Pneumonia, a broad term encompassing various syndromes, denotes infections of the lung parenchyma caused by a multitude of organisms. Effective classification systems are crucial for identifying causative agents in different types of pneumonia and are instrumental in formulating treatment guidelines for both hospitalized and outpatient care. Optimizing collaborative strategies among healthcare professionals is essential to improve care coordination and communication, ultimately enhancing patient outcomes in pneumonia cases.
Objectives:
- Delineate the various classifications of pneumonia.
- Characterize typical physical examination findings in pneumonia patients.
- Discuss key factors influencing pneumonia management strategies.
- Summarize interprofessional approaches to enhance care coordination and communication for improved pneumonia patient outcomes.
Access free multiple choice questions on this topic.
Introduction
Pneumonia, fundamentally defined as an infection affecting the lung parenchyma, is not a singular disease entity. Instead, it is recognized as an umbrella term for a spectrum of syndromes. These syndromes arise from a diverse array of pathogens, leading to varied clinical presentations and subsequent health consequences.[1] The alterations in health diagnosis of pneumonia are continuously evolving with advancements in medical understanding and technology.
Classifying pneumonia has been approached through numerous methods, considering etiology, the clinical setting of infection acquisition, and the patterns of lung parenchyma involvement, among others. This discussion will focus on pneumonia classification as structured by the American Thoracic Society, providing a framework for understanding the nuances of this condition.
Community-Acquired Pneumonia (CAP)
Community-acquired pneumonia (CAP) is defined as pneumonia contracted outside of a hospital setting, within the general community.[2] This is a crucial distinction in health diagnosis pneumonia as it often involves different pathogens and treatment approaches compared to hospital-acquired infections.
Hospital-Acquired Pneumonia (HAP)
Hospital-acquired pneumonia (HAP) is diagnosed when pneumonia develops 48 hours or more after admission to an inpatient facility, such as a hospital, provided it was not incubating at the time of admission. This classification clarifies previous ambiguities surrounding healthcare-associated and hospital-acquired pneumonia. Currently, pneumonia acquired in settings like assisted-living facilities, rehabilitation centers, and other healthcare facilities, excluding acute care hospitals, falls under the community-acquired pneumonia category. A hospital inpatient setting is specifically required for a pneumonia diagnosis to be classified as HAP.[3]
Ventilator-Associated Pneumonia (VAP)
Ventilator-associated pneumonia (VAP) is defined as pneumonia occurring 48 hours or more after endotracheal intubation. VAP represents a significant complication in critically ill patients requiring mechanical ventilation and requires specific diagnostic and management strategies.[4]
These pneumonia classifications are essential for identifying the most likely causative organisms for each type, thereby guiding the development of effective treatment protocols for both inpatient and outpatient management. Accurate health diagnosis pneumonia hinges on correctly categorizing the infection to tailor appropriate interventions.
Historically, pneumonia has also been categorized based on the pattern of lung involvement:
- Focal non-segmental or lobar pneumonia: Affecting a single lobe of the lung, this pattern is often associated with specific bacterial pathogens.
- Multifocal bronchopneumonia or lobular pneumonia: Characterized by patchy involvement across multiple lung areas.
- Focal or diffuse interstitial pneumonia: Involving the lung interstitium, this pattern is frequently seen in viral or atypical pneumonias.[5]
Etiology
Identifying the specific etiologic agent of pneumonia is vital for targeted treatment and epidemiological tracking. However, in clinical practice, pinpointing a single causative agent is often challenging, particularly in community-acquired cases. Studies indicate that a definitive etiology is identified in less than 10% of patients presenting to emergency departments with pneumonia symptoms.[6] Despite this diagnostic challenge, understanding the common organisms associated with different pneumonia types is crucial for effective management and Alterations In Health Diagnosis Pneumonia.
Community-Acquired Pneumonia
Bacterial Causes
Bacterial CAP pathogens are traditionally categorized as “typical” and “atypical,” primarily based on their culturability. Typical bacterial organisms commonly include Streptococcus pneumoniae (pneumococcus), Haemophilus influenzae, Moraxella catarrhalis, Group A Streptococcus, and various aerobic and anaerobic gram-negative bacteria. Atypical organisms, frequently encountered in clinical settings, encompass Legionella, Mycoplasma, and Chlamydia, among others.[7] In the United States, the predominant bacterial causes of CAP are Streptococcus pneumoniae, Staphylococcus aureus, Mycoplasma pneumoniae, and gram-negative enteric bacilli.[8] Accurate identification of these bacterial agents is vital for alterations in health diagnosis pneumonia and guiding antibiotic therapy.
Viral Causes
Viral infections are frequently observed to co-exist with bacterial pathogens in the nasopharynx of CAP patients. The primary role of viruses, whether as sole causative agents or contributors to pathogenesis through secondary bacterial infections, remains an area of ongoing research. However, key viral agents implicated in CAP in the United States include influenza viruses, respiratory syncytial virus (RSV), parainfluenza viruses, and adenoviruses.[8] Differentiating viral from bacterial pneumonia is a critical aspect of alterations in health diagnosis pneumonia, influencing treatment strategies and antibiotic stewardship.
Fungal Causes
Fungal pneumonias are often associated with immunocompromised individuals, such as those with HIV or organ transplant recipients. However, it’s important to note that fungal species can also cause pneumonia in immunocompetent individuals, often leading to delayed diagnosis and poorer outcomes if not considered. The most common fungal pathogens in North America include Histoplasma, Blastomyces, and Coccidioides.[9] Awareness of fungal etiologies is increasingly important for comprehensive alterations in health diagnosis pneumonia, especially in regions with endemic fungal infections.
Hospital-Acquired Pneumonia and Ventilator-Associated Pneumonia
There is a significant overlap in the causative agents for HAP and VAP, making it practical to consider them together in terms of etiology. Common pathogens include:
- Gram-negative bacilli: Escherichia coli, Pseudomonas aeruginosa, Acinetobacter, and Enterobacter, among others. These organisms are often associated with antibiotic resistance, complicating treatment.
- Gram-positive cocci: Staphylococcus aureus, including both methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA), with MRSA being increasingly prevalent in hospital settings.[10], [11] The rise of antibiotic-resistant pathogens significantly impacts alterations in health diagnosis pneumonia and necessitates careful antibiotic selection.
- Other pathogens: Viruses and fungi, which are more frequently observed in immunocompromised and severely ill hospitalized patients, can also contribute to HAP and VAP.
Epidemiology
Pneumonia is a widespread disease with a substantial global health burden across all populations. A study by the U.S. Centers for Disease Control and Prevention (CDC) assessing the burden in North America highlighted CAP as the eighth leading cause of mortality in the United States and the seventh in Canada, after adjusting for age and gender variations.[8] The significant mortality associated with pneumonia underscores the importance of ongoing research and improvements in alterations in health diagnosis pneumonia and treatment.
A large-scale study over two years in Louisville, involving 587,499 adults from 2014 to 2016, found the annual age-adjusted incidence of CAP requiring hospitalization to be 649 per 100,000 adults (95% confidence interval, 628.2 to 669.8). This translates to approximately 1,591,825 annual adult CAP hospitalizations in the United States. [12] In-hospital mortality was reported at 6.5%, equating to 102,821 annual deaths in the U.S. Mortality rates at 30 days, 6 months, and 1 year post-hospitalization were 13.0%, 23.4%, and 30.6%, respectively, indicating a significant long-term impact. These rates were disproportionately higher in socioeconomically disadvantaged populations and in predominantly Hispanic or African-American communities.[12] These disparities highlight the need for targeted public health interventions and improved access to care.
Data from the Community-Acquired Pneumonia Organization (CAPO) database, based on incidence across 16 countries in the United States/Canada, Europe, and Latin America, revealed mortality rates of 7.3%, 9.1%, and 13.3% respectively.[13] These regional variations underscore the influence of healthcare infrastructure and socioeconomic factors on pneumonia outcomes.
Epidemiological data for HAP and VAP are less comprehensive, primarily due to confounding factors related to patient comorbidities and the complexities of hospital-acquired infections. Estimates suggest VAP incidence ranges from 2 to 16 episodes per 1000 ventilator days, with attributable mortality rates between 3% and 17%.[14] A major concern in HAP and VAP management is the high prevalence of multidrug-resistant organisms, which significantly impacts treatment strategies and alterations in health diagnosis pneumonia. Key risk factors for drug resistance include patient comorbidities, recent antibiotic exposure, functional status, and illness severity.[15]
Pathophysiology
Pneumonia development arises from a disruption in the delicate balance between resident lower respiratory tract microorganisms and the host’s local and systemic defense mechanisms (both innate and adaptive). This imbalance leads to inflammation of the lung parenchyma, the hallmark of pneumonia. Understanding the pathophysiology is crucial for grasping the alterations in health diagnosis pneumonia and developing targeted therapies. Key compromised defense mechanisms include:
- Systemic immune deficiencies: Impairments in humoral and complement-mediated immunity, seen in conditions like common variable immunodeficiency (CVID), X-linked agammaglobulinemia (inherited), and acquired functional asplenia, increase susceptibility to pneumonia. Compromised cell-mediated immunity predisposes individuals to infections by intracellular pathogens, such as viruses and low-virulence organisms like Pneumocystis jirovecii (PJP), as well as fungal agents.
- Mucociliary clearance dysfunction: This protective mechanism is often impaired by cigarette smoking, post-viral states, Kartagener syndrome, and other related conditions, increasing the risk of pathogen colonization and infection.
- Impaired cough reflex: Conditions like coma and substance abuse can suppress the cough reflex, hindering the clearance of secretions and pathogens from the respiratory tract.
- Secretion accumulation: Conditions such as cystic fibrosis and bronchial obstruction lead to the buildup of secretions, creating a favorable environment for bacterial growth and pneumonia development.
Resident alveolar macrophages play a critical role in lung defense against pathogens. Paradoxically, the inflammatory response initiated by these macrophages is central to the histopathological and clinical manifestations of pneumonia. Macrophages engulf pathogens and release signaling molecules or cytokines, including TNF-α, IL-8, and IL-1, which recruit inflammatory cells like neutrophils to the infection site. These macrophages also present antigens to T cells, triggering both cellular and humoral immune responses, activating complement, and stimulating antibody production against the invading organisms. This complex cascade of immune events leads to inflammation of the lung parenchyma and increased capillary permeability, resulting in exudative congestion, a key feature in pneumonia pathogenesis. These pathophysiological processes directly influence alterations in health diagnosis pneumonia, guiding diagnostic and therapeutic approaches.
Histopathology
The histopathological features of pneumonia can be broadly categorized into two main patterns: bronchopneumonia/lobular pneumonia and lobar pneumonia. Understanding these patterns is essential for interpreting diagnostic imaging and appreciating the alterations in health diagnosis pneumonia.
Lobar Pneumonia
Lobar pneumonia involves diffuse consolidation affecting an entire lung lobe. Its progression is classically described in four stages:
- Congestion: This initial stage is characterized by lung tissue that appears heavy and boggy. There is diffuse congestion, vascular engorgement, and accumulation of alveolar fluid rich in infectious organisms. Few red blood cells (RBCs) and neutrophils are present at this stage.
- Red hepatization: Marked infiltration of red blood cells, neutrophils, and fibrin into the alveolar spaces occurs. Grossly, the lung becomes firm and red, resembling liver tissue, hence the term “hepatization.”
- Gray hepatization: Red blood cells begin to break down, and fibrinopurulent exudates accumulate, leading to a color transformation from red to gray.
- Resolution: This final stage is marked by the clearance of exudates by resident macrophages, with or without residual scar tissue formation. Successful resolution is crucial for restoring normal lung function.
Bronchopneumonia
Bronchopneumonia is characterized by suppurative inflammation localized in patchy areas around the bronchi and bronchioles. This inflammation may or may not be confined to a single lobe and tends to be more multifocal than lobar pneumonia.
In severe cases, pneumonia can lead to complications such as lung abscess formation, representing tissue breakdown and pus-filled cavities within the lung. Furthermore, infection can spread to the pleural space, causing empyema, a fibrinopurulent exudate accumulation within the pleural cavity. These severe histopathological alterations in health diagnosis pneumonia often necessitate more aggressive interventions.
History and Physical Examination
Historically, patients with pneumonia commonly present with systemic symptoms such as fever with chills, malaise, loss of appetite, and myalgias. These systemic manifestations are often more pronounced in viral pneumonia compared to bacterial pneumonia. A subset of patients may exhibit altered mental status, abdominal pain, chest pain, and other systemic findings. Pulmonary symptoms primarily include cough, which may be productive or non-productive. Bacterial pneumonia is typically associated with purulent sputum, and in some instances, blood-tinged sputum. Viral pneumonia is more likely to produce watery or occasionally mucopurulent sputum. Pleuritic chest pain may accompany pneumonia if the pleura is concurrently involved. Dyspnea and a sensation of chest heaviness are also occasionally reported.
Common physical examination findings in pneumonia patients include:
- Tachypnea (increased respiratory rate)
- Tachycardia (increased heart rate)
- Fever, with or without chills
- Decreased or bronchial breath sounds on auscultation
- Egophony and tactile fremitus, both indicative of lung consolidation
- Crackles (rales) heard on auscultation over the affected lung regions
- Dullness to percussion over consolidated lung areas
These clinical signs and symptoms are crucial for initial assessment and guiding further diagnostic evaluations in alterations in health diagnosis pneumonia.
Evaluation
Evaluation of both community-acquired pneumonia (CAP) and hospital-acquired pneumonia (HAP) involves a combination of clinical, radiological, and laboratory assessments. These evaluations are essential for accurate alterations in health diagnosis pneumonia and appropriate management.
Clinical Evaluation
Clinical evaluation begins with a thorough history and physical examination, as detailed in the preceding section. This step helps to assess the patient’s overall condition and identify potential risk factors or comorbidities.
Radiological Evaluation
According to guidelines from the Infectious Diseases Society of America (IDSA) and the American Thoracic Society (ATS), radiographic evidence of lung infiltrate on chest x-ray is a necessary criterion for pneumonia diagnosis. Chest x-ray remains the cornerstone of pneumonia diagnosis, providing visual confirmation of lung pathology when combined with supportive clinical findings.[2] Radiographic findings can range from lobar consolidation to interstitial infiltrates and, in more severe cases, cavitary lesions with air-fluid levels, indicating necrotizing pneumonia or abscess formation. Computed tomography (CT) scans may be used in complex cases or when chest x-ray findings are inconclusive. Advancements in radiological techniques represent significant alterations in health diagnosis pneumonia, allowing for more precise and earlier detection.
Laboratory Evaluation
Laboratory tests for pneumonia may include blood cultures, sputum culture and Gram stain, routine blood counts (complete blood count with differential), and lymphocyte count. Specialized tests, such as urinary antigen tests for Streptococcus pneumoniae and Legionella, bronchoalveolar lavage (BAL), or induced sputum analysis, may be employed to identify specific pathogens, particularly in severe or atypical cases. Procalcitonin and C-reactive protein (CRP) levels can aid in differentiating bacterial from viral etiologies when clinical and radiological findings are ambiguous. However, it’s important to note that empiric antibiotic therapy is often initiated in typical pneumonia cases, and extensive laboratory testing is not always necessary, especially in outpatient CAP management.[2] The judicious use of laboratory tests is an important consideration in alterations in health diagnosis pneumonia, balancing diagnostic accuracy with cost-effectiveness and timely treatment initiation.
Evaluation of ventilator-associated pneumonia (VAP) differs somewhat from CAP and HAP. Diagnosis of VAP requires both radiological and microbiological evidence before initiating antimicrobial therapy. VAP should be suspected in mechanically ventilated patients who develop new-onset dyspnea, decreased oxygen saturation despite stable ventilator settings, fever with chills, or new pulmonary infiltrates. All suspected VAP cases warrant a chest x-ray (or CT scan if x-ray findings are unclear). Invasive sampling techniques, such as mini-BAL, bronchoscopic BAL, or protected specimen brush (PSB), are frequently used to obtain lower respiratory tract samples for culture and pathogen identification. Once VAP diagnosis is confirmed and causative organisms are identified, targeted antimicrobial therapy can be initiated.[16] The emphasis on microbiological confirmation in VAP reflects the need for precise alterations in health diagnosis pneumonia in this high-risk population, guiding antibiotic selection and minimizing the risk of antibiotic resistance.
Treatment / Management
Management of community-acquired pneumonia (CAP) begins with initial risk stratification to determine the appropriate care setting: outpatient, general medical ward, or intensive care unit (ICU). The CURB-65 severity score is a widely used tool for this purpose. CURB-65 assesses five factors: Confusion, Urea (blood urea nitrogen >20 mg/dL), Respiratory rate (≥30 breaths/min), Blood pressure (systolic <90 mmHg or diastolic ≤60 mmHg), and age ≥65 years. One point is assigned for each criterion met.
Patient disposition based on CURB-65 score:
- Score 0-1: Outpatient management is generally appropriate. Empiric treatment options include fluoroquinolones or beta-lactams plus macrolides for patients with comorbidities. Macrolides or doxycycline are suitable for patients without comorbidities.
- Score 2-3: Hospital admission to a general medical ward is typically indicated. First-line treatment options include fluoroquinolones or a combination of macrolides and beta-lactams.
- Score ≥4: ICU management is warranted. Empiric regimens often involve a combination of a beta-lactam plus either a fluoroquinolone or a macrolide.[17], [2]
Management of hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) adheres to ATS/IDSA guidelines. Treatment is typically more complex, prolonged, and involves broader-spectrum antibiotics compared to CAP management. Early recognition of pneumonia signs and comprehensive evaluation, as discussed earlier, are crucial before initiating empiric therapy. Empiric antibiotic selection is guided by local resistance patterns and patient-specific risk factors for multidrug-resistant organisms (MDROs). Generally, regimens targeting Staphylococcus aureus, Pseudomonas aeruginosa, and gram-negative bacilli are designed for HAP and VAP.
For HAP/VAP patients without MDRO risk factors, a common empiric regimen includes piperacillin/tazobactam plus cefepime plus levofloxacin. In patients with MDRO risk factors, preferred regimens often involve an aminoglycoside combined with imipenem, meropenem, aztreonam, piperacillin/tazobactam, ceftazidime, or cefepime.[3] Antibiotic stewardship and ongoing monitoring for treatment response are essential components of HAP/VAP management, particularly in light of increasing antibiotic resistance and its impact on alterations in health diagnosis pneumonia and treatment outcomes.
Differential Diagnosis
The differential diagnosis of pneumonia is broad and includes conditions that mimic pneumonia clinically and radiographically. These include asthma and chronic obstructive pulmonary disease (COPD) exacerbations, pulmonary edema, lung malignancies, non-infectious lung consolidation processes (e.g., atelectasis, organizing pneumonia), pleuritis, pulmonary embolism, foreign body aspiration, bronchiectasis, bronchiolitis, and others. In cases where differentiation is challenging, biomarkers such as C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), procalcitonin levels, leukocyte count, and body temperature may aid in establishing the correct diagnosis.[18] Careful consideration of the differential diagnosis is crucial to avoid misdiagnosis and ensure appropriate management, representing a key aspect of alterations in health diagnosis pneumonia.
Complications
Complications of untreated or inadequately treated pneumonia can be severe and life-threatening. These include respiratory failure, sepsis, metastatic infections (spread of infection to other organs), empyema, lung abscess, and multi-organ dysfunction syndrome (MODS).[7] Early diagnosis and appropriate treatment are essential to prevent these complications and improve patient outcomes.
Enhancing Healthcare Team Outcomes
Pneumonia remains a significant cause of morbidity and mortality, presenting diagnostic and management challenges, particularly in complex patients with comorbidities and underlying lung disease. Effective interprofessional collaboration is crucial to optimize patient outcomes. A strong interplay among physicians, ICU teams, nursing staff, pharmacists, and radiologists is essential. Nurses play a vital role in continuous patient monitoring, recording temperature fluctuations and other vital signs critical for physician assessment and diagnosis. In the ICU setting, nursing staff is paramount in maintaining hygienic ventilator circuits and implementing aspiration prevention strategies. Pharmacists ensure accurate medication dosing and drug selection, and infectious disease pharmacists can provide specialized expertise in antibiotic stewardship and dosing of complex antibiotics like vancomycin, often consulting on antibiogram data to guide antimicrobial choices. Radiologists are central in interpreting the diverse radiological findings associated with different pneumonia types, providing expert image analysis.
Current guidelines for CAP, VAP, and HAP management, jointly issued by the American Thoracic Society and the Infectious Diseases Society of America, are periodically updated to reflect the latest evidence and best practices.[2], [3] [Level 1] An interprofessional team approach to pneumonia care is essential for optimizing patient outcomes, facilitating quicker recovery, and improving overall patient safety. [Level 5] This collaborative model underscores the importance of integrated care in alterations in health diagnosis pneumonia and its management.
Review Questions
Figure
Chest X-ray Illustrating Ventilator-Associated Aspiration Pneumonia: A Diagnostic Imaging Tool for Mechanically Ventilated Patients. This image showcases the typical radiographic appearance of ventilator-associated aspiration pneumonia, emphasizing the importance of chest radiography in diagnosing pneumonia in ventilated patients. Melvil, Public Domain, via Wikimedia Commons.
Figure
Chest Radiograph Demonstrating Aspiration Pneumonia: Alveolar Infiltrates in the Right Lower Lobe. This chest x-ray clearly shows alveolar infiltrates in the superior segments of the right lower lobe, a characteristic finding in aspiration pneumonia, highlighting radiographic alterations in health diagnosis pneumonia. Contributed by O Chaigasame
Figure
Chest X-ray of Mycobacterium Avium-Intracellulare Pneumonia: Illustrating Pulmonary Manifestations of MAC Infection. This image presents a chest x-ray revealing Mycobacterium Avium-Intracellulare (MAC) pneumonia, demonstrating the radiological appearance of this specific type of bacterial pneumonia and its unique alterations in health diagnosis pneumonia. Contributed by S Bhimji, MD
Figure
Lung Pneumonia With Fibrosis: Radiographic Evidence of Pulmonary Fibrosis in Pneumonia. This chest x-ray shows lung pneumonia complicated by fibrosis, highlighting the long-term pulmonary sequelae that can occur post-pneumonia and the alterations in health diagnosis pneumonia in chronic cases. Contributed by Fabiola Farci, MD
References
1.Mackenzie G. The definition and classification of pneumonia. Pneumonia (Nathan). 2016;8:14. [PMC free article: PMC5471962] [PubMed: 28702293]
2.Mandell LA, Wunderink RG, Anzueto A, Bartlett JG, Campbell GD, Dean NC, Dowell SF, File TM, Musher DM, Niederman MS, Torres A, Whitney CG., Infectious Diseases Society of America. American Thoracic Society. Infectious Diseases Society of America/American Thoracic Society consensus guidelines on the management of community-acquired pneumonia in adults. Clin Infect Dis. 2007 Mar 01;44 Suppl 2(Suppl 2):S27-72. [PMC free article: PMC7107997] [PubMed: 17278083]
3.Kalil AC, Metersky ML, Klompas M, Muscedere J, Sweeney DA, Palmer LB, Napolitano LM, O’Grady NP, Bartlett JG, Carratalà J, El Solh AA, Ewig S, Fey PD, File TM, Restrepo MI, Roberts JA, Waterer GW, Cruse P, Knight SL, Brozek JL. Executive Summary: Management of Adults With Hospital-acquired and Ventilator-associated Pneumonia: 2016 Clinical Practice Guidelines by the Infectious Diseases Society of America and the American Thoracic Society. Clin Infect Dis. 2016 Sep 01;63(5):575-82. [PMC free article: PMC4981763] [PubMed: 27521441]
4.Canadian Critical Care Trials Group. A randomized trial of diagnostic techniques for ventilator-associated pneumonia. N Engl J Med. 2006 Dec 21;355(25):2619-30. [PubMed: 17182987]
5.Gharib AM, Stern EJ. Radiology of pneumonia. Med Clin North Am. 2001 Nov;85(6):1461-91, x. [PubMed: 11680112]
6.Bartlett JG. Diagnostic tests for agents of community-acquired pneumonia. Clin Infect Dis. 2011 May;52 Suppl 4:S296-304. [PubMed: 21460288]
7.Sattar SBA, Nguyen AD, Sharma S. StatPearls [Internet]. StatPearls Publishing; Treasure Island (FL): Feb 26, 2024. Bacterial Pneumonia. [PubMed: 30020693]
8.Jain S, Self WH, Wunderink RG, Fakhran S, Balk R, Bramley AM, Reed C, Grijalva CG, Anderson EJ, Courtney DM, Chappell JD, Qi C, Hart EM, Carroll F, Trabue C, Donnelly HK, Williams DJ, Zhu Y, Arnold SR, Ampofo K, Waterer GW, Levine M, Lindstrom S, Winchell JM, Katz JM, Erdman D, Schneider E, Hicks LA, McCullers JA, Pavia AT, Edwards KM, Finelli L., CDC EPIC Study Team. Community-Acquired Pneumonia Requiring Hospitalization among U.S. Adults. N Engl J Med. 2015 Jul 30;373(5):415-27. [PMC free article: PMC4728150] [PubMed: 26172429]
9.Hage CA, Knox KS, Wheat LJ. Endemic mycoses: overlooked causes of community acquired pneumonia. Respir Med. 2012 Jun;106(6):769-76. [PubMed: 22386326]
10.Weiner LM, Webb AK, Limbago B, Dudeck MA, Patel J, Kallen AJ, Edwards JR, Sievert DM. Antimicrobial-Resistant Pathogens Associated With Healthcare-Associated Infections: Summary of Data Reported to the National Healthcare Safety Network at the Centers for Disease Control and Prevention, 2011-2014. Infect Control Hosp Epidemiol. 2016 Nov;37(11):1288-1301. [PMC free article: PMC6857725] [PubMed: 27573805]
11.Jones RN. Microbial etiologies of hospital-acquired bacterial pneumonia and ventilator-associated bacterial pneumonia. Clin Infect Dis. 2010 Aug 01;51 Suppl 1:S81-7. [PubMed: 20597676]
12.Ramirez JA, Wiemken TL, Peyrani P, Arnold FW, Kelley R, Mattingly WA, Nakamatsu R, Pena S, Guinn BE, Furmanek SP, Persaud AK, Raghuram A, Fernandez F, Beavin L, Bosson R, Fernandez-Botran R, Cavallazzi R, Bordon J, Valdivieso C, Schulte J, Carrico RM., University of Louisville Pneumonia Study Group. Adults Hospitalized With Pneumonia in the United States: Incidence, Epidemiology, and Mortality. Clin Infect Dis. 2017 Nov 13;65(11):1806-1812. [PubMed: 29020164]
13.Arnold FW, Wiemken TL, Peyrani P, Ramirez JA, Brock GN., CAPO authors. Mortality differences among hospitalized patients with community-acquired pneumonia in three world regions: results from the Community-Acquired Pneumonia Organization (CAPO) International Cohort Study. Respir Med. 2013 Jul;107(7):1101-11. [PubMed: 23660396]
14.Barbier F, Andremont A, Wolff M, Bouadma L. Hospital-acquired pneumonia and ventilator-associated pneumonia: recent advances in epidemiology and management. Curr Opin Pulm Med. 2013 May;19(3):216-28. [PubMed: 23524477]
15.Shorr AF, Zilberberg MD, Reichley R, Kan J, Hoban A, Hoffman J, Micek ST, Kollef MH. Validation of a clinical score for assessing the risk of resistant pathogens in patients with pneumonia presenting to the emergency department. Clin Infect Dis. 2012 Jan 15;54(2):193-8. [PubMed: 22109951]
16.Torres A, Niederman MS, Chastre J, Ewig S, Fernandez-Vandellos P, Hanberger H, Kollef M, Li Bassi G, Luna CM, Martin-Loeches I, Paiva JA, Read RC, Rigau D, Timsit JF, Welte T, Wunderink R. International ERS/ESICM/ESCMID/ALAT guidelines for the management of hospital-acquired pneumonia and ventilator-associated pneumonia: Guidelines for the management of hospital-acquired pneumonia (HAP)/ventilator-associated pneumonia (VAP) of the European Respiratory Society (ERS), European Society of Intensive Care Medicine (ESICM), European Society of Clinical Microbiology and Infectious Diseases (ESCMID) and Asociación Latinoamericana del Tórax (ALAT). Eur Respir J. 2017 Sep;50(3) [PubMed: 28890434]
17.Mbata GC, Chukwuka CJ, Onyedum CC, Onwubere BJ. The CURB-65 scoring system in severity assessment of Eastern Nigerian patients with community-acquired pneumonia: a prospective observational study. Prim Care Respir J. 2013 Jun;22(2):175-80. [PMC free article: PMC6443104] [PubMed: 23633130]
18.Castro-Guardiola A, Armengou-Arxé A, Viejo-Rodríguez A, Peñarroja-Matutano G, Garcia-Bragado F. Differential diagnosis between community-acquired pneumonia and non-pneumonia diseases of the chest in the emergency ward. Eur J Intern Med. 2000 Dec 20;11(6):334-339. [PubMed: 11113658]
Disclosure: Vardhmaan Jain declares no relevant financial relationships with ineligible companies.
Disclosure: Rishik Vashisht declares no relevant financial relationships with ineligible companies.
Disclosure: Gizem Yilmaz declares no relevant financial relationships with ineligible companies.
Disclosure: Abhishek Bhardwaj declares no relevant financial relationships with ineligible companies.
