Week 9 Renal Fluids Electrolytes Class Slides PDF

Fluids and Electrolytes Renal Medications NUR 2303 – Week 9 Housekeeping Questions from last week Chapter 30 Fluids & Electrolytes Fluid Balance Total body water Composed of: Intracellular fluid: 67% Interstitial fluid: 25% Plasma volume (IVF): 8% 60% of adult human body...

Fluids and Electrolytes Renal Medications NUR 2303 – Week 9 Housekeeping Questions from last week Chapter 30 Fluids & Electrolytes Fluid Balance Total body water Composed of: Intracellular fluid: 67% Interstitial fluid: 25% Plasma volume (IVF): 8% 60% of adult human body is water Higher water in infants Lower water in elderly Fluid Balance Intracellular fluid Electrolytes and glucose Extracellular fluid Transport nutrients and waste Made up of intravascular and interstitial fluid IVF (‘plasma’) has 4x the protein as ISF Intravascular fluid ‘plasma’ Fluid inside blood vessels (blood, protein rich plasma, lots of albumin) Interstitial fluid Fluid in body compartments, little protein (synovial, CSF, pleural cavity) Fluid Balance Antidiuretic Hormone Thirst Aldosterone (ADH) Triggers fluid intake when Also known as Is a hormone from the the body detects low vasopressin adrenal glands that blood volume or high Is released by the prompts sodium (and osmolarity pituitary gland in subsequently water) response to high blood retention in the kidneys, osmolarity, causing the helping regulate blood kidneys to retain water volume and pressure and concentrate urine Oncotic and Hydrostatic Pressure Plasma proteins exert constant oncotic pressure. Helps draw water in the blood vessels from surrounding tissues, maintaining fluid in the vascular space Normally 24 mm Hg Interstitial fluid exerts hydrostatic pressure. Pushes water out of the capillaries in the surrounding tissues Normally 17 mm Hg ** balance between oncotic and hydrostatic pressure helps regulate fluid movement between blood vessels and tissues, maintaining fluid distribution and preventing edema** Colloid Oncotic Pressure Colloids too large to leave the vessel Hydrostatic Pressure exerted by the colloids pulls fluids into the vessel Tonicity of Intravenous Solutions Isotonic (osmotic pressure same) 0.9% NaCl (Normal Saline), LR (Lactated Ringers), D5W Similar concentration of solutes such as blood plasma Hypotonic (solution has lower osmotic pressure) 0.45% NaCl, O.33% NaCl, D5W (5% Dextrose in Water) Causes fluid to move out of the veins into the surrounding tissues Hypertonic (solution has higher osmotic pressure) 3% NaCl, 5% NaCl, D10W (10% Dextrose in Water), D5NS, D5L Causes fluid to move into the veins from the surrounding tissues Crystalloids Solutions contain fluids and electrolytes normally found in the body Do not contain proteins (colloids) No risk for viral transmission, anaphylaxis, or alteration in coags Better for treating dehydration rather than expanding plasma volume Used as maintenance fluids to: Compensate for insensible fluid losses Replace fluids Manage specific fluid and electrolyte disturbances Promote urinary flow Crystalloids Normal saline (NS): 0.9% NaCl (isotonic) Lactated Ringer’s solution (D5LR)(isotonic) Dextrose 5% in water (D5W) (isotonic) 3.3% dextrose and 0.3% NS (“2/3 & 1/3”) (isotonic) D5W and 0.225% NS (D51/4NS) (isotonic) Plasma-Lyte (isotonic) 0.45% NaCl “half-normal” (hypotonic) 3% NaCl (hypertonic) D5W and 0.45% NS (D51/2NS) (hypertonic) Crystalloids: Indications Acute liver failure Acute nephrosis Adult respiratory distress syndrome Burns Cardiopulmonary bypass Hypoproteinemia Hemodialysis Deep vein thrombosis (reduction of risk) Shock Crystalloids: Adverse Effects May cause edema, especially peripheral or pulmonary May dilute plasma proteins, reducing colloid oncotic pressure Effects may be short-lived Prolonged infusions may worsen alkalosis or acidosis Colloids Protein substances Increase colloid oncotic pressure Move fluid from interstitial compartment to plasma compartment (when plasma protein levels are low) Albumin 5% and 25% (from human donors) Dextran 40 or 70 (available in sodium chloride and 5% dextrose) Hetastarch (synthetic) May cause altered coagulation, resulting in bleeding Have no clotting factors or oxygen-carrying capacity Colloids: Albumin Natural protein that is normally produced by the liver Responsible for generating approximately 70% of colloid oncotic pressure Sterile solution of serum albumin that is prepared from pooled blood, plasma, serum, or placentas obtained from healthy donors Pasteurized to destroy any contaminants Blood Products Only class of fluids that can carry oxygen Increase tissue oxygenation Increase plasma volume Most expensive and least available fluid Blood Products Increase colloid oncotic pressure and plasma volume Pull fluid from extravascular space into intravascular space (plasma expanders) Red blood cell products also carry oxygen. Indications Cryoprecipitate and plasma protein factors Management of acute bleeding (greater than 50% slow blood loss or 20% acutely) Fresh frozen plasma Increase clotting factor levels in patients with demonstrated deficiency Blood Products: Indications Packed red blood cells To ↑ oxygen-carrying capacity in patients with anemia, in patients with very low hemoglobin, and in patients who have lost up to 25% of their total blood volume Whole blood Same as packed red blood cells except - whole blood is more beneficial in cases of extreme (>25%) loss of blood volume, because whole blood also contains plasma Contains plasma proteins, which help draw fluid back into blood vessels from surrounding tissues Blood Products: Adverse Effects Incompatibility with recipient’s immune system Cross-match testing Transfusion reaction Anaphylaxis Transmission of pathogens to recipient (hepatitis, HIV, etc.) Question A patient is taken to the trauma unit after a motorcycle accident. It is estimated that the patient has lost 30% of blood volume, and the patient is in hypovolemic shock. The nurse anticipates a transfusion with which blood product? A. Packed red blood cells B. Whole blood C. Cryoprecipitate D. Fresh frozen plasma Electrolytes Principal Extracellular Fluid (ECF) electrolytes Sodium cations (Na+) Chloride anions (Cl−) Principal Intracellular Fluid (ICF) electrolyte Potassium cation (K+) Others Calcium, magnesium, phosphorus Potassium (K+) Most abundant positively charged (cationic) electrolyte inside cells 95% of body’s potassium is intracellular. Potassium content outside of cells ranges from 3.5 to 5 mmol/L. Potassium levels are critical to normal body function. Muscle contraction Transmission of nerve impulses Regulation of heartbeat Maintenance of acid–base balance Isotonicity Hyperkalemia: Excessive Serum Potassium Potassium supplements Angiotensin-converting enzyme inhibitors Kidney failure Excessive loss from cells Potassium-sparing diuretics Burns Trauma Metabolic acidosis Infections Hypokalemia: Deficient Serum Potassium Alkalosis Corticosteroids Diarrhea Ketoacidosis Hyperaldosteronism Increased secretion of mineralocorticoids Burns Thiazide, thiazide-like, and loop diuretics Vomiting Malabsorption Potassium Main indication Treatment or prevention of potassium depletion when dietary means are inadequate Other therapeutic uses Stop irregular heartbeats Management of tachydysrhythmias that can occur after cardiac surgery Potassium: Adverse Effects Oral preparations Diarrhea, nausea, vomiting, GI bleeding, ulceration IV administration Pain at injection site Phlebitis Excessive administration Hyperkalemia Toxic effects Cardiac arrest Hyperkalemia Manifestations Muscle weakness, paresthesia, paralysis, cardiac rhythm irregularities (leading to Treatment of severe hyperkalemia possible v-fib and cardiac arrest) IV sodium bicarbonate, calcium gluconate or calcium chloride, dextrose with insulin PO Sodium polystyrene sulphonate (Kayexalate®) or hemodialysis to remove excess potassium Sodium Most abundant positively charged electrolyte outside cells Normal concentration outside cells is 135 to 145 mmol/L Maintained through dietary intake of sodium chloride Salt, fish, meats, foods flavoured or preserved with salt Sodium is responsible for: Control of water distribution Fluid and electrolyte balance Osmotic pressure of body fluids Participation in acid–base balance Hyponatremia: Serum levels ˂135 mmol/L Symptoms Lethargy, stomach cramps, hypotension, vomiting, diarrhea, seizures Causes Some of the same conditions that cause hypokalemia Also, excessive perspiration, prolonged diarrhea or vomiting, kidney disorders, and adrenocortical impairment Hypernatremia: Serum levels ˃145 mmol/L Symptoms Water retention (edema), hypertension Red, flushed skin; dry, sticky mucous membranes; increased thirst; elevated temperature; decreased or absent urinary output Causes Poor kidney excretion stemming from kidney malfunction; inadequate water consumption and dehydration Nursing Implications: Electrolytes Assess baseline fluid volume and electrolyte status. Assess baseline vital signs. Assess skin, mucous membranes, daily weights, and input and output. Before giving potassium, assess electrocardiogram. Assess for contraindications to therapy. Assess transfusion history. Establish venous access as needed. Nursing Implications: Electrolytes Monitor serum electrolyte levels during therapy. Monitor infusion rate, appearance of fluid or solution, and infusion site. Observe for infiltration and other complications of IV therapy. Nursing Implications: Electrolytes Parenteral infusions of potassium must be monitored closely. IV potassium must not be given at a rate faster than 10 mmol/hr to patients who are not on cardiac monitors. For critically ill patients on cardiac monitors, rates of 20 mmol/hr may be used. Never give as an IV bolus or undiluted Oral forms of potassium Must be diluted -water or fruit juice (100 to 250 mL) and taken with food or immediately after meals to minimize GI distress and to prevent too rapid absorption Monitor reports of nausea, vomiting, GI distress Chapter 29 Diuretic Drugs Diuretic Drugs Drugs that accelerate the rate of urine formation Result in the removal of sodium and water Mainstay of therapy for the treatment of Hypertension (HTN) and Heart Failure (HF) and for prevention of kidney damage during acute kidney injury 1st choice in Canada for treatment of Hypertension (HTN) Sodium In the nephron, where sodium goes, water follows. 60 to 70% of sodium and water is returned to the bloodstream by the proximal convoluted tubule. 20 to 25% of all sodium is reabsorbed into the bloodstream in the ascending loop of Henle. 5 to 10% is reabsorbed in the distal convoluted tubule. Collecting duct is the final common pathway for the filtrate that started in the glomerulus. If water is not absorbed, it is excreted as urine. Types of Diuretic Drugs Carbonic anhydrase inhibitors Loop diuretics Osmotic diuretics Potassium-sparing diuretics Thiazide and thiazide-like diuretics Carbonic Anhydrase Inhibitors (CAIs) MOA Carbonic anhydrase helps to make H+ ions available for exchange with sodium and water in the proximal tubules. Carbonic anhydrase inhibitors block the action of carbonic anhydrase, thus preventing the exchange of H+ ions with sodium and water. Inhibition of carbonic anhydrase reduces H+ ion concentration in renal tubules. Results in increased excretion of bicarbonate, sodium, water, and potassium. Resorption of water is decreased, and urine volume is increased. Carbonic Anhydrase Inhibitors: Indications Adjunct drugs in the long-term management of open-angle glaucoma and adjunct therapy for secondary glaucoma Used with miotics to lower intraocular pressure before ocular surgery in certain cases Also useful in the treatment of Edema, secondary to heart failure, High- altitude sickness, and Epilepsy Carbonic Anhydrase Inhibitors Acetazolamide (Acetazolam®) Most commonly used carbonic anhydrase inhibitor Oral and parenteral forms Potential benefits may warrant use in pregnant women despite potential fetal risks Carbonic Anhydrase Inhibitors Interactions Adverse Effects Because carbonic anhydrase CAIs can raise blood glucose levels inhibitors can cause hypokalemia, an and cause glucose in the urine, increase in digoxin toxicity may occur especially in diabetics. when they are combined with digoxin. They may also lead to acidosis Use with corticosteroids may also (increased acidity in the blood), low cause hypokalemia. potassium (hypokalemia), Increased effects of amphetamines, drowsiness, appetite loss, tingling, carbamazepine, cyclosporine, blood in urine, skin reactions, light phenytoin, and quinidine sulphate sensitivity, and dark stools. with concurrent use of carbonic anhydrase inhibitors Loop Diuretics Furosemide (Lasix®) (most used) Bumetanide Ethacrynic acid (rarely used clinically) Loop Diuretics: MOA 1 2 3 Possess kidney, Act directly on the Increase kidney cardiovascular, and ascending limb of the prostaglandins, resulting metabolic effects loop of Henle to block in the dilation of blood chloride and sodium vessels and reduced resorption kidney, pulmonary, and systemic vascular resistance Loop Diuretics: Indications Edema associated with heart failure and liver or kidney disease Hypertension Kidney excretion of calcium in patients with hypercalcemia Heart failure resulting from diastolic dysfunction Loop Diuretics: Drug Effects Rapid onset; last at least 2 hours Potent diuresis and subsequent loss of fluid Decreased fluid volume causes a reduction in: Blood pressure Pulmonary vascular resistance Systemic vascular resistance Central venous pressure Left ventricular end-diastolic pressure Potassium and sodium depletion Small calcium loss Loop Diuretics: Adverse Effects Body system/adverse effects Central nervous system: Dizziness, headache, tinnitus, blurred vision Gastrointestinal: Nausea, vomiting, diarrhea Hematological: Agranulocytosis, neutropenia, thrombocytopenia Metabolic: Hypokalemia, hyperglycemia, hyperuricemia Osmotic Diuretics: MOA Works along entire nephron but mostly in the proximal tubule and descending loop of Henle Nonabsorbable, producing an osmotic effect Pull water into the renal tubules from the surrounding tissues Inhibit tubular resorption of water and solutes, thus producing rapid diuresis Mannitol (Osmitrol®) Most used osmotic diuretic Osmotic Diuretics: Drug Effects Increase glomerular filtration rate and renal plasma flow; help to prevent kidney damage during acute kidney injury Reduce intracranial pressure or cerebral edema associated with head trauma Reduce excessive intraocular pressure Osmotic Diuretics: Mannitol (Osmitrol) Intravenous (IV) infusion only May crystallize when exposed to low temperatures. Therefore, vials are often stored in a warmer. Use of a filter is required. Question While preparing an infusion of mannitol (Osmitrol), the nurse notices small crystals in the IV tubing. The most appropriate action by the nurse is to A. administer the infusion slowly. B. discard the solution and obtain another bag of medication. C. obtain a filter and then infuse the solution. D. return the fluid to the IV bag to dissolve the crystals. Potassium-Sparing Diuretics: MOA Work in collecting ducts and distal convoluted tubules Interfere with sodium–potassium exchange Competitively bind to aldosterone receptors Block resorption of sodium and water usually induced by aldosterone secretion Amiloride (Midamor®) Spironolactone (Aldactone®) Potassium-Sparing Diuretics: Drug Effects Relatively weak compared with the thiazide and loop diuretics Competitively block aldosterone receptors and inhibit their action Promote the excretion of sodium and water Interactions with: Lithium Angiotensin-converting enzyme inhibitors Potassium supplements NSAIDs Potassium-Sparing Diuretics: Adverse Effects Body system/adverse effects Spironolactone (Aldactone®) Central nervous system: Dizziness, Gynecomastia headache Amenorrhea Gastrointestinal: Cramps, nausea, Irregular menses vomiting, diarrhea Postmenopausal bleeding Other: Urinary frequency, weakness, hyperkalemia Thiazide and Thiazide-Like Diuretics: MOA Hydrochlorothiazide (Urozide®) Inhibit tubular resorption of sodium, chloride, and potassium ions Action primarily in the distal convoluted tubule Result in osmotic water loss Dilate the arterioles by direct relaxation Decrease preload and afterload Should not be used if creatinine clearance is less than 30 to 50 mL/min (normal is 125 mL/min). Thiazide/Thiazide-Like Diuretics: Indications Hypertension Edematous states Idiopathic hypercalciuria Diabetes insipidus Heart failure caused by diastolic dysfunction Thiazide/Thiazide-Like Diuretics: AE Body system/adverse effects Central nervous: Dizziness, headache, blurred vision Gastrointestinal: Anorexia, nausea, vomiting, diarrhea Genitourinary: Erectile dysfunction Hematological: Jaundice, leukopenia, agranulocytosis Integumentary: Urticaria, photosensitivity Metabolic: Hypokalemia, glycosuria, hyperglycemia, hyperuricemia, hypochloremic alkalosis Nursing Implications for Diuretics Perform a thorough patient history and physical examination. Assess baseline fluid volume status, intake and output, serum electrolyte values, weight, and vital signs (*postural BP). Assess for disorders that may contraindicate or necessitate cautious use of these drugs. Instruct patients to take the medication in the morning to avoid interference with sleep patterns. Monitor serum potassium levels during therapy. Nursing Implications for Diuretics Teach patients to maintain proper nutritional and fluid volume status. Teach patients to eat more potassium-rich foods when taking any diuretics but the potassium-sparing drugs. Foods high in potassium include bananas, oranges, dates, apricots, raisins, broccoli, green beans, potatoes, tomatoes, meats, fish, wheat bread, and legumes. Nursing Implications for Diuretics Patients taking diuretics along with digoxin should be taught to watch for digoxin toxicity. Patients with diabetes mellitus who are taking thiazide or loop diuretics should be told to monitor blood glucose and watch for elevated levels. Patients who have been ill with nausea, vomiting, or diarrhea should notify their primary care provider because fluid and electrolyte imbalances can result. Signs and symptoms of hypokalemia include anorexia, nausea, lethargy, muscle weakness, mental confusion, and hypotension Nursing Implications for Diuretics Teach patients to change positions slowly and to rise slowly after sitting or lying, to prevent dizziness and fainting related to orthostatic hypotension. Encourage patients to keep a log of their daily weight. Remind patients to return for follow-up visits and laboratory work. Nursing Implications for Diuretics Instruct patients to notify their primary care provider immediately if they experience rapid heart rates or syncope (reflects hypotension or fluid loss). Excessive consumption of licorice can lead to additive hypokalemia in patients taking thiazides. Question When administering a loop diuretic to a patient, it is most important for the nurse to determine if the patient is also taking which drug? A. lithium B. acetaminophen (Tylenol®) C. penicillin D. theophylline Chapter 23 Antihypertensive Drugs Normal Regulation of Blood Pressure Antihypertensive Drugs Adrenergic drugs Angiotensin-converting enzyme (ACE) inhibitors Angiotensin II receptor blockers (ARBs) Calcium channel blockers Diuretics Vasodilators Direct renin inhibitors Site & MOA Adrenergic Drugs: Indications All used to treat hypertension Some treat Glaucoma and BPH Management of severe heart failure (HF) when used with cardiac glycosides and diuretics clonidine is also used for menopausal flushing. Adrenergic Drugs: Five Subcategories Adrenergic neuron blockers (central and peripheral) α2-Receptor agonists (central) α1-Receptor blockers (peripheral) β-Receptor blockers (peripheral) Combination α1- and β-receptor blockers (peripheral) Angiotensin-Converting Enzyme (ACE) Inhibitors Large group of safe and effective drugs Often used as first-line drugs for HF and hypertension May be combined with a thiazide diuretic or a calcium channel blocker. captopril (Capoten®) benazepril (Lotensin®) enalapril (Vasotec®) fosinopril sodium lisinopril (Prinivil®) perindopril (Coversyl®) ACE Inhibitors: MOA Inhibit ACE, which is responsible for converting angiotensin I (through the action of renin) to angiotensin II Angiotensin II is a potent vasoconstrictor and causes aldosterone secretion from the adrenal glands. Block ACE, thus preventing the formation of angiotensin II Prevent the breakdown of the vasodilating substance bradykinin Ability to decrease SVR (a measure of afterload) and preload Can stop the progression of left ventricular hypertrophy ACE Inhibitors: Indications Hypertension HF (drug used either alone or in combination with diuretics or other drugs) Slow progression of left ventricular hypertrophy after myocardial infarction (MI) (cardioprotective) Renal protective effects in patients with diabetes ACE Inhibitors: Captopril and Lisinopril Captopril and lisinopril are not prodrugs. Prodrugs are inactive in their administered form and must be metabolized in the liver to an active form to be effective. Captopril and lisinopril can be used if a patient has liver dysfunction, unlike other ACE inhibitors that are prodrugs. ACE Inhibitors: Adverse Effects Fatigue, dizziness, headache, impaired taste Mood changes First-dose hypotensive effect Possible hyperkalemia Dry, nonproductive cough, which reverses when therapy is stopped Angioedema: rare but potentially fatal Others Angiotensin II Receptor Blockers Also referred to as angiotensin II blockers Well tolerated Do not cause a dry cough losartan (Cozaar®) eprosartan mesylate (Teveten®) valsartan (Diovan®) Angiotensin II Receptor Blockers: MOA Selectively block the binding of angiotensin II to the type 1 angiotensin II receptors in these tissues (smooth muscle, adrenal gland) Block vasoconstriction and the secretion of aldosterone Adjunctive drugs for the treatment of HF May be used alone or with other drugs such as diuretics Comparison of ACE Inhibitors and ARBs ACE inhibitors and angiotensin II receptor blockers (ARBs) appear to be equally effective for the treatment of hypertension. Both are well tolerated. ARBs do not cause cough. Evidence that ARBs are better tolerated and are associated with lower mortality after MI than are ACE inhibitors. Not yet clear whether ARBs are as effective as ACE inhibitors in treating HF (cardioprotective effects) or in protecting the kidneys (as in diabetes). Angiotensin II Receptor Blockers: AE Upper respiratory infections and headaches most common Dizziness, inability to sleep Diarrhea Dyspnea, heartburn Nasal congestion Back pain Fatigue Hyperkalemia is less likely to occur than with the ACE inhibitors. Calcium Channel Blockers: MOA and Usage Primary use: treatment of hypertension and angina Hypertension: cause smooth muscle relaxation by blocking the binding of calcium to its receptors, thereby preventing contraction Decreased peripheral smooth muscle tone Results in: Decreased SVR Decreased BP Calcium Channel Blockers: Indications Angina Hypertension: amlodipine (Norvasc®) Antidysrhythmias Migraine headaches Raynaud’s disease Cerebral artery spasms after subarachnoid hemorrhage (prevention): nimodipine Vasodilators: Directly relax arteriolar or venous smooth muscle (or both) Used for their ability to cause peripheral vasodilation Results in decreased SVR Treatment of hypertension May be used in combination with other drugs Sodium nitroprusside and IV diazoxide are reserved for the management of hypertensive emergencies. Vasodilators: Orally: routine cases of essential Hydralazine (Apresoline®) hypertension Injectable: hypertensive emergencies Sodium Nitroprusside Used in critical care setting for severe hypertensive emergencies; titrated to (Nipride®) effect by IV infusion New class: Selective Aldosterone Blockers Eplerenone (Inspra) Blocks action of aldosterone in kidney, heart, blood vessels, and brain Contraindicated in patients with known drug allergy, elevated potassium (>5.5 mmol/L), or severe kidney impairment Drug interactions Nursing Implications for Antihypertensives Before beginning therapy, obtain a thorough health history and perform a head-to-toe physical examination. Assess for contraindications to specific antihypertensive drugs. Assess for conditions that require cautious use of these drugs. Educate patients about the importance of not missing a dose and taking the medications exactly as prescribed. Monitor BP during therapy; instruct patients to keep a journal of regular BP checks. Nursing Implications for Antihypertensives Instruct patients that these drugs should not be stopped abruptly, because this may cause a rebound hypertensive crisis and perhaps lead to stroke. Oral forms should be given with meals so that absorption is more gradual and effective. Male patients who take these drugs may not be aware that impotence is an expected effect Administer IV forms with extreme caution (use pump) Nursing Implications for Antihypertensives Remind patients that medication is only part of therapy. Encourage patients to watch their diet, stress level, weight, and alcohol intake. Instruct patients to avoid smoking and to avoid eating foods high in sodium. Encourage supervised exercise. Teach patients to change positions slowly to avoid syncope from postural hypotension. Question A patient with a history of pancreatitis and cirrhosis is also being treated for hypertension. Which drug will most likely be ordered for this patient? A. clonidine B. prazosin C. diltiazem D. captopril This Photo by Unknown Author is licensed under CC BY-SA Reflection Take home questions to reflect on: Indigenous populations experience more significant health concerns of cardiovascular disease such as angina, myocardial infarction, coronary artery disease, and stroke, despite lower measures of blood pressure (Foulds, Bredin, & Warburton, 2016). Why might this be? Wrap-up Week 10: HTN Angina HF