratory rate >30 breaths/min – PaO 2 /FiO 2 ratio <250 – Multilobar infiltrates – Confusion – BUN level, >20 mg/dL – Leukopenia c (WBC count, <4000 cells/mm 3 – Thrombocytopenia (platelet count, < 100,000 cells/mm 3 – Hypothermia (core temperature, <36 degrees C – Hypotension requiring aggressive fluid resuscitation Major criteria – Invasive mechanical ventilation – Septic shock with the need for vasopressors

CAP Pathogens Mandell LA, Wunderink RG, Anzueto A, et al. Infectious Diseases Society of America/American Thoracic Society consensus guidelines on the management of community-acquired pneumonia in adults. Clin Infect Dis 2007; 44 Suppl 2:S27.

CAP Treatment Outpatient Mandell LA, Wunderink RG, Anzueto A, et al. Infectious Diseases Society of America/American Thoracic Society consensus guidelines on the management of community-acquired pneumonia in adults. Clin Infect Dis 2007; 44 Suppl 2:S27.

CAP Inpatient Mandell LA, Wunderink RG, Anzueto A, et al. Infectious Diseases Society of America/American Thoracic Society consensus guidelines on the management of community-acquired pneumonia in adults. Clin Infect Dis 2007; 44 Suppl 2:S27.

Prevention All persons >50 years of age, others at risk for influenza complications, household contacts of high-risk persons, and health care workers should receive inactivated influenza vaccine Health care workers in inpatient and outpatient settings and long-term care facilities should receive annual influenza immunization. Pneumococcal polysaccharide vaccine is recommended for persons >65 years of age and for those with selected high-risk concurrent diseases Smoking cessation should be a goal for persons hospitalized with CAP who smoke. Respiratory hygiene measures, including the use of hand hygiene and masks or tissues for patients with cough, should be used in outpatient settings and EDs as a means to reduce the spread of respiratory infections.

References Mandell LA, Wunderink RG, Anzueto A, et al. Infectious Diseases Society of America/American Thoracic Society consensus guidelines on the management of community-acquired pneumonia in adults. Clin Infect Dis 2007; 44 Suppl 2:S27. American Thoracic Society, Infectious Diseases Society of America. Guidelines for the management of adults with hospital- acquired, ventilator-associated, and healthcare-associated pneumonia. Am J Respir Crit Care Med 2005; 171:388. Schuetz P, Christ-Crain M, Thomann R, et al. Effect of procalcitonin-based guidelines vs standard guidelines on antibiotic use in lower respiratory tract infections: the ProHOSP randomized controlled trial. JAMA 2009; 302:1059.