The effect of the InterLink cannula on fluid flow rates and haemolysis.

OBJECTIVE

To examine the effect of the InterLink cannula system (Becton Dickinson, New Jersey, NY, USA) on intravenous fluid flow rates and red blood cell haemolysis.

METHODS

An in vitro study was performed with crystalloid and packed red blood cells run through intravenous catheters of various sizes, with and without the InterLink cannula. Data recorded and analysed included fluid flow rates and plasma free haemoglobin concentration.

RESULTS

The InterLink cannula significantly reduced flow of crystalloid through a 14G catheter (reduction of median flow rate by 0.72 L/h, 12.3%, P < 0.001). There was a reduction of flow of packed red blood cells through a 14G catheter (0.11 L/h) but this was not statistically significant. There was no significant reduction of flow through smaller catheters and no significant effect on red blood cell haemolysis.

CONCLUSIONS

The InterLink cannula reduced flow rates through large diameter intravenous catheters. Because of other factors affecting fluid infusion in vivo this is of minor clinical significance. No increased haemolysis of red blood cells occurred with the InterLink cannula.