Details Title: 3312 Description: Diuretics Total Flash Cards: 53 Created: 03/21/2009 10:13:44		New Users: To study from this flashcard set, or to create your own your own study flash cards, REGISTER HERE. Existing Users: CLICK HERE. Additional Biology Flashcards
Cards in this set: Term Edema: Definition excess fluid in tissues Hydrostatic pressure: created by fluid in closed space Term Oncotic pressure: Definition created by plasma proteins Term Polyuria: Definition large urine output Term Oliguria Definition small urine output Term Anuria Definition no urine output Term Diuretics Definition agents “..that increase renal excretion of water, sodium, and other electrolytes thereby increasing urine formation and output” Term Goals of Diuretic Therapy Definition The most common reason for giving diuretics is to eliminate excess fluid, electrolytes, and/or wastes. Term General Actions Definition Although various classes of diuretics act in different ways, they commonly increase urine formation by 􀂃 increasing the glomerular filtration rate and/or 􀂃 decreasing reabsorption from renal tubules Term Who would need a diuretic? Definition If you said, a person who is retaining fluid, you are correct. Excess fluid in body tissues is edema. Term Some causes of edema are: Definition 􀂄 Heart failure 􀂄 Poor circulation 􀂄 Renal failure Diuretics might be used for all of these problems. Term Can you think of other conditions that might be treated with diuretics? Definition Perhaps you know someone who has hypertension (high blood pressure). Diuretics often are used to treat hypertension. 􀂄 Go to www.nih.gov/news/pr/dec2002/nhlbi- 1.7.htm to see recent recommendations about the use of diuretics for hypertension. Term Did you know that some diuretics can lower the pressure in the eye, called the intraocular pressure or IOL? When might we want to reduce IOL? Definition 􀂄 When IOL is abnormally elevated 􀂄 To soften the eye for ophthalmic surgery Term Test Yourself!! Definition 􀂄 How many uses for diuretics do you recall? 􀂄 If necessary, go back and review the last 4 slides Term Common Adverse Effects Definition As you might expect, the most likely adverse effects of diuretic therapy are fluid and electrolyte imbalances including 􀂅Hypokalemia (most diuretics) 􀂅Fluid volume deficit and hypotension 􀂅Hyponatremia 􀂅Hyperglycemia Term Do you recognize the terms for various fluid and electrolyte imbalances? Definition Remember, “hypo” means too little, and “hyper” means too much. 􀂄 Kal refers to potassium; cal to calcium; and natr to sodium. 􀂄 Vol refers to fluid volume 􀂄 The suffix “-emia” refers to the blood. 􀂄 So, hyperkalemia is high blood potassium, and hypovolemia is low blood volume! Other adverse effects are specific to certain classes of diuretics. I will mention these as we go along. 􀂄 Now let’s talk about the various diuretic classes. Term Classes of Diuretics Definition 􀂄 Thiazides 􀂄 High ceiling (loop) 􀂄 Potassium sparing 􀂄 Osmotic 􀂄 Carbonic anhydrase inhibitors Term Thiazide Diuretics Definition 􀂄 These drugs act in the renal tubules to 􀂅decrease reabsorption of Na, Cl, K, Mg, bicarbonate, water 􀂅increase reabsorption of glucose, calcium, lipids 􀂄 Our prototype for the thiazides is hydrochlorozide (HCTZ) Term Features of thiazides Definition 􀂅Not strong diuretic 􀂅Slow onset of action (2 hours) 􀂅 Useful in treating elevated urine calcium (hypercalciuria) because it causes tubules to reabsorb calcium 􀂅Poor choice with diabetes because it increases serum glucose and lipids 􀂅 Risk of allergy in people who are allergic to sulfonamides Term High Ceiling (Loop) Diuretics Definition 􀂄 These drugs act by decreasing the reabsorption of Na, Cl, and Ca 􀂄 The prototype for this class is furosemide (Lasix) Term Features of High Ceiling Diuretics Definition 􀂄 Stronger, faster onset of action than thiazides 􀂄 Na restriction often is needed because of post-diuretic rebound effect 􀂄 Treats hypercalcemia: unlike thiazides, these drugs increase calcium in the urine 􀂄 Ototoxic, so assess hearing and balance Term Potassium-Sparing Diuretics Definition 􀂄 Action: These drugs are aldosterone antagonists 􀂅Aldosterone normally promotes Na retention; the drug prevents Na retention 􀂅K is not excreted in exchange for Na, so excess K is not lost 􀂄 Prototype: spironolactone (Aldactone) Term Features of Potassium Sparing Diuretics Definition 􀂄 The potential for hyperkalemia exists 􀂄 Potassium supplements are not needed 􀂄 Monitor heart rate and rhythm because abnormal potassium affects the conduction of cardiac nerve impulses and myocardial contraction. Term Osmotic Diuretics Definition 􀂄 These drugs act by increasing osmotic pressure in blood and in the glomerular filtrate 􀂄 The prototype is mannitol (Osmitrol) 􀂄 Considerations 􀂅Uses: anuria, increased IOP, cerebral edema 􀂅Risk of hypervolemia, then hypovolemia Term Features of Osmotic Diuretics Definition 􀂄 Mannitol is given by the IV route only 􀂄 It is used to treat 􀂅 Anuria (absence of urine production) 􀂅 Cerebral edema 􀂅 Increased intraocular pressure 􀂄 As excess fluid is drawn from the tissues into the bloodstream, hypervolemia can occur. 􀂄 As the kidneys excrete the mannitol, fluid is excreted, possibly in excess resulting in hypovolemia. Term It’s important to understand how osmotic diuretics work, so let’s review what happens when it is administered intravenously. Definition 􀂅 Mannitol, which has a high molecular weight, is delivered to the bloodstream where it increases osmotic pressure. 􀂅 The large molecules do not pass out of the blood into body tissues. 􀂅 By osmosis, mannitol causes water to move out of edematous tissue into the bloodstream. 􀂅When blood circulates through the kidneys, mannitol is excreted in the tubules so it becomes part of the urine. 􀂅 The osmotic pressure of the mannitol holds water causing both to be eliminated. Term Carbonic Anhydrase Inhibitors Definition 􀂄 These drugs act by inhibiting 􀂅bicarbonate reabsorption 􀂅production of aqueous humor and cerebrospinal fluid (CSF) 􀂄 The prototype is acetazolamide (Diamox) Term Diuretics: Nursing Assessment Definition 􀂄 Which of the following data are needed when patients are taking diuretics? 􀂅 Intake and output 􀂅 Daily weights 􀂅 Edema 􀂅 Serum electrolytes 􀂅 Neuromuscular status 􀂅 Serum glucose 􀂅 Mental status Term Did you select all options? If so, you are right! Let’s review the usefulness of each option. Definition 􀂅Intake and output will help you determine whether the patient is eliminating excess fluid. You would expect output to exceed intake during diuresis. This will be most apparent when patients are retaining a lot of fluid. When patients take diuretics long-term, fluid intake and output may remain about equal. Term Daily weights: Definition this is a simple, useful way to detect fluid loss or gain because body mass changes very little from day to day. Daily weights must be done on the same scale and under the same conditions each day in order to be useful. Term Edema Definition the accumulation of fluid in tissues. Because water tends to flow downhill, edema is most apparent in dependent body areas. Check the ankles of ambulatory patients and the backs of bed patients. Auscultation of the lungs may reveal pulmonary edema. Effective diuretic therapy should cause edema to decrease. Term Serum electrolyte Definition reports reveal actual blood levels and enable you to detect abnormalities such as low potassium. Notify the physician if values are significantly abnormal. Term Neuromuscular status Definition may have been a less obvious choice to you. However, impulse conduction and muscle activity depend on specific concentrations of electrolytes, especially potassium and calcium. Therefore, assessment of reflexes and muscle tone may yield indicators of electrolyte imbalances. Term Serum glucose Definition is most likely to be affected by the thiazides. This is not usually significant unless a patient has diabetes. Term Mental status Definition is affected by fluid and electrolyte balance. For example, fluid excess can include cerebral edema which causes confusion or decreased alertness. A fluid deficit such as dehydration decreases blood flow and also can cause mental changes. Term Nursing Diagnoses and Interventions for Patients on Diuretic Therapy Definition 􀂄 Risk for deficient fluid volume r/t excess diuresis (hypovolemia) 􀂅Your first role is to monitor for hypovolemia. Some indicators include hypotension, tachycardia, dry mucous membranes, and concentrated urine. 􀂅You also may be administering fluid replacement by oral and parenteral routes. Term Decreased cardiac output r/t electrolyte imbalances 􀂅 Hypokalemia: Definition assess for irregular pulse, hypotension, weak respirations, muscle weakness, abdominal distention. Administer potassium replacement cautiously as ordered. ALWAYS DILUTE POTASSIUM; GIVE SLOWLY!!!!!!! Term Hyponatremia Definition Assess for hypotension, tachycardia, oliguria, confusion, abdominal cramps. Term Risk for injury r/t abnormal serum calcium 􀂅Hypocalcemia: Definition Assess for neuromuscular irritability. Provide calcium replacement as ordered Term Hypercalcemia Definition Assess for depressed neuromuscular function. Encourage fluids to prevent urinary calculi (stones). Administer high ceiling diuretic as ordered. Term Deficient knowledge of diuretic therapy. The patient teaching plan should include: Definition 􀂅 Take diuretics in the morning to avoid nighttime voiding 􀂅 Report weakness, palpitations, muscle cramps, confusion 􀂅 Reduce sodium intake if ordered. This is not always necessary or wise. Elderly patients are at risk for sodium depletion. 􀂅 Ask the physician before using salt substitutes. They contain potassium. Term Diuretics are used for their ability to promote the excretion of water and ___________ Definition Term The most serious adverse effects of most diuretics is _______________ which can cause fatal alterations in cardiac rhythm. Definition Term __________ diuretics are weak, slow, and are not advised with diabetes because they increase serum glucose and lipids. Definition Term High ceiling diuretics promote calcium excretion whereas ___________ promote calcium retention. Definition Term Patients taking ___________ diuretics may also require sodium restriction because of post-diuretic rebound effect. Definition Term Only potassium sparing diuretics place the patient at risk for ___________ which also can cause fatal cardiac disturbances. Definition Term ______________ diuretics can cause fluid excess initially. Definition Term The type of diuretic used to lower increased intraocular pressure is _______. Definition Term Signs and symptoms of ____________ include hypotension, tachycardia, dry mucous membranes, and concentrated urine. Definition Term When a patient on diuretic therapy has an irregular pulse, weakness, and abdominal distention, you should suspect _____________. Definition Term Potassium that is administerd too rapidly or in concentrated form can cause _____________________. Definition Term Diuretics usually are given in the morning to prevent _______________. Definition Term A patient on a potassium sparing diuretic who uses salt substitutes is at risk for _______________. Definition