Question

Order: dobutamine in 5% dextrose in water is to be titrated at 16 - 40 mcg/kg/min. The I.V. solution was prepared by adding 0.5 grams of dobutamine to dextrose 5% water. The final solution contains a total of 250 mL. The client's current weight is 156.2 lbs. The pump would be set to administer the solution at a rate of _______to ______mL per hour.

A) 8 mL/hr to 20 mL/hr
B) 10 mL/hr to 25 mL/hr
C) 12 mL/hr to 30 mL/hr
D) 14 mL/hr to 35 mL/hr

Answer 1

The correct pump rate for administering dobutamine at given concentrations and patient weight is within the range of 34 mL/hr to 85 mL/hr.

Step-by-step explanation:

To calculate the pump rate for administering dobutamine in dextrose 5% water, we use the formula: (dose in mcg/kg/min) x (patient weight in kg) x (60 min/hr) / (concentration in mcg/mL).

First, convert the patient's weight from pounds to kilograms by dividing by 2.2 (156.2 lbs / 2.2 = 71 kg). The concentration of dobutamine is found by converting 0.5 grams to 500 mg, and dividing by the total solution volume (500 mg / 250 mL = 2 mg/mL or 2000 mcg/mL).

The pump rate ranges from minimim pump rate at the lowest dose to maximum pump rate at the highest dose:

• Minimum rate = (16 mcg/kg/min) x (71 kg) x (60 min/hr) / (2000 mcg/mL) = 34.08 mL/hr (rounded to 34 mL/hr)
• Maximum rate = (40 mcg/kg/min) x (71 kg) x (60 min/hr) / (2000 mcg/mL) = 85.2 mL/hr (rounded to 85 mL/hr)

Therefore, the appropriate pump rate would be set within the range of 34 mL/hr to 85 mL/hr.