There is often a dose range as opposed to a set dose per hour. Some CRIs are calculated to be titratable, meaning the dose of drugs is changed by adjusting the fluid rate until the appropriate response from the patient is reached. This new dose of 1.14 mg metoclopramide/kg/day can be compared to the therapeutic dose for metoclopramide and steps taken as needed to ensure patient safety. (dose per day ÷ patient weight in kg = dose for patient weight in kg per day) (dose per hour x hours in a day = dose per day)ġ9.44 mg metoclopramide/day ÷ 17 kg = 1.14 mg metoclopramide/kg/day (mg of medication needed per ml of fluid x fluid rate = dose per hour)Ġ.81 mg metoclopramide/hr x 24 hr/day = 19.44 mg metoclopramide/day (mg of medication added ÷ ml of fluid it is added to = dose per ml of fluid)Ġ.0108 mg metoclopramide/ml x 75 ml/hr = 0.81 mg metoclopramide/hr If the dog’s fluid rate is changed to 75 ml/hr, how much metoclopramide is the dog receiving?ġ0.8 mg metoclopramide ÷ 1000 ml = 0.0108 mg metoclopramide/ml This calculation should be taken one step further to determine how many milligrams of metoclopramide are in each milliliter of fluid so if the fluid rate changes the dose is known. If you add 10.8 mg metoclopramide (5mg/ml) to 1 liter of fluids running at 65 ml/hr, a 17 kg dog will receive 1 mg/kg/day of metoclopramide (drug dose ÷ drug concentration = drug dose needed in total fluids) (hours of fluids in liter x drug dose per hour = medication needed per liter of fluids)ġ0.8 mg metoclopramide/L ÷ 5 mg metoclopramide/ml = 2.16 ml metoclopramide (1000ml in a liter ÷ hourly fluid rate = hours of fluids in liter)ġ5.4 hr/L x 0.7 mg metoclopramide/hr = 10.8 mg metoclopramide/L (1mg/kg/day means the dog needs 17mg/day (24 hours) of metoclopramide)ġ7 mg/day ÷ 24 hr/day = 0.7 mg metoclopramide/hr How many ml of metoclopramide do you add to a liter of fluids that will run at 65 ml/hr?ġ7 kg x 1 mg/kg/day = 17 mg metoclopramide/day You are asked to make a metoclopramide (5 mg/ml) CRI at a dose of 1 mg/kg/day. If the drug is to be added to fluids running at a set rate, you will need to know:įor example, a 17 kg dog has fluids running at 65 ml/hr. Drugs can be administered without dilution, calculated to be mixed in to IV fluids running at a pre-determined rate, or prepared to be titrated to different rates depending on patient needs.Ĭalculations for Fluids Running at a Pre-Set Rate CRIs are also utilized for blood pressure management medications, electrolyte supplementation, GI motility medications, anesthesia, and insulin administration.
We are most used to CRIs for pain management, as in this form the drug can be maintained at effective plasma concentrations for the duration of treatment and avoid pain peaks and valleys. A Constant Rate Infusion (CRI) is utilized to administer a continuous dose of drug in intravenous fluids.