pneumonia Flashcards
What is pneumonia?
Inflammation of the substance of the lungs, usually caused by bacteria.
Pneumonia can be classified in various ways, including anatomically and by setting.
What are the two main anatomical classifications of pneumonia?
Lobar pneumonia and bronchopneumonia.
These classifications denote the location of the inflammation within the lungs.
Define community-acquired pneumonia.
Pneumonia that occurs in the community or within the first 48 hours of hospitalization.
It can be typical or atypical.
What is the most common bacteria causing community-acquired pneumonia?
Streptococcus pneumoniae.
This organism is often the primary pathogen in cases of typical pneumonia.
Define hospital-acquired pneumonia.
Pneumonia that occurs after 48 hours of hospitalization.
It is often due to gram-negative organisms or Staphylococcus aureus.
What are common symptoms of pneumonia?
- Fever
- Cough with sputum
- Pleuritic chest pain
- Shortness of breath
- Signs of consolidation
- Pleural effusion
- Pleural rub
Symptoms can vary based on the type and severity of pneumonia.
What are risk factors for developing pneumonia?
- Extremes of age (under 16 or over 65)
- Underlying lung disease
- Smoking
- Alcohol use
- IV drug use
- Immunosuppressive drugs
- HIV
- Diabetes mellitus
- CKD
- Malnutrition
- Recent viral respiratory infection
These factors can increase susceptibility to pneumonia.
List typical causes of community-acquired pneumonia.
- Streptococcus pneumoniae
- Viruses
- Haemophilus influenzae
- Moraxella catarrhalis
- Staphylococcus aureus
- Aerobic gram-negative organisms (E. coli, Klebsiella)
- Anaerobes (often linked to aspiration)
Atypical causes include Mycoplasma pneumoniae, Legionella, and Chlamydia pneumoniae.
What pathogens are commonly associated with community-acquired pneumonia in healthy individuals?
- Streptococcus pneumoniae
- Mycoplasma pneumoniae
- Influenza A
- Chlamydia pneumoniae
These pathogens are often identified in previously healthy patients with pneumonia.
What are some complications of pneumonia?
- Abscess formation
- Pleural effusion
- Empyema
- Septicemia
These complications can arise due to untreated or severe cases of pneumonia.
Name some differential diagnoses for pneumonia.
- Pulmonary embolism
- Pulmonary edema or hemorrhage
- Bronchial carcinoma
- Hypersensitivity pneumonitis
- Diffuse parenchymal lung disease
Differentiating pneumonia from these conditions is crucial for appropriate treatment.
What investigations are used to confirm pneumonia?
- Chest x-ray
- Sputum Gram stain and culture
- CBC
- Urine antigen tests for Legionella and pneumococcus
- Cold agglutinins for Mycoplasma
- Serology for Mycoplasma
- ABG if SpO2 <92% or PaCO2 rising
These tests help confirm the diagnosis and assess severity.
What does the CURB-65 scoring system assess?
Severity of pneumonia based on:
* Confusion
* Urea >7 mmol/L
* Respiratory rate >30
* Blood pressure <90 systolic or <60 diastolic
* Age >65
Each factor scores 1 point, helping to guide treatment decisions.
What is the typical management for pneumonia?
- Analgesia for pleuritic pain
- Humidified oxygen if hypoxemic
- IV fluids
Management depends on the severity and type of pneumonia.
What is the first-line antibiotic therapy for outpatient CAP?
- Macrolide (e.g., clarithromycin)
- Amoxicillin if resistance is suspected
This combination addresses common pathogens effectively.
What factors increase the risk of antibiotic resistance in pneumonia patients?
- Age >65
- Comorbidities
- Immunosuppression
- Prior antibiotic use in past 3–6 months
These factors necessitate careful selection of antibiotics.
What treatment is recommended for inpatient CAP?
- Macrolide plus ceftriaxone
- Or a respiratory fluoroquinolone (e.g., levofloxacin, moxifloxacin)
Hospitalized patients need more aggressive treatment due to potential complications.
What should be done if there is a risk of pseudomonal infection?
Treat with fluoroquinolone plus:
* Piperacillin/tazobactam
* Imipenem
* Meropenem
* Cefepime
This approach targets resistant organisms often seen in severe cases.
What is the treatment for suspected MRSA pneumonia?
Use vancomycin or linezolid.
These antibiotics are effective against methicillin-resistant strains.
What is required for anaerobic coverage in pneumonia treatment?
Use metronidazole.
This is especially important in cases of aspiration pneumonia.
What organism-specific clues are associated with Streptococcus pneumoniae?
- Rust-colored sputum
- High fever
- Pleuritic chest pain
- Acute flu-like onset
- Positive blood cultures
These features can help in identifying the pathogen.
What are some characteristics of Mycoplasma pneumonia?
- Mild illness in young patients
- Radiographic findings worse than symptoms
- Extrapulmonary features
- Normal WBC
These traits are key in differentiating Mycoplasma from other pathogens.
What symptoms are associated with Legionella pneumonia?
- Severe disease
- Neuro and GI symptoms
- Hyponatremia
- High liver enzymes
These symptoms can indicate a more serious infection.
What is an important clue for pneumonia in alcoholics?
Klebsiella or TB infection.
These organisms are more likely to affect this population due to lifestyle factors.
What is a common pathogen in smokers or COPD patients?
- Haemophilus influenzae
- Moraxella
- Streptococcus pneumoniae
These bacteria are frequently isolated in these individuals.
What organisms are linked to aspiration pneumonia?
- Anaerobes
- Gram-negative organisms
Aspiration can lead to infections from the oral flora.
What is a key feature of pneumonia caused by Staphylococcus aureus?
It is often post-influenza.
This pattern highlights the opportunistic nature of Staphylococcus aureus following viral infections.
What symptom is associated with Chlamydia pneumonia?
Hoarseness.
This symptom can be a distinguishing feature of this infection.
