Intravenous Solutions, Equipment, and Calculations Chapter 14

IV Components Abbreviation Solution Component D Dextrose W Water S Saline NS Normal Saline (0.9% NaCl) NaCl Sodium Chloride RL Ringer’s Lactate LR Lactated Ringer’s

Normal Serum Osmolarity Hypotonic Used to dilute excess serum electrolytes e.g.: 0.45% Saline Isotonic Used to expand volume and maintain normal tonicity e.g.: 0.9% Saline, Lactated Ringer’s, 5% Dextrose

Normal Serum Osmolarity Hypertonic Used to correct electrolyte imbalances e.g.: 5% Dextrose and 0.9% Saline; 5% Dextrose and Lactated Ringer’s

IV Solution Label

Standard Straight Gravity Flow IV

IV with Piggyback (IV PB)

IV Flow Rate: mL per hour Regulate an IV volume by electronic infusion pump or controller calibrated in mL per hour (rounded to a whole number)

Calculation of IV Flow Rate: mL per hour Order reads: D5W 250 mL IV over the next 2 hours by infusion pump

Calculation of IV Flow Rate: mL per hour Step 1 - Think 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

IV Flow Rate: mL per hour Step 2 - Use ratio-proportion formula: Therefore, set pump at 125 mL per hour (125 mL per hour)

IV Flow Rate in mL per hour: Infusion Rate is less than 1 hour (rounded to a whole number)

Calculation of mL per hour: Infusion Rate is less than 1 hour Order: Ampicillin 500 mg IV in 50 mL D5½NS in 30 min by controller

Calculation of mL per hour: Infusion Rate is less than 1 hour Step 1 – Think Controller is set by the rate of mL per hour If 50 mL is to be infused in 30 minutes 100 mL will be infused in 60 minutes

Calculation of mL per hour: Infusion Rate is less than 1 hour Step 1 – Think Because 100 mL is twice as much as 50 mL and 60 minutes is twice as much as 30 minutes Set rate of controller at 100 mL per hour to infuse 50 mL per 30 min

Calculation of mL per hour: Infusion Rate is less than 1 hour Step 2

IV Flow Rate: drops per min Formula for IV flow rate for manually regulated IVs ordered in mL per hour or for minutes Calibration or drop factor (drops per mL) Volume (mL) Time (min) gtt per min

IV Flow Rate: drops per min Carry calculations to one decimal. Round drops per min to the nearest whole number. Watch - count only whole drops

Calculation of drops per min Physician orders: D5W IV at 125 mL per hour Infusion set is calibrated for a drop factor of 10 drops per mL Calculate IV flow rate in drops per min Notice that the mL cancel out, leaving drops per min

Calculation of drops per min 1 6 Use your watch to count drops and adjust roller clamp to deliver 21 drops per min

Calculation of drops per min: Microdrip Drop Factor When IV drop factor is 60 drops per mL (microdrip sets) Flow rate in drops per min is same as volume ordered in mL per hour

Calculation of drops per min: Microdrip Drop Factor Order: D5W NS IV at 50 mL per h Drop factor is 60 drops per mL Notice order, 50 mL per hour, is the same as the flow rate of 50 drops per min when drop factor is 60 drops per mL

Calculation of gtt per min: Microdrip Drop Factor

Drop Factor Constants Drop Factor Drop Factor Constant 10 drops per mL

Drop Factor Constants Administer 125 mL per hour IV with 20 drops per mL infusion set 1 3

IV Flow Rate Shortcut Method Shortcut to calculate IV flow rate is:

Adjusting IV Flow Rate Check for institutional policy regarding correcting off-schedule IV rates and the percentage of variation allowed. Variation should not exceed 25 percent

Adjusting IV Flow Rate If adjustment is permitted Use following formula to recalculate the mL per hour and gtt per min for the time remaining and the percentage of variation.

Adjusting IV Flow Rate Step 1: Step 2: Step 3:

Adjusting IV Flow Rate % variation will be positive (+) if administration is slow and rate has to be increased Negative () if administration is too fast and rate has to be decreased

Calculation of IV Flow Rate Adjustment Order: 500 mL LR to run over 10 hour at 50 mL per hour Drop factor is 60 drops per mL and IV is correctly infusing at 50 drops per min After 2½ hours, 300 mL is remaining Almost half of total volume infused in one-quarter the time

Calculation of IV Flow Rate Adjustment IV infusion is ahead of schedule Compute a new rate of 300 mL to complete IV fluid order in remaining 7½ hours. Patient would require close assessment for fluid overload

Calculation of IV Flow Rate Adjustment Adjusted flow rate 1 1

Calculation of IV Flow Rate Adjustment

IV Push Rate Calculation Caution: IV drugs are potent and rapid acting. Never infuse IV push drugs more rapidly than recommended.

IV Push Rate Calculation Caution: Some drugs require further dilution after reconstitution. Read package inserts and drug resources for administration guidelines.

IV Push Rate Calculation

Calculation of IV Push Incremental Rate Order: Ativan 3 mg IV Push 20 min preoperatively Supply: Ativan 4 mg per mL with drug literature guidelines of “IV infusion not to exceed 2 mg/min”

Calculation of IV Push Incremental Rate How much Ativan should you prepare? Step 1. Convert No conversion is necessary Step 2. Think You want to give less than 1 mL

Calculation of IV Push Incremental Rate How much Ativan should you prepare? Step 3. Calculate

Calculation of IV Push Incremental Rate What is a safe infusion time?

Calculation of IV Push Incremental Rate How much should you infuse every 15 seconds? 1 min = 60 seconds 1½ min = 1½ 60 = 90 seconds

Calculation of IV Push Incremental Rate X = 0.125 mL = 0.13 mL of Ativan 4 mg per mL infused IV push every 15 seconds will deliver 3 mg of Ativan

IV Infusion Time To calculate IV infusion time mL is known: Or, use ratio-proportion:

IV Infusion Time To calculate IV infusion time Flow rate in drops per min Drop factor and volume are known

IV Infusion Time Or, use ratio-proportion: “T” is the unknown

IV Fluid Volume To calculate total infusion volume mL is known: Or, use ratio-proportion:

IV Fluid Volume To calculate IV volume Flow rate (drops per min), drop factor, and time are known: “V” is the unknown