What do systematic reviews say?

Heparin vs normal saline solution locking

It is very uncertain whether heparin changes haemorrhage from any site compared with normal saline solution locking (very low certainty).

• Heparin versus 0.9% sodium chloride locking for prevention of occlusion in central venous catheters in adults 2022 · Cochrane Headline outcomes only
  RR 1.54
  3 studies · 1197 participants
  Very low