Lower Respiratory Tract Infections Overview

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Questions and Answers

What distinguishes lower respiratory tract infections from upper respiratory tract infections?

LRTIs affect the nose and sinuses.

LRTIs affect the airways and lungs. (correct)

LRTIs are mainly caused by viruses.

LRTIs do not require antibiotic treatment.

Which organism is NOT typically associated with lower respiratory tract infections?

Escherichia coli (correct)

Streptococcus pneumoniae

Haemophilus influenzae

Staphylococcus aureus

Which of the following is classified as an acute lower respiratory tract infection?

Tuberculosis

Aspergillosis

Lung abscess

Aspiration pneumonia (correct)

What is the primary reason for the lack of investigation in typical bronchitis cases?

Common causes show known antibiotic sensitivity. Signup and view all the answers

How is whooping cough categorized in terms of infection significance in the UK?

A notifiable disease at all times. Signup and view all the answers

What is the CRB65 score that indicates a low risk of mortality (less than 1%) in adults with pneumonia?

0 Signup and view all the answers

What is the initial dose of Doxycycline for treating pneumonia in a penicillin-allergic patient?

200mg stat dose on day 1 Signup and view all the answers

Which antibiotic should be avoided in patients known to be allergic to penicillin?

Amoxicillin Signup and view all the answers

What is a side effect of Clarithromycin that a patient should be informed about?

Diarrhoea Signup and view all the answers

What does a CURB65 score of 2 indicate regarding mortality risk?

3% to 15% risk Signup and view all the answers

Which statement is true regarding antibiotic treatment in pneumonia patients?

Patients must complete the entire course of antibiotics. Signup and view all the answers

What vaccination is indicated yearly for a patient aged 65 and older?

Flu vaccination Signup and view all the answers

Which of the following symptoms is considered normal after completing pneumonia antibiotic treatment?

Persistent cough for 2-3 weeks Signup and view all the answers

Which pathogen is primarily associated with acute pneumonia in young children aged 2 months to 3 years?

Streptococcus pneumoniae Signup and view all the answers

What is a common complication of bacterial pneumonia in very young children?

Septic arthritis Signup and view all the answers

Which organism is associated with 'walking pneumonia' due to its mild and gradual onset?

Mycoplasma pneumoniae Signup and view all the answers

Which antibiotic class is ineffective against Mycoplasma pneumoniae due to its lack of a cell wall?

Cephalosporins Signup and view all the answers

What characterizes the sputum in a Klebsiella pneumoniae infection?

Jelly-like appearance Signup and view all the answers

Which organism can cause severe pneumonia and has the potential for intrabronchial spread, leading to systemic infection?

Legionella pneumophila Signup and view all the answers

What is a common diagnostic test for Legionella pneumophila infection?

Urinary antigen test Signup and view all the answers

Which treatment is recommended for Legionnaires' disease caused by Legionella pneumophila?

Macrolides Signup and view all the answers

What condition leads to the production of very viscid bronchial secretions and predisposes individuals to lung infections?

Cystic fibrosis Signup and view all the answers

In diagnosing community-acquired pneumonia (CAP), which of the following is NOT a common symptom?

Increased appetite Signup and view all the answers

Which of the following is true about Staphylococcus aureus in pneumonia?

It usually follows an influenza virus infection. Signup and view all the answers

What does the CURB-65 score assess in pneumonia patients?

Risk of mortality Signup and view all the answers

Which statement regarding Haemophilus influenzae is accurate?

Stays localized during infections. Signup and view all the answers

What findings would likely be present in a chest X-ray of a Legionella pneumophila pneumonia patient?

Infiltates with consolidation in one lobe Signup and view all the answers

What is the primary causative agent of acute bronchiolitis in children under 2 years?

Respiratory syncytial virus Signup and view all the answers

Which of the following is the recommended drug of choice for treating whooping cough?

Clarithromycin Signup and view all the answers

What percentage of pneumonia cases are caused by viral infections in children?

20-30% Signup and view all the answers

What is the significance of the CURB-65 score in pneumonia cases?

It assesses the severity of pneumonia. Signup and view all the answers

Which organism is most commonly associated with community-acquired pneumonia (CAP)?

Streptococcus pneumoniae Signup and view all the answers

What symptom is commonly associated with pneumonia that involves the presence of colored sputum?

Cough with green or brown phlegm Signup and view all the answers

What is one of the key risk factors for hospital-acquired pneumonia (HAP)?

Mechanical ventilation for more than 48 hours Signup and view all the answers

Which of the following organisms is associated with both community-acquired pneumonia (CAP) and hospital-acquired pneumonia (HAP)?

Klebsiella pneumoniae Signup and view all the answers

What laboratory test is commonly used for pneumonia diagnosis to identify causative bacteria?

Blood cultures Signup and view all the answers

What is a common presentation symptom of pneumonia that indicates the presence of pleural involvement?

Pleuritic chest pain Signup and view all the answers

Which of the following antibiotics is recommended for severe hospital-acquired pneumonia?

Co-amoxiclav IV Signup and view all the answers

What characterizes the treatment approach for acute bronchitis?

Symptomatic treatment only Signup and view all the answers

What aspect of atypical pneumonia pathogens makes beta-lactam antibiotics ineffective against them?

Absence of a cell wall Signup and view all the answers

What is the expected consequence of a severe underlying illness in relation to pneumonia risk?

Increased susceptibility to hospital-acquired pneumonia Signup and view all the answers

Study Notes

Lower Respiratory Tract Infections (LRTIs)

LRTIs affect the airways and lungs, distinct from URTIs affecting the nose, sinuses, ears, and throat.
Typical causative organisms include Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Staphylococcus aureus, Mycoplasma pneumoniae, Legionella, other Gram-negative bacilli (Pseudomonas, Klebsiella), fungi, and viruses (adenovirus, influenza).

LRTI Infections: Acute

Pneumonia: Inflammation of air sacs in the lungs. Types include community-acquired (CAP), hospital-acquired (HAP), aspiration pneumonia.
Acute Bronchitis: Inflammation of the trachiobroncheal tree, usually viral but can be secondary bacterial infection (Streptococcus pneumoniae or Haemophilus influenzae). Treatment is symptomatic.
Acute Bronchiolitis: Primarily caused by respiratory syncytial virus (RSV), affecting children under 2 years. Treatment is symptomatic, plus possible hospitalization.
Whooping Cough (Pertussis): Caused by Bordetella pertussis, a notifiable disease. Characterized by catarrhal illness progressing to a dry, non-productive cough with a "whoop" sound. Treatment is typically Clarithromycin (Erythromycin for pregnancy).

LRTI Infections: Chronic

Tuberculosis: Chronic lung infection.
Aspergillosis: Fungal infection of the lungs.
Lung Abscesses: Localized pus-filled pockets in the lungs.
Empyema: Pus in the pleural space surrounding the lungs.
Infections in Cystic Fibrosis Patients: Recurring infections, often with Pseudomonas aeruginosa, difficult to eradicate.

Investigations for LRTIs

Bronchitis: Investigations less common, as organism sensitivities are usually known.
Pneumonia: Chest X-ray, sputum culture, and laboratory tests are often indicated.

Pneumonia: CAP vs HAP

CAP: Illness originates outside a healthcare setting.
HAP: Develops 48-72 hours after hospital admission. Can include a wider range of bacteria, including more opportunistic ones (Pseudomonas aeruginosa, Klebsiella pneumoniae), and antibiotic resistance is a potential concern, but similar bacteria to CAP can cause it.
Risk Factors for HAP: Mechanical ventilation over 48 hours; ICU stay, longer hospital stays, comorbidities (immunocompromised, elderly, diabetic, COPD), and conditions that impair the gag reflex (brain injury).

Pneumonia: Causative Organisms

Bacteria (most common): Streptococcus pneumoniae, Haemophilus influenzae, Klebsiella pneumoniae, Pseudomonas.
Mycoplasma pneumoniae and Legionella pneumophila (Atypical pneumonia, are common, but don't have a cell wall, making b-lactam antibiotics ineffective).

Diagnostic Tools: Pneumonia

Cultures: Pleural fluid, sputum, blood, and urine samples. Important to note potential for antibiotic influence on results.
Serological tests: For atypical pneumonias (e.g., Mycoplasma pneumoniae, Legionella pneumophila).

CAP Diagnosis and Severity Assessment

Diagnosis: Symptoms of LRTI (cough and other respiratory symptoms), new focal chest signs, systemic features (fevers, sweats, rigors).
CURB-65: A clinical score used to assess severity in community-acquired pneumonia. Components: Confusion, BUN, Respiratory rate, Blood pressure, Age.

CAP Treatment

Penicillin allergy: Doxycycline or Clarithromycin.
Course of antibiotics essential to complete. Patient should stay hydrated, ensure rest, and the cough may endure for a couple of weeks.

HAP Treatment

Non-severe: Oral amoxicillin, metronidazole, review within 48hrs.
Severe: IV co-amoxiclav. Add anti-pseudomonal antibiotics when needed (e.g., Ceftazidime), Flucloxacillin for Staphylococcus aureus.

Atypical Organisms (Pneumonia)

Mycoplasma pneumoniae ("walking pneumonia") - mild, gradual onset. Treated with macrolides or fluoroquinolones.
Legionella pneumophila (Waterborne outbreaks): Requires specific treatment, such as quinolones (Levofloxacin) or macrolides (Azithromycin) (with or without rifampicin) and system decontamination.

Chronic LRT Infections

Cystic Fibrosis: Viscous secretions leading to persistent infections requiring specialized management. Pseudomonas is common, although others (Staphylococcus aureus and Haemophilus influenzae).

Clinical Case: Mrs. G (Possible CAP)

Symptoms suggest CAP – high fever, cough, feeling unwell.
Possible causative organisms for CAP include Streptococcus pneumoniae, Haemophilus influenzae, atypical bacteria (Chlamydophila pneumoniae, Mycoplasma pneumoniae), Moraxella catarrhalis, Staphylococcus aureus, influenza viruses, and fungi.
Investigation points: Chest X-ray, sputum culture, lab tests, CURB-65 scoring.
Mrs. G’s examination demonstrates temperature, heart rate, BP, and respiratory rate indicative of possible CAP. The penicillin allergy and occasional smoking are considerations. A CURB-65 assessment determines severity.

Vaccination

High risk patients such as Mrs. G (65 years old) should prioritize annual flu vaccination, plus once only pneumococcal vaccination.

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Description

This quiz covers various aspects of lower respiratory tract infections (LRTIs), including their causes, types, and treatment options. Key topics include pneumonia, acute bronchitis, and acute bronchiolitis, with emphasis on causative organisms and symptoms. Test your knowledge of these critical respiratory conditions.