NURS 1060: Fluid and Electrolytes PDF

Introduction to Fluid and Electrolytes NURS 1060: Exam 3 OUTCOME  Describe principles of safe, patient-centered, evidence-based nursing care to adults at the basic level, guided by the Caritas philosophy.  Discuss critical thinking and clinical reasoning to provide qu...

Introduction to Fluid and Electrolytes NURS 1060: Exam 3 OUTCOME  Describe principles of safe, patient-centered, evidence-based nursing care to adults at the basic level, guided by the Caritas philosophy.  Discuss critical thinking and clinical reasoning to provide quality patient care. COMPETENCY  Describe factors that create a culture of safety related to medication administration.  Discuss critical thinking and clinical judgment used to provide accurate and safe medication administration. CONCEPT  Fluid and Electrolyte: The physiological mechanisms that maintain fluid and electrolyte balance that promote bodily functions. Unit Outcomes  Discuss the role of body fluids and electrolytes in maintaining homeostasis.  Describe the processes involved in the movement of water and electrolytes between the fluid compartments.  Describe the composition and indications of common IV fluid solutions. Normal Physiology  Maintenance of homeostasis  Composition of fluids and electrolytes kept within narrow limits of normal  Water content varies with age, gender, and fat content Normal Physiology  Body fluids and electrolytes maintain homeostasis, the stable internal environment of the body.  Body fluids play an important role in transporting nutrients, electrolytes, and oxygen to cells as well as carrying waste products away from cells.  Water content in an adult constitutes 50% to 60% of body weight. This percentage decreases to 45% in the older adult, putting the older adult population at a higher risk for fluid imbalances.  The more fat content in the body, the less amount of water. Leaner muscle mass has a higher percentage of water. Body Water Over the Lifespan Fluid Compartments Intracellular fluid (ICF) body water located within cells Extracellular fluid (ECF) body water is located outside the cells Interstitial fluid refers to fluid located in the spaces between the cells and lymph Intravascular (plasma) fluid refers to the fluid portion of blood, which is plasma Transcellular These include cerebrospinal fluid; fluid in the gastrointestinal (GI) tract; and pleural, synovial, peritoneal, intraocular, and pericardial fluid. Electrolytes  Substances whose molecules dissociate into ions  Ions are electrically charged particles  Cation and anion combine within the body fluids to maintain electroneutrality Electrolytes Cations: positivel Examples: sodium (Na+), potassium (K+), calcium (Ca2+), and magnesium (Mg2+) y ions charged Anions: negative Examples: bicarbonate (HCO3–), chloride ly (Cl–), and phosphate (PO43–) ions charged Mechanisms Controlling Fluid and Electrolyte Movement  Diffusion  The movement of molecules from an area of high concentration to one of low concentration. Movement stops when the concentration equalizes (see next slide).  Facilitated diffusion involves the use of a protein carrier in the cell membrane to move molecules that cannot otherwise pass through the membrane. Example: Glucose transport into the cell is facilitated diffusion.. Diffusion   Active transport  Process in which molecules move against Mechanisms concentration gradient from an area of low Controlling concentration to an area of high concentration. Fluid and  Example: sodium-potassium Electrolyte pump. ATP is used to move sodium out of the cell and Movement potassium into the cell. Sodium-Potassium Pump Mechanisms Controlling Fluid and Electrolyte Movement Osmosis  Movement of water against concentration gradient  Water moves from the less concentrated side (has more water- less solute) to the more concentrated side (has less water-more solute) Osmosis Osmolality or Tonicity Hypertoni Solutions in which solutes are more concentrated c than the cells Solutions with the same osmolality, or tonicity, Isotonic as the cell interior Hypotoni Solutions in which the solutes are less c concentrated than the cells Effects of Water Status on RBC  A visual to understand the impact of tonicity on fluid movement is to picture what may happen to red blood cells when you administer different IV fluids.  Isotonic fluids have no impact on the red blood cells.  If a cell is surrounded by hypotonic fluid, water moves into the cell, causing it to swell and possibly to burst.  If a cell is surrounded by hypertonic fluid, water leaves the cell to dilute the ECF; the cell shrinks and eventually may die. Effects of Water Status on RBC  Capillary hydrostatic pressure and interstitial oncotic pressure Fluid move water out of the capillaries into tissue Exchange Plasma oncotic pressure and Between interstitial hydrostatic pressure move fluid into the capillaries Capillary If there are changes in capillary or interstitial and Tissue pressures, fluid may shift abnormally from one compartment to another, resulting in either edema or dehydration.  Plasma-to-interstitial fluid shift results in edema When capillary hydrostatic pressure rises, fluid shifts into the interstitial space and causes edema. Fluid Shifts Interstitial fluid to plasma decreases edema When plasma oncotic pressures increase, fluid is drawn from the Interstitial space into the plasma space. This can occur with administration hypertonic solutions. Fluid Exchange Between Capillary and Tissue  Blood to tissue with oxygen Exchange and nutrients and electrolytes of Nutrients and Waste Tissue to blood with carbon Summary dioxide and waste  First spacing Second spacing Third spacing Normal distribution Abnormal: Abnormal: Third- of fluid in the ICF accumulation of spaced fluid is and ECF interstitial fluid trapped and compartments (edema) unavailable for functional use. Example: Ascites- accumulation of fluid in the peritoneal cavity Fluid Spacing  Hypothalamic-pituitary regulation Regulation Renal regulation of Water Adrenal cortical regulation Balance Insensible water loss Regulation of Water Balance Hypothalamic-Pituitary regulation  Receptors in hypothalamus sense fluid deficit or increase  Deficit stimulates thirst and antidiuretic hormone (ADH) release from the pituitary gland  Water excess suppresses ADH release Regulation of Water Balance Renal Regulation  Primary organs for regulating fluid and electrolyte balance  Adjusting urine volume  Selective reabsorption of water and electrolytes  Renal tubules are sites of action of ADH and aldosterone  In the average adult, the kidney produces approximately 1.5 L of urine per day.  Minimum amount required for RENAL FUNCTION = 30 ml/hr  With severely impaired renal function, the kidneys cannot maintain fluid and electrolyte balance- results in edema, potassium and phosphorous retention, acidosis, and other electrolyte imbalances. Regulation of Water Balance Adrenal Cortical Regulation  Releases hormones to regulate water and electrolytes  Mineral Corticoids- Aldosterone causes sodium retention and potassium excretion. Water is retained with sodium.  Decreased renal perfusion to the distal portion of the renal tubule activates the renin- angiotensin-aldosterone system (RAAS) Regulation of Water Balance Insensible Water Loss  Invisible vaporization from lungs and skin  Loss of approximately 600 to 900 mL/day  No electrolyte loss  Excessive sweating (sensible perspiration) caused by exercise, fever, or high environmental temperatures may lead to large losses of water and electrolytes. I+O  Fluid intake  2,500 – 3,000 mL/day at moderate activity and temperature  Food contributes  Thirst regulator in hypothalamus  Fluid output  1,400–1,500 mL/day of urine  30 ml/hr minimum  Insensible loss through skin and lungs  Feces Genetic and Lifespan Considerations Average Suggested sodium intake sodium intake in the United is ≤1,500– States is 2,300 mg/day >3,400 mg/day Gerontological Considerations Structural changes in kidneys decrease ability to conserve water Hormonal changes lead to decrease in renin and aldosterone and increase in ADH Loss of subcutaneous tissue leads to increased loss of moisture Gerontological Considerations Reduced thirst mechanism results in decreased fluid intake Functional changes affect ability to independently obtain fluids Musculoskeletal changes, such as stiffness of the hands and fingers, can lead to a decreased ability to hold a glass or cup. Gerontological Considerations Mental status changes, such as confusion or disorientation, or changes in ambulation status may lead to a decreased ability to obtain fluids. To reduce incontinent episodes, the older adult may intentionally restrict fluid intake. All of these factors put the older adult at risk for fluid deficit. IV Fluids Overview  Purposes  Maintenance  When oral intake is not adequate  Replacement  When losses have occurred  Types of fluids categorized by tonicity  Tonicity (osmotic pressure of fluid related to the concentration of electrolytes in fluid) is important when correcting water and solute imbalances.  Fluids are classified as hypotonic, isotonic, and hypertonic Apply your Knowledge Question  Since 0.9% Sodium Chloride (Normal Saline) is an isotonic solution:  What is 0.45% Sodium Chloride? ________________  What is 3% Sodium Chloride? ________________ IV Fluids by Tonicity Hypotonic More water than electrolytes dilutes the ECF Usually maintenance fluids Maintenance fluids are usually hypotonic solutions because normal daily losses are hypotonic. EXAMPLE: 0.45% sodium chloride Monitor for changes in LOC Because hypotonic solutions have the potential to cause cellular swelling, monitor patients for changes in mental status (confusion, lethargy) that may indicate cerebral edema IV Fluids by Tonicity Isotonic Administration of an isotonic solution expands only the ECF. Example: 0.9% Sodium Chloride An isotonic solution is the ideal fluid replacement for a patient with an ECF volume deficit.. IV Fluids by Tonicity Hypertonic A hypertonic solution initially raises the osmolality of ECF and expands it higher osmotic pressure draws water out of the cells into the ECF. Useful in the treatment of hypovolemia and hyponatremia. Example: 3% Sodium Chloride Hypertonic solutions require monitoring of: blood pressure, lung sounds, and serum sodium levels because of the risk for intravascular fluid volume excess. Types of IV Fluids Normal Saline (NS)  Isotonic  Expands Circulating Volume  Preferred fluid for immediate response  Risk for fluid overload higher  Compatible with most medications  Emergency Situation administer NS D5W (5% Dextrose in Water)  Not enough to meet caloric requirements  One liter of a 5% dextrose solution provides 50 g of dextrose, or 170 calories  Isotonic initially but becomes hypotonic as dextrose is quickly metabolized by the cells and free water remains  Free water increases renal excretion  Used to replace water losses and treat Hypernatremia (will discuss later)  Does not provide electrolytes Lactated Ringer’s (LR) Solution  Isotonic  LR contains sodium, potassium, chloride, calcium, and lactate (the precursor of bicarbonate)  NO Magnesium.  Expands ECF—treat burns and GI losses  Contraindicated with hyperkalemia  Why? Dextrose 5% and 0.45% Sodium Chloride (D5 ½ NS)  Hypertonic  Free water in addition to Na+ and Cl-  Common maintenance fluid  Replaces fluid loss  Does not replace other electrolyte only sodium  Manufactured Premixed 1,000 ml IV bags with added K+ (20mEq and 40mEq are typical)  D5 ½ NS 20mEq KCL D5 ½ NS 40mEq KCL 1060 Pharmacology Lecture: Exam 3  Format: Multiple Choice or Select All That Apply (45 questions)  Time: 68 minutes (1.5 minutes per question)  Covers all 1060 content including:  PowerPoints from Lecture  Drug Interactions  Nursing Process in Pharmacology  Antiseptics and Disinfectants  Introduction to Fluid and Electrolytes  In-class activities, study guides and homework