Question

A 68 kg patient is receiving a drug in standard concentration of 400mg/250 mL of ½ NS running at 15 mL/hr. Calculate the dose the patient is receiving in mcg/kg/min. Round to the nearest hundredth

Answer 1

Answer: Dose the patient is receiving = 5.88 mcg/kg/min (nearest hundredth)

or approximately 6 mcg/kg/min

Solution:

Body weight of the client = 68 kg

Infusion rate = 15 mL/hr

Concentration of the drug = 400 mg/250 mL (Normal saline (NS) strength is not taken into consideration as it is just the vehicle and the concentration of normal saline i.e 1/2 NS is the same throughout the infusion period)

By using Dimensional analysis method: In this method, the equation is set up in a manner such that, only required units (i.e mcg/kg/min) are obtained and all other units are cancelled off using appropriate conversion factors (like mg to mcg, hr to min etc).

Dose the patient is receiving in mcg/kg/min =

=

= () mcg/kg/min [remaining units are cancelled off]

= (400/68) mcg/kg/min

= 5.88 mcg/kg/min (rounded to nearest hundredth)

= 6 mcg/kg/min (approximately)

Dose the patient is receiving in mcg/kg/min = 5.88 mcg/kg/min (rounded to nearest hundredth) or 6 mcg/kg/min (approximately)