Intravenous fluid therapy

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This page is for adult patients. For pediatric patients, see: Intravenous fluid therapy (peds) or critical care quick reference for bolus doses by weight.

Background

Composition of Different Intravenous Fluids

Fluid [1] Osm Na Cl Glucose(g/L) pH Buffer K Ca Mg
Plasma 289 140 103 7.4 HCO3 22-32 4 5 2
Normal Saline (NS) 308 154 154 0 5.0 0 0 0 0
D5NS 560 154 154 50 0 0 0
Lactated Ringers 273 130 109 0 6.5 Lactate 28 4 3 0
Plasmalyte 295 140 98 0 5.0 Gluconate 23/Acetate 27 5 0 3
D5 1/2NS 406 77 77 500 4.5 0 0 0 0
D5Water 252 0 0 50
5% Albumin 309 130-160 130-160 6.4-7.4 <1

Total Body Water

  • Total Body Water (TBW) = 0.6 x weight (kg)
    • Of which, 2/3 is intracellular and 1/3 extracellular
      • 1/4 of extracellular is vascular

Acute Repletion (Bolus)

Adult

Pediatric

See critical care quick reference for drug doses by weight.

Maintenance Fluids

Adult

  • Insensible losses = 300-400 cc/m2/d
  • Adult Standard: D5 0.45%NS at 75-125 mL/hr + 20meq/L of KCl
  • Deficit: % dehydration x baseline weight
  • Daily volume needed = maintenance + deficit - fluid already given (i.e. boluses)
    • Hourly rate daily volume/24 hr
      • (or correct 1/2 of deficit in first 8 hr, remainder in next 16)
  • Calculation 1
    • 100 cc/kg/d (4cc/kg/h) 1st 10 kg
    • 50 cc/kg/d (2cc/kg/h) 2nd 10 kg
    • 20 cc/kg/d (1cc/kg/h) each kg > 20
  • Calculation 2
    • 1500 cc/m2/d (bsa (m2) = sqr rt [wt (kg) x ht (cm)]/3600

Pediatric

  • Maintenance fluid default: D5-LR + 20meq/L of KCl or other isotonic solution
    • Isotonic fluids are now preferred (2019 AAP update)[2]

4-2-1 Rule

Rule

  • mL/hr =
    • (4 x first 10kg) +
    • (2 x second 10kg) +
    • (1 x every 1kg after)
  • Example: For a 34 kg infant, you should run the IVF at 74 mL/hr. Often people choose to round to multiples of 5.

Alternative Method

Weight (kg)

Fluid Rate
Example
<10
4 mL/kg per hour

8 kg infant:

4mL/kg per hour x 8 kg

10 to 20

40 mL/h +

2 mL/kg per hour per each add kg

15 kg child:

40 mL/h +

2 mL/kg per hour x 5 kg

>20

60 mL/h +

1 mL/kg per hour per each add kg

30 kg child:

60 mL/h +

1 mL/kg per hour x 10 kg

Quick Reference (Peds)

Age Weight (kg) IVF (mL/hr)
Premature 2 8
Newborn 3.5 14
2mo 5 20
4mo 6.5 26
6mo 8 32
8mo 9 36
12mo 10 40
15mo 11 42
2yr 13 46
3yr 15 50
5yr 19 58

Electrolytes

  • Maintenance Na = 3 mEq/kg/d; K = 2 mEq/kg/d
  • Deficit = [desired - measured mEq/L] x fD x wt (kg)
  • fD (distribution factor) Na = 0.6, K = 0.6, Cl = 0.2-0.3, HCO3 = 0.5
  • (Maintenance + deficit)/daily volume = concentration of electrolyte in fluid to be given
  • 4mL/kg of H2O lost, ups Na by 1meq
  • Normal saline (NS) = 154 mEq Na/L, 1/2 NS = 77 mEq/L, 1/4NS = 38 mEq/L

See Also

External Links

References

  1. Paucis Verbis: Composition of intravenous fluids. http://www.aliem.com/paucis-verbis-composition-of-intravenous-fluids/ Published January 3, 2013. Accessed August 29, 2015
  2. Leonard G. Feld, Daniel R. Neuspiel, Byron A. Foster, Michael G. Leu, Matthew D. Garber, Kelly Austin, Rajit K. Basu, Edward E. Conway, James J. Fehr, Clare Hawkins, Ron L. Kaplan, Echo V. Rowe, Muhammad Waseem, Michael L. Moritz, SUBCOMMITTEE ON FLUID AND ELECTROLYTE THERAPY; Clinical Practice Guideline: Maintenance Intravenous Fluids in Children. Pediatrics December 2018; 142 (6): e20183083. 10.1542/peds.2018-3083