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).
A 53-year-old man presents to the emergency department due to chest pain with inspiration, shortness of breath, and a cough productive of yellow sputum. His symptoms developed two days prior and have progressively worsened. The patient was in good health prior to returning from an overseas trip to Europe five days ago. Medical history is notable for atrial fibrillation and coronary artery disease. Temperature is 39.2 °C (102.6 °F), blood pressure is 125/81 mmHg, pulse is 114/min, respiratory rate is 24/min, and oxygen saturation is 90% on room air. Physical examination is notable for decreased breath sounds in the left lower lung. Which of the following would be most helpful for confirming this patient’s diagnosis?
A) Serum alpha-fetoprotein levels
B) Sputum culture and Gram stain
C) CT angiography of the chest
D) Frontal and lateral view chest radiographs
E) Quantiferon gold assay
The diagnosis of pneumonia can be made based on a patient’s history, physical examination, and laboratory studies, and is confirmed with imaging. Chest radiograph is the first-line imaging modality. This patient presents with dyspnea, pleuritic chest pain, and a productive cough. Vital signs are notable for fever, tachypnea, and decreased oxygen saturation. Lung exam is significant for decreased breath sounds in the left lower lung field. In combination, these findings are most suggestive of community-acquired pneumonia. Chest radiography, ideally both frontal and lateral views, would be most helpful for confirming the patient’s condition. Pneumonia is an infection of the lung parenchyma that results in inflammation of one or both lungs. The diagnosis is made based on a combination of the history, physical examination, and laboratory studies. It is typically confirmed with chest imaging. Laboratory studies such as a complete blood count and arterial blood gas are often ordered. For imaging, chest radiography is the first-line modality. A CT scan of the chest can be obtained if there is strong clinical suspicion for pneumonia but the chest radiograph is negative. Once a diagnosis has been made, patients should be started on empiric antibiotics. This is typically a beta-lactam plus a macrolide, though a macrolide, doxycycline, or amoxicillin alone can be used in certain patients with mild CAP. Supplemental oxygen should be given to maintain oxygen saturation levels above 92%.
What are the common chest X-ray findings in typical (bacterial) pneumonia?
Lobar consolidation (typical bacteria).
What are the common chest X-ray findings in atypical pneumonia?
interstitial infiltrates (atypical pathogens)
What are the common chest X-ray findings in pneumonia secondary to anaerobes, TB, fungal infections?
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), a common complication of ARDS.
What should be the first diagnostic step in VAP?
An increased requirement for ventilatory support (going from 5 to 10 mmHg on PEEP, increasing FiO2, with lowering oxygen levels) is consistent with ventilator-associated pneumonia (VAP), VAP can develop after ≥ 48 hours of mechanical ventilation and is most commonly caused by microaspiration of virulent oropharyngeal organisms (eg, Escherichia coli, Streptococcus species). Other signs of VAP include leukocytosis, tachypnea, and decreased oxygenation. Due to the nonspecific nature of its presentation and the increasing prevalence of drug-resistant organisms, respiratory sampling is necessary to confirm the diagnosis and appropriately tailor antibiotic therapy. Options include bronchoalveolar lavage or tracheobronchial aspiration. Once sampling has been performed, empiric antibiotics can be initiated while awaiting culture data. The specific regimen depends on individual risk factors for multidrug-resistant organisms and typically includes gram-positive and gram-negative coverage. Patients with risk factors for resistant pathogens should receive coverage for methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa.
What is the empiric antibiotic therapy for HAP/VAP?
Vancomycin or linezolid (MRSA) + Pip/tazo, cefepime, or meropenem (Pseudomonas).
What is the best approach for VAP following positive cultures but declining condition?
Change Abx and assess for VAP complications such as abscess or empyema.
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. Consolidations and walled off abscesses generally takes 7-14 days, patients usually present with subacute symptoms. Common manifestations include fever, dyspnea, and cough productive of sour-tasting sputum. Chest imaging usually shows a fluid-filled space with an air-fluid level amid a pulmonary consolidation. Treatment with antibiotics (eg,
ampicillin-sulbactam) is generally curative. Aspiration is common in individuals who have impaired cough or gag reflex due to periods of altered sensorium from seizure disorder, alcohol/substance use disorder, delirium, or dementia (eg, vascular dementia). Advanced age, poor dentition, and esophageal dysmotility also increase risk.
How is a lung abscess diagnosed?
CXR or CT, showing pulmonary infiltrate with a cavitary region
What techniques can help prevent aspiration pneumonia?
To prevent recurrent aspiration, patients with risk factors for aspiration should undergo a full speech and swallow evaluation. This evaluation is typically performed at the bedside; the patient is observed while ingesting liquids and solids of different consistencies. Modifications to position (eg, chin tuck) and diet (eg, thickened liquids) can often prevent additional episodes.
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.
An 83-year-old man presents to the emergency department for evaluation of shortness of breath. EMS reports that the patient was eating dinner when he suddenly started coughing and developed difficulty breathing. Past medical history includes Parkinson disease, hypertension, and hyperlipidemia. Temperature is 36.3°C (97.3°F), pulse is 120/min, blood pressure is 177/83 mmHg, respiratory rate is 18/min and oxygen saturation is 77% on room air. Physical exam shows an elderly patient unable to follow commands. Respiratory accessory muscle use, perioral cyanosis, and poor dental hygiene are noted. Which of the following is the best next step in management?
A) Administer ceftriaxone and azithromycin
B) Obtain ECG
C) Rapid sequence intubation
D) Administer albuterol nebulizer
E) Bi-level positive airway pressure
Patients with suspected aspiration pneumonia/pneumonitis should first have their airway, breathing, and circulation evaluated. In patients with unstable vital signs and those at high risk for respiratory failure, endotracheal intubation and mechanical ventilation should be performed. This patient presents with acute onset shortness of breath. Given that the shortness of breath occurred abruptly while eating, this is likely an acute aspiration of Gl contents, likely causing aspiration pneumonitis. Given the patient’s unstable vital signs and concern for airway compromise, the next best step in management is endotracheal intubation. Aspiration pneumonia and pneumonitis typically occur in individuals with impaired swallowing function or a decreased level of consciousness. In general, aspiration pneumonia occurs due to microaspirations of oropharyngeal contents, which are frequently colonized by pathogenic bacteria (most commonly Streptococcus pneumoniae, Staphylococcus aureus, and Haemophilus influenzae). Anaerobic bacteria may also be present. In general, aspiration (chemical) pneumonitis occurs due to aspiration of a large volume of sterile acidic gastric content, resulting in subsequent lung inflammation. Aspiration (chemical) pneumonitis can also predispose to aspiration pneumonia. Patients with symptoms suggestive of aspiration pneumonia/pneumonitis should first have their airway, breathing, and circulation evaluated. All unstable patients should have IV access established and continuous vital sign monitoring. Patients may require oropharyngeal or nasotracheal suctioning. Patients with normal mental status may benefit from noninvasive ventilation (e.g. bilevel positive airway pressure or high flow nasal cannula). Patients with findings of impending respiratory arrest, including persistent hypoxia, cyanosis, and altered mental status, should undergo endotracheal intubation and mechanical ventilation.
A 79-year-old woman comes to the emergency department from an assisted living facility due to shortness of breath, cough, and fever. Past medical history is significant for dementia, prior right MCA stroke, hypertension, and diabetes mellitus. Temperature is 39.0°C (102.2°F), pulse is 108/min, blood pressure is 114/53 mmHg, respirations are 16/min, and oxygen saturation is 92% on room air. Physical examination shows a frail-appearing patient with poor dentition.
Coarse lung sounds are auscultated over the right lung base. The patient is unable to pass a bedside swallow evaluation. Which of the following elements would favor a diagnosis of aspiration pneumonia over aspiration (chemical) pneumonitis?
A) Recent administration of general anesthesia
B) Gradual onset of symptoms
C) Infiltrates in the dependent zones of the lungs
D) Fever
E) History of alcohol use disorder
Aspiration pneumonia and aspiration pneumonitis share many overlapping clinical features. A key differentiating clinical feature is that aspiration pneumonia tends to occur gradually in patients with impaired swallowing function, whereas aspiration pneumonitis tends to occur acutely after an inciting event. This patient presents with cough, shortness of breath, and fever without an acute inciting event. Examination is significant for rales over the right lung base, and the patient is unable to pass a bedside swallow evaluation. Together, these findings are concerning for aspiration pneumonia. In general, symptoms in aspiration pneumonia develop gradually, whereas symptoms typically occur acutely in aspiration (chemical) pneumonitis. Aspiration pneumonia occurs due to microaspiration of oropharyngeal contents and takes time for the pneumonia to develop, hence the gradual onset of symptoms. Aspiration pneumonitis, on the other hand, occurs due to large volume aspiration of sterile gastric contents. The acidic gastric contents cause an abrupt chemical irritation to the lungs, resulting in severe inflammation and the acute development of symptoms. Aspiration pneumonia and aspiration pneumonitis share many overlapping clinical features. Symptoms include chest discomfort, shortness of breath, cough, and fever. Physical examination may show labored breathing; rales or decreased breath sounds are usually auscultated in the gravity-dependent portions of the lung (usually the right lung base). Aspiration pneumonia is typically associated with impaired swallowing conditions (e.g. stroke, seizure disorder, motor neuron disease). Aspiration pneumonitis typically develops acutely, is more likely to be a witnessed event, and usually follows a state of impaired consciousness (e.g. severe alcohol intoxication or following administration of general anesthesia).
A 75-year-old man is brought to the emergency department for evaluation of cough and shortness of breath. The patient’s spouse is at the bedside and reports that the patient currently resides in a nursing facility due to advanced multiple sclerosis. The patient has had increased difficulty swallowing over the past week. Temperature is 39.0°C (102.2°F), pulse is 114/min, blood pressure is 148/91 mmHg, and oxygen saturation is 95% on room air. Physical examination is significant for a chronically ill-appearing male with contractures in the bilateral upper and lower extremities. The patient is coughing but has no significant increased work of breathing. Blood work is obtained and is pending, and chest radiograph is shown below. Which of the following is the best next step in management?
A) Administer ampicillin-sulbactam
B) Bi-level positive airway pressure
C) Endotracheal intubation
D) Administer azithromycin
E) Bronchoscopy
Diagnosis of aspiration pneumonia can be made based on history, physical examination, and chest radiography findings that are consistent with aspiration. Ampicillin-sulbactam is an appropriate empiric antibiotic for treatment of aspiration pneumonia, especially if anaerobic bacteria are likely to be involved. This chronically ill patient presents for evaluation of cough, shortness of breath, and recent increased difficulty swallowing. Chest radiography shows a left lower lobe opacity, confirming aspiration pneumonia. Based on this patient’s clinical history and exam and radiography findings, the best treatment to initiate is ampicillin-sulbactam. Aspiration pneumonia and pneumonitis share many overlapping clinical features. Symptoms include chest discomfort, shortness of breath, cough, and fever. Physical examination may show labored breathing, and rales or decreased breath sounds may be heard in the gravity-dependent portions of the lung, typically the right lung base. Aspiration pneumonia is typically gradual in onset and is usually associated with impaired swallowing conditions (e.g. stroke, seizure disorder, motor neuron disease). Aspiration pneumonitis generally develops acutely, is more likely to be a witnessed event, and usually occurs in patients with impaired consciousness (e.g. severe alcohol intoxication or following administration of general anesthesia). Chest radiography along with history and physical exam can be used to make the diagnosis. Chest radiography can show infiltrates in the dependent portions of the lungs, primarily the right basal segments of the lower lobes (if the patient has been upright) or the superior segments of the lower lobe/posterior segments of the upper lobes (if the patient has been supine). Appropriate treatment for uncomplicated aspiration pneumonia includes ampicillin-sulbactam or respiratory fluoroquinolones (levofloxacin or moxifloxacin).
