Heparin Calculator for Adult General Cardiovascular and Adult and Children’s Deep Vein Thrombosis and Peripheral Edema

Introduction: Heparin is an anticoagulant agent widely used in inpatient settings to prevent the formation of blood clots which can develop into deep vein thrombosis (DVT) and pulmonary embolism (PE). The risk for development of DVT and PE is highest in the hospital due to long-term bed rest. Signs and symptoms of DVT include unilateral leg swelling, pain, warmth, redness, palpable cord, and Homan’s sign; whereas, signs and symptoms of PE include cough, chest pain/tightness, shortness of breath, palpitations, hemoptysis, tachypnea, tachycardia, diaphoresis, and extension of neck pain. Heparin dosing is very complicated. The provider has to calculate the initial bolus dose and infusion dose based on the patient’s weight until the maximum dose is reached. From there a patient needs to be monitored closely using the Activated Partial Thromboplastin Time (aPTT) tool to see if a heparin dose adjustment is needed to prevent an adverse event from occuring. For instance, if a supra-therapeutic dose of heparin and sub-therapeutic dose of heparin is given it can cause bleeding and induce clots forming, respectively.

The Importance of Heparin Therapeutic Monitoring:
All hospitals have a standardized heparin nomogram that utilizes the Activated Partial Thromboplastin Time (aPTT) to guide heparin dosing to reduce delays in therapy and adverse events. The aPTT is a measure of how long it takes for an individual to form a blood clot. With that being said, there are different heparin nomograms created for specific patient indications. For the sake of simplicity, we focused on creating a clinical calculator based on VCU’s heparin dosing protocol for the adult general cardiovascular (CV), adult DVT/PE, and pediatric DVT/PE.
Therefore, a patient on heparin needs to be monitored closely using the Activated Partial Thromboplastin Time (aPPT).

Use of KNIME in Heparin Calculations:
We utilized a free data analytics software called KNIME to create our simple input-output heparin dosing calculator. Our clinical calculator provides the initial bolus dose, initial infusion rate, infusion rate/bolus dose adjustment and time to repeat aPTT measurement for adult general CV, adult DVT/PE and pediatric DVT/PE cases. The goal of developing a heparin dosing calculator is to help ease the burden and stress for the healthcare provider, to reduce dosing errors, and to retrieve a dosing regimen rapidly.

External resources

• Video demonstration of the calculator