Friday, May 20, 2005

Calc Qs

1.
A client admitted to the hospital with diabetic ketoacidosis is getting a continuous infusion of regular insulin. The health care provider orders an I.V. containing 1 liter of dextrose 5% in water at 150 ml/hour to be started when the client's blood glucose level reaches 250 mg/dl. The drip factor of the I.V. tubing is 15 gtt/ml. What's the drip rate for the I.V. infusion in drops per minute?__________________________________________________
2.
A health care provider prescribes heparin 25,000 units in 250 ml of normal saline solution to infuse at 600 units/hour for a client who suffered an acute myocardial infarction. After 6 hours of heparin therapy, the client's partial thromboplastin time is subtherapeutic. The provider orders an increase in the infusion to 800 units/hour. The nurse should set the infusion pump to deliver how many milliliters per hour?__________________________________________________
3.
A septic client with hypotension is being treated with dopamine hydrochloride (Inotropin). The nurse asks a colleague to double-check the dosage that the client's getting. The bag contains 400 mg of dopamine hydrochloride in 250 ml, the infusion pump is running at 23 ml/hour, and the client weighs 79.5 kg. How many micrograms per kilogram per minute is the client getting?__________________________________________________
4.
A 64-year-old client has a cerebral aneurysm. The health care provider orders hydralazine (Apresoline), 15 mg I.V., every 4 hours as needed to keep systolic blood pressure under 140 mm Hg. The label on the hydralazine vial reads "hydralazine 20 mg/ml." To administer the correct dose, how many milliliters of medication should the nurse draw up in the syringe?__________________________________________________
5.
After a retropubic prostatectomy, a client needs continuous bladder irrigation. The client has an I.V. of D5W infusing at 40 ml/hr, and a triple-lumen urinary catheter with normal saline solution infusing at 200 ml/hr. The nurse empties the urinary catheter drainage bag three times during an 8-hour period for a total of 2,780 ml. How many milliliters does the nurse calculate as urine?__________________________________________________
6.
A 3-year-old child is to get 500 ml of dextrose 5% in normal saline solution over 8 hours. At what rate (in ml/hr) should the nurse set the infusion pump?

1 comment:

Bonnie Boss said...

1. 37.5 gtts/minute
Rationale: To calculate the drip rate, set up the equation: 150 ml/60 minutes x 15 gtt/1 minute
2,250 gtts/60 minutes = 37.5 gtts/minute
2. 8 ml/hour
Rationale: To find out how many milliliters per hour to deliver, remember that the dose on hand divided by the quantity on hand equals the dose desired divided by x. Use these equations:
25,000 units/hour/250 ml = 800 units/hour/X. Cross multiply to solve for X and divide each side of the equation by 25,000 units to get the result X = 8 ml/hour.
3. 7.71 mcg/kg/min
Rationale: First, calculate how many micrograms per milliliter of dopamine hydrochloride are in the bag: 400 mg/250 ml = 1.6 mg/ml. Next, convert milligrams to micrograms: 1.6 mg/ml x 1,000 mcg/mg = 1,600 mcg/ml. Finally, calculate the dose: 1,600 mcg/ml x 23 ml/hour/79.5 kg
79.5 kg/60 min/hr = 7.71 mcg/kg/min.
4. 0.75 ml
Rationale: Use the following formula to calculate the drug dosage: Dose on hand/quantity on hand = Dose desired/X. Plug in the values for this equation: 20 mg/ml = 15 mg/X to get the result 0.75 ml.
5. 1,180 ml
Rationale: During 8 hours, 1,600 ml of bladder irrigation has been infused (200 ml x 8 hr - 1,600 ml/8 hr). Then subtract this amount of infused bladder irrigation from the total volume in the drainage bag (2,780 ml - 1,600 ml = 1, 180 ml) to determine urinary output.
6. 62.5 ml/hr
Rationale: To calculate the rate per hour for the infusion, divide 500 ml by 8 hours, which results in 62.5 ml/hr.