A client admitted with cardiogenic shock weighs 198\text{ lbs}. The provider initially ord… — NCLEX-RN

A client admitted with cardiogenic shock weighs $198\text{ lbs}$ . The provider initially orders a continuous intravenous (IV) infusion of dopamine at $4\text{ mcg/kg/min}$ . The pharmacy dispenses a premixed IV bag containing $800\text{ mg}$ of dopamine in $250\text{ mL}$ of $5\%\text{ Dextrose}$ in water ( $D_5W$ ). Two hours later, the client's mean arterial pressure (MAP) remains at $55\text{ mmHg}$ , and the provider increases the dopamine infusion order to $7\text{ mcg/kg/min}$ . At what rate in $\text{mL/hr}$ should the nurse set the infusion pump to deliver the newly ordered dose? (Record your answer rounding to the nearest tenth. Do not include units in your answer.)

Answer: 11.8 mL/hr

Answer

11.8

To calculate the new IV pump rate, first convert the client's weight to kilograms (

198\text{ lbs} \div 2.2 = 90\text{ kg}

). Next, identify the correct active dose to administer, which is the newly ordered

7\text{ mcg/kg/min}

. Calculate the hourly dose required:

7\text{ mcg/kg/min} \times 90\text{ kg} = 630\text{ mcg/min}

, then multiply by

60\text{ minutes}

to determine the hourly requirement of

37,800\text{ mcg/hr}

. Convert this value to milligrams (

37.8\text{ mg/hr}

) so it matches the supplied medication's unit of measurement. Determine the IV bag concentration by dividing the total drug amount by the total volume:

800\text{ mg} \div 250\text{ mL} = 3.2\text{ mg/mL}

. Finally, divide the required hourly dose by the concentration:

37.8\text{ mg/hr} \div 3.2\text{ mg/mL} = 11.8125\text{ mL/hr}

. According to the rounding instructions, this rounds to

11.8\text{ mL/hr}

Step-by-Step Solution

Convert the client's weight from pounds to kilograms.

198 \div 2.2 = 90\text{ kg}

Weight-based medication dosing requires the weight to be in kilograms.

Determine the active prescribed dose.

7\text{ mcg/kg/min}

The provider increased the dose from the initial

4\text{ mcg/kg/min}

due to the client's hypotensive state.

Calculate the required dose per minute.

7\text{ mcg/kg/min} \times 90\text{ kg} = 630\text{ mcg/min}

This establishes the total micrograms of dopamine the client needs every minute.

Convert the minute dose to an hourly dose.

630\text{ mcg/min} \times 60\text{ min/hr} = 37,800\text{ mcg/hr}

Intravenous infusion pumps are programmed in milliliters per hour, so the time unit must be converted.

Convert micrograms to milligrams.

37,800\text{ mcg} \div 1,000\text{ mcg/mg} = 37.8\text{ mg/hr}

The medication supplied by the pharmacy is measured in milligrams, so the units must match.

Calculate the concentration of the supplied IV bag.

800\text{ mg} \div 250\text{ mL} = 3.2\text{ mg/mL}

This determines exactly how many milligrams of dopamine are in each milliliter of fluid.

Calculate the final infusion rate in mL/hr.

37.8\text{ mg/hr} \div 3.2\text{ mg/mL} = 11.8125\text{ mL/hr}

Dividing the required hourly dose by the fluid concentration provides the correct pump rate.

Round the final answer to the nearest tenth.

11.8

The question explicitly specifies rounding to the nearest tenth.

Key Concept

Weight-based continuous IV infusion calculation with dose titration.

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