Heparin Drip Therapy Changes

1
Heparin Drip Therapy Changes

• Monitoring Heparin Drips using UFH Level and Not
  the aPTT
• Catherine Davis, Pharm.D., BCPS
• Exempla Good Samaritan Medical Center
• daviscw_at_exempla.org

2
Background

• Heparin weight based dosing protocols are
  currently available for DVT/PE and CV based on
  aPTT values
• Protocols are being updated to adjust therapy
  based on unfractionated heparin levels (UFH)
• Protocols will be changed over on September 20

3
Why Not aPTT?

• Problems with aPTT
• Relationship between heparin dose and heparin
  level cannot be reliably predicted (non-specific)
• e.g., patient may have therapeutic aPTT but low
  heparin level (risk of thromboembolism)
• e.g., patient may have subtherapeutic aPTT but
  high heparin level (risk of hemorrhage)
• aPTT does not reliably correlate with heparin
  blood concentration
• aPTT does not reliably correlate with heparin
  antithrombotic effect
• aPTT reagents (even different batches from same
  manufacturer) vary in responsiveness to heparin,
  therefore
• lab must calibrate a new therapeutic range for
  each aPTT reagent
• therapeutic range must be re-calibrated with new
  reagent, reagent lot, new clot timer, heparin
  preparation, etc.

4
Why Not aPTT?

• The Solution UFH level, anti-factor Xa assay
  (heparin activity level)
• A test of actual enzyme activity (rather than
  heparin blood concentration)
• Measures the amount of heparin needed to
  neutralize a fixed amount of either thrombin or
  factor Xa added to the sample.
• Better reflects the desired effect of heparin
• better correlation between heparin activity and
  the UFH level than between aPTT and heparin level
• Target levels
• therapeutic range 0.3-0.7 units/mL
• High Dose Therapy used in DVT / PE
• Low Dose Therapy used for cardiovascular
• Cost
• may be higher than aPTT but as patients are
  therapeutic more quickly and need fewer
  monitoring tests, end result is only a slight
  increase in cost and improved therapy

5
New Weight Based Protocols

• Protocol adjusted based on UFH
• Weight Based dosing still for bolus and initial
  infusion
• Re-bolusing now is now weight-based
• Same therapeutic range for Low and High Dose
  Protocol, dosing changes are lower for Low Dose

6
Study Data for Boulder Community Hospital 2004

• 72 of patients are therapeutic within 24 hours
• Increased of patients who are therapeutic
  during entire treatment
• Decreased doses to get patients therapeutic
  increased safety
• 30 fewer changes while dosing less work for
  nurses

7
How RNs are being educated to write the change
orders

• Nurse to write order stating if a bolus dose is
  needed (dose in units)
• Nurse to write order in units per hour or in
  ml per hour what the new rate will be.
• Pharmacy can change the rate in Epic each time a
  change in the dose occurs
• Do NOT write change BY x units per hour
• DO write change TO x units per hour
• Always get another nurse to double check math and
  all dosing calculations

8
Start dates

• All patients on heparin drips before September
  20th will continue to be monitored with the aPTT
• All patients starting on heparin drips on or
  after September 20th will be monitored with the
  UFH level
• Patients on protocol during the transition phase
  will continue with aPTT monitoring until therapy
  is completed.

9
Lab ordering process

• RNs or UCs will order UFH levels in place of
  aPTTs based on the protocols,
• There is different heparin level for low
  molecular weight heparin the lab order for this
  in LMWH. This test is available at ELMC only.
• Heparin in Epic, will only call up the
  medication, NOT the lab

10
(No Transcript)