Heparin Infusion

<Medications>

<Index>

 

 

 

Definition

-  Infusion of Heparin to maintain state of antcoagulation

 

Features

-  Infusion rate determined by APTT

-  Effect of Heparin is immediate & lasts 3-6hrs

 

Mechanism

-  Potentiates antithrombin III leading to decreased clot formation

-  Nil effect on existing thrombi

 

Indications

-  DVT, PE

-  Stroke, TIA

-  Unstable angina, AMI, prolonged AF

 

Procedure

-  Baseline

-  APTT, INR

-  FBE for Plts

-  If abnormal D/W Haematologist

-  Premixed Heparin Infusion

-  Heparin 25,000 Units diluted to 250mls w N.Saline

-  100 Units/ml

-  Loading dose

-  80 Units/kg up to 5,000 Units slow IV bolus

-  Consider recent bleeds or Sx

-  APTT 4hrs later

-  Infusion Rate

-  Based on APTT

-  <35

-   5,000 Units Heparin STAT

-   Increase rate by 150 Units/hr

-   Repeat APTT 4-8hrs

-  35-49

-   Increase rate by 100 Units/hr

-   Repeat APTT 4-8hrs

-  50-70

-   Nil change

-   APTT next morning

-  71-85

-   Decrease rate by 50 Units/hr

-   APTT next morning

-  85-110

-   Stop infusion for 30min

-   Decrease rate by 100 Units/hr

-   Repeat APTT 4-8hrs

-  >110

-   Stop infusion for 60min

-   Decrease rate by 150 Units/hr

-   Repeat APTT 4-8hrs

 

Side Effects

-  Bleeding

-  Mild: Mx as necessary

-  Moderate to Major --> cease infusion

-  +/- Protamine Sulphate

-  1mg per 100 Units Heparin in last 2 hrs

-  Anticoagulant at > 50mg

-  Heparin Induced Thrombocytopaenia