A comparison of three ported cannulae available in New Zealand.

A comparison was made of the three 22-gauge ported intravenous cannulae available in New Zealand--Venflon 2, Vasofix Braunule and Insyte. All cannulae performed satisfactorily in terms of overall success of cannulation although significant differences were apparent in both clinical and laboratory performance. Anaesthetists' clinical preference was for Insyte and Venflon 2 brands, perceiving these to have greater ease of handling and better packaging. In a series of laboratory studies, Vasofix was found to have the highest flowrate, the fastest time to flashback and the lowest valve opening pressure. Insyte required the least force of penetration. Venflon 2 had the greatest margin of safety between pressure to inject through the port and pressure required to blow the syringe/port assembly apart. Potential problems were identified with the Insyte port valve mechanism.