-
Chest x-ray
-
Consideration of alternative diagnoses (eg, heart failure, pulmonary embolism, inflammatory lung conditions)
Bạn đang xem: Community-Acquired Pneumonia
-
Sometimes identification of pathogen
-
Xem thêm : Retinol and Laser Hair Removal – When Can You Use Retinols?
Evaluation of severity and risk stratification
Diagnosis of pneumonia is suspected on the basis of clinical presentation and infiltrate seen on chest x-ray. When there is high clinical suspicion of pneumonia and the chest x-ray does not reveal an infiltrate, doing computed tomography (CT) or repeating the chest x-ray in 24 to 48 hours is recommended.
Severity of the pneumonia is estimated using a variety of clinical and laboratory factors (see Risk Stratification), which are sometimes organized using quantitative scoring systems.
Typically, testing includes oxygen saturation, complete blood count, and a basic or complete metabolic profile.
Xem thêm : Bultos de grasa en la espalda: ¿qué provoca su aparición?
Differential diagnosis in patients presenting with pneumonia-like symptoms includes acute bronchitis and exacerbation of chronic obstructive pulmonary disease (COPD), which can be distinguished from pneumonia by the absence of infiltrates on chest x-ray. Other disorders such as heart failure, organizing pneumonia, and hypersensitivity pneumonitis should be considered, particularly when findings are inconsistent. The most serious common misdiagnosis is pulmonary embolism, which may be more likely in patients with acute onset of dyspnea, minimal sputum production, no accompanying upper respiratory infection or systemic symptoms, and risk factors for thromboembolism (see table Risk Factors for Deep Venous Thrombosis and Pulmonary Embolism); thus, testing for pulmonary embolism should be considered in patients with such symptoms and risk factors.
Quantitative cultures of bronchoscopic or suctioned specimens, if they are obtained before antibiotic administration, can help distinguish between bacterial colonization (ie, presence of microorganisms at levels that provoke neither symptoms nor an inflammatory response) and infection. However, bronchoscopy is usually done only in patients receiving mechanical ventilation or for those with other risk factors for unusual microorganisms or complicated pneumonia (eg, immunocompromise, failure of empiric therapy).
Distinguishing between bacterial and viral pneumonias is challenging. Many studies have investigated the utility of clinical, imaging, and routine blood tests, but no test is reliable enough to make this differentiation. Even identification of a virus does not preclude concomitant infection with a bacteria; therefore, antibiotics are indicated in almost all patients with a community-acquired pneumonia.
In outpatients with mild pneumonia, with the exception of COVID-19 testing and influenza testing during influenza season, no further diagnostic testing is needed (see table Risk Stratification for Community-Acquired Pneumonia). In patients with moderate or severe pneumonia, a white blood cell count and measurement of electrolytes, blood urea nitrogen (BUN), and creatinine are useful to classify risk and hydration status. Pulse oximetry or arterial blood gas (ABG) testing should also be done to assess oxygenation. For patients with moderate or severe pneumonia who require hospitalization, 2 sets of blood cultures are obtained to assess for bacteremia and sepsis. Additional tests indicated in these patients include sputum Gram stain and culture, urine pneumococcal and Legionella antigen testing, respiratory viral panel by multiplex polymerase chain reaction (PCR), and HIV screening. In selected severely ill patients, especially if they are immunocompromised, bronchoscopy to obtain lower airway specimens is indicated (1).
Nguồn: https://blogtinhoc.edu.vn
Danh mục: Info
