Advanced Adult Intravenous Calculations. IV Flow Rate: mL/h To regulate an IV volume by electronic infusion pump or controller calibrated in mL/h, calculate:

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Advanced Adult Intravenous Calculations Slide 2 IV Flow Rate: mL/h To regulate an IV volume by electronic infusion pump or controller calibrated in mL/h, calculate: (rounded to a whole number) Slide 3 Calculation of IV Flow Rate: mL/h (continues) Order reads: D 5 W 250 mL IV over the next 2 h by infusion pump Step 1 Think. The pump is set by the rate of mL per hour. So, if 250 mL is to be infused in two hours, how much will be infused in one hour? 125 mL will be infused in one hour. You would set the pump at 125 mL per hour. Slide 4 Calculation of IV Flow Rate: mL/h (continued) Step 2 Use the formula: Therefore, set the pump at 125 mL per hour (125 mL/h). Slide 5 Calculation of IV Flow Rate: mL/h (continued) Step 2 Use the formula: Therefore, set the pump at 125 mL per hour (125 mL/h). Slide 6 Calculation of IV Flow Rate: mL/h (continued) Step 2 Use the formula: Therefore, set the pump at 125 mL per hour (125 mL/h). Slide 7 Calculation of mL/h: Infusion Rate is < 1 h (continued) Step 2 1 2 Slide 8 IV Flow Rate: gtt/min The formula method to calculate IV flow rate for manually regulated IVs ordered in mL/h or for a prescribed number of minutes is: Volume (mL) Time (min) Calibration or drop factor (gtt/mL) gtt/min Slide 9 IV Flow Rate: gtt/min Carry calculations to one decimal. Round gtt/min to the nearest whole number, because you can watch-count only whole drops. Slide 10 Calculation of gtt/min The physician orders D 5 W IV @ 125 mL/h. The infusion set is calibrated for a drop factor of 10 gtt/mL. Calculate the IV flow rate in gtt/min. Notice that the mL cancel out, leaving gtt/min. 6 1 Use your watch to count the drops and adjust the roller clamp to deliver 21 gtt/min. Slide 11 Calculation of gtt/min: Microdrip Drop Factor When the IV drop factor is 60 gtt/mL (microdrip sets), then the flow rate in gtt/min is the same as the volume ordered in mL/h. Slide 12 Calculation of gtt/min: Microdrip Drop Factor Order: D 5 W NS IV @ 50 mL/h. The drop factor is 60 gtt/mL. Notice that the order, 50 mL/h, is the same as the flow rate of 50 gtt/min when the drop factor is 60 gtt/mL. Slide 13 Drop Factor Constants Drop FactorDrop Factor Constant 10 gtt/mL 15 gtt/mL 20 gtt/mL 60 gtt/mL Slide 14 Adjusting IV Flow Rate (continued) Step 1 Step 2 Step 3 The % variation will be positive (+) if the administration is slow and the rate has to be increased, and negative ( ) if the administration is too fast and the rate has to be decreased. Slide 15 Calculation of IV Flow Rate Adjustment (continued) 1 1 Adjusted flow rate Slide 16 IV Push Rate Calculation Dosage Desired Supply Dosage Recommended Quantity of Time Recommended IV Push Rate Time Slide 17 Calculation of IV Push Incremental Rate (continues) Order: Ativan 3 mg IV Push 20 min preoperatively Supply: Ativan 4 mg/mL with drug literature guidelines of IV infusion not to exceed 2 mg/min. Slide 18 Calculation of IV Push Incremental Rate (continues) Order: Ativan 3 mg IV Push 20 min preoperatively Supply: Ativan 4 mg/mL with drug literature guidelines of IV infusion not to exceed 2 mg/min. Slide 19 Calculation of IV Push Incremental Rate (continued) What is a safe infusion time? Use Formula Or, ratio-proportion Slide 20 Calculation of IV Push Incremental Rate (continued) How much should you infuse every 15 seconds? 1 min = 60 sec; 1 min = 1 60 = 90 sec X = 0.125 mL = 0.13 mL of Ativan 4 mg/mL infused IV push every 15 seconds will deliver 3 mg of Ativan. Slide 21 IV Fluid Volume To calculate total infusion volume; mL is known: To calculate IV volume; flow rate (gtt/min), drop factor, and time are known: V is the unknown Or, use ratio-proportion: Slide 22 Standard Weight Based Heparin Protocol For all patients on heparin drips: 1. Weight in KILOGRAMS. Required for order to be processed: kg 2. Heparin 25,000 U in 250 mL of NS. Boluses to be given as 1000 U/mL. 3. APTT q.6h or 6 hours after rate change; q.d. after two consecutive therapeutic APTTs. 4. CBC initially and repeat every day(s). 5. Obtain APTT and PT/INR on day one prior to initiation of therapy. 6. Guaiac stool initially then every day(s) until heparin discontinued. Notify if positive. 7. Neuro checks every hours while on heparin. Notify physician of any changes. 8. D/C APTT and CBC once heparin drip is discontinued, unless otherwise ordered. 9. Notify physician of any bleeding problems. 10. Bolus with 80 U/kg. Start drip at 18 U/kg/h. 11. If APTT is < 35 secs: Rebolus with 80 U/kg and increase rate by 4 U/kg/h 12. If APTT is 3644 secs: Rebolus with 40 U/kg and increase rate by 2 U/kg/h 13. If APTT is 4575 secs: Continue current rate 14. If APTT is 7690 secs: Decrease rate by 2 U/kg/h 15. If APTT is > 90 secs: Hold heparin for 1 hour and decrease rate by 3 U/kg/h Slide 23 Standard Weight Based Heparin Protocol Worksheet (continues) Standard Weight Based Heparin Protocol Worksheet Round Patients Total Body Weight to Nearest 10 kg kg DO NOT Change the Weight Based on Daily Measurements FOUND ON THE ORDER FORM Initial Bolus (80 U/kg) U mL Initial Infusion Rate (18 U/kg/h) U/h mL/h Make adjustments to the heparin drip rate as directed by the order form. ALL DOSES ARE ROUNDED TO THE NEAREST 100 UNITS DateTimeAPTTBolusRate Change U/h mL/h New RateRN 1RN 2 Slide 24 Standard Weight Based Heparin Protocol Worksheet (continued) If APTT isThen < 35 secs:Rebolus with 80 U/kg and increase rate by 4 U/kg/h 3644 secs:Rebolus with 40 U/kg and increase rate by 2 U/kg/h 4575 secs:Continue current rate 7690 secs:Decrease rate by 2 U/kg/h > 90 secs:Hold heparin for one hour and decrease rate by 3 U/kg/h Signatures Initials Slide 25 IV Heparin Protocol Bolus patient with heparin 80 U/kg body weight and start drip at 18 U/kg/h Patients weight 110 lb How many units of heparin should the patient receive? Step 1: Calculate pt.s wt. in kg ( 1kg=2.2 lb) Step 2: Calculate the heparin bolus dosage. 80 U/kg X 50 kg = 4000 U This pt should receive 4000 U IV hep. As a bolus Slide 26 Calculate the number of milliliters to admin. For the bolus Supply: heparin 1000 U/mL Think: You want to give 4000 U, which is 4 times 1000 U/mL, so you want to give 4 times 1 mL or 4 mL. 4 D 4000 U H X Q = 1000 U X 1 mL = 4 mL Admin. 4 mL of heparin for the bolus Slide 27 Calculate the infusion rate for the heparin IV drip Protocol: Start drip at 18 U/kg/h Supply: heparin 25,000 U/250 mL or 100 U/ml 18 U/kg/h X 50 kg = 900 u/h Think, you want to admin. 9 times 1 mL or 9mL for the heparin infusion 9 D 900 U/h H X Q 100 U X 1 mL/h = 9 mL/h 1 Slide 28 To calculate IV heparin flow rate in mL/h D (U/h desired) H (U have on hand) X Q (mL you have on hand)=R (mL/h) Or ratio or supply is equiv. to ratio of desired dosage rate Supply U Desired U/h Supply mL X mL/h Slide 29 Order: D5W 500 mL w/ heparing 25,000 U IV at 1000 U/h D 1000 U/h H X Q = 25,000 U X 500 mL = R (mL/h 1000 U/h 1 20 25,000 U X 500 mL= 1000mL/h = 20 mL/h 50 50 1 Slide 30 Order: D5W 500 mL w/ hep 25,000 U IV at 850 U/h Calculate the flow rate in mL/h D 1 17 H X Q = 850 U/h X 500mL = 850 mL/h = 17 25,000 U 50 50 1 Slide 31 IV Flow Rate Ordered Per Minute To determine the flow rate (mL/h) for IV medications ordered per minute (such as mg/min): Step 1 Calculate the dosage in mL/min: Step 2 Calculate the flow rate of the quantity to administer in mL/h: Slide 32 Ratio/Proportion 25,000 U = 850 U/h 500 mL X mL/h 25,000 X = 425,000 25,000 X = 17 mL/h Slide 33 IV Flow Rate Ordered by kg/min To calculate flow rate (mL/h) for IV medications ordered by weight per minute (such as mg/kg/min): Step 1 Convert to like units, such as mg to mcg or lb to kg. Step 2 Calculate desired dosage per minute. Step 3 Calculate the desired dosage in mL/min. Step 4 Calculate the flow rate of the quantity to administer in mL/h. Slide 34 Verifying Safe Drug Dosage Recommended Per Minute To check safe dosage of IV medications ordered in mL/h: Step 1 Calculate mg/h. Step 2 Calculate mg/min. Step 3 Compare recommended dosage and ordered dosage to decide if the dosage is safe. Slide 35 Verifying Safe Drug Dosage Recommended by kg/min To check safe dosage of IV medications recommended in mg/kg/min and ordered in mL/h: Step 1 Convert to like units, such as mg to mcg or lb to kg. Step 2 Calculate recommended mg/min. Step 3 Calculate ordered mg/h. Step 4 Calculate ordered mg/min. Step 5 Compare ordered and recommended dosages; decide if safe. Slide 36 IV and IV PB Flow Rates with Fluid Volume Restrictions (continues) Follow these six steps to calculate the flow rate of an IV, which includes IV PB. Calculate: Step 1 IV PB flow rate: or use Slide 37 IV and IV PB Flow Rates with Fluid Volume Restrictions (continued) Step 2 Total IV PB time: Step 3 Total IV PB volume: Step 4 Total regular IV volume: Step 5 Total regular IV time: Time for one dose # of doses in 24 h Volume of one dose # of doses in 24 h Total volume IV PB volume Total time IV PB time Slide 38 IV and IV PB Flow Rates with Fluid Volume Restrictions (continued) Step 6 Regular IV flow rate: or use Slide 39 THE END