Fluid and Electrolytes Balance

Fluid and Electrolytes (F&E)

• F&E maintains homeostasis, ensuring a stable internal body environment.

Body Water Content

• Water constitutes 50-60% of adult body weight.
• Body mass, gender, and age influence water content.
• More body fat correlates with less water.
• Men generally have more water than women.
• Older individuals have reduced lean body mass, heightening their risk for fluid-related issues.
• Daily weight measurements are used to track fluid retention or loss.
• Babies have a higher water content compared to elderly individuals.

Body Fluid Compartments

• Intracellular fluid is found inside cells, accounting for 2/3 of body water and about 40% of adult body weight.
• Extracellular fluid is outside cells and consists of three compartments.
• Interstitial fluid is located in spaces between cells, edema/swelling.
• Intravascular fluid is the plasma or liquid part of blood within blood vessels.
• Transcellular fluid exists in body compartments/joints and the gastrointestinal tract, making up about 1/3 of body water.

Calculation of Fluid Gain or Loss

• 1 liter equals 1000 ml.
• 1 liter is equivalent to 2.2 lbs.
• Sudden body weight changes indicate overall fluid volume loss or gain.
• Losing more than 2 lbs over 3 days signals fluid loss.
• Gaining more than 2 lbs over 3 days suggests fluid retention.

Electrolytes

• Electrolytes are substances that dissociate into ions when placed in water.
• Cations carry a positive charge.
• Anions carry a negative charge.
• Electrolyte levels are measured in MEQ/L.

Electrolyte Composition

• ICF's main cation is potassium (K+), with small amounts of sodium and magnesium.
• The main anion in ICF is phosphate (PO).
• ECF's main cation is sodium (Na+) in normal saline, with trace amounts of potassium, calcium, and magnesium, with circulating blood volume at 0.9% normal saline.

Electrolyte Diffusion

• Molecules move across permeable membranes from high to low concentration without external energy.
• Movement of oxygen and carbon dioxide happens through diffusion.
• Facilitated diffusion uses a carrier to move molecules that are to large to pass threw cell membrane.

Electrolyte- Active Transport

• Molecules move against the concentration gradient, requiring external energy.
• Sodium-potassium pump is an example of active transport.
• Cells use active transport to move sodium out and potassium into the cell, utilizing ATP as the energy source.

Electrolyte- Osmosis

• Water moves from areas of low to high concentration across a semipermeable membrane without energy.
• Higher concentration increases the solution's pull, known as osmotic pressure.
• Osmotic pressure is the force needed to stop particle movement.

Electrolyte- Osmotic Movements of Fluids

• Isotonic fluids have the same osmolality as the cell interior; red blood cells remain unchanged in this environment.
• Hypotonic solutions contain fewer solutes than inside cells, causing water to enter the cell, leading to swelling and potential bursting.
• Hypertonic solutions contain more solutes than inside cells, causing cells to shrink and shrivel up, cells are hyperosmolar.

Fluid Shifts

• Fluid shifts into the interstitial space, causing edema as fluid moves out of cells and blood vessels into tissues.
• Sodium causes the body to retain fluid, leading to fluid retention.
• Changes in pressure can cause abnormal fluid shifts between compartments, leading to edema or dehydration.

Fluid Spacing

• 1st spacing is the normal distribution of ICF and ECF without changes.
• 2nd spacing involves fluid leaving cells and accumulating abnormally in interstitial fluid, leading to edema.
• 3rd spacing occurs when fluid is trapped and cannot easily return to cells or blood vessels.

Regulation of Water Balance

• Normal adults need 2000-3000 ml of fluid intake for proper water balance.
• Hypothalamic-pituitary regulation involves nerves signaling the hypothalamus when fluid deficits or increases occur.
• Thirst indicates a deficit, triggering the need to go to the bathroom if excessive.
• Elderly individuals may have a decreased thirst mechanism
• The release of ADH is stimulated due to deficit.
• Decreased plasma osmolality causes water excess or fluid volume overload and suppresses ADH hormone.
• Adrenal cortical regulation involves hormone release to manage water and electrolyte levels.
• Glucocorticoids, including cortisol, are stress hormones that increase sugar levels.
• Decreased plasma osmolality suppresses ADH hormone release.

Cardiac Regulation

• BNP hormones made by cardiomyocytes, are produced by the heart muscle in response to increased atrial pressure in conditions like heart failure (HF)
• Enzymes are released when the left ventricle stretches and overworks.
• Cardiocytes produce this hormone in response to increased atrial pressure to suppress secretion of aldosterone, renin, and ADH, lowering blood volume and pressure.

Gastrointestinal Regulation

• The GI tract typically secretes 8000 ml of digestive fluid per day. Fluid loss from diarrhea, vomiting can lead to fluid and electrolyte loss.

Gerontologic Considerations

• Elderly individuals often have dry skin, structural kidney changes, reduced thirst, subcutaneous tissue loss, and dry, brittle skin, and hormone changes, which affect fluid and electrolyte balance.

Fluid Volume Imbalance

• Fluid volume deficit (hypovolemia) results from body fluid loss, inadequate fluid intake, or fluid shift from plasma to interstitial space, affecting circulating blood volume.
• Dehydration is the loss of pure water without sodium loss.
• Symptoms include dryness, thirst, and confusion.

Fluid Volume Imbalance Management

• Interprofessional care manages deficits by identifying the cause, administering water and electrolytes orally, using blood products, or via isotonic IV solutions.
• Blood products are used for fluid replacement.
• Oral rehydration is used in mild cases, while severe cases require blood products or isotonic IV solutions.

Fluid Volume Excess/Overload (Hypervolemia)

• Tachycardia (high HR).
• It stems from excess fluid intake, abnormal fluid retention, or fluid shifting from interstitial fluid to plasma.
• Weight gain of more than 3 pounds is common, crackles in lungs, edema, and jugular vein distention are symptoms.

Interprofessional Care

• Eliminates fluid and manages excess by removing fluid without changing electrolyte composition or ECF osmolality
• Utilize Diuretics like loop diuretics, hydrochlorothiazide, and potassium sparing diuretics, as well as aldosterone antagonists.
• Restrict fluid intake to 1200-1800 ml per 24-hour period with medication in between.
• Restrict sodium intake.
• Abdominal paracentesis or thoracentesis may be needed to treat ascites or pleural effusion from fluid overload.

Nursing Management for Fluid Imbalances

• Assess health history: kidney, heart, GI, and respiratory problems.
• Look for prior fluid balance issues.
• Track recent weight changes.
• Assess exercise patterns and activity levels.
• Review current and past medications.
• Check for dialysis or surgeries.
• Monitor metabolic panel, kidney function, albumin, and creatinine levels.
• Clinical problems: hypervolemia, hypovolemia, knowledge deficits, impaired tissue perfusion, altered BP, and impaired respiratory and urinary function.
• Assess risk of injury or to impaired skin integrity.

Nursing Management Implementation

• Monitor daily weights and I&O.
• Assess cardiovascular system: edema and capillary refill.
• Provide respiratory support: high Fowler's position for breathing difficulties and monitor crackles in lungs.
• Ensure patient safety: assist with ambulation
• Provide skin care: keep moist skin clean and dry.

Fluid Therapy

• Administer IV fluids as prescribed, and carefully monitor infusion rate.
• Maintain adequate oral intake.
• Assess ability to obtain fluids independently, express thirst, and swallow effectively.
• Encourage oral fluid intake, support those with limitations, and monitor for symptoms of fluid volume overload.

Sodium

• Associated with CNS function and nerve conduction, generates and transmits nerve impulses, responsible for muscle contractility, and regulates ECF volume.
• Normal levels are 135-145.
• Hypernatremia (over 145) causes hypersmolality in the bloodstream.
• Hyponatremia (less than 136) manifests as thirst, changes in mental status, drowsiness, confusion, lethargy, seizures, and coma.
• Treat the underlying cause, water fluid loss replace the fluids orally or IV with isotonic or hypotonic fluid
• Treat related to much sodium, dilute sodium free IV fluids and promote sodium excretion with diuretics
• Hyponatremia symptoms: mild headache, irritability, difficulty concentrating, vomiting, and seizures.
• Hyponatremia management: fluid restriction if caused by excess water; fluid replacement with isotonic sodium chloride if caused by abnormal sodium loss.

Potassium

• Normal levels are 3.5-5.0.
• Major for heart muscle contractility, conducts nerve/muscle impulses, and maintains cardiac rhythms.
• Potassium is lost in urine
• Found in fruits and veggies (banana, apricots, spinach, carrots, oranges)
• Hyperkalemia is levels higher than 5.1, impaired kidney function causes it.
• Hyperkalemia symptoms include fatigue, confusion, tetany, muscle cramps, paresthesia, and weakness.
• Hyperkalemia management includes stopping both oral and IV potassium intake.
• Kayexalate is used therapeutically to lower potassium, but can cause diarrhea.
• Monitor continuous ECG to detect dysrhythmias and if severe, administer IV calcium ASAP.
• Hypokalemia is low potassium level (less than 3.5), a diet low in potassium contributes to it.
• Abnormal losses from the kidneys or GI tract leads to common causes.
• Manifestations such as confusion, lethargy, anorexia, nausea, vomiting, severe hypokalemia and glucose intolerence.
• Giving oral or IV potassium chloride supplements and increased dietary intake will help manage
• Dilute and give KCL, never give IV push or bolus with rates that should not exceed 10 meq/hr.
• At risk pt should have blood draws and regular monitoring. Teach signs, symptoms of digoxin to HCP

Calcium

• Normal range: 9.0-11.
• Main cation in bones and teeth and functions in blood clotting, nerve impulse transmission, myocardial contractions, and muscle function.
• The main source is dietary intake, vitamin D, with 1200 g in calcium content.
• Parathyroid (PTH) and calcitonin regulate calcium levels.
• Hypercalcemia (above 10.5) is caused by hyperparathyroidism (2/3 of persons) or cancers.
• Neurologic manifestations- fatigue, lethargy, weakness, confusions, seizures, coma
• Mild cases managed by consuming a diet low in calcium, promoting weight bearing activity, and maintaining adequate hydration.
• Drink 3000-4000 ml of fluid, cranberry/prune juice to help the increase renal stones
• Severe cases with isotonic saline, bisphosphate, calcitonin, as fluid overload can occur
• Hypocalcemia-less than 9.0, PTH, tranfusions, alkalosis causes it
• Tetany Chvostek-face, trousseau- arm
• Management with calcium rich foods or Vit D and calcium supplements
• Promote CO2 rentention or sedating

Phosphate

• Normal range: 3.0-4.5.
• It is the primary anion in ICF and the second most abundant element after calcium.
• Essential for muscle, red blood cell, and nervous system function.
• Adequate renal function
• Hyperphosphatemia: more than 4.5, kidney injury and disease, hyperparathyroidism, increases kidney phosphate reabsorption
• Asymptomatic unless calcium binds to phosphate
• Management identifying cause, and retrict foods high in phosphorus
• Result from decresed intestinal absorption, increased urinary excretion or ICF
• Manifestations; cellular energy and oxygen delivery, rickets, muscle weakness, heart problems, CNS depressions

Magnesium

• Normal range: 1.3-2.1.
• Magnesium levels increase when digestion and renal reabsorption is present.
• Magnesium needed to use ATP
• 50-60% in muscles and bones
• Hypermagnesemia is levels higher than 2.1, comes from the renal insufficiency
• Manifestations: hypotension, facial flushing, lethargy, retenion, can cause cardiac arrest
• Mg-stop drugs

IV Fluid Replacement

• Used to correct fluid and electrolyte loss.
• Replace water, potassium, sodium and glucose
• When pt can't take in fluids- during and after surgery
• Purpose inroute
• Hypotonic- hypernatremia, given to maintain fluids
• Water moves from ECF to ICF, potential to monitor
• D5W used to prevent keto
• Lactated ringers contains sodium, calcium, chloride, potassium, lacatate
• IDEal for surgery- expand water fluids
• Hyptonic solution to head injury
• Complications-802-chart, IV needle vein
• Potassoum causes string
• Inflammation- treatment
• stop treatment, start IV site, warm compress