Anticoagulants & Bleeding Surveillance

Heparin

Unfractionated heparin acts immediately and clears quickly, which makes it the anticoagulant of choice when the situation may change. Monitoring is by aPTT, drawn six hours after any rate change.

Heparin-induced thrombocytopenia is an immune reaction that paradoxically causes clotting, not bleeding. It typically appears five to ten days into therapy with a platelet drop of 50 percent or more from baseline. The response is to stop all heparin — including flushes and coated catheters — and start a non-heparin anticoagulant.

Warfarin

Warfarin inhibits vitamin K–dependent clotting factors, so full effect takes three to five days. Clients are commonly bridged with heparin or enoxaparin until the INR reaches range.

Dietary vitamin K does not need to be eliminated — it needs to be consistent. A client who suddenly starts a daily kale smoothie will drop their INR into a subtherapeutic range.

• INR below range → increased clotting risk
• INR above range → increased bleeding risk; hold and notify above 5
• Teach a soft toothbrush, an electric razor, and no NSAIDs or aspirin without approval
• Report black tarry stools, pink urine, bleeding gums, or a new severe headache

Enoxaparin technique

Enoxaparin is a low-molecular-weight heparin with a predictable response, so routine aPTT monitoring is not required. Administration technique is heavily tested.

• Give in the anterolateral or posterolateral abdominal wall, two inches from the umbilicus
• Leave the air bubble in the prefilled syringe — it clears the drug from the needle
• Do not aspirate and do not massage the site afterward
• Alternate sides with each dose