FLUID AND ELECTROLYTES

What is homeostasis in terms of fluid and electrolytes?

Maintenance of fluid and electrolyte composition kept within a narrow limit of normal — things need to be even/equal in the body

What fraction of body fluid is located within the cells (intracellular)?

Two-thirds of body fluid is intracellular

What are the three parts of extracellular fluid (ECF)?

Interstitial spaces (fluid between cells)

Approximately how many liters of plasma

interstitial fluid

How does water content in the body change with age?

Infants have the highest percentage of water in the body; water content decreases with age

What causes a plasma-to-interstitial fluid shift

and what does it result in?

What is given to help shift fluid from interstitial back to plasma?

Albumin

Can a nursing student hang (administer) albumin?

No — albumin is a blood product; students can only watch

Define osmosis.

Movement of water from an area of low solute concentration to high solute concentration until the solutes are equal on both sides

What is first spacing?

Normal fluid distribution

What is second spacing?

Edema

What is third spacing?

Fluid accumulates in a part of the body where it shouldn't be and can't easily get out (e.g.

Define ascites.

Accumulation of fluid in the peritoneal cavity causing abdominal distension

What are common causes of ascites?

Cirrhosis of the liver

What are signs/symptoms of ascites in a patient?

Large

What is insensible water loss?

Continuous loss of water through the skin and respiratory tract that cannot be measured (e.g.

What factors increase insensible water loss?

Fever

About how much fluid is lost daily through insensible respiratory loss

skin loss

What is sensible water loss?

Measurable fluid loss such as urine

What increases stool fluid loss and by how much is normal?

Normal is 100-200 mL/day; increases with diarrhea

What fluid/electrolyte losses occur with burns?

Fluid loss through damaged skin and loss of electrolytes (mainly sodium and potassium)

Why does heart failure cause fluid/electrolyte imbalance?

Fluid retention due to poor heart function; dilution of electrolytes can lead to swelling

What causes fluid volume deficit (FVD)?

Abnormal loss of normal body fluids

What neurological changes are seen in fluid volume deficit?

Restlessness

What are key assessment findings in fluid volume deficit?

"Thirst

What cardiovascular signs occur with fluid volume deficit?

Hypotension and tachycardia

What happens to weight in fluid volume deficit vs excess?

Deficit: acute weight loss. Excess: weight gain

What lab values are elevated in fluid volume deficit?

"Elevated hematocrit

What does a high BUN indicate?

That the patient is not drinking enough fluid / is dehydrated

What is the priority assessment for fluid volume deficit?

Assess blood pressure (hypotension) to prevent the patient from going into shock

What are nursing interventions for fluid volume deficit?

"Start IV fluids

Why should IV fluids be started for a patient with fluid volume deficit?

To begin correcting dehydration and getting their numbers back to normal

Why elevate the legs in fluid volume deficit management?

To promote venous return to the heart and reduce ankle swelling

What is a key reason seniors avoid drinking fluids?

They don't want to get up to urinate because they're afraid of falling

What foods/drinks should be avoided or limited due to their dehydrating effect?

Caffeinated drinks (e.g.

What skin findings indicate fluid volume deficit?

"Diminished skin turgor

What oral finding indicates severe dehydration?

Dry oral mucous membranes and a furrowed tongue (visible grooves/lines in the tongue)

What is fluid volume excess (hypervolemia)?

Excessive intake of fluids or abnormal retention of fluids resulting in too much fluid in the body (e.g.

What is the treatment goal for fluid volume excess?

Remove the fluid without changing the electrolyte composition

What clinical manifestations occur with fluid volume excess?

"Headache

What happens to urine output in fluid volume excess with normal renal function?

Polyuria (increased urine output)

What lab value changes occur with fluid volume excess?

"Decreased hematocrit

What nursing management is used for fluid volume excess?

"Explain the reason for fluid restriction

Why should salty foods be avoided with a fluid restriction?

Salt makes patients thirsty

What skin findings are seen with fluid volume excess?

"Edema

What bony areas should be assessed for pitting edema/pressure injury risk?

Soft tissues overlying the tibia

How is pitting edema assessed?

By pressing with the thumb or forefinger over the edematous area and watching if/how far it stays indented

Compare neurological effects of fluid deficit vs excess.

"Deficit: lethargic

What is paresthesia?

A pins-and-needles tingling sensation (like when a limb 'falls asleep' and is coming back)

Compare cardiovascular effects of fluid deficit vs excess.

"Deficit: weak thready pulse

What is orthostatic hypotension?

A drop in blood pressure that occurs with position change (e.g.

Compare respiratory effects of fluid deficit vs excess.

"Deficit: rapid

Compare GI effects of fluid deficit vs excess.

"Deficit: decreased GI motility

Compare skin/mouth effects of fluid deficit vs excess.

"Deficit: dry scaly skin

What are the nursing diagnoses associated with hypovolemia?

"Deficient fluid volume

What are the nursing diagnoses associated with hypervolemia?

"Excess fluid volume

How much does 1 liter of water weigh

and how many pounds is that?

Why should daily weights be done at the same time each day?

To get an accurate

What is the overall goal of treatment for fluid imbalances?

Correct the underlying cause so the imbalance doesn't keep recurring

What are the three types of IV fluids based on tonicity?

Isotonic

What happens to a cell in a hypotonic solution (memory trick)?

"The cell expands/gets bigger — remember ""hypo-hippo

What happens to a cell in a hypertonic solution?

The cell shrinks (lyses/gets smaller)

Describe hypotonic IV fluids.

More water than electrolytes; water moves from ECF into the cell (ICF) by osmosis; monitor for changes in mentation

Describe isotonic IV fluids.

Expand only the extracellular fluid compartment with no net loss or gain from the ICF; ideal to replace ECF volume deficit; must watch for fluid overload

Describe hypertonic IV fluids.

Initially expand and raise the osmolality of the ECF

What type of solution is D5W and what are its key features?

"Isotonic; contains dextrose (sugar) for calories

What is ketosis?

When the body uses fat as its main fuel source instead of glucose

What type of solution is normal saline and what are its key features?

"Isotonic; sodium chloride; expands IV volume; preferred fluid for immediate response but has risk of fluid overload and hyperchloremic acidosis; compatible with blood products and most medications"

What is hyperchloremic acidosis?

A condition where blood pH drops below 7.35 and chloride in the body increases

Why is normal saline always used when administering blood?

Because it is compatible with blood products (used to prime blood tubing)

What type of solution are lactated ringers and what electrolytes do they contain?

"Isotonic; similar in composition to plasma; contains potassium

When are lactated ringers contraindicated and why?

"Contraindicated in hyperkalemia (high potassium)

What conditions are lactated ringers used to treat?

Burns and GI losses

What type of solution is D5 half normal saline (D5 1/2NS) and its features?

"Hypertonic; provides ~170 calories; common maintenance fluid; potassium chloride can be added"

What type of solution is D10W and its features?

"Hypertonic; provides ~340 calories; provides some free water but no electrolytes; should not be given in a peripheral line for long due to risk of clogging veins with sugar buildup"

What are plasma expanders (colloids) and give examples.

"Fluids that stay in the vascular space and increase osmotic pressure; examples include albumin

What role does sodium play in the body?

"Major role in water balance and neuromuscular activity; affects water distribution between ECF and ICF; cerebral cells are very sensitive to changes in serum sodium

Define hypernatremia.

Elevated serum sodium occurring with water loss or sodium gain

What is the body's primary protection against hypernatremia?

Thirst triggered by the hypothalamus

What are symptoms of hypernatremia?

"Thirst

What does the FRIED SALT mnemonic stand for (hypernatremia)?

"Fever

How is hypernatremia treated?

"Treat the underlying cause; replace fluid orally or IV with isotonic or hypotonic fluid; for excess sodium

Define hyponatremia.

Low serum sodium resulting from loss of sodium-containing fluids and/or water excess

What are symptoms of hyponatremia?

"Confusion

How is hyponatremia caused by water excess treated?

Fluid restriction; severe cases may need small amounts of IV hypertonic saline (3% normal saline)

What nursing interventions treat hyponatremia from abnormal fluid loss?

Fluid replacement with sodium-containing solutions and drugs that block vasopressin (ADH)

What does the SALT LOSS mnemonic stand for (hyponatremia)?

"Stupor/coma

What is potassium's classification and main functions?

"Major intracellular fluid (ICF) cation; necessary for transmission/conduction of nerve and muscle impulses

What foods are sources of potassium?

"Fruits and vegetables such as bananas

Do salt substitutes contain potassium?

"Yes — salt substitutes contain potassium and should be avoided by patients with high potassium levels"

How is potassium regulated in the body?

"Stored in the blood

What causes hyperkalemia?

"Impaired renal excretion

What are manifestations of hyperkalemia?

"Cramping leg pain

What does a tall

peaked T wave on an EKG indicate?

What medication is used to treat hyperkalemia and what is its generic name?

Sodium polystyrene sulfonate (brand name Kaexalate)

What newer medication treats hyperkalemia without causing the patient to run to the bathroom?

Lokelma (a powder mixed with juice or water)

How does IV insulin with sodium bicarbonate help treat hyperkalemia?

It shifts potassium from the extracellular fluid into the intracellular fluid

What does IV calcium gluconate do in hyperkalemia treatment?

Reverses the membrane effects of elevated ECF potassium

What does the MURDER mnemonic stand for (hyperkalemia)?

"Muscle cramps

What causes hypokalemia?

"Increased loss through kidneys or GI tract (vomiting