Guideline sources The following summarized guidelines for the evaluation and management of community-acquired pneumonia (CAP) are prepared by our editorial team based on guidelines from the European Society of Intensive Care Medicine (ESICM/ALAT/ERS/ESCMID 2023), the British Thoracic Society (BTS 2023), the Center for Disease Control (CDC 2022; 2019), the American College of Physicians (ACP 2021), the Infectious Diseases Society of America (IDSA/ATS 2019), and the Infectious Diseases Society of America (IDSA 2007). 1 2 3 4 5 6 7 8 8 8 9 10 Definition CAP is an acute infection of the lungs occurring in an individual who has had little contact with the healthcare system. 8 Epidemiology Common causes of CAP include bacterial infections (such as S. pneumoniae, H. influenzae, S. aureus) and respiratory viruses (such as influenza virus, RSV, adenovirus, coronavirus, human https://web.pathway.md/diseases/recfFJ2nbJyhHRNVf 1/11 6/23/23, 3:36 AM Community-acquired pneumonia Pathway metapneumovirus, rhinovirus). No causative organism is identified in over 50% of patients. 8 Pathophysiology In the United States, the incidence of CAP is estimated at 248 cases per 100,000 person-years. In adults 65 years of age, the incidence increases to 630-1640 cases per 100,000 person-years. 9 Disease course The most common complications of CAP include respiratory failure, metastatic infections, complicated pleural effusion, sepsis, and multiorgan failure. Influenza and bacterial pneumonia are strongly associated with cardiac events including myocardial infarction, arrhythmias, and HF. 8 Prognosis and risk of recurrence In patients requiring hospitalization, CAP is associated with an estimated in-hospital mortality of 11%. 10 Calculator Calculator Pathway CURB 65 score Drug Resistance in Pneumonia s Communit Investigatio Guidelines 1. Screening and diagnosis Diagnostic criteria: diagnose pneumonia on the basis of a demonstrable infiltrate by CXR or other imaging technique, with or without supporting microbiological data, in addition to a constellation of suggestive clinical features. B 2. Classification and risk stratification Risk prediction rules: use a validated clinical prediction rule, preferentially the Pneumonia Severity Index B over the CURB-65 tool, in addition to clinical judgment, to assess the risk and determine the need for hospitalization in adult patients with CAP. B 3. Diagnostic investigations General principles: obtain evaluation for specific pathogens that would significantly alter standard (empirical) management decisions, when the presence of such pathogens is suspected on the basis of clinical and epidemiologic clues, in patients with CAP. B https://web.pathway.md/diseases/recfFJ2nbJyhHRNVf 2/11 6/23/23, 3:36 AM Community-acquired pneumonia Pathway Bacterial sputum cultures (outpatient setting): Recognize that routine diagnostic tests to identify an etiologic diagnosis are optional for outpatients with CAP. B Do not obtain sputum Gram stain and culture routinely in adults with CAP managed in the outpatient setting. D Bacterial sputum cultures (inpatient setting): Obtain pretreatment Gram stain and culture of respiratory secretions in adult patients with severe CAP managed in the hospital setting, especially if intubated. B Obtain pretreatment Gram stain and culture of respiratory secretions in adult patients with CAP managed in the hospital setting with any of the following: being empirically treated for methicillin-resistant S. aureus or P. aeruginosa B previously infected with methicillin-resistant S. aureus or P. aeruginosa, especially with prior respiratory tract infection B hospitalized and received parenteral antibiotics, whether during the hospitalization event or not, in the last 90 days. B Specific sputum cultures (Legionella): Consider collecting lower respiratory tract secretions for Legionella culture on selective media or Legionella NAAT in adults with severe CAP. C Obtain sputum cultures on specialized media for Legionella in patients with a positive urinary Legionella antigen test. Specific sputum cultures (fungal/tuberculsosis): obtain fungal and mycobacterial sputum cultures in patients with cavitary infiltrates. Multiplex sputum PCR testing: consider collecting lower respiratory tract samples (either sputum or endotracheal aspirates) for multiplex PCR testing (virus and/or bacterial detection), if available, whenever non-standard antibiotics are prescribed or considered in patients with severe CAP. C Urinary pneumococcal antigen (nonsevere CAP): avoid obtaining urine pneumococcal antigen testing in adult patients with non-severe CAP. D Urinary pneumococcal antigen (severe CAP): consider obtaining urine pneumococcal antigen testing in adult patients with severe CAP. C Urinary Legionella antigen (nonsevere CAP): Consider obtaining urine Legionella antigen testing where indicated by epidemiological factors, such as in the context of a Legionella outbreak or recent travel. C Consider avoiding routine urine Legionella antigen testing in adults with nonsevere CAP. D Urinary Legionella antigen (severe CAP): consider obtaining urine Legionella antigen testing in adult patients with severe CAP. C Blood cultures (outpatient setting): do not obtain blood cultures in adult patients with CAP managed in the outpatient setting. D https://web.pathway.md/diseases/recfFJ2nbJyhHRNVf 3/11 6/23/23, 3:36 AM Community-acquired pneumonia Pathway Blood cultures (inpatient setting, nonsevere CAP): avoid obtaining blood cultures routinely in adult patients with CAP managed in the hospital setting. D Show 2 more Blood cultures (inpatient setting, severe CAP): obtain pretreatment blood cultures in adult patients with severe CAP managed in the hospital setting. B Influenza testing: test for influenza with a rapid influenza molecular assay (influenza NAAT) rather than a rapid influenza diagnostic test (antigen test) in patients with CAP presenting during periods of influenza transmission. B Procalcitonin levels: As per ERS 2023 guidelines, consider measuring procalcitonin levels to reduce the duration of antibiotic therapy in patients with severe CAP. C As per IDSA 2019 guidelines, do not base on initial serum procalcitonin level to decide on initiating empiric antibiotic therapy in adult patients with clinically suspected and radiographically confirmed CAP. D Evaluation for adrenal insufficiency: screen for occult adrenal insufficiency in patients with severe CAP remaining hypotensive after fluid resuscitation. B 4. Respiratory support High-flow nasal oxygen therapy: consider initiating high-flow nasal oxygen therapy instead of standard oxygen supplementation in patients with severe CAP and acute hypoxemic respiratory failure not requiring immediate intubation. C Noninvasive ventilation: As per ERS 2023 guidelines, consider initiating noninvasive mechanical ventilation in certain patients with persistent hypoxemic respiratory failure not requiring immediate intubation, irrespective of high-flow nasal oxygen therapy. C As per IDSA 2007 guidelines: Initiate a cautious trial of noninvasive ventilation in patients with hypoxemia or respiratory distress unless immediate intubation is required because of severe hypoxemia (PaO /FiO ratio 150) and bilateral alveolar infiltrates. B Use low tidal volumes (6 mL/kg ideal body weight) in patients with diffuse bilateral pneumonia or ARDS undergoing ventilation. A 5. Medical management Setting of care (hospital admission): offer more-intensive treatment (hospitalization or, where appropriate and available, intensive in-home health care services) in patients with CURB-65 scores 2. B Show 2 more https://web.pathway.md/diseases/recfFJ2nbJyhHRNVf 4/11 6/23/23, 3:36 AM Community-acquired pneumonia Pathway Setting of care (ICU admission): Admit patients with CAP with hypotension requiring vasopressors or respiratory failure requiring mechanical ventilation to an ICU. B Consider admitting patients not requiring vasopressors or mechanical ventilator support to a higher level monitoring unit, using the IDSA/ATS minor severity criteria together with clinical judgment. C Empiric antibiotic therapy (outpatient setting, patients without comorbidities): Administer amoxicillin 1 g PO TID (strong recommendation, moderate quality of evidence) or doxycycline 100 mg PO BID in outpatients with CAP without comorbidities or risk factors for antibiotic-resistant pathogens. B Administer a macrolide (azithromycin 500 mg PO on the first day and 250 mg daily thereafter, clarithromycin 500 mg PO BID, or clarithromycin ER 1,000 mg PO daily) in areas with pneumococcal resistance to macrolides < 25%. B Empiric antibiotic therapy (outpatient setting, patients with comorbidities): Administer combination therapy of a -lactam (amoxicillin/clavulanate, cefpodoxime, or cefuroxime) and a macrolide (azithromycin 500 mg PO on the first day and 250 mg PO daily thereafter, clarithromycin 500 mg PO BID, or clarithromycin ER 1,000 mg PO once daily) or monotherapy with a respiratory fluoroquinolone (levofloxacin 750 mg PO daily, moxifloxacin 400 mg PO daily, or gemifloxacin 320 mg PO daily) in outpatients with CAP with comorbidities, such as chronic heart, lung, liver, or renal disease, diabetes mellitus, AUD, malignancy, or asplenia. B Administer combination therapy of a -lactam (amoxicillin/clavulanate, cefpodoxime, or cefuroxime) and doxycycline 100 mg PO BID as another option. B Empiric antibiotic therapy (inpatient setting, nonsevere CAP): Administer combination therapy with a -lactam (ampicillin/sulbactam 1.5-3 g every 6 hours, cefotaxime 1-2 g every 8 hours, ceftriaxone 1-2 g daily, or ceftaroline 600 mg every 12 hours) and a macrolide (azithromycin 500 mg daily or clarithromycin 500 mg BID) or monotherapy with a respiratory fluoroquinolone (levofloxacin 750 mg daily or moxifloxacin 400 mg daily) in adult inpatients with non-severe CAP and no risk factors for methicillin-resistant S. aureus or P. aeruginosa. A Consider administering combination therapy with a -lactam (ampicillin/sulbactam, cefotaxime, ceftaroline, or ceftriaxone) and doxycycline 100 mg BID as an alternative option in adult patients with CAP with contraindications to both macrolides and fluoroquinolones. C Empiric antibiotic therapy, inpatient setting, severe CAP: As per ALAT/ESCMID/ESICM/ERS 2023 guidelines, consider integrating specific risk factors (eventually computed into clinical scores) based on local epidemiology and previous colonization to guide decisions regarding drug-resistant pathogens (excluding immunocompromised patients) and empirical antibiotics in patients with severe CAP. C Show 2 more As per ATS/IDSA 2019 guidelines: https://web.pathway.md/diseases/recfFJ2nbJyhHRNVf 5/11 6/23/23, 3:36 AM Community-acquired pneumonia Pathway Administer combination therapy with -lactam and a macrolide B or a respiratory fluoroquinolone in adult inpatients with severe CAP without risk factors for methicillin-resistant S. aureus or P. aeruginosa. B Discontinue use of the previously recommended categorization of healthcare-associated pneumonia as a means to guide extended-spectrum antibiotic coverage in adult patients with CAP. B Definitive antibiotic therapy: Target antimicrobial therapy towards the pathogen causing CAP, if such a pathogen has been identified on the basis of reliable microbiological methods. B Switch from IV to PO therapy when patients are hemodynamically stable, are improving clinically, are able to ingest medications, and have a normally functioning gastrointestinal tract. B Duration of antibiotic therapy: As per ERS 2023 guidelines, consider measuring procalcitonin levels to reduce the duration of antibiotic therapy in patients with severe CAP. C As per ACP 2021 guidelines, complete at least a 5-day course of antibiotics in patients with CAP. Extend the antibiotic therapy beyond 5 days guided by validated measures of clinical stability, including resolution of vital sign abnormalities, ability to eat, and normal mentation. B As per IDSA 2019 guidelines, decide on the duration of antibiotic therapy based on validated measures of clinical stability (resolution of vital sign abnormalities, normal mentation, and ability to tolerate oral intake) Continue antibiotics until the patient achieves stability and for at least 5 days in patients with CAP. B Landmark trials: Duration of antibiotics in community-acquired pneumonia In hospitalized patients with community-acquired pneumonia (CAP), protocolized discontinuation of antibiotics after 5 days were noninferior to physician-guided antibiotic discontinuation with respect to clinical success at day 10. Uranga A et al. JAMA Intern Med. 2016 Sep 1. Corticosteroids: As per ERS 2023 guidelines, consider administering corticosteroids in patients with severe CAP in shock. C As per IDSA 2019 guidelines, do not use corticosteroids routinely in adult patients with non- severe CAP. D Show 2 more Updated evidence: ESCAPe https://web.pathway.md/diseases/recfFJ2nbJyhHRNVf 6/11 6/23/23, 3:36 AM Community-acquired pneumonia Pathway In adult patients with severe community-acquired pneumonia presenting in hospital within 72- 96 hours, methylprednisolone was not superior to placebo with respect to death from all causes at day 60. G Umberto Meduri et al. Intensive Care Med. 2022 Aug. Anti-influenza therapy: As per ERS 2023 guidelines: Consider administering oseltamivir in patients with severe CAP due to influenza confirmed by PCR. C Consider administering empirical oseltamivir during the influenza season when PCR is not available to confirm influenza. C As per IDSA 2019 guidelines: Administer anti-influenza treatment, such as oseltamivir, in adult patients with CAP who test positive for influenza in the inpatient setting, independently of the duration of illness before diagnosis. B Consider administering anti-influenza treatment in adult patients with CAP who test positive for influenza and are being treated in the outpatient setting, independently of the duration of illness before diagnosis. C 6. Nonpharmacologic interventions Smoking cessation: advise smoking cessation in smoker patients hospitalized with CAP. B 7. Specific circumstances Patients with aspiration pneumonia (diagnosis): recognize that aspiration pneumonia is particularly common in persons with a learning disability, in older persons, and in patients with neurological or upper gastrointestinal conditions. E Show 6 more Patients with aspiration pneumonia (maintenance of oral health): ensure that all hospitals and care homes have at least one oral health 'champion' promoting good oral healthcare. E Show 3 more Patients with aspiration pneumonia (management of swallowing difficulties): refer patients with swallowing difficulties to a speech and language therapist. E Show 9 more Patients with aspiration pneumonia, choice of antibiotics: As per BTS 2023 guidelines: Decide on the choice of antibiotic regimen in hospitalized patients with aspiration pneumonia based on medical microbiology guidance on local epidemiology, taking into account recent https://web.pathway.md/diseases/recfFJ2nbJyhHRNVf 7/11 6/23/23, 3:36 AM Community-acquired pneumonia Pathway antibiotic exposure, recent microbiology results when available, and where the patient was when pneumonia began. E Consider administering a 5-day course of antibiotics in patients with aspiration pneumonia unless there is a failure to improve. Assess for alternative sources of illness or complications of aspiration pneumonia and/or administer an alternative antibiotic regimen in case of failure. E As per IDSA 2007 guidelines, avoid adding anaerobic coverage routinely in patients with suspected aspiration pneumonia unless there is a concern for lung abscess or empyema. D Patients with aspiration pneumonia (thromboprophylaxis): administer thromboprophylaxis in patients with aspiration pneumonia unless contraindicated. E Patients with aspiration pneumonia (supportive and palliative care): administer adequate hydration in patients with aspiration pneumonia. Administer supplemental oxygen if required. E Show 2 more Patients with influenza: administer standard antibiotic therapy in adult patients with clinical and radiographic evidence of CAP testing positive for influenza, either in the inpatient or outpatient settings. B 8. Preventative measures Pneumococcal vaccination: As per CDC 2022 guidelines, offer 1 dose of pneumococcal conjugate vaccine (either PCV20 or PCV15) in adults aged 19-64 years with certain underlying medical conditions or other risk factors not previously received pneumococcal conjugate vaccine or if previous vaccination history is unknown. E Show 5 more As per CDC 2019 guidelines, offer 1 dose of PPSV23 in all adults aged 65. E Show 7 more 9. Follow-up and surveillance Hospital discharge criteria: discharge patients as soon as they are clinically stable, have no other active medical problems, and have a safe environment for continued care. Avoid offering inpatient observation while administering oral therapy. B Follow-up imaging: avoid obtaining follow-up chest imaging routinely in adult patients with CAP if symptoms have resolved within 5-7 days. D Likelihood Ratios Pertinent positives https://web.pathway.md/diseases/recfFJ2nbJyhHRNVf 8/11 6/23/23, 3:36 AM Community-acquired pneumonia Pathway The following findings increase the probability of community-acquired pneumonia in adults. 1 1 1 1 Finding LR+ Value Presence of egophony 5.6 Presence of dullness to percussion 4.3 History of no asthma 3.8 Presence of bronchial breath sounds 3.3 < 95% > 38 C >22 breaths/min > 100 BPM Show 10 more Pertinent negatives The following findings decrease the probability of community-acquired pneumonia in adults. 1 1 1 1 Finding LR- Value No history of no asthma 0.1 No history of cough 0.2 serum CRP not increased 0.4 O2 saturation not decreased* 0.6 < 95% > 38 C >22 breaths/min > 100 BPM Show 10 more References 1. Metlay JP, Waterer GW, Long AC et al. Diagnosis and Treatment of Adults with Community-acquired Pneumonia. An Official Clinical Practice Guideline of the American Thoracic Society and Infectious Diseases Society of America. Am J Respir Crit Care Med. 2019 Oct 1;200 7):e45-e67. Open 2. Ignacio Martin-Loeches, Antoni Torres, Blin Nagavci et al. ERS/ESICM/ESCMID/ALAT guidelines for the management of severe community-acquired pneumonia. Intensive Care Med. 2023 Apr 4;1 18. Open 3. 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 Mar 1;44 Suppl 2 S27 72. Open 4. A John Simpson, Jamie-Leigh Allen, Michelle Chatwin et al. BTS clinical statement on aspiration pneumonia. Thorax. 2023 Feb;78 Suppl 1):s3-s21. Open 5. Almea Matanock, Grace Lee, Ryan Gierke et al. Use of 13 Valent Pneumococcal Conjugate Vaccine and 23 Valent Pneumococcal Polysaccharide Vaccine Among Adults Aged 65 Years: Updated https://web.pathway.md/diseases/recfFJ2nbJyhHRNVf 9/11 6/23/23, 3:36 AM Community-acquired pneumonia Pathway Recommendations of the Advisory Committee on Immunization Practices. MMWR Morb Mortal Wkly Rep. 2019 Nov 22;68 46 1069 1075. Open 6. Rachael A Lee, Robert M Centor, Linda L Humphrey et al. Appropriate Use of Short-Course Antibiotics in Common Infections: Best Practice Advice From the American College of Physicians. Ann Intern Med. 2021 Apr 6. Open 7. Miwako Kobayashi, Jennifer L Farrar, Ryan Gierke et al. Use of 15 Valent Pneumococcal Conjugate Vaccine and 20 Valent Pneumococcal Conjugate Vaccine Among U.S. Adults: Updated Recommendations of the Advisory Committee on Immunization Practices United States, 2022. MMWR Morb Mortal Wkly Rep. 2022 Jan 28;71 4 109 117. Open 8. Musher DM, Thorner AR. Community-acquired pneumonia. N Engl J Med. 2014 Oct 23;371 17 1619 28. Open 9. Jain S, Self WH, Wunderink RG et al. Community-Acquired Pneumonia Requiring Hospitalization among U.S. Adults. N Engl J Med. 2015 Jul 30;373 5 415 27. Open 10. Steel HC, Cockeran R, Anderson R et al. Overview of community-acquired pneumonia and the role of inflammatory mechanisms in the immunopathogenesis of severe pneumococcal disease. Mediators Inflamm. 2013;2013 490346. Open 11. American Academy of Pediatrics. Choosing Wisely AAP recommendations. Choosing Wisely. 2018. Open 12. Elena Prina, Otavio T Ranzani, Antoni Torres. Community-acquired pneumonia. Lancet. 2015 Sep 12;386 9998 1097 108. Open 13. Charles W Lanks, Ali I Musani, David W Hsia. Community-acquired Pneumonia and Hospital-acquired Pneumonia. 2019 May;103 3 487 501.2019 May;103 3 487 501. Open 14. Karen K Giuliano, Dian Baker, Barbara Quinn. The epidemiology of nonventilator hospital-acquired pneumonia in the United States. 2018 Mar;46 3 322 327.2018 Mar;46 3 322 327. Open 15. Elizabeth Alexander, Lisa Goldberg, Anita F Das et al. Oral Lefamulin vs Moxifloxacin for Early Clinical Response Among Adults With Community-Acquired Bacterial Pneumonia: The LEAP 2 Randomized Clinical Trial. JAMA. 2019 Sep 27;322 17 1661 1671. Open 16. Ane Uranga, Pedro P Espa a, Amaia Bilbao et al. Duration of Antibiotic Treatment in Community- Acquired Pneumonia: A Multicenter Randomized Clinical Trial. JAMA Intern Med. 2016 Sep 1;176 9 1257 65. Open 17. Antoni Torres, Oriol Sibila, Miquel Ferrer et al. Effect of corticosteroids on treatment failure among hospitalized patients with severe community-acquired pneumonia and high inflammatory response: a randomized clinical trial. JAMA. 2015 Feb 17;313 7 677 86. Open 18. Pedro P Espa a, Alberto Capelastegui, Jos M Quintana et al. Validation and comparison of SCAP as a predictive score for identifying low-risk patients in community-acquired pneumonia. J Infect. 2010 Feb;60 2 106 13. Open 19. Catherine Liu, Arnold Bayer, Sara E Cosgrove et al. Clinical Practice Guidelines by the Infectious Diseases Society of America for the Treatment of Methicillin-Resistant Staphylococcus aureus Infections in Adults and Children. Clin Infect Dis. 2011 Feb 1;52 3):e18 55. Open https://web.pathway.md/diseases/recfFJ2nbJyhHRNVf 10/11 6/23/23, 3:36 AM Community-acquired pneumonia Pathway 20. Panel on Opportunistic Infections in Adults and Adolescents with HIV. Guidelines for the Prevention and Treatment of Opportunistic Infections in Adults and Adolescents with HIV. Department of Health and Human Services. 2023. Open 21. G Umberto Meduri, Mei-Chiung Shih, Lisa Bridges et al. Low-dose methylprednisolone treatment in critically ill patients with severe community-acquired pneumonia. Intensive Care Med. 2022 Aug;48 8 1009 102. Open 22. American Academy of Pediatrics. Choosing Wisely AAP recommendations. Choosing Wisely. 2020. Open 23. Julian Legg, Jamie-Leigh Allen, Morag Andrew et al. BTS Clinical Statement on the prevention and management of community-acquired pneumonia in people with learning disability. Thorax. 2023 Feb;78 Suppl 1):s22-s52. Open 24. Pierre-Fran ois Dequin, Ferhat Meziani, Jean-Pierre Quenot et al. Hydrocortisone in Severe Community-Acquired Pneumonia. N Engl J Med. 2023 May 25;388 21 1931 1941. Open https://web.pathway.md/diseases/recfFJ2nbJyhHRNVf 11/11