A nurse is caring for a client receiving a continuous IV infusion of heparin. The client's activated partial thromboplastin time (aPTT) is 105 seconds (normal range 30-40 seconds). The heparin protocol indicates that for an aPTT >90 seconds, the nurse should decrease the infusion rate by 2 units/kg/hr and recheck aPTT in 4 hours. The client's current heparin infusion rate is 1,200 units/hr, and the client weighs 75 kg. What is the new infusion rate in units/hr?

Question: A nurse is caring for a client receiving a continuous IV infusion of heparin. The client's activated partial thromboplastin time (aPTT) is 105 seconds (normal range 30-40 seconds). The heparin protocol indicates that for an aPTT >90 seconds, the nurse should decrease the infusion rate by 2 units/kg/hr and recheck aPTT in 4 hours. The client's current heparin infusion rate is 1,200 units/hr, and the client weighs 75 kg. What is the new infusion rate in units/hr?

Answer options:

• 750 units/hr ✅ 900 units/hr
• 1,050 units/hr
• 1,150 units/hr

Correct answer: 900 units/hr

Explanation: First, calculate the current infusion rate in units/kg/hr: 1200 units/hr / 75 kg = 16 units/kg/hr. Then, decrease the rate by 2 units/kg/hr: 16 - 2 = 14 units/kg/hr. Finally, convert this back to units/hr: 14 units/kg/hr * 75 kg = 1050 units/hr.