IV Fluid Management

1. IV Fluid Management DFM Fellows Summer 2010

2. Objectives • Understand the basics of fluid administration • Review basics of various fluid options • Be able to calculate maintenance fluid rates based on patient weight • Be able to estimate fluid losses • Be able to calculate fluid replacement

3. The Learning Curve • The information provided is general information regarding fluid administration. Keep in mind that different clinical situations require you to integrate your clinical knowledge of the body and its physiology to make an educated decision. Always consider the patients age, condition, medications and co morbidities before administering fluids. • And as you screw up you will learn!

4. IV Fluids • The role of IV fluid administration is to • Provide volume replacement • Administer medications, electrolytes, blood products, or diagnostic reagents • Maintenance/correction of nutritional status • Components of fluid and electrolyte therapy • Maintenance • Replacement

5. Normal Plasma Electrolyte Composition

6. 0 Commonly Used IV Solutions

7. Components of Fluid and Electrolyte Therapy • Maintenance • meeting the requirements for fluid and electrolyte intake that balance daily obligatory losses 2. Replacements (Ongoing Losses) • providing for ongoing and additional losses that occur during the course of therapy (surgery phases: pre/intra/post operative)

8. The Balancing Act • IN • Drinking • Eating • Metabolism • 3mL/kg • IV Fluids? • OUT (~1-1.6L/day for ave. adult) • Urine • 12-15mL/kg/day • Feces • 3mL/kg • Insensible losses • 10-13mL/kg/day With no unusual stresses or losses and normal renal function intake can be balanced to outputs

9. Maintenance: Water and Electrolyte Needs • Replace Urine and insensible losses (1-2 L/day) • Replace sodium and potassium loss • Na: need 47-147 mEq/day (1-3mEq/kg/day) • K: leak about 20mEq/day

10. Calculating Maintenance Dosing • 4-2-1 rule to calculate hourly rate • In one hour, a person needs: • 4mL/kg for the first 10kg (0-10) • 2mL/kg for the next 10kg (10-20) • 1mL/kg for the remaining kg (>20) • 100-50-20 rule for daily requirements • In one day a person needs: • 100 mL/kg for the first 10kg • 50 mL/kg for the second 10kg • 20 mL/kg for the remaining • *Remember to divide by 24 for hourly rate*

11. 0 Maintenance Considerations • Fever or high ambient temperatures • Water loss increases by 100-150ml/day for every degree above 37C • Sweating • Consider using a hypotonic solution for fluid replacement (0.45% saline) • Humidity • Breathing humid air decreases loss while dry air may increase relative losses

12. Example Calculate maintenance fluids for a 75 kg patient who is NPO • 4-2-1 Rule • 10 x 4 = 40 mL • 10 x 2 = 20 mL • 55 x 1 = 55 mL • Total 115 mL/hr • 100-50-20 Rule • 10 x 100 = 1000mL • 10 x 20 = 200 mL • 55 x 20 = 1100 • Sub total 2300mL/day • Total 96 mL/hr

13. 0 So you know how to calculate fluid maintenance requirements but what happens if the patient has an initial deficit requiring rehydration other than maintenance?

14. 0 Think About It • A 50 kg patient comes into the ED with gastroenteritis What are you concerned about? • Dehydration • Electrolyte imbalance • Decrease in blood pressure What do you want to do? • Administer medication for nausea • Normalize Electrolytes • Expand her intravascular volume • Maintain normal fluid homeostasis (maintenance) • Replace lost fluid (resuscitation) • Account for ongoing losses if present (replacement) • She has had vomiting and has diarrhea x 3days

15. 0 Clinical Signs of Dehydration

16. 0 Clinical Signs of Dehydration • This is an objective finding • This is a rough estimate of fluid loss • Clinical signs may not be evident in adults • Adults are able to compensate better than children • Calculation • Fluid Deficits(L) = weight (kg) x % dehydration • Example: Our 50 kg patient with 5% dehydration: • 50kg x 5%= 2.5L deficit

17. 0 Estimate Deficit by Weight • Fluid and Weight • 1 L of fluid = 1 kg of weight • 1kg= 2.2 lbs • Use weight change to determine fluid loss/gain Calculate his fluid deficit 5lb = 2.3kg = = 2.3L fluid deficit Example: Suppose our gastroenteritis patient reports a 5lb weight loss with illness

18. Fluid Deficits • After deficit is determined • Our pt has a 2.3L deficit by weight • Replace half in 8 hours • 1,150mL/8hrs =143mL/hr for the first 8 hrs • Replace other half in the next 16 hours • 1150mL/16hrs =72mL/hr for the next 16hrs

19. 0 Total Flow Rate for Maintenance • Add maintenance to deficit and you’ll have a flow rate • Our 50kg patient with gastroenteritis has had a 5lb (2.3kg) weight loss Maintenance • 4mL/kg x 10kg = 40mL (0-10) plus • 2mL/kg x 10kg = 20mL (10-20) plus • 1cc/kg x 30kg = 30mL (20-50) TOTAL maintenance= 90mL/hr Deficit • 1,150mL/8hrs=143mL/hr for the first 8 hrs • 1150mL/16hrs=72mL/hr for the next 16hrs

20. Total Flow Rate • For the first 8 hrs • 90mL/hr + 143mL/hr = 233mL/hr • For the next 16 hours • 90mL/hr + 72mL/hr = 162mL/hr

21. Try it! • A 176lb athlete presents to the ER after collapsing during football practice. He weighed 184lbs at the beginning of practice. Write an order for IV fluids to correct for deficit and maintenance for the next 24 hours Note: Use patients current weight to determine maintenance

22. 0 Answer Maintenance 176lb = 80kg • 40mL (0-10) plus • 20mL (10-20) plus • 60mL (20-80) Total= 120mL/hr Deficit 184 - 176= 8lb = 3.6kg =3.6L = 3,600mL loss • 1,800mL/ 8 = 225ml/hr • 225 + 120= • 345 mL/ hr for the 1st 8 hrs • 1,800/16 = 112.5mL/hr • 112.5 + 120 = • 232.5 mL/ hr for the next 16 hrs