Pneumonia

Exam Cram

• Pneumonia: infection of the lung tissue, usually bacterial

• Presentation: green sputum, short of breath, fevers

• Diagnosis: consolidation on chest XR

• Management: amoxicillin + doxycycline, IVF

Outline

Background

• Infection is predominantly bacterial

• Core medical/ respiratory cause of admission

Assessment

History

• SoB, pleurisy

• Green/ yellow/ brown sputum

• Lethargy, < 7d

Examination

• Focal consolidation

• Hypoxia

• Increased wob

Investigations

• CXR: focal consolidation

• Blood cultures ?bacteraemia

• Creatinine ?AKI

• Sputum sample

• Viral PCR

Diagnosis

Diagnostic criteria: clinical / consolidation on CXR

Differentials: viral pneumonitis, sepsis, 

Classify: 

• By aetiology- organism or predicted organism based upon the setting, i.e. community, 

• Severity: CURB 65 or PSI/PORT score

• Location within lung

Management

1. Antibiotics- dependent upon setting or organisms

2. Oxygen -> Nasal HF -> NIV -> Intubation

3. IVF (if hypovolaemic)

4. Nebulisers- salbutamol, ipratropium, saline if wheezy

5. Admission if hypoxic

Classifications

• By environment

• By organism

• By location

• By severity

A fully classified pneumonia diagnosis would be: streph pneumonia, community acquired pneumonia of the left upper lobe

By Environment

The environment dictates the likely organisms responsible and so the choice of antibiotics. 

• Community acquired (CAP)

• Hospital acquired (HAP)

• Aspiration pneumonia

• Ventilation acquired (VAP)

CAP

• Streph pnuemonia 80%, haemophilius, 

• Severity based on CURB65 score

• Amoxicllin + doxycyline

HAP

• Within 10d of discharge

• Organisms: pseudomonas, enterobacter, staph aureus

• Management: Tazocin

Aspiration pneumonia

• Aspirated food falls into RLL

• Pneumonitis: chemical injury prior to infection

• CXR: RLL consolidation

• Amoxicillin +- Metronidazole

By Organism

Highest level of diagnosis, as accurately describes responsible organism facilitating narrow accurate antibiotics. Which organisms is a common MCQ question: 

Core 

Streph pneumonia

• Responsible for 80% of CAPs

• Ix: urinary antigen

• Associations: HSV 1,2

• Rusty brown sputum

• Management: penicillin: amoxicillin, ben pen OR ceftriaxone, (not cefalexin)

Haemophilus

• Associations: COPD

Klebsiella

• Associations: alcoholics

• CXR: cavitating lung lesions

• Management: ceftriaxone 1-2 weeks, 

• Also fluoroquinolones

Mycoplasma

• Presentation: dry cough, erythema multiforme

• Ix: serology

• Mx: doxycyline or macrolide

Legionella

• Presentation: hyponatraemia

• Associations: travel to foreign hotel, found in luke warm water tanks

• Ix: urinary antigen

• Management: macrolide

Staph aureus

• Post influenza

• Abscesses +/- tricuspid regurgitation in IE

Rarer causes

Chlamydia Psittaci

• Associations: Pigeons

• Presentation: dry cough, fevers, muscle aches

• Management: doxycycline

Pneumocystis jiroveci pneumonia (PJP) 

• Fungal infection in lymphopenic patients

• Associatoins: HIV, oncology (particlarly haemoatological malignancies) patients

• Management: co-trimoxazole

By Location

Anatomy: left lung has two lobes (heart in the way) and right lung has three

Right Upper Lobe

• Right upper zone opacification

• Upper zone's associated with Tuberculosis 

Right Middle Lobe

• Right middle zone opacification

• Loss of right heart border

Right Lower Lobe

• Right lower zone opacification or collapse

• Associated with aspiration pneumonia

Left Upper Lobe (LUL)

• LUL extends across whole lung therefore

• Opacification appears mild across whole left lung

• Upper lobes associated with Tuberculosis 

Left Lower Lobe

• Loss of left heart border (sail sign)

By Severity

CURB-65 commonest score used to predict severity (1 score per factor). PSI/PORT score also used. 

• Confusion

• Urea > 7

• RR > 30

• BP < 90/60

• Age > 65

Management

Curb 0-1: PO amoxicillin + doxycycline & d/c home

Curb 2-3: Admit to ward, likely IV co-amoxiclav + clarithromycin

Curb > 3: consider HDU, ICU, IV co-amoxiclav + clarithromycin

Med Reg Notes

Nursing Home Acquired Pneumonia

Nursing home acquired pneumonia is an interesting concept, however not used currently in clinical practice. There is speculation that a nursing home pneumonia is more similar to a HAP than a CAP. 

Atypical pneumonia 

Atypical pneumonias are those that present with a dry cough, may not have classic consolidation on chest XR and may not grow on standard blood cultures. For myself (and others) this is an outdated term, that makes clinicians presume all pneumonias are streph pneumoniae. Therefore I dont use this term as I feel it makes it harder to be opened minded. 

Inflammatory markers

• CRP, Neutrophils and Procalcitonin are inflammatory markers used in pneumonia

• They are often used but can be difficult to interpret and of variable use

Chest XR

• Principle method of diagnosis of pneumonia

• Can take 48hrs to show consolidation and miss small pneumonias picked up by CT

Disposition

If hypoxic, requires admission

If not hypoxic and low CURB 65 score of 0-1 and safe social setting, can aim home with PO antibiotics

Resources and References

Written 2024