Fluid and Electrolytes Slideshow PDF

Chapter 42 Fluid & Electrolytes (not including Acid-Based balance) NURS 300  Objectives ⚫ Describe the processes that regulate fluid distribution, extracellular fluid volume (ECV), and body fluid osmolality. ⚫ Explain the processes that regulate electrolyte balance. ⚫...

Chapter 42 Fluid & Electrolytes (not including Acid-Based balance) NURS 300  Objectives ⚫ Describe the processes that regulate fluid distribution, extracellular fluid volume (ECV), and body fluid osmolality. ⚫ Explain the processes that regulate electrolyte balance. ⚫ Re-call common fluid and electrolyte imbalances. ⚫ Identify risk factors for fluid and electrolyte imbalances. ⚫ Use clinical judgement while applying the nursing process when caring for patients with fluid and electrolyte imbalances. ⚫ Use clinical judgement to choose appropriate clinical assessments for specific fluid and electrolyte imbalances. ⚫ Describe purpose and procedure for measuring and recording daily weights and fluid intake and output. ⚫ Identify how to evaluate the outcomes of care of patients with fluid and electrolyte imbalances. Functions of Water in the Body Transporting nutrients to cells & wastes from cells Transporting hormones, enzymes, blood platelets, red & white blood cells Facilitating cellular metabolism & proper cellular chemical functioning Acting as a solvent for electrolytes & nonelectrolytes Maintaining normal body temperature Facilitating digestion & promoting elimination Acting as a tissue lubricant Total Body Fluid Representing 50%–60% of Body Weight of Normal Adult Characteristics of Body Fluids Fluid = Water that contains dissolved or suspended substances such as glucose, mineral salts, and proteins. Fluid amount = Volume Fluid concentration = Osmolality fluid concentration Fluid composition (electrolyte concentration) Degree of acidity = pH  Location and Movement of Water and Electrolytes Intracellular Fluid Extracellular Fluid (ECF) = Fluid (ICF) = Fluids within outside of cells cells ⬤ ~1/3 of total body water ⬤ ~2/3 of total body water – Interstitial - fluids between cells & outside the blood vessels - lymph (fluid in the lymphatic channels) – Intravascular - blood plasma found in the vascular system – Transcellular - secreted by epithelial cells - cerebrospinal, pleural, peritoneal, & synovial fluids. Fluid in the joints Body Fluid Compartments  Electrolytes and Ions ⚫ Electrolytes (mineral salts) - Compounds that separate into ions (charged particles) when they dissolve in water ⚫ Ions (charged particles) ⚫ Cations: positively charged (sodium, potassium, calcium, magnesium) ⚫ Anions: negatively charged (chloride, bicarbonate, sulfate) ⚫ Osmolality of a fluid ⚫ A measure of the number of particles per kilogram of water ⚫ Electrolytes - dissolved in plasma ⚫ The liquid in which a solute is dissolved is called a solvent.  Movement of Water and Electrolytes Diffusion Active transport Passive movement of electrolytes or Movement of ions against osmotic other particles down the pressure to an area of higher concentration gradient (from higher pressure; requires energy to lower concentration) Filtration Osmosis Movement of fluid into and out of Movement of water (or other solute) capillaries ( between the vascular from an area of lesser to one of and interstitial compartments) from greater concentration higher to lower pressure  Active Transport ⚫ Movement of ions against osmotic pressure ⚫ Requires energy - adenosine triphosphate (ATP) to move electrolytes across cell membranes against the concentration gradient from lower concentration higher concentration) ⚫ Carrier molecules within a cell bind to incoming molecules. ⚫ Ie: sodium-potassium pump, which moves Na+ out of a cell and K+ into it, keeping ICF lower in Na+ and higher in K+ than ECF. Active transport – lower to Higher Concentration  Diffusion ⚫ Passive movement of electrolytes or particles down the concentration gradient (from higher to lower concentration) ⚫ Affected by molecular size, concentration, & temperature of a solution. ⚫ Electrolytes diffuse easily until the concentration is the same in all areas. ⚫ Fluids & electrolytes shift through compartments, which are separated by cell walls & capillary membranes. Diffusion – Higher to Lower Concentration  Osmosis ⚫ Movement of water or solute against the concentration gradient from lower concentration to higher concentration through a semi-permeable membrane. ⚫ Movement across cell membrane (separates interstitial fluid from ICF) - water crosses easily, not permeable to all particles & electrolytes ⚫ Water moves into the compartment that has a higher particle concentration until concentration is equal on both sides of the membrane Osmosis – Lower to Higher Concentration Isotonic, Hypotonic & Hypertonic Solutions Particles that cannot cross cell membranes determine the concentration of a fluid. Isotonic solutions Same concentration as cell No fluid shift, no change in cells Hypotonic lessconcentrated than the cell Less concentrated than cell Fluid shifts into cell- cell swells (large plump cell) Hypertonic More concentrated than cell Fluid shifts out of cell- cell shrinks (small skinny cell) Isotonic, Hypotonic, and Hypertonic Solutions  Filtration ⚫ Capillary filtration moves fluid between vascular and interstitial compartments from higher pressure to lower pressure ⚫ Filtration is affected by four forces ⚫ Hydrostatic pressure is force of fluid pressing outward against a surface ⚫ Capillary hydrostatic pressure - pushes fluid from capillaries into interstitial area where⚫ Interstitial fluid hydrostatic pressure - pushes fluid from interstitial area starts back into capillaries ⚫ Colloid osmotic pressure is exerted by large particles (proteins) ⚫ Blood colloid osmotic pressure (also called oncotic pressure)- proteins in blood pull fluid from interstitial area back into capillaries ⚫ Interstitial fluid colloid osmotic pressure is a very small opposing force, pulls fluid from capillaries into interstitial area  Filtration Arterial - capillary hydrostatic pressure is strongest, & fluid moves from the capillary into the interstitial area, bringing nutrients to cells. Venous - capillary hydrostatic pressure is weaker & blood colloid osmotic pressure is stronger, fluid moves into the capillary, removing waste products from cellular metabolism. Edema – accumulation of excess fluid in interstitial space Ex. Heart failure: venous congestion increases capillary hydrostatic pressure Ex. Inflammation: increases capillary blood flow, allows capillaries to leak colloids into interstitial space which increases capillary hydrostatic pressure and increases interstitial colloid osmotic pressure Filtration – Higher to lower Pressure  Fluid Balance Fluid intake ⬤ Thirst regulates fluid intake ~2300 mL/day ⬤Foods contain water and food metabolism creates water ⬤ Other routes: Intravenous, or irrigation of body cavities Fluid distribution ⬤ Movement of fluid among compartments ⬤Extracellular and intracellular movement by osmosis ⬤ Vascular and interstitial movement by filtration Fluid output ⬤ Through kidneys, skin, lungs, and GI tract ⬤ Insensible loss – not visible (skin and lungs, continuous) ⬤ Sensible loss – Visible (urine, feces, sweat)  I can quantify Fluid Intake & Losses: About Equal in Health should be equal  Fluid Output ⚫ Normally - skin, lungs, GI tract, kidneys ⚫ Abnormally - vomiting, wound drainage, hemorrhage ⚫ Kidneys are regulators of fluid & respond to hormones that influence urine production. ⚫ Increased intake = increased urine production ⚫ Decreased intake = decreased urine production ⚫ Hormonal adjustments  Fluid Imbalances ⚫ Two major types of fluid imbalances ⚫ Volume imbalances - Extracellular fluid volume imbalances ⚫ ECV deficit – Decreased volume in ECF but normal osmolality ⚫ Example- Hypovolemia - decreased vascular volume ⚫ ECV excess – Increased volume in ECF but normal osmolality ⚫ Osmolality imbalances - disturbances of concentration of body fluids, fluids become hypertonic or hypotonic, causes osmotic shifts of water across cell membranes ⚫ Hypernatremia, “water deficit”; hypertonic (body fluids too concentrated, causes cells to shrivel) ⚫ Hyponatremia, “water excess”; hypotonic (body fluids too dilute, causes cells to swell) ⚫ Clinical dehydration – Combined ECV deficit and hypernatremia at the same time Fluid Volume and Osmolality Imbalances Hypovolemic Hypervolemic Dehydration Hypernatremic Hyponatremic  Electrolyte Disorders Signs and Symptoms Electrolyte Excess Deficit Hypernatremia Hyponatremia Decreased level of Sodium (Na) Decreased level of consciousness (confusion, consciousness (confusion, 136 – 145 mEq/L lethargy, coma), perhaps lethargy, coma), seizures if thirst, seizures if severe or severe or develops rapidly develops rapidly Aneverpushpotassium Hypokalemia Hyperkalemia Bilateral muscle weakness, Potassium (K) Bilateral muscle weakness, abdominal distention, abdominal cramps, diarrhea, 3.5 – 5 mEq/L decreased bowel sounds, cardiac dysrhythmias, cardiac constipation, cardiac arrest if severe dysrhythmias  Electrolyte Disorders Signs and Symptoms Electrolyte Excess Deficit Hypercalcemia Hypocalcemia Calcium (Ca) Anorexia, nausea/vomiting, Numbness/tingling, positive 9.0 – 10.5 constipation, fatigue, diminished Chvostek’s sign, hyperactive mg/dL reflexes, lethargy, decreased level reflexes, muscle twitching of consciousness, confusion, and cramping, tetany, personality changes, cardiac seizures, laryngospasm, arrest if severe dysrhythmias Hypomagnesemia Hypermagnesemia Hyperactive DTRs Magnesium Hypoactive deep tendon reflexes (DTRs), lethargy, bradycardia, muscle cramps and (Mg) twitching, grimacing, hypotension, flushing, warm, 1.3 – 2.1 mEq/L dysphagia, tetany, seizures, decreased rate of respirations, dysrhythmias, cardiac arrest insomnia, tachycardia, hypertension, dysrhythmias Hypocalcemia Positive Chvostek’s Sign Positive Trousseau’s Sign Contraction of facial muscles when Carpal spasm with hypoxia facial nerve is tapped  Gerontologic Considerations ⚫ Kidneys have decrease ability to conserve water ⚫ Hormonal changes results in inability to concentrate urine and conserve water ⚫ Loss of subcutaneous tissue leads to increased loss of moisture ⚫ Reduced thirst mechanism results in decreased fluid intake ⚫ Nurse must assess for these changes and implement treatment accordingly  Types of Intravenous Fluids ⚫ Crystalloids – simple solutions of small solutes ⚫ Isotonic solutions: ⚫ 5% Dextrose in Water (D5W) ⚫ 0.9% NaCl (Normal saline) ⚫ Lactated Ringer’s solution (LR) more water less concentration ⚫ Hypotonic solutions: ⚫ 0.33% NaCl (1/3 strength normal saline) ⚫ 0.45% NaCl (1/2 strength normal saline) less water more concentration ⚫ Hypertonic solutions: ⚫ 5% dextrose in 0.45% NaCl (D51/2NS) ⚫ 10% dextrose in water (D10W) ⚫ 5% dextrose in 0.9% NaCl (D5NS) ⚫ Colloids – suspensions of macromolecules, or cells ⚫ blood ⚫ plasma / albumin