Fluid Balance

Name 2 isotonic IV fluids.

0.9% NS, Lactated Ringers

How is weight gain related to fluid retention?

1 L fluid retention = 1 kg or 2.2 lbs weight gain This is the relationship of weight to ___ gain.

Name 3 types of third spacing

1. Ascites - excess fluid accumulation w/i the peritoneal space, 2. Pulmonary edema - excess fluids that collect within the interstitium and alveolar spaces in the lungs, 3. Blistering - excess fluid collection under the skin r/t burns. These are types of _______ spacing.

What are the 3 main categories of fluid losses?

1. Inadequate intake, 2. Excessive loss, 3. Impairment of the body's ability to balance and manage fluids/electrolytes are the 3 main categories of ____________.

What is "pitting edema"?

A small depression or pit is left after finger pressure applied over swollen area.

What are some causes of hypovolemia?

Abnormal losses through the skin, GI tract or kidneys; Bleeding; Movement of fluids into a 3rd space

What is "fluid volume excess"? What is it also known as?

An actual excess of total body fluids, or a relative fluid excess in one or more fluid compartments. aka Fluid Overload.

What are some primary S/S of hypovolemia?

Cardiac manifestations (hypotension, tachycardia, weak pulse, irregular heart rhythm) are some primary s/s of___.

What are the primary clinical manifestations of fluid volume excess?

Cardiovascular overload and generalized edema

Give an example of a hypotonic IV fluid

D5 0.45% NS w/ 20 mEq KCl

What are some causes of dehydration?

Decreased fluid intake Decreased thirst mechanism Hyperventilation (loss of water vapor) Fever (sweating)

Which of the elevated electrolyte levels causes the neurological symptoms of lethargy, irritability, seizures, hyperreflexia, confusion, decreased LOC associated with dehydration?

Elevated serum Sodium levels (hypernatremia) cause _______ manifestations of dehydration. (Brain cells shrink as fluid is pulled out.)

What is brawny edema?

Firm, non-compressible __ that accompanies tissue injury and includes the release of clotting factors.

Where does the fluid go if you give hypotonic fluids via IV?

First to the interstitial space to increase the fluid level there

Where does the fluid go if you give isotonic fluids via IV?

First to the vasculature to increase the fluid level there

What are some causes of overhydration?

Fluid replacement with water only SIADH: Syndrome of Inappropriate ADH Excessive irrigation of a body cavity such as tap-water enemas

What occurs during the 2nd phase of third spacing? What can the patient present with?

Fluid shifts back into the vasculature. Patient may present with clinical manifestations of fluid volume excess.

What occurs during the 1st phase of third spacing? What can the patient present with?

Fluid shifts from the intravascular space into nonfunctional fluid spaces. Patient can present with clinical manifestations of hypovolemia.

What causes edema?

Fluid volume excess with increased water and sodium in the interstitial spaces causes ___.

What feature of dehydration causes electrolyte values to be abnormally elevated?

Hemoconcentration

What condition is pitting edema generally associated with?

Hypernatremia is generally associated with this.

What kind of solution is given for maintenance IV therapy?

Hypotonic solutions

What are the primary clinical manifestations of fluid volume deficit?

Increase in neurological activity and decreased cardiac output are the primary clinical manifestations of___ .

What are some causes of hypervolemia?

Increase in total body sodium (water follows) Impaired fluid balance regulation (r/t CHF, renal failure, cirrhosis, Cushing's) Excess ingestion of sodium in diet or medication

What is second spacing? What is this also known as?

Increased fluids in the interstitial compartment (aka edema.)

What are some causes of 2nd and 3rd spacing?

Increased venous pressure (increased osmotic pressure); Hypoalbuminemia (decreased oncotic pressure); Increased interstitial oncotic pressure; Increased interstitial hydrostatic pressure (obstructs lymph return); Inflammation; Acute intestinal obstruction; Abdominal surgery

Fluid volume excess could be caused by overhydration or hypervolemia or edema. How can you tell which is causing it?

Lab values for sodium can help tell you the cause of FVE. Overhydration has decreased sodium. Hypervolemia/edema has increased sodium.

What is dehydration?

Loss of the body's water or hypotonic fluids only, without a loss of significant amounts of electrolytes. Serum becomes concentrated, serum sodium increases, water is drawn into the intervascular space resulting in cellular ____.

What are the 3 levels of dehydration?

Mild = 2% body wt or 1-2L Moderate = 5% body wt or 3-5L Severe = 8% body wt or 5-10L

What is the correct maintenance therapy IV rate?

No more than 126 mL/hr, or 2 mL/min

What is first spacing?

Normal distribution of body fluids among compartments.

Name 4 types of edema

Pitting, generalized, periorbital and scrotal region, brawny are 4 types of _______ .

What is the role of protein in fluid volume distribution?

Proteins (albumin) draw water after them. Hypoalbuminemia (low blood levels of albumin) may cause 3rd spacing (ascites) since the reduced oncotic pressure in the vasculature allows the fluid to escape (starving children w/ big bellies.)

What are the critical complications of fluid overload?

Pulmonary congestion/pulmonary edema Cerebral edema in overhydration

What are the primary S/S of fluid overload or overhydration?

Rapid weight gain; Respiratory changes (SOB, dyspnea, irritative cough, moist crackles); Edema (generalized or anasarca or pitting)

What is the rule of thumb for replacing a major fluid deficit (rate)?

Replace approximately 1/2 the fluid deficit w/i the first 24 hours. Replace the rest w/i the next 48-72 hours.

What electrolyte abnormalities are caused by dehydration?

Sodium > 150 mEq/L Elevated Hemoglobin/Hematocrit & BUN Serum osmolality > 300mOsm/kg Urine specific gravity > 1.030

What is third spacing?

This is abnormal fluid collection in areas that normally contain minimal or no fluids.

What is overhydration?

This is an excess of body fluids due to fluid intake or retention greater than the body's need.

What is generalized edema?

This is an excess of interstitial fluids accumulating predominantly in the lower extremities of ambulatory patients, and in the dependent regions in bedridden patients.

What is hypervolemia?

This is increased blood volume, with the body retaining both water and sodium in normal proportions. It is excess fluid in the vascular circuit itself.

What is hypervolemia?

This is isotonic overhydration with excess fluids in the extracellular fluid spaces resulting in circulatory overload and edema.

What is hypovolemia?

Too low of blood volume. Isotonic fluids (water and electrolytes both) lost from the intravascular compartment.

What happens to urine lab values in FVE?

Urine specific gravity <1.010 Urine osmolarily < 50 mOsm/L In FVE the kidneys will be putting out large amounts of dilute urine.

What is overhydration?

Water intoxication. The body gains water only. This leads to water being drawn into cells causing cellular swelling, and in the brain cerebral edema and impaired neuro function.

If a patient is hypovolemic, which IV fluids do you give second?

You give hypotonic IV fluids 2nd, when a patient is hemodynamically stable, in the case of ____.

If a patient is hypovolemic, which IV fluids do you give first?

You give isotonic IV fluids first if a patient is ____.