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• The objective is to define normal ranges of electrolytes, compare/contrast intracellular, extracellular, and intravascular volumes, and describe the clinical manifestations of various electrolyte imbalances.

Cations vs Anions

• A cation is an atom or group of atoms bearing one or more positive electric charges.
• An anion is an atom or group of atoms bearing one or more negative electric charges.
• Milliequivalent is the chemical combining power of the ion, equivalent to the combining power of the hydrogen ion (H+).

Normal Ranges of Electrolytes in Plasma

• Sodium (Na+) normal levels are 135 - 145 mEq/L
• Potassium (K+) normal levels are 3.5 – 5.0 mEq/L
• Calcium (Ca2+) normal levels are 8.0 - 10.5 mEq/L
• Magnesium (Mg2+) normal levels are 1.5-2.5 mEq/L
• Chloride (Cl-) normal level is 95-105 mEq/L
• Bicarbonate normal levels are 24 - 30 mEq/L
• Phosphate normal levels are 2.5- 4.5 mEq/L
• Sulfate normal level is 1.0 mEq/L
• Organic Acids (Lactate) normal level is 2.0 mEq/L
• Total Protein normal levels are 6.0 -8.4 mEq/L

Fluids

• Types of fluids include:
  • Intracellular
  • Extracellular
  • Interstitial
  • Intravascular

Fluid Distribution

• Females have approximately 55% fluids and 45% solids in their body composition.
• Males have approximately 60% fluids and 40% solids in their body composition.
• Intracellular fluid (ICF) accounts for about 2/3 of the body's fluid.
• Extracellular fluid (ECF) accounts for about 1/3 of the body's fluid.
• Interstitial fluid makes up 80% of the ECF, while plasma constitutes 20%.

Intracellular vs Extracellular

• Intracellular fluid contains Potassium, Magnesium, Phosphate, Sulfate, and proteins.
• Extracellular fluid contains Sodium, Calcium, Magnesium, Chloride, and Bicarbonate and lactate.
• Compositions of ions are maintained in both intracellular and extracellular fluids.
• Movement of water is passive.

Body Fluid Compartments

• Intravascular compartments refers to fluid inside a blood vessel
• Intracellular compartments refers to all fluid inside the cell
• Extracellular compartments refers to fluid outside the cell and includes interstitial fluid, blood, lymph, bone, connective tissue, water and transcellular fluid

Percentages of Body Fluids

• Total body water consists of Intracellular fluid (63%), interstitial fluid, plasma, lymph, and transcellular fluid
• Extracellular fluid is comprised of 75% interstitial fluid and 20% plasma

Terminology

• Fluid and electrolyte homeostasis is maintained in the body
• Neutral balance is input equals output
• Positive balance is input greater than output
• Negative balance is input less than output
• Electrolytes are substances minerals, salts, an element or compound when melted or dissolved, separates into ions
• Electrolytes are able to carry electrical current, positive charge- cations and negative charge- anions
• Diffusion is movement of particles down a concentration gradient.
• Osmosis is diffusion of water across a selectively permeable membrane
• Active transport is movement of particles up a concentration gradient; requires energy
• Osmosis refers to movement of solvent through a semipermeable membrane from an area of lesser concentration to higher concentration with a normal level of mOsm 280-295mOsm/kg
• terms include crystalloids, colloids, solvent, osmolality and tonicity
• Isotonic, Saline, Hypertonic, Hypotonic, Osmotic pressure, Oncotic pressure
• Hypertonic: higher osmotic pressure, pulls fluid from cells
• Isotonic: neutral osmotic pressure, solution with same osmolarity as blood
• Hypotonic: solution of lower osmotic pressure, moves fluid into cells, causes them to enlarge
• Diffusion means movement of solute in solution across membrane from area of higher concentration to lower concentration
• Diffusion Terms include Filtration, Hydrostatic pressure and Edema
• Filtration: Water & diffusable substances move together in response to fluid pressure
• Active transport requires energy to move solute across a membranes, example is the Na & K pump
• Edema is where intravascular volume moves to the interstitium, e.g. CHF, pulmonary edema, edema generalized, anaphylaxis
• Edema is an excess accumulation of fluid in the interstitial space
• Localized edema occurs as a result of traumatic injury from accidents or surgery, local inflammatory processes, or burns.
• Generalized edema, also called anasarca, is an excessive accumulation of fluid in the interstitial space throughout the body and occurs as a result of conditions such as cardiac, renal, or liver failure.

IV Solutions

• D5W, .9% NS, and LR are isotonic solutions.
• D10W, 3%-5%, D5 in .9% NS, and D5 in .45% NS, D5 in LR are hypertonic solutions.
• .45% NS is a hypotonic solution.

Homeostasis and Hormonal Regulation

• Homeostasis is internal balance or equilibrium
• Body fluids are regulated by fluid intake, hormonal controls & fluid output, responds to disturbances in fluids & lytes to prevent or repair damage
• Hormonal regulation, hormones regulate fluid intake through various mechanisms
• ADH is stored in the posterior pituitary gland, and release in response to changes in blood osmolarity
• Aldosterone is released by the adrenal cortex, and is a great NA conserver.
• The RAA system works to combat hypovolemia
• Renin: proteolytic enzyme secreted by kidneys responds to decreased renal perfusion, produces Angiotensin I
• Angiotensin I causes vasoconstriction
• Angiotensin I converted to II (by ACE enzyme), causes massive vasoconstriction and stimulates release of aldosterone

Electrolyte Imbalances

• Dysfunction and/or trauma leads to: Decreased amount of water in body, Increased amount of Na + in the body, Increased blood osmolality, and Decreased circulating blood volume
• Hyponatremia is Na<135mEq/L, with a Critical level 115 mEq/L; physical exam includes apprehension, personality changes, Postural hypotension, Dizziness, Abdominal cramping, N/V, Diarrhea Tachycardia Convulsions and Coma
• Hypernatremia is Na>145mEq/L, with a Critical level > 160 mEq/L; and a physical exam reveals thirst, dry & flushed skin, dry & sticky tongue, mucus membranes, fever, agitation, convulsions, restlessness, irritability
• Hypokalemia is K<3.5mEq/L, and a Critical level 2.5 mEq/L; with a physical exam revealing weakness, fatique, decreased muscle tone, intestinal distention, decreased bowel sounds, ventricular dysrhythmias, paresthesias, weak, irregular pulse **** EKG changes, ventricular dysrhythmias, cardiac arrest
• Hyperkalemia is K>5.5 (5.3), with a physical exam including anxiety, dysrhythmias, paresthesias, weakness, abd cramping & diarrhea *** EKG changes bradycardia, heart blocks, dysrhythmias, QRS widens, cardiac arrest
• Hypocalcemia is Ca<9.0, and a physical exam includes numbness & tingling of fingers, circumoral region, hyperactive reflexes, positive Trousseau's sign (carpopedal spams with hypoxia), and Chvostek's (contraction of facial muscles when facial nerve is tapped), tetany, muscle cramps, & pathological fxs.
• Hypercalcemia is Ca>11.0, with a physical exam including anorexia, N/V, weakness, lethargy, low back pain, (from kidney stones), decreased LOC, personality changes, cardiac arrest and *** EKG changes
• Hypomagnesemia has Mg<1.8 mEq/L, with a physical exam revealing muscular tremors, hyperactive DTR's, confusion, disorientation, dysrhythmias
• Hypermagnesium Mg> 3.0mEq/L, with a physical exam including hypoactive DTR's, decreased rate & depth of RR's, hypotension, flushing
• Hypophosphatemia has a serum level < 2.5 mg/dL, caused by Alcoholism, excessive antacid intake, low vitamin D, inadequate phosphate intake, Increased phosphate excretion Shift from extracellular phosphate into the intracellular space, and is Asymptomatic with symptoms General weakness and treated with Acetazolamide, pentamidine...
• Hyperphosphatemia has a serum level > 7 mEq/L, caused by Excessive intake of phosphorus and is Asymptomatic orIncrease symptoms of an underlying disease Ex. uncontrolled diabetes and is caused byMineral and bone disorders and calcification and treated with Sevelamer Carbonate, but can also have Positive Chvostek (low calcium levels) and Trousseau sign (low calcium levels)
• Hypochloremia has a serum level < 95 mEq/L caused by Loop diuretics-excessive usage, Nasogastric suction, Vomiting, Urine chloride <10 mEq/L, related to chloride alkalosis, Urine chloride > 40 mEq/L, related to volume overload (dilution), causing Metabolic alkalosis No specific signs and symptoms, treated with IV Normal Saline
• Hyperchloremia, with a serum level > 107 mEq/L is caused by Bicarbonate loss and Metabolic acidosis, Renal Secretion of hydrogen in urine which leads to alkalotic urine and acidosis of the blood, which presents and Fatigue Muscle weakness Excessive thirst High blood pressure, and is treated with Calcium chlorideMagnesium sulfateCholestyramine

Fluid Volume Deficit and Overload

• Fluid volume deficits have two main categories: Volume and Osmolality
• Fluid volume overload results from excess fluid in the extracellular space that causes electrolyte imbalances
• P/E from fluid volume deficit: postural hypotension, tachycardia, dry mucus membranes, poor skin turgor, thirst, confusion, rapid weight loss, slow vein filling, lethargy, oliguria, weak pulse e.g. fever, hemorrhage, diuretics, Gl losses, hypovolemia, dehydration
• P/E from fluid volume excess: rapid weight gain, edema, hypertension, polyuria, neck vein distention, increased venous pressure, crackles in lungs, Dyspnea, Orthopnea Polyuria Ascites anasarca

Nursing Care

• Labs to Monitor: Serum electrolytes, Serum hematocrit, Hemoglobin ,BUN, Creatinine, Renal function test, Liver function test and Monitor laboratory test Hypo or hypervolemia
• Assessment: Respiratory, Circulatory and Integumentary
• Nursing assessment should cover Assessment Medication Cellular regulation and Cognition along with communication Perfusion Thermoregulation Elimination Bed position from the patient (Semi Fowlers) Monitor intake and output while restricting fluids NPO or Intake of Sodium including daily weights

Diagnostic Tests

• Diagnostic tests include laboratory blood tests of serum electrolytes, serum hematocrit, hemoglobin, BUN, creatinine, renal function test, and liver function test

Medications and Volume Imbalances

• Medications that may cause disturbances include:;Diuretics, Steriods, and K supplements
• Medications for respirtory center conditions and antibiotics may cause imbalances or dysfuntion as well as calcium carbonate, Mg hydroxide (MOM) and Laxatives

Risk Factors for Volume Imbalances

• Age: very young or very old
• Chronic disease: cancer, CHF, endocrine diseases (Cushings, DM), malnutrition, COPD, renal failure, changes in LOC or trauma: crush injuries, head injuries, burns
• Therapies where diuretics, steriods, IV therapy, and TPN are used
• GI Losses: vomiting, diarrhea gastroenteritis, NG suctioning, fistulas Renal Losses: diuretics, Diabetes Inspidus, kidney disease, adrenal insufficiency, osmotic diuresis Third spacing - peritonitis intestinal obstruction, ascites, burns
• Hemorrhage
• Altered intake - NPO

Evaluate Assessment and monitoring Medication Diet Fluids Patient and family education