Synopsis
Decide whether a new hospital-onset pulmonary deterioration is bacterial pneumonia, use prior colonisation and local resistance data to choose proportionate treatment, and de-escalate safely once respiratory microbiology and the clinical trajectory are known.
- Hospital-acquired pneumonia is considered when symptoms begin at least 48 hours after admission and infection was not incubating on arrival; disease appearing on days 3 to 5 without resistance risk may still follow the community-acquired regimen.
- Diagnosis requires a new lower-respiratory syndrome and new or progressive imaging change after considering oedema, atelectasis, aspiration pneumonitis, pulmonary embolism, ARDS and alveolar haemorrhage.
- Endotracheal tubes become colonised quickly. A resistant organism in sputum or tracheal aspirate changes probability but does not prove that it is invading lung tissue.
Key red flags
After more than 48 hours of intubation, new infiltrates accompany worsening oxygenation or ventilator settings, altered secretion burden and systemic inflammatory change; several findings together are required.
Investigation priorities
Define the onset and severity of the new pulmonary deterioration.
Management branches
A hospital inpatient develops a new lower-respiratory deterioration after the admission boundary.
- Perform ABCDE, prescribe oxygen to an individual target and involve critical care for shock, exhaustion or escalating respiratory support.
- Compare current and previous imaging, review aspiration and fluid balance, and examine for pulmonary and non-pulmonary alternatives.
Key medicines
Co-amoxiclav for low-risk non-severe HAPGive 500/125 mg orally three times daily for 5 days, then review.
Piperacillin with tazobactamGive 4.5 g intravenously three times daily, increasing to four times daily for severe infection under the adopted policy.