Module 5: Fluid and Electrolytes (ch. 10)

Fluid

Fluid

• 60% of a healthy individual is fluid (water and electrolytes)

• 40% is intracellular fluid

• 20% is extracellular

  • 5% = intravascular fluid (blood, plasma)

  • 14% = interstitial fluid (surrounding cells; lymph)

  • 1% = transcellular (cerebrospinal, pericardial, sweat, digestive)

Regulation of fluid

Fluid moves freely through compartments through permeable membranes; filtration and osmosis

hydrostatic pressure

Pressure exerted on the fluid via the walls of blood vessels; push force

Osmotic pressure

Fluid is pulled via a concentration gradient; pull force

Fluid volume deficit

• Hypovolemia

• When the loss of extracellular fluid volume exceeds the intake of fluid

• Water and electrolytes are lost in the same proportion

Pathophysiology of FVD

• Results from the loss of body fluids; can occur rapidly with decreased fluid intake

• Prolonged periods of inadequate fluid intake

Causes of FVD

• Vomiting

• Diarrhea

• GI suctioning

• Sweating

• Decreased fluid intake

• Inability to gain access to fluids

• Third space fluid shifts

• Diabetes insipidus

• Adrenal insufficiency

• Osmotic diuresis

• Hemorrhage

• Coma

Risk factors of FVD

• Decreased fluid intake

• Inability to gain access to fluids

• Third space fluid shifts

• Diabetes insipidus

• Adrenal insufficiency

• Osmotic diuresis

• Hemorrhage

• Coma

s/s of FVD

• Low BP

• High pulse

• Increased temperature

• Increased capillary refill time

• Acute weight loss

• Decreased skin turgor

• Oliguria

• Concentrated urine

• Low central venous pressure

• Flattened jugular

• Dizziness

• Weakness

• Thirst and confusion

• Sunken eyes

• Cool, clammy, pale skin

• Concentrated lab values (H/H. osmolality, specific gravity, BUN, creatinine, sodium)

Priorities of FVD

• Laboratory values

  • BUN (7-20)

  • Creatinine (0.7-1.3 for males; 0.6-1.1 for females)

• Daily weights

  • Same time every day

Treatment of FVD

• Oral fluid intake

• IV fluids

  • Isotonic electrolyte crystalloid solutions (lactated ringers; 0.9% normal saline) to expand volume

  • Hypotonic electrolyte solutions (0.45% normal saline) to provide electrolytes and water

Nursing considerations of FVD

• I&Os

• Daily weights

• Vitals

• Central venous pressure

• Level of consciousness

• Breath sounds

• Skin color, temperature, and turgor

Dehydration

The loss of water (alone) along with increased serum sodium levels

Fluid volume excess

An expansion of the extracellular fluid caused by the abnormal retention of water and electrolytes in the same proportion in which they exist in the extracellular fluid space

Pathophysiology of FVE

Simple fluid overload or the diminished function of the homeostatic mechanisms responsible for regulating fluid balance

Causes of FVE

• HF

• Kidney dysfunction

• Cirrhosis of the liver

• Consumption of excessive amounts of sodium

• Administration of excessive sodium containing fluid

s/s of FVE

• High BP

• Bounding pulse

• SOB; increases RR

• Elevated central venous pressure

• Increased urine output

• Edema

• Distended jugular

• Crackles heard in lungs

• Acute weight gain

• Low laboratory values (H/H, osmolality, specific gravity)

Priorities of FVE

• laboratory values

  • BUN

  • Hematocrit

• Chest x-ray for pulmonary congestion

Treatment of FVE

• Diuretics

  • Choice dependent of severity of hypervolemia, degree of renal impairment, and potency

  • Thiazide for mild to moderate hypervolemia

  • Loop for sever hyerpolemia

• Hemodialysis

• Sodium restrictions

Nursing considerations of FVE

• I&Os

• Daily weights

• Breath sounds

• Distilled water vs. local supply/bottled water

• Fluid restrictions

• Semi-fowlers positioning

• Skin care

• Patient education

Electrolytes

Active chemicals that carry positive (cation) or negative (anion) charges

Major cations

• Sodium

• Potassium

• Calcium

• Magnesium

• Hydrogen

Major anions

• Chloride

• Bicarbonate

• Phosphate

• Sulfate

Sodium

• Cation; positively charged

• High concentration in the ECF

• Important in regulating the volume of body fluid

• 135-145 mEq/L (hyponatremia; hypernatremia)

Potassium

• Cation; positively charged

• High concentration in ICF; low concentration in ECF

• 3.5-5 mEq/L (hypokalemia; hyperkalemia)

Calcium

• 8.6-10.2 mEq/L

• Hypocalcemia; hypercalcemia

Magnesium

• 1.8-3.6 mEq/L

• Hypomagnesia; hypermagnesia

Phosphorus

• 2.5-4.5 mEq/L

• Hypophosphatemia; hyperphosphatemia

Chloride

• 98-106 mEq/L

• Hypochloremia; hyperchloremia

Hyponatremia

A serum sodium level less than 135 mEq/L

Pathophysiology of hyponatremia

• Occurs due to an imbalance of water rather than sodium

• Acute = result of a fluid overload; dilution of sodium in the blood stream

• Low sodium in the urine occurs due to the kidneys retaining sodium to compensate for nonrenal fluid loss

Causes of hyponatremia

• Adrenal insufficiency

• Medication

• Nonrenal fluid loss (vomiting; diarrhea, sweating)

• Syndrome of inappropriate antidiuretic hormone secretion

s/s of hyponatremia

• Elevated pulse

• Hypotension weight gain

• Edema

• Orthostatic BP

• Altered mental status

• Poor skin turgor

• Dry mucosa

• Headache

• Decreased saliva

• Nausea vomiting abdominal cramping

Priorities of hyponatremia

• Urine sodium level

• Neurologic examination

• Laboratory values

• Medication review

• Demylination with fluids

Treatment of hyponatremia

• Sodium replacement

  • Oral

  • NG tube

  • Parenteral

• Isotonic IV solutions

  • Lactated ringers

  • 0.9% NS

• Fluid restriction

• Hypertonic solutions (only in acute/severe cases)

• AVP receptor agonists

Nursing considerations of hyponatremia

• I&Os

• Daily body weight

• Health history

• Level of AxO

• Encourage foods with high sodium contents

• Monitor lithium toxicity when hyponatremic

• Hypernatremia

  • A serum sodium level greater than 145 mEq/L

Pathophysiology of hypernatremia

Caused by a gain of sodium in excess of ware or a loss or water in excess or sodium

Causes of hypernatremia

• Fluid deprivation

• Lack of thirst response

• Administration of hypertonic enteral feedings without adequate water

• Diabetes insipidus

• Heat stroke

• Drowning in salt water

• Impaired hemodialysis

• IV hypertonic solutions

• Excessive sodium bicarb use

Risk factors of hypernatremia

• Age (old, young)

• Cognitive impairment

s/s of hypernatremia

• Elevated pulse

• High BP

• Thirst

• Elevated temperature

• Swollen dry tongue

• Sticky mucous membranes

• Lethargy

• Restlessness

• Pulmonary edema

• Anorexia

Priorities of hypernatremia

• laboratory values

  • Specific gravity

Treatment of hypernatremia

• Hypotonic IV solutions

  • 0.45% NS

• Isotonic IV solutions

  • D5W

Nursing considerations of hypernatremia

• Daily weights

• Medication history

• Vitals

• Changes in mental status

Hypokalemia

• A serum potassium level less than 3.5 mEq/L

  • Deficit in total potassium stores but can occur in patients with normal levles

Causes of hypokalemia

• Thiazide and loop diuretics

• Corticosteroids

• GI loss (voliting; gastric suction)

• Diarrhea

• Alterations in acid-base balance; alkalosis

• Hyperaldosteroism

• Insulin hypersecretion

• Poor intake

s/s of hypokalemia

• Low BP

• Fatigue

• Anorexia

• Nausea

• Vomiting

• Muscle weakness

• Polyuria

• Decreased bowel motility

• Ventricular asystole or fibrillation

• Abdominal distention

• ECG changes

  • Flattened T waves

  • Prominent U waves

  • ST depression

  • Prolonged PR interval

Priorities of hypokalemia

• ECG/EKG monitoring

Treatment of hypokalemia

• Intake

  • Dietary

  • Oral supplements

• IV for severe deficit

Nursing considerations of hypokalemia

• ECG changes

• Drug toxicities

• Encourage dietary intake

  • Banana

  • Melons

  • Citrus

  • Vegetables

  • Lean meats

  • Milk

  • Whole grains

Hyperkalemia

• A serum potassium level greater than 5 mEq/L

Causes of hyperkalemia

• Decreased renal excretion

• Rapid administration

• Movement from the ICF to the ECF

• Untreated kidney injury

• Excessive intake deficient adrenal hormones

• Medications

• Acidosis

s/s of hyperkalemia

• Tachycardia then bradycardia

• Arrhythmias

• Muscle weakness

• Anxiety

• ECG changes

  • Tall tented T waves

  • Prolonged PR interval and QRS

  • Absent P waves

  • ST depression

Priorities of hyperkalemia

• Serum levels

• ECG changes

• ABG analysis

Treatment of hyperkalemia

• Dietary restriction

• Cation exchangie resins (kayexylate)

• IV sodium bicarbonate

• IV calcium gluconate

• Insulin

• Beta agonists

• Dialysis

Nursing considerations of hyperkalemia

• Monitor renal function

• I&Os

• s/s monitoring

• Monitor potassium solutions