Advanced Calculations Nursing 201 Ms. Frasier Summer 2014

Dimensional Analysis  Simple technique with a fancy name  Allows manipulation of units  Also referred as factor label method or the unit factor method  Less errors  The advantage of dimensional analysis is only one equation is needed

Review  ml/hr  gtt/min

Drops per minute (gtt/min)  Knowing the drop factor is the first step  The drop factor always appears on the IV package  Macrodrops are large and deliver 10, 15, 20 gtt/mL  Microdrops are small and deliver 60 gtt/mL  Drop factor = gtt/mL Example: order: D5W to infuse at 100ml/hr. drop factor 10gtt/mL. at what rate in gtt/min should the IV be regulated? 1.You are calculating for gtt/min, so write gtt/min to the left of the equation, (that is what you are looking for) 2.Extract the information that contains gtt/min from the problem; drop factor is 10gtt/mL. add this factor into the equation. X gtt = 10gtt min mL

Practice Problems Calculate the flow rate in mL/hr using dimensional analysis 1.1,800 mL of D5W in 24 hr by infusion pump _____________ 2.2,000 mL D5W in 24 hr by infusion pump _______________ mL RL in 12 hr by infusion pump __________________ mL 0.45% NS in 45 min by infusion pump ___________ 5.1,500 mL D5LR in 24 hr by infusion pump _______________ 6.750mL D5W in 16 hr by infusion pump ________________ 7.30 mL of Ancef in 0.9% NS in 20min by infusion pump _____

Practice Problems Calculate the flow rate in gtt / min using dimensional analysis 1.Administer D5LR at 75mL/hr. the drop factor is 10gtt/mL 2.Administer D5NS at 30mL/hr. the drop factor is a microdrop 3.Administer RL at 125mL/hr. the drop factor is 15gtt/mL 4.Administer 1000 mL D5NS in 6 hrs. the drop factor is 15gtt/mL 5.An IV medication in 60mL of NS is to be given in 45 min. the drop factor is a microdrop mL of LR is to infuse in 16 hr. the drop factor is 15gtt/mL 7.Infuse 150mL of D5W in 2hr. The drop factor is 20gtt/mL

Critical Care Calculations  Critically ill clients receive medications that are potent and require close monitoring  Titrated medications are added to a specific volume of fluid and rate adjusted to desired effect; when a solution is titrated, the lowest dosage of the med is set first and ↑ or ↓ as necessary  The drugs that are titrated are potent antiarrhythmics, vasopressor, and vasodilator medications  Infusion pumps are used for titration

Critical Care Calculations Volume mL / hr Dosage mg / min mg / hr mcg / min mcg / hr mcg / kg / min mg / kg / min mcg / kg / hr mg / kg / hr

Practice Problems 1.A client weighing 50kg is to receive a Dobutrex solution of 250mg in 500ml D5W ordered to titrate between 2.5 and 5 mcg/kg/min. a.Determine the flow rate setting for a volumetric pump. b.If the IV flow rate is being maintained at 25mL/hr after several titrations, what is the dosage infusing per minute? 2. Order: Epinephrine at 30mL/hr. The solution available is 2mg of epinephrine in 250mL D5W. Calculate the following: a.mg/hr b.mcg/hr c.mcg/min

3. Aminophylline 0.25g is added to 500mL D5W to infuse at 20mL/hr. Calculate the following: a.mg/hr 4. Order: 3mcg/kg/min of Nipride: Available: 50mg of Nipride in 250mL D5W. Client’s weight is 60 kg. a.Calculate the flow rate in mL/hr that will deliver this dosage. 5. A nitroglycerin drip is infusing at 3mL/hr. The solution available is 50mg of nitroglycerin in 250mL D5W. Calculate the following: a.mcg/hr b.mcg/min

Heparin IV HIGH ALERT MEDICATION Heparin is a potent anticoagulant that prevents clot formation and blood coagulation Expressed in units (no “U” abbreviation) The therapeutic range for heparin is determined individually by monitoring the client’s blood clotting value (APTT – activated partial thromboplastin time) Heparin is considered to be more therapeutic when based on weight in kg. May be given SQ or IV. Never IM. Should always be on a pump…will be ordered either ml/hr or units/hr Remember heparin comes in many different strengths. Make sure you have the correct one.

A client weighs 176 lb. Heparin infusion 20,000 units in 1000mL 0.9% sodium chloride. Order: bolus with heparin sodium at 80units/kg, then initiate drip at 18units/kg/hr. Calculate the following: a. ___________ bolus dosage b. ___________ infusion rate (initial) c. ___________ mL/hr Answers: 6400 units, 1440units/hr, 72mL/hr 46. pg.519 Order: Heparin drip at 18units/kg. Available: 25,000units of heparin in 1,000mL of D5W. The client weighs 80 kg. At what rate will you set the infusion pump? First determine units/kg the client should receive. 18x80 = 1440units then mL/hr Answer: 58 mL/hr

Practice! Practice! Practice! Review Heparin Weight Based Protocol