IV FLUIDS PRESENTATION

1. IV Fluids

2. Types of Fluids
Crystalloids
•Isotonic
•Hypotonic
•Hypertonic
Colloids
•Always hypertonic

3. Objectives
• Understand daily fluid and electrolyte
requirements for an average adult
• Understand the major components of
replacement fluid
• Maintenance versus Resuscitation
• Complications of fluid therapy

4. Input and Output
of the “Normal” Adult
• Minimal Obligatory Daily input:
– Ingested water: 500mL
– Water content in food: 800mL
– Water from oxidation : 300mL
» TOTAL: 1600mL
• Minimal Obligatory Daily water output:
– Urine: 500mL
– Skin: 500mL
– Respiratory tract: 400mL
– Stool: 200mL
» TOTAL: 1600ml
On average, an adult input and output is 30-35mL/kg/day (about
2.4L/day)

5. Electrolyte Requirements
• Sodium: 100-250meq (western diet)
• Potassium: 50-100meq
• Chloride: 60-150meq
• Bicarb: 1-3meq/kg/day

6. Contents of IV Fluid Preparations
Na
(mEq/L)
K
(mEq/L)
Cl
(mEq/L)
HCO3
(mEq/L)
Dextrose
(gm/L)
mOsm/L
D5W 50 253
NS 154 154 308
D5NS 154 154 50 564
Ringers
Lactate
(RL)
130 4 109 28 50 273

7. Maintenance Therapy
• Replaces the ongoing losses of water and
electrolytes under NORMAL physiological conditions.
• Used when the patient is not expected to eat or
drink normally for prolonged period of time.
• Patients who are afebrile, not eating, not physically
active require less that 1 L of electrolyte free water
per day.

8. Fluid Resucitation
• Correct existing abnormalities in volume status or
serum electrolytes
• Parameters used to assess volume deficit:
– Blood pressure
– Jugular venous pressure
– Urine sodium concentration
– Urine output
– Pre and post deficit body weight

9. Calculations of Fluid Requirement
Body Wt Fluid needed per day Per hour
First 10 kg BW 100ml/kg 4ml/kg
Second 10 kg BW 50ml/kg 2ml/kg
Subsequent kg 20ml/kg 1ml/kg
Other practical calculations
Body wt + 40 = ml of fluid per hour
or
2ml/kg/hr avg maintenance (esp post-op)

10. Rate of Repletion
• Severe volume depletion or hypovolemic shock: rapid
infusion of 1-2L isotonic saline (NS); 25-30ml/kg
• Mild to moderate hypovolemia:
– Choose a rate that is 50-100mL/h greater than estimated
fluid losses
• urine output 50ml/h
• insensible losses = 30ml/h
• additional loss such as GI, high fever (additional
100ml/day for each degree of temp >37C, etc)
– Choice of fluid: based on type of fluid that has been lost
and any co-existing electrolyte disorders

11. Understanding Salt and Water
Normal saline has
no free water and is
confined to ECF
space

12. Where is the Fluid Going?

13. Where is the Fluid Going?
Free water
content
ICF ECF Interstitial Intravascular
D5W 1000cc 660cc 340cc 226cc 114cc (11%)
½ NS 500cc 500cc 500 330cc
+ 55cc from
free water
content
170cc + 55cc
=225cc (22%)
NS 0 0 1000cc 660cc 330cc (33%)

14. Crystalloids
• A solution of small and low molecular wt particles.
• Solutes (MW<30,000) either ionic (Na+ , Cl-) or non-
ionic (e.g mannitol).
• Osmotic pressure zero
• Pass freely across the microvascular membrane.
• Inexpensive

15. Hypotonic Crystalloid Solutions
• Contain free water
• e.g. 0.45% saline and 5% Dextrose in water

16. Uses of Hypotonic Crystalloid Solutions
• Fluid loss & dehydration
• Hypernatremia
• Gastric fluid loss
• Cellular dehydration from excessive diuresis
• Slow rehydration

17. Isotonic Crystalloid Solutions
• e.g. Ringer’s solution, 0.9% normal saline
Uses of Normal Saline Uses of Lactated Ringers
• Shock Dehydration
• Resuscitation Burns
• Fluid challenges (?assess) GI tract fluid loss
• Blood transfusions Acute blood loss
• Hyponatrenia Hypovolemia
• DKA

18. Hypertonic Crystalloid Solutions
• e.g. DNS, 3% Saline
• Used in:
Heat related disorders
Fresh water drowning
Correction of severe hyponatremia (3% NaCl)

19. Adverse effects of large volume crystalloid infusion
• Extravascular accumulation in tissues like skin,
connective tissue & lungs.
• Inhibition of gastrointestinal motility due to gut
edema.
• Delayed healing of anastomosis.
• Saline-induced hyperchloremic acidosis.

20. Colloids
• High molecular wt substance.
• Largely remains in the intravascular compartment;
Generates oncotic pressure.
• e.g., human albumin, gelatins & dextrans.
• Molecular wt of a colloid directly influences its
intravascular persistence. Gelatins have smallest MW
and HES the highest.
• HES solutions have highest MW.

21. Human Albumin Solutions
•Contributes to 80% of normal oncotic pressure.
Hydroxyethyl Starch Solutions (Heta/Pentastarch)
•Starches derived from glycopectins & modified by
addition of hydroxyethyl groups.
•Increase in colloid osmotic pressure with HES equal to
that with albumin.
Gelatin solutions
•Derived from bovine collagen.
•Low MW substances

22. Summary
• Treat IV fluids as “prescription” like any other medication
• Determine if patient needs maintenance or resuscitation
• Choose fluid type based on co-existing electrolyte
disturbances
• Don’t forget about additional IV medications patient is
receiving
• Choose rate of fluid administration based on weight and
minimal daily requirements
• Avoid fluids in patients with ECF volume excess
• Always reassess whether the patient continues to require IVF