Achieving large-bore venous access in a shocked patient is a frequent problem encountered by the emergency department physician. Alternatives^1–3 to standard cannula-over-needle percutaneous cannulation are time/operator dependent, and confer increased potential morbidity. We aimed to prospectively validate the anecdotally described, but largely overlooked, technique of utilising an initial distending volume of saline to facilitate large-bore peripheral venous cannulation.

With regional ethics committee approval and verbal consent, adult (⩾16 years) patients presenting to our tertiary emergency department with a clinical diagnosis of hypovolaemia (pulse ⩾100 bpm, …