Flashcards in IV Fluids Deck (76):
Things to Consider with IV Fluids
Why an IV?
Know your patient: age, heart/lung/kidney problems
Watch for signs of dehydration
Monitor: weight, BP, HR, BMP, & urine output
Disorders of Volume in a Surgical Patient
Disorders of Electrolyte Concentrations
Sequelae of Inappropriate Fluid & Electrolyte Management
Increased length of stay
Delayed wound healing
Cerebral edema, seizures, death
Pulmonary edema, CHF, renal failure
3 Things to Accomplish with IV Therapy
Reason for Maintenance Therapy
Patient not expected to eat or drink for a while
Reason for Replacement Therapy
Correct abnormalities in volume and/or electrolytes
Reasons for Volume Resuscitation
What does total body water depend on?
Total Body Water as a % of Weight Decreases in
Morbidly obese individuals
People with low muscle mass due to disease or injury
How much of total body weight does the intracellular fluid hold?
How much of total body weight does the extracellular fluid hold?
What does the plasma portion of the ECF contain?
Cations: K+, Ca++, Mg++
Anions: Cl-, HCO3-, proteins, sulfates, organic acids
What does the ICF contain?
Main: K+, Mg++
Anions: phosphates, sulfates, & proteins
What can flow freely among all of the compartments in the body?
Normal Body Fluid Osmolarity
Types of Fluid Replacement Products
Types of Crystalloids
Dextrose in water
Ringer's Lactate (physiologic)
Examples of Colloids
Solution that contains small molecules & are able to pass through semi-permeable membranes
Solutions that contain high molecular weight proteins or starch
Can not cross semi-permeable membranes
Remain in the intravascular space
When are colloids indicated?
Rapid hemodynamic equilibration is required
What is important when addressing a specific situation?
Composition of the solution
Rate of administration
Why are isotonic solutions given?
To expand the ECF volume
Why are hypotonic solutions given?
To reverse dehydration
Why are hypertonic solutions given?
To increase the ECF volume & decrease cellular swelling
Examples of Isotonic Fluids
What does Ringer's solution contain?
What is missing from Ringer's solution?
What does Lactated Ringer's contain?
What is missing from Lactated Ringer's
What is hypotonic solutions used for?
Prevent & treat cellular dehydration by providing free water to the cells
Contraindications to Hypotonic Solutions
Acute brain injuries
Why are hypotonic solutions contraindicated in acute brain injuries?
Cerebral cells are very sensitive to free water, absorbing it rapidly & leading to cerebral cellular edema
Examples of Hypotonic Fluids
5% dextrose in water (D5W)
D5W & the Body
Free water shifts from vessels to cells
1/2 NS & 1/4 NS & the Body
Provide free water to cell as well as small amounts of sodium & chloride
Frequently used as maintenance therapy
Adverse Effects of Normal Saline (NS)
Adverse Effects of Lactated Ringer's
Adverse Effect of D5W
Clinical Types of Volume Deficit
Total body water
Total Body Water Volume Deficit
Ex: diabetes insipidus, osmotic diarrhea
Extracellular Volume Deficit
Salt & water loss
GI tract losses
Examples of Salt & Water Loss in Extracellular Volume Deficit
Examples of GI Tract Losses
Intravascular Volume Deficit
Define "Third Space"
Acute sequestration in a body compartment that is not in equilibrium with ECF
Causes of Third Spacing
Major venous obstruction
Capillary leak syndrome
Clinical Parameters to Help Judge Degree of Volume Loss
Urine sodium concentration
States of Increased Fluid Loss
Other states of increased metabolic activity
Clinical Findings of Extracellular Fluid Depletion
Decreased urine output
Drowsiness to coma
Decreased skin turgor
Dry mucous membranes
Orthostatic hypotension progressing to hypotension
Lab Findings in Extracellular Fluid Depletion
Elevated urine sodium
Urine specific gravity >1.020
Clinical Signs to Monitor in Extracellular Fluid Depletion
Daily labs: HCT, BMP
Signs of HypOvolemia
Flat neck veins
Decreased skin turgor
Signs of HypERvolemia
Management of Hypovolemic Shock
1-2 L of isotonic solution on rapid infusion
Continue until clinical signs begins to improve
Type of Replacement Fluid in Hypovolemic Shock
Blood up to a HCT of 35%
Then crystalloid vs. colloid (need more crystalloid than colloid)
Advantages of Albumin over an Isotonic Saline
More rapid volume expansion
Lesser risk of pulmonary edema due to dilutional hypoalbuminemia
Disadvantages of Albumin over an Isotonic Solution
Not as readily available
Why not hyperoncotic starches in treatment of hypovolemia?
Increased risk of acute kidney injury
What should be given if a patient becomes acidotic on isotonic saline for the treatment of hypovolemia?
Add sodium bicarbonate to the infusate
Treatment of Mild to Moderate Hypovolemia
Administer isotonic solution at a rate greater than the rate of continued fluid losses
Continued Fluid Loss is the Sum of
Other fluid losses (GI)
How much more fluid than fluid losses should be administered?
What type of fluid should be used in hypernatremia?
What type of fluids should be used in hyponatremia?
What type of fluid should be used in blood loss?
When would potassium or bicarbonate need to be added to the fluids?
What are disorders of sodium regulated by?
Renal water handling
What is hypernatremia usually due to?
Management of Hypernatremia
Correct slowly: 10 mEq/L
Rate of infusion calculated using the Midas Formula
Things to Consider When Determining how Much Fluid to Give
What is your starting point?
What are expected losses?
Measureable: urine, GI
Insensible: sweat, exhaled, fever
Fever: increase by 100 mL/day/degree centigrade
Who needs maintenance therapy?
Unable to eat or drink for a prolonged period of time
Goal of Maintenance Therapy
Maintain fluid & electrolyte balance
Provide good "nutrition"