Peripheral vein IV Catheter & IV line – Patency Maintenance

Versus Maintenance

Saline-flush Versus Heparinised-saline flush

What I’ve been doing to-date:

1. My ‘go to’ primary protocol: no regularly timed flushing protocol observed – react as required only

2.Use a heparinised-saline flush (HSF) if the catheter or IV line becomes blocked and after initial placement of catheter-only placements



Catheter only (e.g. for IV access intra/post surgery or repeat blood-sampling)

After placement of the bung; introduce a small amount of HSF into the bung ‘hub’ to help maintain patency. React with further HSF as required

Catheter and giving-set (e.g. for a surgical or hospitalised patient)

  • Undertake checks that the catheter, the giving-set, bandaging, the vein and patient remain uncompromised – either at regulated times or when alerted (e.g. by a monitor alarm)
  • If there are no abnormalities: no further action taken
  • If there is a blocked IV catheter or line: use an HSF to clear the obstruction and flush through afterwards with an appropriate sterile fluid

The latest research and guidelines


For the majority of purposes (peripheral vein)
Regular flushing of the catheter with 0.9% sterile NaCl is as effective as 10 IU/mL HSF in maintaining patency for up to 42 hours.

Continuous fluids administration (peripheral vein)
Q4hr sterile NaCl flush is advised

Serial blood sampling (peripheral vein)
Regular use of HSF is generally indicated to aid on-going patency

I’m changing my methods!

Thanks Alison – RVN