A nurse is caring for a client with a deep vein thrombosis who is receiving a continuous intravenous heparin infusion. The client weighs 198 lb.
The hospital's weight-based heparin protocol includes the following instructions:
| aPTT (seconds) | Bolus Dose | Continuous Infusion Adjustment |
|---|---|---|
| < 35 | 80 units/kg | Increase by 4 units/kg/hr |
| 35 - 45 | 40 units/kg | Increase by 2 units/kg/hr |
| 46 - 70 | None | No change |
| 71 - 90 | None | Decrease by 2 units/kg/hr |
| > 90 | Hold infusion for 1 hour | Decrease by 3 units/kg/hr |
The client's current heparin infusion is infusing at a rate of 15 units/kg/hr. The most recent aPTT result is 42 seconds. The available intravenous solution contains heparin 25,000 units in 250 mL of 5% dextrose in water (D5W).
What should the nurse set the new continuous intravenous infusion pump rate to, in mL/hr?
(Record your answer to the nearest tenth. Do not use a trailing zero.)
Answer: 15.3 mL/hr
Answer
15.3
The correct pump setting is 15.3 mL/hr. First, the client's weight must be converted to kilograms: 198 lb / 2.2 = 90 kg. According to the protocol, an aPTT of 42 seconds falls into the 35-45 seconds tier, which dictates an increase of the continuous infusion by 2 units/kg/hr. The current running rate is 15 units/kg/hr, meaning the new ordered rate becomes 17 units/kg/hr (15 + 2). The total hourly dose is calculated by multiplying the new rate by the client's weight: 17 units/kg/hr * 90 kg = 1530 units/hr. The available concentration is 25,000 units in 250 mL, which simplifies to 100 units/mL. To find the final intravenous pump rate, divide the hourly dose by the concentration: 1530 units/hr / 100 units/mL = 15.3 mL/hr. This meets the rounding requirement of the nearest tenth.
Step-by-Step Solution
Key Concept
Weight-Based Continuous Intravenous Medication Titration