Fluids and Electrolyte Balance

Plasma

3 L of the body

Interstitial Fluid

10 L of the body /

Intracellular Fluid

28 L of the body / potassium (K+), phosphate (HPO4^2-), protein

Adult I&O

2600 ML/Day

Fluid Volume Deficit

Hypovolemia (Isotonic dehydration) lack of both water and electrolytes causing a decrease in circulating blood volume

Compensatory Mechanisms to FVD

Increased Thirst, Antidiuretic hormone release (ADH) and aldosterone release

Adverse reaction to FVD

seizures, hypovolemic shock

Causes of FVD (Hypovolemia)

• Skin Loss

• GI loss

• Renal system loss

• Burns

• Hemorrhage or plasma loss

Causes of dehydration

• hyperventilation

• prolonged fever 

• diabetic ketoacidosis

• Osmotic diuresis 

• Excessive salt intake  

Expected Findings for Hypovolemia / Dehydration

Hypothermia (FVD) or hyperthermia (dehydration), tachycardia, tachypnea, decreased central venous pressure, oliguria, flattened neck veins, sunken eyeballs

Lab Tests Findings for Hypovolemia / Dehydration

• HCT increased in both

• Blood osmolarity increased 

• Urine Gravity increased 

• Blood Sodium increased 

• BUN increased 

Nursing Care for Hypovolemia / Dehydration

• Measure client weight daily at same time

• Blood pressure 

• Neurological status 

• Monitor I&O

Hypervolemia

excess water and electrolytes (ex. increase sodium causes the body to retain more water) 

Adverse effects of FVE (Hypervolemia)

pulmonary edema and heart faliure

Compensatory Mechanisms to FVE (Hypervolemia)

increase release of natriuretic peptides (causes increased excretion of sodium and water by kidneys) then decreased release of aldosterone

Hypervolemia Causes

• Kidney Failure

• Heart Failure 

• Cirrhosis

• Increased glucocorticosteroids  

• Hypertonic fluids

Overhydration Causes

• excessive water intake w/ no electrolyte replacement 

• Syndrome of Inappropriate antidiuretic hormone (SIADH) (excess of ADH)

• Excess D5W, hypotonic Solutions, Enemas  

Expected findings of Hypervolemia / overhydation

Tachycardia, Tachypnea, hypertension, Crackles, edema, distended neck veins, weight gain

Hypervolemia Lab tests

• Hct decreased

• BUN decreased 

Overhydration Lab Tests

• Decreased Hct = hemodilution

• Sodium decreased

• Respiratory alkalosis

• Chest x-rays can indicate pulmonary congestion.

Nursing Care for Hypervolemia / Overhydration

• Sodium restriction

• Fluid restriction 

• Lung sounds for crackles

• ABGs

• Semi-fowlers 

• Reposition every 2hr / support arms and legs (decrease dependent edema)

Main objectives of Electrolytes

• regulate fluid balance

• hormone production,

• strengthen skeletal structures,

• act as catalysts in nerve response,

• muscle contraction,

• metabolism of nutrients.

Sodium Range

135 to 145 mEq/L

Calcium Range

9 to 10.5 mg/dL

Potassium Range

3.5 to 5 mEq/L

Magnesium Range

1.3 to 2.1 mEq/L

Chloride Range

98 to 106 mEq/L

Phosphorus Range 

3 to 4.5 mg/dL

Sodium

major electrolyte found in ECF and is present in most body fluids or secretions

Sodium Objectives

maintenance of acid-base and fluid balance, active and passive transport mechanisms, and irritability and conduction of nerve and muscle tissue.

THINK NEURO

Hyponatremia

• an excess of water in the plasma or loss of sodium-rich fluids.

• x impairs the cell's ability to generate an action potential

• Water moves from the ECF into the ICF, which causes cells in the brain and nervous system to swell.

• Need Isotonic or hypertonic IV

Hyponatremia Risk Factors

• Deficient ECF volume

• adrenal insufficiency

• SIADH (Syndrome of Inappropriate Antidiuretic Hormone Secretion)

• heart failure, cirrhosis, nephrotic syndrome

• Hyperglycemia

Hyponatremia Findings

hypothermia, Tachycardia, rapid thready pulse, hypotension, muscle weakness with possible respiratory compromise, hyperactive bowel sounds,, cramping

Hypertonic IV fluids

solutions that has a greater concentration of particles as blood, such as 3% or 5% sodium chloride

Hypernatremia

• cause significant neurologic, endocrine, and cardiac disturbances.

• Increased sodium causes hypertonicity of the blood. This causes a shift of water out of the cells, making the cells dehydrated

Hypernatremia Risk Factors

Heat stroke, sodium retention (Cushing’s Syndrome), fluid losses, diabetes insipidus

Hypernatremia Findings

dry and sticky mucous membranes, dry and swollen tongue that is red in color,

Hypotonic IV fluids

solutions that has a lesser concentration (dilute) of particles as blood, including

• Dextrose 5% in water, Dextrose 10% in water,

• 0.225% sodium chloride, 0.45% sodium chloride, and Dextrose 5% in 0.45% sodium chloride.

Potassium

• cell metabolism; transmission of nerve impulses; functioning of cardiac, lung, and muscle tissues; and acid-base balance.

• Potassium has reciprocal action with sodium.

THINK CARDIAC

Extracellular Fluid (ECF)

High in sodium (Na+), calcium (Ca2+), and chloride (Cl-) ions. 

Hypokalemia Risk Factors

• Hyperaldosteronism

• Receiving total parenteral nutrition

• Metabolic alkalosis

Aldosterone

a steroid hormone regulates blood volume and pressure by controlling sodium and potassium balance in the kidneys, promoting sodium retention and potassium excretion

Hypokalemia Expected Findings

• decreased muscle tone and hypoactive reflexes

• paresthesias

• Flatt T and U wave / arrhythmias 

• ileus

• Anxiety 

Care for Hypokalemia

• Never IV bolus (cardiac arrest)

• If clients take digoxin x can cause digoxin toxicity

Hyperkalemia

• uncommon in clients who have adequate kidney function.

• potentially life-threatening due to the risk of cardiac dysrhythmias and cardiac arrest

Expected Findings for Hyperkalemia

hypotension, slow irregular pulse, lack of refluxes, Muscle cramps (EARLY) and Muscle paralysis (LATE)

Peaked T waves, Widened PR and QRS

Care for Hyperkalemia

• continuous ECG

• potential dialysis 

• administer dextrose or regular insulin to promote potassium movement into ICF, Kayexalate, Thiazide diuretics

Meds for Hyperkalemia

Loop diuretic and Sodium polystyrene

Hypocalcemia risk factors

chronic diarrhea, laxative missus, crohn’s disease, bariatric surgey

Hypocalcemia Expected findings

• Numbness and tingling (fingers and around mouth)

• Muscle spasms

• Positive Chvostek’s sign (tapping on the facial nerve triggering facial twitching)

• Positive Trousseau’s sign (hand/finger spasms with sustained blood pressure cuff inflation)

• Seizures

(NOT ENOUGH SEDATIVE)

Hypercalcemia risk factors

thiazide diuretic or long-term glucocorticoid use, Paget’s disease, hyperthyroidism and hyperparathyroidism, and bone cancer.

Hypercalcemia Findings

shortened QT and ST intervals / cardiac arrest (TOO MUCH SEDATIVE)

Where is Magnesium found

Most of the body’s x is found in the bones, very small amount is found in ECF.

THINK MUSCLES

Hypomagnesemia Expected findings

positive Chvostek’s and Trousseau’s signs, hypertension (NOT ENOUGH SEDATIVE)

Hypermagnesemia expected findings

prolonged PR interval and widened QRS, decreased respiratory rate, Muscle paralysis (TOO MUCH SEDATIVE)

Osmosis

the net movement of water molecules across a semipermeable membrane from a region of higher water concentration (lower solute concentration) to a region of lower water concentration (higher solute concentration) to achieve equilibrium

Phosphate

2.4-4.4

HYPERphosphatemia findings and interventions

Calcified deposits in joints, arteries, kidneys, skin. Tetany

Administer Ca supplement

HYPOphosphatemia findings

CNS depression

Blood pH

7.35 to 7.45

Sodium and Potassium

Inverse Relationship

Magnesium and Potassium

Direct Relationship

Calcium and Phosphate

Inverse Relationship

Magnesium and calcium

Direct Relationship