Point-of-care ultrasound (POCUS) puts imaging in the hands of the treating clinician. Used well, it shortens the time to diagnosis for shock, trauma and breathlessness. Used without an understanding of its limits, it creates false reassurance.
Focused questions, focused answers
POCUS works best when it answers a binary question: is there free fluid, is there a pericardial effusion, is the lung sliding? It is not a replacement for a comprehensive scan by a sonographer or radiologist.
Common applications:
- eFAST – free fluid in the abdomen, pericardium and pleura, plus pneumothorax
- Lung ultrasound – B-lines in pulmonary oedema, absent sliding in pneumothorax
- Focused echo – effusion, gross ventricular function, right heart strain
- Aorta – screening for abdominal aortic aneurysm
- Two-point compression – proximal deep vein thrombosis
The limits
A negative FAST does not exclude intra-abdominal injury, particularly hollow-organ and retroperitoneal injury. Obesity, bowel gas and subcutaneous emphysema all degrade the image. Findings are operator-dependent, so training, credentialing and image archiving matter.
“Ultrasound rules things in far more reliably than it rules them out.”
Building a safe service
Departments that use POCUS well document each scan, store images for review and run regular quality assurance with radiology. Every scan should be recorded as a focused examination with a clear clinical question and answer.
This article is for education only and does not replace clinical judgement or local guidelines.
