Pneumonia Flashcards
What is pneumonia?
Inflammation of the alveolar space with consolidation, usually due to acute LRTI.
What are the commonest causes of community acquired pneumonia?
- Streptococcus pneumoniae
2. H. influenzae, M. catarrhalis
What are the commonest causes of hospital acquired pneumonia?
- Gram -ve enterobacteria (e.g. E. coli)
2. Pseudomonas (common in ITU and ventilated)
What is aspiration pneumonia and what are the risk factors?
- Inhalation of oropharyngeal contents into lower airways.
2. Low GCS, swallowing dysfunction, stroke, intubation, feeding tube, oesophageal disease.
What are the organisms that cause atypical pneumonia?
Mycoplasma pneumoniae, chlamydophila pneumoniae, legionella pneumophila, klebsiella, chlamydophila psittac, pneumocystis pneumoniae.
What is ventilator associated pneumonia?
Pneumonia >48hrs after endotracheal intubation.
What is the difference between bronchopneumonia and lobar pneumonia on autopsy?
- Broncho - widespread patchy inflammation centred on airways, often bilateral.
- Lobar - diffuse inflammation affecting entire lobe/lobes.
What is consolidation and what is it in a pneumonia?
- Replacement of air in alveoli by fluid or other material.
2. Acute inflammatory exudate
What is the pathophysiology of pneumonia?
- Develops subsequent to invasion and overgrowth of pathogenic microorganisms in lungs (overwhelms host defences and produces intra-alveolar exudates.
- Pathogens reach lower respiratory tract by - inhalation, aspiration, haematogenous spread, direct extension from adjacent infected foci.
What is this a presentation of?
Fever, rigors, malaise, anorexia, dyspnoea, cough, purulent sputum, haemoptysis, pleuritic chest pain. Pyrexia, cyanosis, confusion, hypothermia, tachypnoea, tachycardia, hypotension, reduced expansion, dull to percussion, increased fremitus, crackles on auscultation.
Pneumonia
What are the risk factors for community-acquired pneumonia?
> 65, COPD, exposure to cigarette smoke, alcohol abuse, poor oral hygiene, contact with children, PPI use.
What are the risk factors for hospital-acquired pneumonia?
Poor infection control, intubation, mechanical ventilation.
Which pathogen is causing this atypical pneumonia and what is the treatment?
Flu-like symptoms followed by dry cough. CXR patchy consolidation in one lower lobe. Young patient treated with antibiotics prior to presentation.
- Mycoplasma pneumoniae
2. Clarithromycin/doxycycline/ciprofloxacin
Which pathogen is causing this atypical pneumonia and what is the treatment?
Biphasic illness: pharyngitis, hoarseness, otitis, followed by pneumonia.
- Chlamydophila pneumoniae
2. Doxycycline/clarithromycin
Which pathogen is causing this atypical pneumonia and what is the treatment?
Hotel, jacuzzi, cooling tower. Flu symptoms then dry cough and dyspnoea. Anorexia, D&V, renal failure, hyponatraemia, hepatitis, confusion. CXR bilateral consolidation, urinary antigen.
- Legionella pneumophila
2. Ciprofloxacin for 3 weeks or clarithromycin
Which pathogen is causing this atypical pneumonia and what is the treatment?
May complicate influenza infection or occur in the young, elderly, IVDU, patients with cancer or cystic fibrosis.
- Staphylococcal pneumonia
2. Flucloxacillin +/- rifampicin
Which pathogen is causing this atypical pneumonia and what is the treatment?
Rare. Occurs in elderly, diabetics, and alcoholics. Cavitating pneumonia especially in upper lobes and causes pleural empyema. Current jam sputum.
- Klebsiella
2. Often drug resistant - cefotaxime or imipenem
Which pathogen is causing this atypical pneumonia and what is the treatment?
From infected birds (typically parrots). Diagnose on serology.
- Chlamydophila psittaci
2. Doxycycline or clarithromycin
Which pathogen is causing this atypical pneumonia and what is the treatment?
Common in immunosuppressed (HIV). Dry cough, exertional dyspnoea, fever. Diagnose on sputum.
- Pneumocystis pneumonia
2. Co-trimoxazole (prophylactically in low CD4 count), steroids if hypoxaemia.
How is a suspected pneumonia investigated?
- CXR - air bronchograms hallmark of consolidation, silhouette sign.
- FBC - neutrophil dominance (bacterial)
- CRP - monitor disease course
- U&Es - high urea = increased severity, hyponatraemia in legionella, monitor for dehydration.
- ABG/sats
- Blood culture - all hospitalised patients
- Urinary antigen testing - legionella and pneumococcal
- Sputum culture - before Abx, not in outpatient setting
How is the severity of a pneumonia assessed?
CURB-65: C - confusion (8 or less on abbreviated mental test) U - urea (>7mmol/L) R - respiratory rate (>30/min) B - BP (<90 SYS and/or <60 DIA) 65 - age 65 or older
0-1: PO Abx/home treatment
2: IV Abx/hospital therapy
3+: severe pneumonia, 15-40% mortality, consider ITU
What is the management for pneumonia?
- A-E, aim sats >92%, CXR, bloods, ABG
- Analgesia
- Fluids
- Calculate CURB-65
- Antibiotics - IV if severe, anaerobic cover in aspiration, 5-7 days uncomplicated, 10 days severe, 14-21 if staphylococcal/legionella/gram -ve, switch to oral ASAP.
What should you check for if suspecting a pneumonia?
- Type 1 respiratory failure
- Hypotension due to dehydration and sepsis
- Empyema if 5 days Abx but persistent fever and WCC.
- AF - may need BBs short term
- Lung abscess
- Jaundice - secondary to sepsis/Abx treatment
Which antibiotics are recommended in this pneumonia first line and if allergic to first line?
CAP with CURB-65 of 0-1
- Doxycycline PO
2. Amoxicillin PO
