Differentials
Community-acquired pneumonia (CAP)
SIGNS / SYMPTOMS
Symptoms include productive cough, breathlessness, pleuritic chest pain, fever, rigors or night sweats, and general malaise. Older people present with atypical symptoms including confusion, lethargy, worsening of pre-existing conditions, and general deterioration.
It is possible that aspiration pneumonia is simply community-acquired pneumonia in an older patient with greater comorbidities.[4]
INVESTIGATIONS
Common organisms detected on sputum culture are Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus, Moraxella catarrhalis, Klebsiella pneumoniae, and other gram-negative bacilli.
Atypical organisms may be detected with appropriate testing (e.g., serology or antigen tests).
Hospital-acquired pneumonia (HAP)
SIGNS / SYMPTOMS
Green-yellow sputum.
No difference in signs and symptoms. HAP refers to any pneumonia that develops after 72 hours of hospitalisation. This includes all types of pneumonia, including aspiration pneumonia.
INVESTIGATIONS
Sputum culture showing growth of gram-negative rods or Staphylococcus aureus is more likely.
Pulmonary oedema
SIGNS / SYMPTOMS
Presents with SOB, fatigue, dyspnoea on exertion, and tachypnoea. History of heart disease or fluid overload can usually be elicited.
Crackles are heard on auscultation.
INVESTIGATIONS
CXR typically shows symmetrical distribution of opacities, although may not be evident early on. Evaluation of left ventricular dysfunction by BNP and echo are helpful.
Leukocytosis usually not present.
Lipoid pneumonia
SIGNS / SYMPTOMS
Form of aspiration pneumonia occurring acutely or chronically from aspiration of vegetable fat or mineral oil (exogenous form). There is a history of ingestion of lipid over periods of time. Acute form may present with fever and cough especially in younger patients. Chronic form may be asymptomatic.
Can be seen resulting from propylene glycol in electronic cigarettes and other vaporisers.
INVESTIGATIONS
CT can occasionally demonstrate low attenuation areas (-30HU).
Use of this content is subject to our disclaimer