Medical Surgical Nursing NCLEX Review PDF
Document Details
Uploaded by TroubleFreeOrbit
2013
NCSBN
Tags
Summary
This is a review module for medical-surgical nursing covering various systems and disorders. It includes information on fluid and electrolyte balance, regulatory mechanisms, and electrolyte imbalances, providing a study guide for the NCSBN exam.
Full Transcript
MEDICAL SURGICAL NURSING NCLEX REVIEW 2013 Edition 1 Table of Contents 1) Fluid and Electrolytes Overview 2) Cardiovascular System Disorders 3) Hematology Disorders 4) Immunology Disorders 5) Oncology Disorders 6) Respiratory System Disord...
MEDICAL SURGICAL NURSING NCLEX REVIEW 2013 Edition 1 Table of Contents 1) Fluid and Electrolytes Overview 2) Cardiovascular System Disorders 3) Hematology Disorders 4) Immunology Disorders 5) Oncology Disorders 6) Respiratory System Disorders 7) Integumentary System Disorders 8) Endocrine System Disorders 9) Gastrointestinal System Disorders 10) Neurological System Disorders 11) Musculoskeletal System Disorders 12) Genitourinary System Disorders 13) Disaster Nursing/ER Nursing 14) Critical Care Nursing/ Shock IMPORTANT: Copyright ©2013 National Council of State Boards of Nursing, Inc. NCLEX, NCLEX-RN, NCLEX-PN, and NCSBN are registered trademarks of the National Council of State Boards of Nursing, Inc. Information in this packet is protected under copyright law. Material has been adapted from www.learningext.com Not intended for sale, distribution or reproduction of this material. Anyone with this manual in their possession must have purchased and must continue to maintain an active membership with NCSBN. Please visit www.learningext.com for more information on how to enroll. 2 FLUID & ELECTROLYTES & ACID-BASED BALANCE OVERVIEW 3 FLUID, ELECTROLYTE & ACID-BASE BALANCE General Concepts Intake = Output = Fluid Balance Sensible losses Urination Defecation Wound drainage Insensible losses Evaporation from skin Respiratory loss from lungs 2 Fluid Compartments Intracellular (inside the cells) 2/3 of body weight Extracellular (outside the cells) 1/3 of body weight Two types INTERSTITIAL (between cells and outside blood vessels) INTRAVASCULAR (liquid portion of blood) Volume versus Osmolality Volume: the amount of fluid in the extracellular compartment Osmolality: the amount of particles in the fluid (the concentration of body fluids) ******************************************************************************************* 4 FLUID AND ELECTROLYTE TRANSPORT Passive Transport Systems Diffusion Filtration Osmosis Diffusion Molecules move across a biological membrane from an area of higher to an area of lower concentration Filtration Movement of solute and solvent across a membrane caused by hydrostatic (water pushing) pressure Occurs at the capillary level If normal pressure gradient changes (as occurs with right-sided heart failure) edema results from “third spacing(fluid accumulating where it is not supposed to be)” Osmosis Movement of solvent (water) from an area of lower solute concentration to one of higher concentration Occurs through a semipermeable membrane using osmotic (water pulling) pressure Active Transport System Solutes can be moved against a concentration gradient Also called “pumping” Dependent on the presence of ATP Active Transport System Pumping Requires energy expenditure ******************************************************************************************* FLUID TYPES Isotonic Hypotonic Hypertonic 5 Isotonic Solution No fluid shift because solutions are equally concentrated Fluid with the same concentration of particles as normal blood Normal saline solution (0.9% NaCl) Hypotonic Solution Lower solute concentration (more dilute than blood) Fluid shifts from hypotonic solution into the more concentrated solution to create a balance (cells swell) Half-normal saline solution (0.45% NaCl) Hypertonic Solution Higher solute concentration( more concentrated than blood) Fluid leaves cell and is drawn into the hypertonic solution to create a balance (cells shrink) 5% dextrose in normal saline (D5/0.9% NaCl) ******************************************************************************************* REGULATORY MECHANISMS Baroreceptor reflex Atrial Natriuretic Peptide Renin-angiotensin-aldosterone mechanism Antidiuretic hormone Baroreceptor Reflex Respond to a fall in arterial blood pressure Located in the atrial walls, vena cava, aortic arch and carotid sinus Constricts afferent arterioles of the kidney resulting in retention of fluid Atrial Natriuretic Peptide Weak hormone in the atria of the heart that inhibits ADH Released by increased extracellular fluid volume Removes excess fluid 6 Renin-Angiotensin-Aldosterone Renin Enzyme secreted by kidneys when arterial pressure or volume drops Interacts with angiotensinogen to form angiotensin I (vasoconstrictor) Angiotensin Angiotensin I is converted in lungs to angiotensin II using ACE (angiotensin converting enzyme) Produces vasoconstriction to elevate blood pressure Stimulates adrenal cortex to secrete aldosterone Aldosterone Mineralocorticoid that controls Na+ and K+ blood levels Increases Cl- and HCO3- concentrations and fluid volume Aldosterone Negative Feedback Mechanism ECF & Na+ levels drop → secretion of ACTH by the anterior pituitary → release of aldosterone by the adrenal cortex → fluid and Na+ retention Antidiuretic Hormone Also called vasopressin Released by posterior pituitary when there is a need to restore intravascular fluid volume Release is triggered by osmoreceptors in the thirst center of the hypothalamus Fluid volume excess decreased ADH Fluid volume deficit increased ADH ******************************************************************************************* FLUID IMBALANCES Dehydration Hypovolemia Hypervolemia Water intoxication 7 DEHYDRATION Loss of body fluids increased concentration of solutes in the blood and a rise in serum Na+ levels Fluid shifts out of cells into the blood to restore balance Cells shrink from fluid loss and can no longer function properly Causes of Dehydration Gastroenteritis (severe vomiting and diarrhea) Clients at Risk Confused Comatose Bedridden Infants Elderly Enterally fed Signs and Symptoms Irritability Confusion Cold, clammy skin Weakness Extreme thirst urine output Fever Dry skin/mucous membranes Sunken eyes Poor skin turgor Tachycardia Postural hypotension 8 Interventions Fluid Replacement - oral or IV over 48 hrs. Monitor symptoms and vital signs Maintain I&O Maintain IV access Daily weights Skin and mouth care ******************************************************************************************* HYPOVOLEMIA Isotonic fluid loss from the extracellular space Can progress to hypovolemic shock Caused by: Excessive fluid loss (hemorrhage) Decreased fluid intake Third space fluid shifting Signs and Symptoms Mental status deterioration Thirst Tachycardia Delayed capillary refill Orthostatic hypotension Urine output < 30 ml/hr Cool, pale extremities Weight loss Interventions Fluid replacement Albumin replacement 9 Blood transfusions for hemorrhage Dopamine to maintain BP Assess for fluid overload with treatment DIFFERENCE BETWEEN DEHYDRATION AND HYPOVOLEMIA Dehydration: excessive loss of body fluid (IE: from vomiting/diarrhea) Hypovolemia: decreased fluid volume of the blood (IE: from hemorrhage) ******************************************************************************************* HYPERVOLEMIA Excess fluid in the extracellular compartment as a result of fluid or sodium retention, excessive intake, or renal failure Occurs when compensatory mechanisms fail to restore fluid balance Leads to CHF and pulmonary edema Signs and Symptoms Tachypnea Dyspnea Crackles Rapid, bounding pulse Hypertension S3 gallop JVD Acute wt gain Edema Increased CVP, pulmonary artery pressure and pulmonary artery wedge pressure (Swan-Ganz: small catheter placed in PA: when deflated, measures PA pressure; when inflated, measures left ventricular failure as blood backs up) Edema Fluid is forced into tissues by the hydrostatic pressure First seen in dependent areas Anasarca - severe generalized edema 10 Pitting edema Pulmonary edema Interventions Fluid and Na+ restriction Diuretics Monitor vital signs Hourly I&O Breath sounds Monitor ABGs and labs Elevate HOB and give O2 as ordered Maintain IV access Skin & mouth care Daily weights ******************************************************************************************* WATER INTOXICATION Hypotonic extracellular fluid shifts into cells to attempt to restore balance Cells swell Causes SIADH (too much ADH: too much fluid) Rapid infusion of hypotonic solution Excessive tap water NG irrigation or enemas Psychogenic polydipsia Signs and Symptoms Signs and symptoms of increased intracranial pressure Early: change in LOC, N/V, muscle weakness, twitching, cramping Late: bradycardia, widened pulse pressure, seizures, coma 11 Interventions Prevention is the best treatment Assess neuro status Monitor I&O and vital signs Fluid restrictions IV access Daily weights Monitor serum Na+ Seizure precautions ******************************************************************************************* ELECTROLYTES Charged particles in solution Cations (+) Anions (-) Integral part of metabolic and cellular processes Positive or Negative? Cations (+) Sodium Potassium Calcium Magnesium Anions (-) Chloride Bicarbonate Phosphate Sulfate 12 MAJOR CATIONS EXTRACELLULAR SODIUM (Na+) INTRACELLULAR POTASSIUM (K+) Electrolyte Imbalances Hyponatremia/ hypernatremia Hypokalemia/ Hyperkalemia Hypomagnesemia/ Hypermagnesemia Hypocalcemia/ Hypercalcemia Hypophosphatemia/ Hyperphosphatemia Hypochloremia/ Hyperchloremia ******************************************************************************************* 13 SODIUM Major extracellular cation Attracts fluid and helps preserve fluid volume Combines with chloride and bicarbonate to help regulate acid-base balance Normal range of serum sodium 135 - 145 mEq/L Sodium and Water If sodium intake suddenly increases, extracellular fluid concentration also rises Increased serum Na+ increases thirst and the release of ADH, which triggers kidneys to retain water Aldosterone also has a function in water and sodium conservation when serum Na+ levels are low Sodium-Potassium Pump Sodium (abundant outside cells) tries to get into cells Potassium (abundant inside cells) tries to get out of cells Sodium-potassium pump maintains normal concentrations Pump uses ATP, magnesium and an enzyme to maintain sodium-potassium concentrations Pump prevents cell swelling and creates an electrical charge allowing neuromuscular impulse transmission ******************************************************************************************* 14 HYPONATREMIA Serum Na+ level < 135 mEq/L Deficiency in Na+ related to amount of body fluid Several types Dilutional Depletional Hypovolemic Hypervolemic Isovolemic Types of Hyponatremia Dilutional - results from Na+ loss, water gain Depletional - insufficient Na+ intake Hypovolemic - Na+ loss is greater than water loss; can be renal (diuretic use) or non-renal (vomiting) Hypervolemic - water gain is greater than Na+ gain; edema occurs Isovolumic - normal Na+ level, too much fluid Signs and Symptoms Primarily neurologic symptoms Headache, N/V, muscle twitching, altered mental status, stupor, seizures, coma Hypovolemia - poor skin turgor, tachycardia, decreased BP, orthostatic hypotension Hypervolemia - edema, hypertension, weight gain, bounding tachycardia Interventions MILD CASE Restrict fluid intake for hyper/isovolemic hyponatremia IV fluids and/or increased po Na+ intake for hypovolemic hyponatremia SEVERE CASE Infuse hypertonic NaCl solution (3% or 5% NaCl) Furosemide to remove excess fluid Monitor client in ICU ******************************************************************************************* 15 HYPERNATREMIA Serum Na+ level > 145 mEq/L Excess Na+ relative to body water Occurs less often than hyponatremia Thirst is the body’s main defense When hypernatremia occurs, fluid shifts outside the cells May be caused by water deficit or over-ingestion of Na+ Also may result from diabetes insipidus Signs and Symptoms Think S-A-L-T Skin flushed Agitation Low grade fever Thirst Neurological symptoms Signs of hypovolemia Interventions Correct underlying disorder Gradual fluid replacement Monitor for s/s of cerebral edema Monitor serum Na+ level Seizure precautions ******************************************************************************************* 16 POTASSIUM Major intracellular cation Untreated changes in K+ levels can lead to serious neuromuscular and cardiac problems Normal K+ levels = 3.5 - 5 mEq/L Balancing Potassium Most K+ ingested is excreted by the kidneys Three other influential factors in K+ balance: Na+/K+ pump Renal Regulation pH level Sodium/Potassium Pump Uses ATP to pump potassium into cells Pumps sodium out of cells Creates a balance Increased K+ levels increased K+ loss in urine Aldosterone secretion causes Na+ reabsorption and K+ excretion pH Potassium ions and hydrogen ions exchange freely across cell membranes Normal conditions=K+ is higher in the cell, while H+ is lower Acidosis hyperkalemia (K+ moves out of cells as H+ moves in; keeps normal balance) Alkalosis hypokalemia (K+ moves into cells and H+ moves out) ******************************************************************************************* 17 HYPOKALEMIA Serum K+ < 3.5 mEq/L Can be caused by GI losses, diarrhea, insufficient intake, non-K+ sparing diuretics (thiazide, furosemide) Signs and Symptoms Think S-U-C-T-I-O-N Skeletal muscle weakness U wave (EKG changes) Constipation, ileus Toxicity of Digitalis glycosides Irregular, weak pulse Orthostatic hypotension Numbness (paresthesias) Interventions Increase dietary K+ Oral KCl supplements IV K+ replacement Change to K+-sparing diuretic Monitor EKG changes IV K+ Replacement ******************************************************************************************* 18 HYPERKALEMIA Serum K+ > 5 mEq/L Less common than hypokalemia Caused by altered kidney function, increased intake (salt substitutes), blood transfusions, meds (K+-sparing diuretics), cell death (trauma) Signs and Symptoms Irritability Paresthesia Muscle weakness (especially legs) EKG changes (tall, tented T waves) Irregular pulse Hypotension Nausea, abdominal cramps, diarrhea Interventions Mild Loop diuretics (Lasix) Dietary restriction Moderate Kayexalate (binds to K+ in intestines) Emergency 10% calcium gluconate for cardiac effects Sodium bicarbonate for acidosis ******************************************************************************************* 19 MAGNESIUM Helps produce ATP Role in protein synthesis & carbohydrate metabolism Helps cardiovascular system function (vasodilation) Regulates muscle contractions ******************************************************************************************* HYPOMAGNESEMIA Serum Mg++ level < 1.5 mEq/L Caused by poor dietary intake, poor GI absorption, excessive GI/urinary losses High risk clients Chronic alcoholism Malabsorption GI/urinary system disorders Sepsis Burns Wounds needing debridement Signs and Symptoms CNS Altered LOC Confusion Hallucinations Neuromuscular Muscle weakness Leg/foot cramps Hyper DTRs Tetany Chvostek’s & Trousseau’s signs 20 Cardiovascular Tachycardia Hypertension EKG changes Gastrointestinal Dysphagia Anorexia Nausea/vomiting Interventions Mild Dietary replacement Severe IV or IM magnesium sulfate Monitor Neuro status Cardiac status Safety Mag Sulfate Infusion Use infusion pump - no faster than 150 mg/min Monitor vital signs for hypotension and respiratory distress Monitor serum Mg++ level q6h Cardiac monitoring Calcium gluconate as an antidote for overdosage ******************************************************************************************* 21 HYPERMAGNESEMIA Serum Mg++ level > 2.5 mEq/L Not common Renal dysfunction is most common cause Renal failure Addison’s disease Adrenocortical insufficiency Untreated DKA Signs and Symptoms Decreased neuromuscular activity Hypoactive DTRs Generalized weakness Occasionally nausea/vomiting Interventions Increased fluids if renal function normal Loop diuretic if no response to fluids Calcium gluconate for toxicity Mechanical ventilation for respiratory depression Hemodialysis (Mg++-free dialysate) ******************************************************************************************* 22 CALCIUM 99% in bones, 1% in serum and soft tissue (measured by serum Ca++) Works with phosphorus to form bones and teeth Role in cell membrane permeability Affects cardiac muscle contraction Participates in blood clotting Calcium Regulation Affected by body stores of Ca++ and by dietary intake & Vitamin D intake Parathyroid hormone draws Ca++ from bones increasing low serum levels (Parathyroid pulls) With high Ca++ levels, calcitonin is released by the thyroid to inhibit calcium loss from bone (Calcitonin keeps) ******************************************************************************************* HYPOCALCEMIA Serum calcium < 8.9 mg/dl Ionized calcium level < 4.5 mg/Dl Caused by inadequate intake, malabsorption, pancreatitis, thyroid or parathyroid surgery, loop diuretics, low magnesium levels Signs and Symptoms Neuromuscular Anxiety, confusion, irritability, muscle twitching, paresthesias (mouth, fingers, toes), tetany, Trousseau’s and Chvostek’s signs Fractures Diarrhea Diminished response to digoxin EKG changes Interventions Calcium gluconate for postop thyroid or parathyroid client Cardiac monitoring Oral or IV calcium replacement ******************************************************************************************* 23 HYPERCALCEMIA Serum calcium > 10.1 mg/dl Ionized calcium > 5.1 mg/dl Two major causes Cancer Hyperparathyroidism Signs and Symptoms Fatigue, confusion, lethargy, coma Muscle weakness, hyporeflexia Bradycardia cardiac arrest Anorexia, nausea/vomiting, decreased bowel sounds, constipation Polyuria, renal calculi, renal failure Interventions If asymptomatic, treat underlying cause Hydrate the patient to encourage diuresis Loop diuretics Corticosteroids ******************************************************************************************* 24 PHOSPHORUS The primary anion in the intracellular fluid Crucial to cell membrane integrity, muscle function, neurologic function and metabolism of carbs, fats and protein Functions in ATP formation, phagocytosis, platelet function and formation of bones and teeth ******************************************************************************************* HYPOPHOSPHATEMIA Serum phosphorus < 2.5 mg/dl Can lead to organ system failure Caused by respiratory alkalosis (hyperventilation), insulin release, malabsorption, diuretics, DKA, elevated parathyroid hormone levels, extensive burns Signs and Symptoms Musculoskeletal Muscle weakness respiratory muscle failure osteomalacia pathological fractures CNS confusion, anxiety, seizures, coma Cardiac hypotension decreased cardiac output Hematologic hemolytic anemia easy bruising infection risk Interventions MILD/MODERATE: Dietary interventions, Oral supplements SEVERE: IV replacement using potassium phosphate or sodium phosphate ******************************************************************************************* 25 HYPERPHOSPHATEMIA Serum phosphorus > 4.5 mg/dl Caused by impaired kidney function, cell damage, hypoparathyroidism, respiratory acidosis, DKA, increased dietary intake Signs and Symptoms Think C-H-E-M-O Cardiac irregularities Hyperreflexia Eating poorly Muscle weakness Oliguria Interventions Low-phosphorus diet Decrease absorption with antacids that bind phosphorus Treat underlying cause of respiratory acidosis or DKA IV saline for severe hyperphosphatemia in patients with good kidney function ******************************************************************************************* 26 CHLORIDE Major extracellular anion Sodium and chloride maintain water balance Secreted in the stomach as hydrochloric acid Aids carbon dioxide transport in blood ******************************************************************************************* HYPOCHLOREMIA Serum chloride < 96 mEq/L Caused by decreased intake or decreased absorption, metabolic alkalosis, and loop, osmotic or thiazide diuretics Signs and Symptoms Agitation, irritability Hyperactive DTRs, tetany Muscle cramps, hypertonicity Shallow, slow respirations Seizures, coma Arrhythmias Interventions Treat underlying cause Oral or IV replacement in a sodium chloride or potassium chloride solution ******************************************************************************************* 27 HYPERCHLOREMIA Serum chloride > 106 mEq/L Rarely occurs alone Caused by dehydration, renal failure, respiratory alkalosis, salicylate toxicity, hyperpara-thyroidism, hyperaldosteronism, hypernatremia Signs and Symptoms Metabolic Acidosis Decreased LOC Kussmaul’s respirations Weakness Hypernatremia Agitation Tachycardia, dyspnea, tachypnea, HTN Edema Interventions Correct underlying cause Restore fluid, electrolyte and acid-base balance IV Lactated Ringer’s solution to correct acidosis ******************************************************************************************* 28 ACID-BASE BALANCE Acid-Base Basics pH= percentage of hydrogen ions in a solution ; ranges from 1-14 Acids= molecules that give up hydrogen ions IE: Carbonic acid (CO2 +water=PaCO2) Bases= molecules that accept hydrogen ions IE: bicarbonate(HCO3) Arterial blood gases are the major diagnostic tool for evaluating acid-base balance Arterial Blood Gases pH 7.35 - 7.45 PaCO2 35 - 45 mmHg HCO3 22-26 mEq/L Acidosis Alkalosis pH < 7.35 pH > 7.45 Caused by accumulation of acids or by a loss of Occurs when bases accumulate or acids are lost bases Regulatory Systems Three systems come into play when pH rises or falls Chemical buffers Respiratory system Kidneys Chemical Buffers Immediate acting Combine with offending acid or base to neutralize harmful effects until another system takes over Bicarb buffer - mainly responsible for buffering blood and interstitial fluid Phosphate buffer - effective in renal tubules Protein buffers - most plentiful - hemoglobin 29 Respiratory System Lungs regulate blood levels of CO2 CO2 + H2O = Carbonic acid High CO2 = slower breathing/hypoventilation (hold on to carbonic acid and lower pH) Low CO2 = faster breathing/hyperventilation (blow off carbonic acid and raise pH) Twice as effective as chemical buffers, but effects are temporary Kidneys Reabsorb or excrete excess acids or bases into urine Produce bicarbonate Adjustments by the kidneys take hours to days to accomplish Bicarbonate levels and pH levels increase or decrease together Arterial Blood Gases (ABG) Uses blood from an arterial puncture Three test results relate to acid-base balance pH PaCO2 HCO3 Interpreting ABGs Step 1 - check the pH Step 2 - What is the CO2? Step 3 - Watch the bicarb Step 4 - Look for compensation Step 5 - What is the PaO2 and SaO2? Step 1 - Check the pH pH < 7.35 = acidosis pH > 7.45 = alkalosis Move on to Step 2 30 Step 2 - What is the CO2? PaCO2 gives info about the respiratory component of acid-base balance If abnormal, does the change correspond with change in pH? High pH expects low PaCO2 (hypocapnia) Low pH expects high PaCO2 (hypercapnia) Step 3 – Watch the Bicarb Provides info regarding metabolic aspect of acid-base balance If pH is high, bicarb expected to be high (metabolic alkalosis) If pH is low, bicarb expected to be low (metabolic acidosis) Step 4 – Look for Compensation If a change is seen in BOTH PaCO2 and bicarbonate, the body is trying to compensate Compensation occurs as opposites: one value indicates the primary source of the pH change, while the other is the body’s effort to compensate for the disturbance Step 5 – What is the PaO2 and SaO2 PaO2 reflects ability to pick-up O2 from lungs; normal=80-100% SaO2 less than 95% is inadequate oxygenation Low PaO2 indicates hypoxemia ******************************************************************************************* ACID-BASE IMBALANCES Respiratory Acidosis Respiratory Alkalosis Metabolic Acidosis Metabolic Alkalosis ******************************************************************************************* 31 Respiratory Acidosis Any compromise in breathing can result in respiratory acidosis Hypoventilation carbon dioxide buildup and drop in pH Can result from neuromuscular trouble, depression of the brain’s respiratory center, lung disease or airway obstruction Clients at Risk Post op abdominal surgery Mechanical ventilation Analgesics or sedation Signs and Symptoms Apprehension, restlessness Confusion, tremors Decreased DTRs Diaphoresis Dyspnea, tachycardia N/V, warm flushed skin ABG Results Uncompensated pH < 7.35 PaCO2 >45 HCO3 Normal Compensated pH Normal PaCO2 >45 HCO3 > 26 32 Interventions Correct underlying cause Bronchodilators Supplemental oxygen Treat hyperkalemia Antibiotics for infection Chest PT to remove secretions Remove foreign body obstruction ******************************************************************************************* Respiratory Alkalosis Most commonly results from hyperventilation (blow off too much CO2) caused by pain, salicylate poisoning, use of nicotine or aminophylline, hypermetabolic states or acute hypoxia (overstimulates the respiratory center) Signs and Symptoms Anxiety, restlessness Diaphoresis Dyspnea ( rate and depth) EKG changes Hyperreflexia, paresthesias Tachycardia Tetany ABG Results Uncompensated pH > 7.45 PaCO2 < 35 HCO3 Normal Compensated pH Normal 33 PaCO2 < 35 HCO3 < 22 Interventions Correct underlying disorder Oxygen therapy for hypoxemia Sedatives or antianxiety agents Paper bag breathing for hyperventilation ******************************************************************************************* Metabolic Acidosis Characterized by gain of acid or loss of bicarb Associated with ketone bodies Diabetes mellitus, alcoholism, starvation, hyperthyroidism Other causes: Lactic acidosis secondary to shock, heart failure, pulmonary disease, hepatic disease, seizures, strenuous exercise Signs and Symptoms Confusion, dull headache Decreased DTRs S/S hyperkalemia (abdominal cramps, diarrhea, muscle weakness, EKG changes) Hypotension, Kussmaul’s respirations Lethargy, warm & dry skin ABG Results Uncompensated pH < 7.35 PaCO2 Normal HCO3 < 22 34 Compensated pH Normal PaCO2 < 35 HCO3 < 22 Interventions Regular insulin to reverse DKA IV bicarb to correct acidosis Fluid replacement Dialysis for drug toxicity Antidiarrheals ******************************************************************************************* Metabolic Alkalosis Commonly associated with hypokalemia from diuretic use, hypochloremia and hypocalcemia Also caused by excessive vomiting, NG suction, Cushing’s disease, kidney disease or drugs containing baking soda Signs and Symptoms Anorexia Apathy Confusion Cyanosis Hypotension Loss of reflexes Muscle twitching Nausea Paresthesia Polyuria Vomiting Weakness 35 ABG Results Uncompensated pH > 7.45 PaCO2 Normal HCO3 >26 Compensated pH Normal PaCO2 > 45 HCO3 > 26 Interventions IV ammonium chloride D/C thiazide diuretics and NG suctioning Antiemetics ******************************************************************************************* 36 IV THERAPY Crystalloids – contain small molecules that flow easily from bloodstream into cells and tissues and vice versa Isotonic (D5W, 0.9% NaCl or Lactated Ringers) Hypotonic (0.45% NaCl) Hypertonic (D5/0.9% NaCl, D5/0.45% NaCl) Colloids – plasma expander (draw fluid into the bloodstream); always hypertonic Albumin Plasma protein Dextran Total Parenteral Nutrition Highly concentrated Hypertonic solution Used for clients with high caloric and nutritional needs Solution contains electrolytes, vitamins, acetate, micronutrients and amino acids Lipid emulsions given in addition ******************************************************************************************* 37 38 CARDIOVASCULAR SYSTEM Anatomy & Physiology Diagnostic Exam Pharmacology Disease Management 39 Anatomy and Physiology A. Anatomy 1. Layers a. pericardium: fibrous sac that encloses the heart b. epicardium: covers surface of heart c. myocardium: muscular portion of the heart d. endocardium: lines cardiac chambers and covers surface of heart valves 2. Chambers of Heart 40 a. right atrium: collecting chamber for incoming systemic venous system b. right ventricle: propels blood into pulmonary system c. left atrium: collects blood from pulmonary venous system d. left ventricle: thick-walled, high-pressure pump that propels blood into system the systemic circulation Heart valves: membranous openings that allow one way blood flow a. atrioventricular valves: prevent backflow from ventricles to atria during systole i. tricuspid - right heart valve ii. mitral - left heart valve (bicuspid) b. semilunar valves prevent backflow from aorta and pulmonary arteries into ventricles during diastole i. pulmonic ii. aortic This might help you to remember the names and location of the heart valves: T iny right side of the heart = Tricuspid valve M ighty (or B ig) left side of the heart = M itral (or B icuspid) valve 41 4. Blood supply to heart a. arteries Cardiovascular: Arteries of the Heart i. right coronary artery supplies right ventricle and part of left ventricle ii. left coronary artery supplies mostly left ventricle b. veins i. coronary sinus veins ii. thebesian veins 5. Conduction system a. SA (sinoatrial) node - referred to as the "pacemaker" of the heart 42 b. junctional tissue - often referred to as the atrioventricular node (AV node) c. bundle branch Purkinje system Follow the link below to view a video about your heart's electrical system developed by the National Heart Lung and Blood Institute. http://www.nhlbi.nih.gov/health/health-topics/topics/hhw/ Physiology 1. Function of the heart is the transport of oxygen, carbon dioxide, nutrients and waste products 2. Cardiac cycle - atria and ventricles work in an asynchronous manner 43 a. systole - phase of contraction during which the ventricles eject blood b. diastole - the phase of relaxation during which the chambers fill with blood; when the heart pumps, myocardial layer contracts and relaxes 3. Blood flow a. deoxygenated blood enters the right atrium through the superior and inferior vena cava b. enters the right ventricle via the tricuspid valve c. travels through the pulmonic valve to pulmonary arteries and lungs d. oxygenated blood returns from lungs through the pulmonary veins into left atrium and enters the left ventricle via bicuspid (mitral) valve e. finally, the blood, from the left ventricle, goes through the aortic valve into the aorta and into the systemic circulation 44 4. The vascular system is a continuous network of blood vessels. a. the arterial system consists of arteries, arterioles and capillaries and delivers oxygenated blood to tissues b. oxygen, nutrients and metabolic waste are exchanged at the microscopic level c. the venous system, veins and venules, returns the blood to the heart 45 5. The heart itself is supplied with blood by the left and right coronary arteries ******************************************************************************************* 46 CARDIOVASCULAR SYSTEM DIAGNOSTIC TESTS Diagnostic Tests for the Cardiovascular System The following laboratory studies can be used in the diagnosis of illnesses and pathology associated with the cardiovascular system. BLOOD (SERUM) STUDIES Diagnostic Test Nursing Considerations Arterial blood gases Blood draw, usually with no preparation; check to see if client should have oxygen turned off for 20 to 30 minutes before the test Standard ABG includes: 1) partial pressure of oxygen (PaO2) 2) partial pressure of carbon dioxide (PaCO2) 3) pH 4) bicarbonate (HCO3) 5) oxygen saturation (O2 sat or SpO2) Basic Metabolic Panel Ordered to assess status of kidneys, blood sugar, and electrolyte and acid/base balance Client should be NPO 10 to 12 hours prior to the blood draw Group of 8 specific tests: glucose, calcium, electrolytes (sodium, potassium, CO2, chloride), kidney tests (blood urea nitrogen [BUN], creatinine) Comprehensive metabolic panel Gives information about the status of the client's kidneys, liver, electrolyte (CMP) and acid/base balance, blood sugar and blood proteins Client should be NPO 10 to 12 hours prior to the blood draw Standard CMP includes a group of 14 tests: albumin, alkaline phosphatase, alanine transaminase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN), (serum) calcium, (serum) chloride, CO2, creatinine, direct bilirubin, gamma-glutamyl transpeptidase (gamma-GT), glucose test, lactate dehydrogenase (LDH), (serum) phosphorus, potassium, (serum) sodium, total bilirubin, total cholesterol, uric acid Chemistry Panel Part of either the CMP or BMP (see above) Standard chem profile includes: 1) sodium 2) potassium 3) chloride 4) bicarbonate (HCO3) Complete blood count (CBC) Typically there are no specific pre-testing restrictions, although the client should avoid eating a fatty meal prior to the test Standard CBC includes: 47 Diagnostic Test Nursing Considerations 1) white blood cells (WBC) 2) red blood cells (RBC) 3) hemoglobin content (Hgb) 4) hematocrit (Hct) 5) mean corpuscular volume (MCV) 6) mean corpuscular hemoglobin (MCH) 7) mean corpuscular hemoglobin concentration (MCHC) 8) platelet count and volume (Serum) Enzymes/Cardiac Serum enzymes typically includes: Markers 1) (total) creatinine kinase: this enzyme is found in muscle and brain tissue; it reflects tissue catabolism resulting from cell trauma 2) creatinine kinase isoenzymes - will increase 4 to 6 hours after injury; peaks in 12 to 24 hours; three different isoenzymes in the body: CK-MB (cardiac) - increases 4 to 6 hours after a heart attack and peaks in 12 to 20 hours; CK-MM (muscles); and CK-BB (brain tissue) 3) lactate dehydrogenase (see BMP above) 4) lactate dehydrogenase isoenzymes: LDH1 (heart muscle & RBCs); LDH2 (concentrated in WBC); LDH3 (highest in the lung); LDH4 (highest in the kidney, placenta, & pancreas); and LDH5 (highest in the liver & skeletal muscle) 5) myoglobin: any injury to skeletal muscle will cause a release of this oxygen-binding protein 6) troponin: a regulatory protein found in striated muscle; troponin levels are elevated 4 to 8 hours after a heart attack; used to diagnose a heart attack and to assess degree of damage to heart muscle; 2 different cardiac-specific isoforms: troponin I and troponin T C-reactive protein (CRP) Protein produced by the liver; levels rise with inflammation throughout the body May help determine risk of future cardiac events in clients who have had a heart attack Blood draw - no special prep Lipid profile Client should be NPO 10 to 12 hours prior to the blood draw; water is permitted Ordered to determine risk of coronary heart disease Lipid profile typically includes 1) total cholesterol 2) high density lipoprotein cholesterol (HDL) - the "good" cholesterol 3) low density lipoprotein (LDL) - often called the "bad" cholesterol 4) triglycerides Erythrocyte sedimentation rate Increased when inflammation is present (ESR) Blood draw - no special prep Drugs such as dextran, methyldopa, oral contraceptives, penicillamine procainamide, theophylline and vitamin A can increase ESR; aspirin, cortisone, and quinine may decrease ESR 48 Diagnostic Test Nursing Considerations Liver enzymes liver enzymes typically includes: 1) aspartate aminotransferase (AST) 2) alkaline phosphatase (ALP) 3) lactic dehydrogenase (LDH) Prothrombin time (PT, INR) Measures how long (in seconds) it takes for a clot to form in a sample of blood Prothrombin is one of the conversion factors produced by the liver Brain natriuretic peptide (BNP) Used to measure production of a hormone found in the left ventricle or N-terminal pro-BNP Helps diagnose and evaluate risk of future cardiac events, including heart failure, prognosis, and to monitor therapy SCANS & X-RAYS Diagnostic Test Nursing Considerations Computed tomography (CT) Noninvasive, painless process Produces two-dimensional images of organs, bones and tissues Takes about 20 minutes Occasionally a contrast dye is used Although very little radiation is used, pregnant women should avoid the test Used to detect fractures not visible on x-rays Magnetic Resonance Imaging Used for diagnosing heart problems (MRI) Client may feel catastrophic inside MRI unit Client must remove all metal prior to test; cannot be used on client with metal implants Nuclear scan Radioactive material is injected and flow through heart and lungs is charted Radiographs (X-Rays) Chest x-ray to detect heart and lung physiology OTHER Diagnostic Test Nursing Considerations Angiogram (cardiac Dye injected through a catheter (from groin or arm) that makes coronary catheterization) arteries visible on x-ray Client should be NPO 8 hours prior to the test Performed with the use of local anesthesia and intravenous sedation Takes approximately 20 to 30 minutes If a blockage is found during the procedure, the surgeon may perform a percutaneous coronary intervention (PCI) to open the blockage If the groin is used, the client will have a compression bandage on the site and must lie flat on his/her back for several hours post procedure Electrocardiogram (EKG) 12 lead EKG takes about 10 minutes to perform at the beside With each beat, an electrical impulse (or wave) travels through the heart: 1) P wave = impulse in the atria, followed by a flat line when the electrical impulse goes to the bottom of the chambers 2) QRS complex = impulse in the ventricles 49 Diagnostic Test Nursing Considerations 3) T wave = represents electrical recovery or return to a resting state for the ventricles Echocardiogram Used to diagnose and monitor heart failure, differentiating from systolic and diastolic heart failure Uses sound waves to produce a video image of your heart 1) painless procedure that usually takes less than an hour to perform 2) the client may be asked to change positions or hold his/her breath at times during the procedure 3) sometimes, the client will receive an injection of either saline or dye to better highlight the heart Image can be used to determine ejection fraction Usually an EKG is performed at the same time Other types of echocardiography 1) stress echocardiography: an exercise stress test using echocardiography prior to and after exercise (see ECST) 2) transesophageal echocardiography (TEE): used for more detailed images of the heart Exercise cardiac stress test Measures how heart and blood vessels respond to exertion (ECST) Client may walk on a treadmill or pedal a stationary bicycle with continuous EKG monitoring Radionuclide stress testing Injection of a radioactive isotope (typically thallium or cardiolite) and then taking nuclear images of the client's heart, first during rest and then following exercise Blockage in a coronary artery results in diminished blood flow, which shows up as a "cold" spot on the scan HEMODYNAMIC MONITORING Hemodynamic monitoring: invasive cardiac catheter o reflects left ventricular end diastolic pressure o use of a balloon-tipped, flow-directed catheter to provide continuous monitoring o catheter introduced via subclavian vein or cutdown and passed through right side of heart to pulmonary artery o may be inserted at the bedside or under fluoroscopy 50 o normal parameters Parameter Equation Normal Range Arterial blood pressure (BP) Systolic (SBP) 90-140 mm Hg Diastolic (DBP) 60-90 mm Hg Mean Arterial Pressure (MAP) SBP + (2 X DBP)/3 70-105 mm Hg Right Ventricular Pressure (RVP) Systolic (RVSP) 15-25 mm Hg Diastolic (RVDP) 0-8 mm Hg Pulmonary Artery Pressure (PAP) Systolic (PASP) 15-25 mm Hg Diastolic (PADP) 8-15 mm Hg Mean Pulmonary Artery Pressure (MPAP) [PASP + (2 X PADP)]/3 10-20 mm Hg Pulmonary Artery Wedge Pressure (PAWP) N/A 6-12 mm Hg o complications of hemodynamic monitoring ▪ pneumothorax ▪ dysrhythmias ▪ infection, sepsis, thrombophlebitis o nursing interventions ▪ monitor values ▪ assess and change dressings ▪ maintain patency with fluids ▪ calibrate equipment ▪ remove lines ▪ obtain specimens ▪ strict asepsis ▪ standard precautions 51 Intra-Arterial Pressure o catheter in a major artery and attached to transducer o most common site: radial artery o usually inserted at bedside o also used to obtain arterial blood gas samples and other diagnostic studies o normal parameters ▪ peak systolic: 100 mm Hg ▪ end diastolic: 60 to 80 mm Hg ▪ mean: 70 to 90 mm Hg o complications: clot formation, decreased or absent pulse, hematoma, infection, hemorrhage Cardiac Output (CO) o volume of blood heart beats per minute o thermodilution technique using blood temperature changes o known volume of solution is injected at a specific rate into the right atrium o temperature-sensitive probe measures temperature of blood as it passes through catheter o contraindications: bleeding disorders, immunosuppression o cardiac output (CO) = ( heart rate x stroke volume ) = 4 to 8 L/min o nursing care of client with cardiac catheter ▪ explain procedure to client ▪ obtain baseline vital signs and rhythm strip ▪ place client in supine position ▪ calibrate pressure monitor ▪ obtain chest x-ray to guide catheter placement ▪ obtain arterial blood gases as ordered ▪ change dressings and tubing as ordered ▪ maintain patency of catheter ▪ monitor and record vital signs and pressures as ordered ▪ observe for complications ▪ 52 CARDIOVASCULAR SYSTEM MEDICATIONS Managing Cardiac Disease: Therapeutic Classes of Drugs ************************************************************************************** ************************************************************************************** 53 ************************************************************************************** ANTIANGINAL AGENTS ************************************************************************************** TYPE: NITRATES a. Action: arterial, venous, and capillary vasodilation by relaxing vascular smooth muscle i. decreases myocardial oxygen consumption ii. decreases preload with venous pooling iii. decreases afterload by decreasing peripheral vascular resistance b. Example: nitroglycerin - see Epocrates Online for greater detail i. (Nitro-Bid) IV (titrate according to blood pressure) ii. (Nitro-Dur) 1 transdermal patch daily iii. Nitrostat) one 0.4 mg sublingual tablet under the tongue; may repeat every 5 minutes up to 3 tablets c. Uses: prophylaxis, treatment, and management of angina, acute myocardial infarction (MI) d. Adverse Effects i. life-threatening: sudden, severe refractory hypotension when taken with sildenafil citrate (Viagra) or tadalafil (Cialis), methemoglobinemia, contact dermatitis ii. most common: headache, nausea, vomiting, dizziness, reflex tachycardia, postural hypotension e. Contraindications i. severe anemia, cardiac tamponade ii. cerebral hemorrhage or trauma iii. hypovolemia, hypotension, shock f. Nursing Care i. establish baseline data and monitor during acute angina or IV administration: blood pressure, heart rate, EKG, chest pain ii. may decrease effectiveness of heparin iii. withdraw treatment gradually to avoid angina iv. toxicity: central nervous system changes, hypotension, flushing, nausea v. buccal area must be moist for sublingual absorption vi. may induce alcohol intoxication (without alcohol intake) vii. maintain a 6 to 8 hour nitrate-free period every 24 hours after acute episode to avoid tolerance g. Client Teaching apply spray under tongue; do not chew tablets sit down when taking, change positions slowly report blurred vision or dry mouth, avoid alcohol keep tablets away from light, moisture, and body heat; change tablets every 6 months use spray or sublingual tablets for immediate relief; combine drug with rest for acute attack rotate site of ointment or patch; remove ointment or patch and clean skin for daily nitrate-free period for acute angina: take 1 tablet sublingual (or 1 spray under the tongue) every 5 minutes up to three doses; seek emergency treatment if there is no pain relief ************************************************************************************** 54 ************************************************************************************** TYPE: ISOSORBIDE (ISOSORBIDE DINITRATE AND ISOSORBIDE MONONITRATE) a. Action: vasodilation by relaxing arterial and venous smooth muscle; decreases preload with venous pooling, peripheral vascular resistance, and myocardial oxygen consumption b. Examples - see Epocrates Online for greater detail i. isosorbide dinitrate (Isordil, Dilatrate-SR): used for both acute attacks and prevention of angina pectoris; can be used to treat chronic CHF (unlabeled) sublingual (adults) a. acute attack of angina pectoris: 2.5-5 mg; may be repeated every 5 to 10 minutes for 3 doses in 15 to 30 minutes b. prophylaxis of angina pectoris: 2.5-5 mg given 15 minutes prior to activities known to provide angina oral (adults) a. prophylaxis of angina pectoris: 5-20 mg, 2 to 3 times daily b. usual maintenance dose: 10-40 mg every 6 hours (immediate-release) or 40-80 mg every 8 to 12 hours (sustained-release) ii. isosorbide mononitrate (Imdur, Monoket): used for prevention of angina pectoris Imdur: 30-60 mg by mouth once daily; may increase to 120 mg once daily (maximum 240 mg/day) Monoket: 5-20 mg twice daily with the 2 doses given 7 hours apart c. Uses: maintenance therapy for angina, coronary artery disease d. Nursing Care i. establish baseline data and monitor during acute angina or IV administration: blood pressure, heart rate, EKG, chest pain ii. may decrease effectiveness of heparin iii. withdraw treatment gradually to avoid angina iv. toxicity: central nervous system changes, hypotension, flushing, nausea v. buccal area must be moist for sublingual absorption vi. may induce alcohol intoxication (without alcohol intake) vii. maintain a 6 to 8 hour nitrate-free period every 24 hours after acute episode to avoid tolerance e. Client Teaching apply spray under tongue; do not chew tablets sit down when taking, change positions slowly report blurred vision or dry mouth, avoid alcohol keep tablets away from light, moisture, and body heat; change tablets every 6 months use spray or sublingual tablets for immediate relief; combine drug with rest for acute attack rotate site of ointment or patch; remove ointment or patch and clean skin for daily nitrate-free period for acute angina: take 1 tablet sublingual (or 1 spray under the tongue) every 5 minutes up to three doses; seek emergency treatment if there is no pain relief ************************************************************************************** 55 ************************************************************************************** TYPE: BETA-ADRENERGIC BLOCKING AGENTS a. Action: selective (beta-adrenergic receptors) and non-selective (beta- and beta-adrenergic) blockers of the sympathetic nervous system (SNS) resulting in ▪ slower heart rate ▪ decreased vasoconstriction ▪ decreased myocardial oxygen consumption b. Examples selective blockers a. atenolol (Tenormin) 50-100 mg by mouth daily; IV 5 mg, may repeat 2 times b. metoprolol (Toprol) 100-450 mg by mouth 1-2 times daily; IV 5 mg every 2 minutes for 3 doses non-selective blocker: propranolol (Inderal) 80-240 mg by mouth in 2-4 divided doses daily; IV 1-3 mg, may repeat in 2 minutes c. Uses: heart failure, primary and secondary hypertension, heart rate control, angina, and migraine headache prophylaxis d. Adverse Effects: life-threatening: orthostatic hypotension, reflex tachycardia, bradycardia, heart block, heart failure, hypotension most common a. depression, decreased exercise tolerance b. suppresses clinical indicators of hypoglycemia precipitous hypotension heart block and heart failure venous pooling, peripheral edema hypotensive effect of diltiazem potentiated with cyclosporine other a. bronchospasm (not as common with cardioselective forms) b. dizziness, weakness, sexual dysfunction c. nausea, vomiting, diarrhea, anorexia, and constipation e. Contraindications thyrotoxicosis, diabetes mellitus (DM) peripheral vascular disease (PVD) chronic obstructive pulmonary disease (COPD) severe deficiencies in electrolytes heart block, pediatrics, hypovolemia f. Nursing Care establish baseline data and monitor breath sounds and peripheral perfusion avoid concomitant use of clonidine and nonsteroidal antiinflammatory drugs (NSAIDs) taper dose before discontinuing, do not discontinue before surgery check with provider for administration limits for heart rate and blood pressure older adults more susceptible to toxicity, labile hypotension and orthostatic hypotension g. Client Teaching AVOID over-the-counter drugs change positions slowly take pulse or blood pressure before administration 56 take medication only as directed, even when feeling well and blood pressure is controlled (indicates that the therapy is effective) therapy most effective when combined with weight loss, smoking cessation, and an active lifestyle ************************************************************************************** 57 ************************************************************************************** TYPE: CALCIUM CHANNEL BLOCKING AGENTS a. Action: block movement of calcium into muscle cell b. Examples ▪ amlodipine (Norvasc) 5-10 mg by mouth daily ▪ diltiazem (Cardizem) 30-120 mg by mouth 3-4 times daily; (Cardizem SR) 180-240 mg by mouth daily ▪ verapamil (Calan XR) 120-240 mg by mouth daily; IV 5-10 mg/kg, may repeat with 10 mg in 15- 30 minutes c. Uses: hypertension, angina, and dysrhythmias d. Adverse Effects ▪ life threatening: orthostatic hypotension, reflex tachycardia, bradycardia ▪ precipitous hypotension, heart block and heart failure ▪ venous pooling, peripheral edema ▪ hypotensive effect of diltiazem potentiated with cyclosporine ▪ other ▪ dizziness, weakness, sexual dysfunction ▪ nausea, vomiting, diarrhea, anorexia, and constipation e. Contraindications ▪ heart block, pediatrics, hypovolemia and sick sinus syndrome ▪ verapamil causes severe constipation and should never be used for elderly clients ▪ severe deficiencies in serum electrolytes f. Nursing Care ▪ establish baseline data and monitor pressure, potassium, fluid and electrolytes and monitor BUN and creatinine, liver function tests ▪ Older clients are more susceptible to toxicity, labile hypotension and orthostatic hypotension ▪ monitor heart rate, EKG g. Client Teaching ▪ grapefruit and grapefruit juice may interact with diltiazem and lead to potentially dangerous effects ▪ calcium channel blockers can act as a "male contraceptive" - male clients should use another antihypertensive agent if trying to start a family ▪ the client may open the diltiazem capsule and sprinkle the medicine into a spoonful of applesauce to make swallowing easier ▪ AVOID over-the-counter drugs ▪ change positions slowly ▪ take medication only as directed, even when feeling well and blood pressure is controlled (indicates that the therapy is effective) ▪ therapy most effective when combined with weight loss, smoking cessation, and an active lifestyle ************************************************************************************** 58 ************************************************************************************** ANTICOAGULANT AGENTS ************************************************************************************** TYPE: ORAL ANTICOAGULANTS a. Action: interferes with vitamin K dependent clotting factors in the liver resulting in prolonged bleeding time b. Example: warfarin (Coumadin) 2.5-10 mg by mouth daily for 2 to 5 days; then, titrate according to international normalized ratio (INR) c. Uses: maintenance therapy and prophylaxis to suppress formation of dangerous clots after myocardial infarction, mechanical heart valve surgery, atrial fibrillation (A fib) and atrial flutter (A flutter), heart failure, deep vein thrombosis, and pulmonary embolism (PE) d. Adverse Effects i. hemorrhage, peripheral skin necrosis ii. bone marrow depression, liver dysfunction iii. anorexia, many drug-drug interactions iv. high-risk drug with older or incompetent clients e. Contraindications i. clients at risk for falls, malabsorption syndrome ii. severe hepatic or renal disease iii. bleeding disorders and active bleeding iv. recent invasive procedure to spinal cord f. Nursing Care i. establish baseline data and monitor prothrombin time (PT) and international normalized ratio (INR), liver function tests (LFTs) ii. assess client for bruising or bleeding, headache, decreased level of consciousness and fall risk iii. IM injections should be avoided iv. apply prolonged pressure to any puncture wounds to stop bleeding v. antidote: administration of vitamin K suppresses warfarin activity for 1 to 3 weeks; may need to provide alternate anticoagulation vi. client teaching avoid alcohol, NSAIDs use electric razor for shaving seek emergency treatment for falls wear MedicAlert® identification, monitor for bleeding take at same time daily, need for follow-up care and testing AVOID these herbal remedies: echinacea, licorice, and ginseng AVOID foods containing vitamin K (decreases effect of warfarin) especially green leafy vegetables, broccoli, and liver ************************************************************************************** 59 ************************************************************************************** TYPE: LOW-MOLECULAR WEIGHT (LMW) HEPARIN a. Action: blocks action of Factors Xa and Ila without appreciably affecting thrombin or prothrombin b. Examples - i. dalteparin (Fragmin) 2500 IU to 5000 IU by subcutaneous injection daily ii. enoxaparin (Lovenox) 30 mg/kg by subcutaneous injection twice daily (prevention dose) c. Uses: prophylaxis against thromboembolic disorders associated with surgery and bedrest d. Adverse Effects i. hemorrhage, thrombocytopenia, angioedema ii. increased bleeding times and bruising iii. inflammation at injection site, dyspnea, rash e. Contraindications i. recent gastrointestinal bleed or invasive spinal cord procedure ii. active bleeding, thrombocytopenia, uncontrolled hypertension f. Nursing Care (see also: anticoagulants: oral, nursing care i. establish baseline data and monitor CBC and platelets ii. does not affect prothrombin time (PT), INR, or activated partial thromboplastin time (aPTT) with therapeutic doses iii. lower risk of heparin-induced thrombocytopenia than unfractionated heparin iv. give subcutaneously according to manufacturer's direction v. client teaching: subcutaneous injection technique ************************************************************************************** 60 ************************************************************************************** TYPE: UNFRACTIONATED HEPARIN a. Action: inhibits conversion of prothrombin to thrombin thus preventing fibrin formation b. Example: heparin sodium - see Epocrates Online for specific dosage information c. Uses: acute illness to suppress dangerous clot formation; unstable angina, myocardial infarction, stroke, deep vein thrombosis (DVT), pulmonary embolism (PE), atrial fibrillation and flutter, disseminated intravascular coagulation (DIC) d. Adverse Effects i. life threatening: heparin-induced thrombocytopenia (HIT) ii. other a. bronchospasm, increased bleeding time b. rebound hyperlipidemia, fever, chills, rash c. impairment of endocrine system d. drug-drug interaction with nitroglycerin, nicotine iii. impairment of endocrine system e. Contraindications i. extensive burns, trauma; severe hypertension ii. recent surgery or invasive spinal cord procedure iii. thrombocytopenia, active bleeding, bleeding disorders f. Nursing Care i. establish baseline data and monitor activated partial thromboplastin time (aPTT), complete blood count and platelets ii. always have two nurses check original order, dose calculation, infusion pump setting and bolus/loading dose for IV administration iii. highest risk of HIT iv. assess client for bruising or bleeding, headache, decreased level of consciousness and fall risk v. apply prolonged pressure to any puncture wounds to stop bleeding vi. IM injections should be avoided vii. adjust dosage when given with nitroglycerin (NTG) viii. high-risk therapy for women, older clients, and with renal or hepatic insufficiency ix. antidote - protamine sulfate (Protamine Sulfate 1.0%) 0.5-1 mg IV/100 units of heparin given g. Client Teaching: i. subcutaneous injection technique ii. avoid alcohol, NSAIDs iii. use electric razor for shaving iv. seek emergency treatment for falls v. wear MedicAlert® identification, monitor for bleeding vi. take at same time daily, need for follow-up care and testing vii. AVOID these herbal remedies: echinacea, licorice, and ginseng For more information about the use of protamine sulfate, visit the Web site of the Food and Drug Administration (FDA) at: http://www.fda.gov/ 61 ************************************************************************************** ANTIDYSRHYTHMIC (OR ANTIARRHYTHMIC) AGENTS ************************************************************************************** INFORMATION COMMON TO ANTI-DYSRHYTHMIC AGENTS 1. Use 1. eradication of frequent premature ventricular contractions that cause hemodynamic instability or loss of consciousness 2. emergency eradication of ventricular dysrhythmias 3. cardiopulmonary resuscitation 4. chemical cardioversion of atrial and ventricular dysrhythmias 2. Adverse Effects 1. heart block 2. most have dysrhythmogenic potential (capable of causing dysrhythmias) 3. prolongation of QTc interval (In medicine, specifically cardiology, the QT interval is a measure of the time between the start of the Q wave and the end of the T wave in the heart's electrical cycle. QTc can be measured by the time between the onset of ventricular depolarization and the completion of ventricular repolarization. A prolonged QT interval is a risk factor for ventricular tachy-arrhythmias and sudden death.) 4. prolongation of QRS complex 5. increased risk of torsades des pointes 3. Assist health care provider to implement Client Teaching Plan 1. count heart rate and pattern of rhythm, i.e., regularity 2. provide acceptable range for heart rate 3. report a. new onset of irregular rhythm b. findings outside of acceptable parameters c. worsening heart rate, dizziness, lightheadedness, loss of consciousness, and edema ************************************************************************************** 62 ************************************************************************************** TYPE: SODIUM CHANNEL BLOCKING AGENTS (CLASS I ANTIDYSRHYTHMIC AGENTS) a. Action: suppresses various phases in myocardial cell action potential by blocking sodium channels; stabilizes myocardial cell membrane b. Examples i. lidocaine (Xylocaine) - titrate according to frequency of ventricular ectopy ii. quinidine gluconate (Quinalan) iii. procainamide (Pronestyl) c. Uses: ventricular dysrhythmias, chemical cardioversion with atrial fibrillation and atrial flutter (except lidocaine) d. Adverse Effects i. life-threatening: dysrhythmias, heart block, Torsades de pointes respiratory depression bone marrow depression ii. other: nausea, vomiting, rash increases risk of digoxin toxicity and risk of bleeding with anticoagulants central nervous system effects including sedation, confusion, and seizures (especially lidocaine) e. Contraindications i. prolonged QTc interval ii. hypotension and shock iii. heart block without pacemaker iv. prolonged therapy, use with cimetidine f. Nursing Care i. establish baseline data and monitor drug levels ii. assess vital signs, EKG, QTc interval, neurologic status iii. prevent client injury - associated with many adverse effects iv. quinidine and procainamide reserved for use after many other therapies have failed g. Client Teaching i. AVOID citrus juices, antacids, and milk products ii. take heart rate daily: report change in rhythm ************************************************************************************** 63 ************************************************************************************** TYPE: BETA-ADRENERGIC BLOCKING AGENTS (CLASS II ANTIDYSRHYTHMIC AGENTS) (See also: Beta-Adrenergic Antagonists) ************************************************************************************** TYPE: POTASSIUM CHANNEL BLOCKING AGENTS (CLASS III ANTIDYSRHYTHMIC AGENTS) a. Action: slows the outward movement of potassium through myocardial cell membranes and prolongs the action potential b. Examples i. amiodarone (Cordarone) 400 mg by mouth daily ii. sotalol (Betapace) 160-320 mg by mouth daily in 2-3 doses c. Uses: ventricular and supraventricular dysrhythmias, chemical cardioversion with atrial fib and atrial flutter d. Adverse Effects i. life-threatening: heart failure, heart block, sinus arrest, liver damage ii. most common: nausea, vomiting, dizziness, weakness, photosensitivity iii. other: pulmonary fibrosis, hypotension e. Contraindications i. prolonged QTc interval ii. concomitant use with quinidine or procainamide iii. severe liver disease, heart block, cardiogenic shock f. Nursing Care i. establish baseline data and monitor vital signs, EKG, hepatic, pulmonary, endocrine, neurological, and GI function ii. follow oral and IV administration guidelines: timing and rates of infusion are very important g. Client Teaching i. AVOID taking with echinacea ii. need for follow-up care and testing iii. protect skin and eyes from UV rays iv. monitor pulse and report changes in rhythm v. may take with meals but must be consistent ************************************************************************************** 64 ************************************************************************************** TYPE: ANTICHOLINERGIC AGENT (see also: Anticholinergics for other uses) a. action: competes with acetylcholine for muscarinic receptor sites to produce mild vagal excitation b. example: atropine (atropine sulfate) 0.5-1 mg, up to 2 mg c. use: bradycardia associated with increased vagal tone d. adverse effects i. life threatening: paradoxical bradycardia with sub-therapeutic dosing; hypotension, angina, tachycardia, dysrhythmias ii. most common: anticholinergic effects, i.e., sedation, dry mouth, blurred vision, urinary retention, constipation, orthostatic hypotension iii. other: paradoxical bradycardia lasting 2 minutes atropine flush 15 to 20 minutes after injection ************************************************************************************** TYPE: ACETYLCHOLINE-SENSITIVE POTASSIUM CURRENT ACTIVATOR a. action: shortens duration of action potential, causes hyperpolarization, and slows normal automaticity b. example: adenosine (Adenocard) 6 mg rapid IV bolus: may administer 12 mg rapid IV bolus in 1 to 2 minutes c. use: chemical conversion of supraventricular tachycardia after failure of vagal maneuver d. adverse effects i. transient asystole, dysrhythmias ii. dyspnea, chest tightness, hypotension, flushing, nausea e. contraindications: 2nd or 3rd degree AV block, sick sinus syndrome, cardiac transplant f. nursing care i. establish baseline data and monitor continuously during therapy: EKG, heart rate, blood pressure, respiratory rate ii. monitor serum electrolytes Updated clinical practice guidelines indicate that individuals with a systolic blood pressure of 120–139 mm Hg or a diastolic blood pressure of 80–89 mm Hg should be considered as "prehypertensive" and will require health-promoting lifestyle modifications to prevent cardiovascular disease (National Heart Lung and Blood Institute, 2003). 65 ************************************************************************************** ANTIHYPERTENSIVE AGENTS ************************************************************************************** INFORMATION COMMON TO ANTIHYPERTENSIVE AGENTS a. Uses: heart failure, primary and secondary hypertension b. Adverse Effects 1. life threatening: orthostatic hypotension, reflex tachycardia, bradycardia 2. other a. dizziness, weakness, sexual dysfunction b. nausea, vomiting, diarrhea, anorexia, and constipation c. Contraindications 1. severe deficiencies in serum electrolytes 2. heart block, pediatrics, hypovolemia d. Nursing Care 1. establish baseline data and monitor blood pressure, potassium, fluid and electrolyte balance, renal function 2. older clients more susceptible to toxicity, labile hypotension, and orthostatic hypotension 3. client teaching a. AVOID over-the-counter drugs b. change positions slowly c. take medication only as directed, even when feeling well and blood pressure is controlled (indicates that the therapy is effective) d. therapy most effective when combined with weight loss, smoking cessation, and an active lifestyle Learn more about hypertension treatment and guidelines from The National Heart, Lung, and Blood Institute at: http://www.nhlbi.nih.gov/guidelines/hypertension/express.pdf ************************************************************************************** 66 ************************************************************************************** TYPE: ANGIOTENSIN-CONVERTING ENZYME (ACE) INHIBITORS a. Action: inhibits conversion of angiotensin I to angiotensin II in the lungs preventing vasoconstriction from angiotensin II and the release of aldosterone b. Examples i. enalapril (Vasotec) 10-40 mg twice daily by mouth, initiate therapy at 2.5-5 mg ii. lisinopril (Zestril) 20-80 mg daily by mouth, initiate therapy at 2.5-5 mg c. Uses: hypertension and heart failure d. Adverse Effects i. refractory cough ii. hyperkalemia iii. rash, renal and hepatic injury e. Contraindications: hyperkalemia and renal insufficiency f. Nursing Care i. administer on empty stomach - take 1 hour before and 2 hours after eating ii. client teaching reduce intake of foods containing potassium (see below) and avoid salt substitutes containing potassium increased risk of hypersensitivity if given with allopurinol seek emergency care for any indications of angioedema ("does my voice sound funny?") ACE inhibitors are teratogenic - female client must use contraception when taking ************************************************************************************** POTASSIUM-RICH FOODS High potassium - greater than 225 milligrams per 1/2 cup serving o protein sources: all meats, poultry and fish o fruits: apricots, banana (1 small = 467 mg), cantaloupe, honeydew, kiwi, oranges, prunes, tomatoes, raisins (1/3 cup = 363) o vegetables: lima beans, potatoes, spinach, (baked) sweet potato with skin, avocado o dairy: milk (1 cup 2% milk = 377 mg), prune juice (1 cup = 707 mg) o other: sunflower seeds (1/4 cup = 241 mg), molasses (1 tablespoon = 498 mg) Moderate potassium - 125 to 225 mg per serving o vegetables: asparagus, beets, broccoli, corn, carrots, green peas, onions, summer squash (zucchini) o fruit: blackberries, cherries, peach, pears, pineapple; apple juice (1/2 cup = 147 mg) o other: salted peanuts (1 ounce = 187 mg) Low potassium - less than 125 mg per serving o fruit: apples, blueberries, cranberries o vegetables: cucumber, green beans, iceberg lettuce ************************************************************************************** 67 ************************************************************************************** TYPE: ANGIOTENSIN II-RECEPTOR BLOCKER (ARB’s) a. action: binds to angiotensin II receptors to block vasoconstriction and release of aldosterone b. examples i. Iosartan (Cozaar) 50-100 mg by mouth daily in 1-2 doses ii. valsartan (Diovan) 160-320 mg by mouth daily c. uses: hypertension and heart failure d. adverse effects: hyperkalemia e. nursing care i. relatively few drug-drug interactions f. client teaching i. may take with food; avoid salt substitutes containing potassium ii. take medication with a full glass of water Adverse effects of anticholinergic agents include dry mouth, constipation, and blurred vision, which are similar to the effects of anticholinergic agents (like atropine or scopolamine). Learn anticholinergic effects and apply the findings to all anticholinergic agents. ************************************************************************************** 68 ************************************************************************************** TYPE: CALCIUM CHANNEL BLOCKER (CCB) a. action: block movement of calcium into muscle cell b. examples - see Epocrates Online for greater detail i. amlodipine (Norvasc) 5-10 mg by mouth daily ii. diltiazem (Cardizem) 30-120 mg by mouth 3-4 times daily; (Cardizem SR) 180-240 mg by mouth daily iii. verapamil (Calan XR) 120-240 mg by mouth daily; IV 5-10 mg/kg, may repeat with 10 mg in 15- 30 minutes c. uses: hyptertension, angina, and dysrhythmias d. adverse effects i. precipitous hypotension ii. heart block and heart failure iii. venous pooling, peripheral edema iv. hypotensive effect of diltiazem potentiated with cyclosporine e. contraindications i. heart block and sick sinus syndrome ii. verapamil causes severe constipation and should never be used for elderly clients f. nursing care (see also: information common to antihypertensive agents and Epocrates Online for greater detail) i. establish baseline and monitor BUN and creatinine, liver function tests ii. monitor heart rate, EKG iii. client teaching grapefruit and grapefruit juice may interact with diltiazem and lead to potentially dangerous effects calcium channel blockers can act as a "male contraceptive" - male clients should use another antihypertensive agent if trying to start a family the client may open the diltiazem capsule and sprinkle the medicine into a spoonful of applesauce to make swallowing easier ************************************************************************************** 69 ************************************************************************************** TYPE: BETA-ADRENERGIC BLOCKING AGENTS (ANTAGONISTS) a. action: selective (beta-adrenergic receptors) and non-selective (beta- and beta-adrenergic) blockers of the sympathetic nervous system (SNS) resulting in i. slower heart rate ii. decreased vasoconstriction iii. decreased myocardial oxygen consumption b. examples i. selective blockers - see Epocrates for greater detail atenolol (Tenormin) 50-100 mg by mouth daily; IV 5 mg, may repeat 2 times metoprolol (Toprol) 100-450 mg by mouth 1-2 times daily; IV 5 mg every 2 minutes for 3 doses ii. non-selective blocker: propranolol (Inderal) 80-240 mg by mouth in 2-4 divided doses daily; IV 1- 3 mg, may repeat in 2 minutes c. uses: heart failure, hypertension, heart rate control, angina, and migraine headache prophylaxis d. adverse effects i. life-threatening: bradycardia, heart block, heart failure, hypotension ii. most common depression, decreased exercise tolerance suppresses clinical indicators of hypoglycemia iii. other: bronchospasm (not as common with cardioselective forms) e. contraindications i. thyrotoxicosis, diabetes mellitus (DM) ii. peripheral vascular disease (PVD) iii. chronic obstructive pulmonary disease (COPD) f. nursing care (see also: antihypertensive agents) i. establish baseline data and monitor breath sounds and peripheral perfusion ii. avoid concomitant use of clonidine and nonsteroidal antiinflammatory drugs (NSAIDs) iii. taper dose before discontinuing, do not discontinue before surgery iv. check with provider for administration limits for heart rate and blood pressure v. client teaching: take pulse or blood pressure before administration ************************************************************************************** 70 ************************************************************************************** TYPE: COMBINED ALPHA AND BETA-ADRENERGIC BLOCKING AGENTS a. action: blocks all SNS receptors and inhibits release of epinephrine (Epi) and norepinephrine (NE) resulting in decreased vasoconstriction, slower heart rate, and increased renal perfusion b. examples - see Epocrates Online for greater detail i. carvedilol (Coreg) 6.25-25 mg twice daily by mouth, increase dose in 2 week intervals ii. labetalol (Normodyne) 400-800 mg 2-3 times daily by mouth iii. guanethidine (Ismelin) 25-100 mg daily by mouth c. uses: heart failure, hypertension secondary to renal failure, refractory hypertension d. adverse effects i. cerebrovascular accident (CVA), bronchospasm, pulmonary edema ii. serious dysrhythmias when combined with CCBs iii. masks signs of hypoglycemia iv. impaired peristalsis, decreased exercise tolerance e. contraindications: heart block, acute asthma, diabetes mellitus, and shock f. nursing care (see also: antihypertensive agents) i. establish baseline data and monitor for heart block, bronchospasm, pulmonary edema, and liver failure ii. taper dose before discontinuing ************************************************************************************** TYPE: ALPHA-ADRENERGIC BLOCKING AGENTS a. action: non-selective blocker of alpha-adrenergic receptors of sympathetic nervous system (SNS) b. examples: phentolamine mesylate (Regitine) c. uses: hypertension associated with pheochromocytoma, extravasation of epinephrine and dopamine d. adverse effects i. life-threatening: angina and myocardial infarction (MI), CVA, profound hypoglycemia ii. other: nausea, vomiting, and diarrhea e. contraindications: coronary artery disease and MI f. nursing care: potentiated by alcohol; suppressed with epinephrine and ephedrine ************************************************************************************** TYPE: ALPHA-BLOCKING AGENTS a. action: blocks alpha1-receptors of SNS b. examples - see Epocrates Online for greater detail i. prazosin (Minipress) ii. terazosin (Hytrin) iii. tamsulosin (Flomax) c. uses: hypertension, benign prostatic hypertrophy (BPH) d. adverse effects: angina, priapism, headache, peripheral edema e. contraindications: hepatic and renal failure; do not take with sildenafil (Viagra) or tadalafil (Cialis) f. nursing care: provide small frequent meals to manage GI discomfort ************************************************************************************** 71 ************************************************************************************** TYPE: ALPHA-AGONISTS a. action: displaces NE and stimulates alpha 2-receptors of sympathetic nervous system (SNS) resulting in decreased release of norepinephrine in the periphery b. example: cloNIDine (Catapres) c. uses: hypertension, chronic pain related to cancer d. adverse effects i. life-threatening: bradycardia ii. other a. dry mouth, sedation, nausea, vomiting, anorexia, headache, urinary retention e. contraindications i. narrow-angle glaucoma ii. vasospastic disease, thyrotoxicosis or diabetes mellitus f. nursing care (see also: information common to antihypertensive agents) i. taper dose before discontinuing ii. do not discontinue before surgery iii. do not administer with tricyclic antidepressants or propranolol Learn more about familial hypercholesterolemia from The American Academy of Family Physicians. ************************************************************************************** TYPE: CENTRALLY ACTING VASODILATORS a. action: directly relaxes arteriolar vascular smooth muscle resulting in lowered peripheral vascular resistance and reflex tachycardia b. example: hyrdALAZINE (Apresoline) 200-300 mg by mouth daily divided in 4 doses; do not confuse with hydrOXYzine c. uses: acute hypertension associated with pregnancy, essential hypertension, hypertensive crisis, congestive heart failure d. adverse effects i. life-threatening: shock, myelosuppression, reflex tachycardia, angina, myocardial infarction, neutropenia, blood dyscrasias, lupus erythematosus, peripheral neuritis ii. most common: headache, tachycardia, tremors, dizziness, peripheral neuritis, angina, palpitations iii. other: anorexia, paralytic ileus, rash, nasal congestion, flushing, nausea, vomiting, diarrhea, e. contraindications: maternal bleeding, coronary artery disease, mitral valve disease, rheumatic heart disease, cardiovascular or cerebrovascular disease and severe renal impairment f. nursing care i. establish baseline data and monitor complete blood count, creatinine and blood pressure, antinuclear antibody testing (ANA) at baseline and then periodically if prolonged treatment ii. assess and monitor fetal heart tones, maternal blood pressure, heart rate, EKG, breath sounds, weight, edema iii. administration give orally with food hypertension in pregnancy: given IV bolus, monitor vital signs every 15 minutes iv. client teaching report chest pain, severe fatigue, muscle or joint pain AVOID over-the-counter drugs; AVOID isosorbide dinitrate change positions slowly 72 ************************************************************************************** TYPE: DIURETICS (Information common to diuretics (except potassium-sparing diuretics) Type: diuretics - especially thiazide and thiazide-like diuretics; to a lesser extent, loop diuretics; used alone or in combination with other antihypertensive agents 1. action: increases the rate of urine flow by effecting a section of the renal tubules to excrete sodium; alters renal handling of other electrolytes 2. uses a. increase rate of urine flow, sodium and chloride excretion b. heart failure, hypertension, hyperkalemia c. rapid fluid excretion, severe edema, pulmonary edema 3. adverse effects a. life-threatening: circulatory collapse, myelosuppression b. most common: hypokalemia, hyponatremia, hypocalcemia, hypercalcemia, hyperglycemia 4. contraindications a. hypokalemia, hypovolemia, anuria b. allergy to sulfonamide, electrolyte depletion 5. nursing care a. establish baseline data and monitor intake, urine output, serum electrolytes especially potassium, blood pressure, cardiac rhythm, serum glucose and pH b. increased risk of digoxin toxicity c. client teaching i. may take with food or milk ii. avoid alcohol and over-the-counter drugs iii. do not stop taking when feeling well iv. administer in early morning to avoid nocturia v. potassium-rich diet (may need to avoid or increase intake of foods containing potassium) vi. report irregular heartbeat, low urine output, dizziness, rash, muscle cramps, twitching, weakness ************************************************************************************** 73 ************************************************************************************** ANTI-LIPID AGENTS ************************************************************************************** TYPE: BILE ACID SEQUESTRANT AGENTS a. action: bind with bile acid in small intestine leading to decreased absorption and increased excretion of fat in stool b. example: cholestyramine (Questran) 4-20 grams by mouth once or twice daily c. uses: in combination with low fat diet to lower serum lipids, primary hypercholesterolemia, and elevated low-density lipoprotein (LDL) d. adverse effects i. increased bleeding time ii. headache, nausea, constipation iii. decreased absorption of fat-soluble vitamins e. contraindications i. bleeding disorders, biliary obstruction ii. post-cholecystectomy, abnormal bowel function f. nursing care i. monitor serum lipids ii. assess bowel sounds prior to administering iii. prevent constipation - assess and record bowel pattern, bleeding iv. monitor for vitamin deficiency and increased bleeding times v. administration do not crush or chew tablets give with food; do not administer in dry form administer 1 hour before or 4 to 6 hours after thiazide, diuretics, digoxin, warfarin, thyroid hormone, or glucocorticoids vi. client teaching must take with food report bleeding, muscle pain prevent constipation with increased fluids, fiber, and physical activity ************************************************************************************