Pneumonia and Pneumonitis Flashcards
What are the major types of pneumonia?
- Community-acquired (CAP)
- Hospital-acquired (HAP)
- Ventilator-associated (VAP)
- Atypical pneumonia (walking pneumonia)
- Aspiration pneumonia
What is the most common cause of pneumonia in neonates (<4 weeks)?
Group B Streptococcus > E. coli > Listeria
What are the most common causes of pneumonia in pediatrics, aged 4 weeks to 18 years?
RSV (viral), Mycoplasma pneumoniae, Chlamydia trachomatis (infants 3 years), Chlamydia pneumoniae (school-aged), Strep pneumoniae.
Children 1 month to 4 months most commonly get pneumonia from … ?
Viruses (most common overall) – Respiratory Syncytial Virus (RSV) is the leading cause. Bacterial causes fall after viral, with Streptococcus pneumoniae being the most common bacterial cause. Chlamydia trachomatis (afebrile pneumonia in neonates and a very common cause in 3 year olds), then Bordetella pertussis (if unvaccinated).
Which pathogens commonly infect children aged 4 months to 5 years and cause pneumonia?
Viruses are the most common overall (RSV, Influenza, Parainfluenza, Adenovirus), followed by bacterial, where Streptococcus pneumoniae is the most common bacterial cause, followed by Haemophilus influenzae type B (if unvaccinated). The pathogen that is the most likely to cause atypical pneumonia is Mycoplasma pneumoniae, however, this form is a less common cause for pneumonia in this group (but still possible).
What are the most common causes for pneumonia between 5 years to 18 years old?
Mycoplasma pneumoniae (most common), followed by Streptococcus pneumoniae (most common typical bacterial cause), and finally viral (RSV, Influenza, Parainfluenza, Adenovirus), however, viral is less common in this age group compared to younger children).
What are the most common causes of pneumonia in adults (18-40 years)?
The most common overall is Mycoplasma pneumoniae and is associated with walking pneumonia (Chlamydia pneumoniae can be implicated as well, but less commonly). The most common bacterial cause is Streptococcus pneumoniae and this is associated with lobar pneumonia, high fever, productive cough. Common in seasonal outbreaks are viral causes for pneumonia like Influenza, RSV, and Adenovirus.
What are the most common causes of pneumonia in older adults (40-65 years)?
The most common cause overall in this group is a bacterial, Strep pneumoniae, which happens to be the most common cause of pneumonia in all adults (overall) because younger adults tend to get walking (atypical) pneumonia more frequently than pneumonia secondary to Strep pneumoniae. Strep pneumoniae presents with lobar consolidation, high fever, and productive cough. In patients who smoke or have lung disease like COPD, the most common organism is Haemophilus influenzae. Anaerobes leading to pneumonia is commonly seen with aspiration pneumonia. Mycoplasma pneumoniae is still a possibility, but less common than Strep pneumoniae. Finally, viral causes (Influenza, RSV, Parainfluenza, Adenovirus) more commonly are seasonal or with outbreaks.
What are the most common causes of pneumonia in elderly (>65 years)?
Strep pneumoniae > Influenza virus > Anaerobes > H. influenzae > Gram-negative rods
When is it appropriate to consider Listeria as a cause of pneumonia in the elderly population?
- Immunocompromised elderly patients
- Severe underlying conditions (e.g., malignancy, end-stage renal disease, diabetes)
- Nursing home residents or patients with chronic illnesses
What condition can be seen in the elderly population that causes pneumonia secondary to nutritional deficits?
Elderly patients with impaired nutritional status may develop a secondary hypogammaglobulinemia, and are at risk of recurrent infections due to encapsulated bacteria (eg, Streptococcus pneumoniae).
What condition can cause of persistent/recurrent lung infections in the elderly, leading to infection in the upper or apical lobes?
Pulmonary tuberculosis is a potential cause of persistent/recurrent lung infections in the elderly. In the majority of cases
(>80%), tuberculosis will involve the upper/apical lung regions rather than the mid and lower lobes.
What is the most common cause of pneumonia in alcoholics?
Klebsiella pneumoniae and anaerobes (aspiration pneumonia).
What is the most common cause of pneumonia in IV drug users?
Staph aureus, Strep pneumoniae, and Pseudomonas
What are the most common causes of pneumonia in cystic fibrosis?
Staph aureus when the patient is less than 20 years old
Pseudomonas aeruginosa when the patient is older than 20 years old
What is a less common but more aggressive colonizer compared to Pseudomonas aeruginosa in cystic fibrosis?
Burkholderia cepacia. Importantly, this can exclude patients from a lung transplantation.
What are the pathogens responsible for pneumonia in post-viral infections?
Strep pneumoniae, Staph aureus, Haemophilus influenzae.
What are the common microbes responsible for pneumonia in aspiration?
Anaerobes (Peptostreptococcus, Fusobacterium, Prevotella, Bacteroides). They commonly can form lung abscesses.
What are the general symptoms of pneumonia?
Fever, chills, productive cough, dyspnea, pleuritic chest pain.
What physical exam findings tend to be found with pneumonia?
Rales, dullness to percussion, increased tactile fremitus, bronchial breath sounds.
What is the gold standard for pneumonia diagnosis?
Chest X-ray (CXR).
What are the common chest X-ray findings in pneumonia?
Lobar consolidation (typical bacteria), interstitial infiltrates (atypical pathogens), cavitation (anaerobes, TB, fungal infections).
What is the role of sputum culture in pneumonia?
Used in severe pneumonia, not always required for mild outpatient cases.
What is the role of urine antigen tests in pneumonia?
Legionella and Strep pneumoniae can be diagnosed via urine antigen testing (according to a video on Osmosis, so can Chlamydia).
What is the purpose of CURB-65 criteria?
This is used to determine pneumonia severity and guide management.
Each factor is 1-point, and more than 2 points requires inpatient stay:
- Confusion
- Uremia (BUN >19)
- Respiratory rate >30
- BP <90/60
- Age >65.
What are the antibiotics given for outpatient treatment for community-acquired pneumonia (CAP)?
- Macrolide (azithromycin) or doxycycline.
- If recent antibiotic use, or high resistance use beta-lactam (Amoxicillin) + macrolide or respiratory fluoroquinolone (levofloxacin, moxifloxacin).
What is the threshold for inpatient treatment for community acquired pneumonia?
2 points on CURB-65
How is Inpatient treatment for CAP (non-ICU) treated?
Beta-lactam (ceftriaxone, ampicillin-sulbactam) + macrolide (azithromycin) OR fluoroquinolone (levofloxacin, moxifloxacin).
What is the threshold for ICU management for CAP?
Usually 3 points on CURB-65.
ICU treatment for CAP
Beta-lactam + macrolide OR Beta-lactam + fluoroquinolone.
Cover MRSA with vancomycin or linezolid if the patient has signs of septic shock or mechanically ventilated.
Cover pseudomonas for patients with structural lung disease such as bronchiectasis with Pip/tazo, cefepime, or meropenem.
What are the common causes of HAP and VAP?
MRSA (Staph aureus), Pseudomonas, Gram-negative rods (E. coli, Klebsiella, Enterobacter).
What is the empiric antibiotic therapy for HAP/VAP?
Vancomycin or linezolid (MRSA) + Pip/tazo, cefepime, or meropenem (Pseudomonas).
What is the recommended imaging modality for recurrent pneumonia?
Computed tomography (CT) scan is frequently performed in patients with recurrent pneumonia to identify a mass lesion in the lung or airway. It can also help identify atypical infections as well as noninfectious pulmonary disorders. Additionally, bronchoscopy and biopsy can be useful in patients with recurrent pneumonia to rule out endobronchial obstruction. This is especially helpful in patients with known or suspected malignancy.
What are the most common causes of atypical pneumonia?
Mycoplasma pneumoniae, Chlamydia pneumoniae, Legionella, Coxiella, Viruses.
What are the distinguishing characteristics for Mycoplasma pneumoniae?
Most common in young adults (ages 5-40), especially, college students in dormitories, Military recruits, and School-aged children.
How is Mycoplasma pneumoniae treated?
Macrolides (azithromycin, clarithromycin) or doxycycline
What are the risk factors for Legionella pneumonia?
Contaminated water sources, smoking, immunosuppressed, lung disease diseases, chronic kidney disease, diabetes, or recent hospitalization.
What are the distinguishing features of Legionella pneumonia?
High fever, GI symptoms (diarrhea), confusion, hyponatremia.
What is the treatment for Legionella pneumonia?
Macrolides (azithromycin), Doxycycline or fluoroquinolones (levofloxacin).
What are the most common aspiration pneumonia organisms?
Anaerobes (Peptostreptococcus, Fusobacterium, Prevotella, Bacteroides).
What can develop from aspiration pneumonia?
Lung abscess, which is a necrotizing pneumonia with cavitation and pus formation.
What are the most common causes of lung abscesses?
Anaerobes (Peptostreptococcus, Fusobacterium, Prevotella, Bacteroides). Additionally MRSA and Klebsiella can cause lung a lung abscess.
How are lung abcessess diagnosed?
CXR or CT, showing pulmonary infiltrate with a cavitary region
What is the empiric treatment of lung abscess?
Clindamycin or ampicillin-sulbactam or carbapenem.
What is the general vaccination recommendations for pneumonia prevention?
Pneumococcal vaccine for adults >65, high-risk patients, and yearly influenza vaccine.
What is pneumonitis?
Inflammation of the lung parenchyma due to non-infectious causes such as aspiration, hypersensitivity reactions, medications, radiation, or environmental exposures.
How does pneumonitis differ from pneumonia?
Pneumonitis is non-infectious lung inflammation, whereas pneumonia is infectious. Pneumonitis presents with dry cough and dyspnea, while pneumonia has productive cough, fever, and purulent sputum.
What are the major types of pneumonitis?
Aspiration pneumonitis, hypersensitivity pneumonitis, radiation pneumonitis, drug-induced pneumonitis, and environmental/exposure pneumonitis.
What are common symptoms of pneumonitis?
Nonproductive cough, dyspnea, fever, tachypnea, hypoxemia, and bibasilar rales.
What causes hypersensitivity pneumonitis?
Organic dust exposure such as moldy hay (Farmer’s lung) or bird droppings (Bird Fancier’s lung).
What medications can cause drug-induced pneumonitis?
Amiodarone, methotrexate, bleomycin, nitrofurantoin, checkpoint inhibitors like nivolumab.
How does radiation pneumonitis occur?
Develops weeks to months after radiation therapy for breast cancer, lung cancer, or lymphoma.
For hypersensitivity pneumonitis, drug-induced pneumonitis, and radiation pneumonitis, what is done first to diagnose?
First: Pulmonary Function Tests (PFTs)
Second: High-Resolution CT (HRCT)
What are the pulmonary function test (PFT) findings in pneumonitis?
Restrictive lung disease pattern (↓ FEV1, ↓ FVC, normal/increased FEV1/FVC) with decreased DLCO.
What are key findings on chest imaging for pneumonitis?
Diffuse ground-glass opacities, bilateral patchy infiltrates, upper lobe fibrosis (chronic cases), honeycombing in late-stage disease.
What is the first-line treatment for radiation pneumonitis?
Corticosteroids and oxygen therapy.
How can hypersensitivity pneumonitis be confirmed?
Positive IgG antibodies against specific organic antigens and lymphocytic predominance on bronchoalveolar lavage.
How is hypersensitivity pneumonitis managed?
Antigen avoidance and corticosteroids for severe cases.
How is drug-induced pneumonitis managed?
Discontinue the offending drug and provide supportive care.
How can exposure-related pneumonitis be prevented?
Avoid exposure to known causative agents (e.g., mold, bird droppings, asbestos).
What are common causes of aspiration pneumonitis?
Post-anesthesia, Mechanical ventilation, GERD, Gastric acid aspiration, dysphagia, altered mental status, neurological disorders like Parkinson Disease and post-stroke, as well as altered consciousness (seizure or alcohol).
How is aspiration pneumonitis managed, especially in patients with chronic diseases?
Supportive care with oxygen therapy, airway suctioning if needed; no routine antibiotics unless secondary infection occurs. For patients with neurological disorders like Parkinson’s disease, oropharyngeal symptoms (dysarthria and drooling), and recurrent right-sided pneumonia, they typically have features of chronic aspiration. Nearly 90% of individuals with Parkinson’s disease suffer from dysphagia during the course of the disease, and the resulting aspiration pneumonia is a leading cause of death. Aspiration pneumonia generally requires more aggressive intervention than typical community-acquired pneumonia. Aspiration often involves polymicrobial and anaerobic organisms, and patients with aspiration pneumonia often have poor underlying functional and nutritional status. Initial management includes blood and sputum cultures with initiation of broad-spectrum antibiotics with anaerobic coverage (eg, clindamycin). Once the patient has been stabilized, a bedside swallowing assessment may be helpful. Definitive diagnosis is made with a videofluoroscopic swallowing study. Based on results, a multidisciplinary dysphagia rehabilitation program can be initiated, usually with input from the dietary service, nursing, and speech therapy. Specific interventions typically include thickened liquids and modified swallowing techniques.
