Chapter 35: Heart Failure
What are some complications of loop diuretics?
Reduction in serum potassium levels, ototoxicity, and possible allergic reaction in patients sensitive to sulfa-type drugs
ACCF/AHA Stages of Heart Failure: Stage C
Patients with prior or current symptoms of HF associated with known, underlying structural heart disease.
What is unique about heart failure in comparison to other cardiovascular diseases?
HF is increasing in incidence and prevalence. This is due to improved survival after cardiac events and the increased aging population
Which diagnostic studies are specific to ADHF and chronic heart failure, respectively?
ADHF: • Measurement of LV function • Endomyocardial biopsy Chronic heart failure: • Exercise stress testing
What is nitric oxide and when is it released?
NO is a counterregulatory substance released from the vascular endothelium in response to the compensatory mechanisms activated in HF NO relaxes the arterial smooth muscle, resulting in vasodilation and decreased afterload
What are the two primary risk factors in heart failure?
Hypertension and CAD
Why is the high Fowler's position beneficial to a patient in ADHF?
The position helps decrease venous return because of the pooling of blood in the extremities, and it increases the thoracic capacity, allowing for improved breathing
What are diagnostic studies used to diagnose heart failure?
- Endomyocardial biopsy (EMB) - Echocardiography and/or nuclear imaging - Chest x-ray - ECG, stress test - Cardiac catheterization - BNP (NT-proBNP), ABGs
What are some collaborative therapies specific to ADHF?
• High Fowler's position • O2 by mask or nasal cannula • BiPAP • Circulatory assist device: intraaortic balloon pump (increases coronary blood flow to the heart muscle and decreases the heart's workload through counterpulsation) • Endotracheal intubation and mechanical ventilation • Vital signs, urine output at least q1hr • Continuous ECG and pulse oximetry monitoring • Hemodynamic monitoring (e.g., intraarterial BP, pulmonary wedge arterial pressure: PAWP, CO) • Drug therapy • Possible cardioversion (e.g., atrial fibrillation) • Ultrafiltration/aquapheresis (remove excess salt and water from the patient's blood)
Heart failure drug therapy: Positive Inotropes β-Adrenergic Agonists (*ADHF ONLY*) • dopamine (Intropin) • dobutamine (Dobutrex) Phosphodiesterase Inhibitor (*ADHF ONLY*) • milrinone (Primacor) Digitalis Glycoside (*Chronic HF ONLY*) • digoxin (Lanoxin)
• Increase contractility (positive inotropic effect) • Increase CO • Increase heart rate (positive chronotropic effect) • Produce mild vasodilation • Increase stroke volume and CO • Promote vasodilation
What are some collaborative therapies specific to chronic heart failure?
• O2 therapy at 2-6 L/min by nasal cannula if indicated (oxygen saturation of the blood can be reduced because the blood is not adequately oxygenated in the lungs, administering oxygen improves saturation and assists in meeting tissue oxygen needs) • Rest-activity periods • Cardiac rehabilitation (structured exercise) • Home health nursing care (e.g., telehealth monitoring) • Drug therapy • Cardiac resynchronization therapy with biventricular pacing and internal cardioverter-defibrillator • LVAD • Cardiac transplantation • Palliative and end-of-life care
Heart failure drug therapy: Antidysrhythmic Drugs
• Prevent or treat dysrhythmias
Heart failure drug therapy: Anticoagulants
• Prevent thromboembolism • Recommended for patients with an ejection fraction <20% and/or atrial fibrillation
NCLEX review questions: Beyond the first year after a heart transplant, the nurse knows that what is a major cause of death?
Cardiac vasculopathy Rationale: Beyond the first year after a heart transplant, malignancy (especially lymphoma) and cardiac vasculopathy (accelerated CAD) are the major causes of death. During the first year after transplant, infection and acute rejection are the major causes of death. Immunosuppressive therapy will be used for posttransplant management to prevent rejection and increases the patient's risk of an infection.
NCLEX review questions: After having an MI, the nurse notes the patient has jugular venous distention, gained weight, developed peripheral edema, and has a heart rate of 108/minute. What should the nurse suspect is happening?
Right sided heart failure Rationale: An MI is a primary cause of heart failure. The jugular venous distention, weight gain, peripheral edema, and increased heart rate are manifestations of right-sided heart failure.
How is heart failure categorized?
Systolic versus diastolic Left-sided versus right-sided
NCLEX review questions: The patient with chronic heart failure is being discharged from the hospital. What information should the nurse emphasize in the patient's discharge teaching to prevent progression of the disease to ADHF?
Take medications as prescribed Rationale: The goal for the patient with chronic HF is to avoid exacerbations and hospitalization. Taking the medications as prescribed along with nondrug therapies such as alternating activity with rest will help the patient meet this goal. If the patient needs to use oxygen at home, it will probably be used all the time or with activity to prevent respiratory acidosis. Many HF patients are monitored by a care manager or in a transitional program to assess the patient for medication effectiveness and monitor for patient deterioration and encourage the patient. This nurse manager can be asked questions or can contact the health care provider if there is evidence of worsening HF.
Which three beta blockers are approved for use in patients with heart failure?
carvedilol (Coreg) bisoprolol (Zebeta) metoprolol CR/XL (Toprol XL)
ACCF/AHA Stages of Heart Failure: Stage D
Patients with refractory HF (e.g., patients with severe symptoms at rest despite maximal medical therapy) who require specialized interventions.
Heart failure complications: pleural effusion
Pleural effusion results from increasing pressure in the pleural capillaries. A transudation of fluid occurs from these capillaries into the pleural space
What are four compensatory mechanisms for heart failure?
(1) sympathetic nervous system (SNS) activation (2) neurohormonal responses (3) ventricular dilation (4) ventricular hypertrophy
Where are natriuretic peptides released and what do they do?
ANP is released from the atria, BNP is released from the ventricles in response to increased blood volume in the heart. Counteracts effects of SNS and RAAS Renal effects: (1) increased glomerular filtration rate and diuresis (2) excretion of sodium (natriuresis). Cardiovascular effects: (1) vasodilation and decreased BP Hormonal effects: (1) inhibition of aldosterone and renin secretion (2) interference of ADH release
Clinical manifestations of acute decompensated heart failure (ADHF) in latest stage
Alveolar edema: alveoli lining cells are disrupted and a fluid containing red blood cells (RBCs) moves into the alveoli --> worsening of ABGs --> progressive respiratory acidemia: lower Pao2 and possible increased partial pressure of carbon dioxide in arterial blood [Paco2]
NCLEX pre-test questions: A 54-year-old male patient who had bladder surgery 2 days ago develops acute decompensated heart failure (ADHF) with severe dyspnea. Which action by the nurse would be indicated first?
Assist the patient to a sitting position with arms on the overbed table Rationale: The nurse should place the patient with ADHF in a high Fowler's position with the feet horizontal in the bed or dangling at the bedside. This position helps decrease venous return because of the pooling of blood in the extremities. This position also increases the thoracic capacity, allowing for improved ventilation. Pursed-lip breathing helps with obstructive air trapping but not with acute pulmonary edema. Restricting fluids takes considerable time to have an effect.
Why are β-adrenergic blockers started slowly, increased every 2 weeks as tolerated
Because beta blockers can reduce myocardial contractility Major adverse effects include edema, worsening of HF, hypotension, fatigue, and bradycardia
Why should the lowest effective dose of a diuretic be used in a heart failure patient?
Because diuretics activate the SNS and RAAS, which can exacerbate the HF syndrome
NCLEX review questions: What is the priority assessment by the nurse caring for a patient receiving IV nesiritide (Natrecor) to treat heart failure?
Blood pressure Rationale: Although all identified assessments are appropriate for a patient receiving IV nesiritide, the priority assessment would be monitoring for hypotension, the main adverse effect of nesiritide.
What is assessed when a pulmonary artery catheter is placed?
CO and pulmonary artery wedge pressure (PAWP). A normal PAWP is generally between 8-12 mm Hg (in ADHF can be as high as 30 mm Hg), and therapy is titrated to maximize CO and reduce PAWP
Heart failure complications: Renal Failure
Decreased CO secondary to chronic HF results in decreased perfusion to the kidneys and can lead to renal insufficiency or failure
What is an additional benefit of BiPAP?
Decreases preload
A patient has heart failure with an ejection fraction of 56% does he have systolic or diastolic heart failure?
Diastolic heart failure because the ejection fraction is normal (55% to 60%)
What is a risk with use of digitalis?
Digitalis toxicity. Risk of toxicity increases with hypokalemia because low serum potassium enhances the action of digitalis, causing a therapeutic dose to reach toxic level
Chronic heart failure: Drug therapy
Diuretics: Loop diuretics Thiazide diuretics Potassium-sparing diuretic RAAS inhibitors: ACE inhibitors Angiotensin II receptor blockers Aldosterone antagonists [Spironolactone (Aldactone) and eplerenone (Inspra): also serve as potassium-sparing diuretic] β-adrenergic blockers Vasodilators - Nitrates - isosorbide dinitrate&hydralazine (BiDil) Positive inotropic agents - Digitalis (digoxin [Lanoxin])
What is heart failure (formerly called congestive heart failure)?
Heart failure is inadequate cardiac pumping/filling This results in insufficient blood supply/oxygen to tissues
NCLEX review questions: What should the nurse recognize as an indication for the use of dopamine (Intropin) in the care of a patient with heart failure?
Hypotension and tachycardia Rationale: Dopamine is a β-adrenergic agonist whose inotropic action is used for treatment of severe heart failure accompanied by hemodynamic instability. Such a state may be indicated by tachycardia accompanied by hypotension. PND, anxiety, edema, and weight gain are common signs and symptoms of heart failure, but these do not necessarily warrant the use of dopamine.
Heart failure complications: Hepatomegaly
Liver becomes congested with venous blood. The hepatic congestion leads to impaired liver function. Eventually liver cells die, fibrosis occurs, and cirrhosis can develop
What are nutritional recommendations for patients with heart failure?
Low sodium diet restricted to 2 g/day If fluids are restricted, restricted to <2 L/day
Bridge to NCLEX questions: A patient with chronic HF and atrial fibrillation is treated with a digitalis glycoside and a loop diuretic. To prevent possible complications of this combination of drugs, what does the nurse need to do (select all that apply)?
Monitor serum potassium levels. Teach the patient how to take a pulse rate. Rationale: Hypokalemia, which can be caused by the use of potassium-depleting diuretics (e.g., thiazides, loop diuretics), is one of the most common causes of digitalis toxicity. Low serum levels of potassium enhance the action of digitalis, causing a therapeutic dose to achieve toxic levels. Hypokalemia can also precipitate dysrhythmias. Monitoring the serum potassium levels of patients receiving digitalis preparations and potassium-depleting diuretics is essential. Patients taking digitalis preparations should be taught how to measure their pulse rate because bradycardia and atrioventricular blocks are late signs of digitalis toxicity. In addition, patients should know what pulse rate would necessitate a call to the health care provider.
NYHA Functional Classification of Heart Disease Class I
No limitation of physical activity. Ordinary physical activity does not cause fatigue, dyspnea, palpitations, or anginal pain.
Right sided heart failure: pathophysiology
Right ventricular dysfunction causes blood to back up into the right atrium and venous circulation manifestation: JVD, HEPATOMEGALY, SPLENOMEGALY, GI TRACT VASCULAR CONGESTION, PERIPHERAL EDEMA primarily caused by left sided heart failure and chronic pulmonary hypertension
What is a complication of a thiazide diuretic?
Thiazide diuretics also can cause severe reductions in potassium levels
What is cardiac decompensation?
When compensatory mechanisms (SNS activation, neurohormonal responses, ventricular dilation, ventricular hypertrophy) can no longer maintain adequate CO and inadequate tissue perfusion results
What are adverse effects of phosphodiesterase inhibitors (inamrinone [Inocor], milrinone [Primacor])?
dysrhythmias, thrombocytopenia, and hepatotoxicity
Precipitating causes of heart failure: Hypervolemia
↑ Preload causing volume overload on the RV
Primary causes of heart failure
• Coronary artery disease, including myocardial infarction • Hypertension, including hypertensive crisis • Rheumatic heart disease • Congenital heart defects (e.g., ventricular septal defect) • Pulmonary hypertension • Cardiomyopathy (e.g., viral, postpartum, substance abuse) • Hyperthyroidism • Valvular disorders (e.g., mitral stenosis) • Myocarditis
Heart failure drug therapy: Morphine (*ADHF ONLY*)
• Decreases anxiety • Decreases preload and afterload
Heart failure drug therapy: β-Adrenergic Blockers (*Chronic HF ONLY*) • metoprolol (Toprol XL) • bisoprolol (Zebeta) • carvedilol (Coreg)
• Promote reverse remodeling • Decrease afterload • Inhibit SNS • Decrease morbidity and mortality
NCLEX pre-test questions: At a clinic visit, the nurse provides dietary teaching for a 56-year-old woman who was recently hospitalized with an exacerbation of chronic heart failure. The nurse determines that teaching is successful if the patient makes which statement?
"I will limit the amount of milk and cheese in my diet." Rationale: Milk products should be limited to 2 cups per day for a 2500-mg sodium-restricted diet. Salt should not be added during food preparation or at the table. Diuretics should be taken as prescribed (usually daily) and not based on sodium intake. Foods labeled as reduced sodium contain at least 25% less sodium than regular.
NCLEX pre-test questions: A70-year-old woman with chronic heart failure and atrial fibrillation asks the nurse why warfarin (Coumadin) has been prescribed for her to continue at home. Which response by the nurse is accurate?
"The medication prevents blood clots from forming in your heart." Rationale: Chronic heart failure causes enlargement of the chambers of the heart and an altered electrical pathway, especially in the atria. When numerous sites in the atria fire spontaneously and rapidly, atrial fibrillation occurs. Atrial fibrillation promotes thrombus formation within the atria with an increased risk of stroke and requires treatment with cardioversion, antidysrhythmics, and/or anticoagulants. Warfarin is an anticoagulant that interferes with hepatic synthesis of vitamin K-dependent clotting factors.
NCLEX review questions: A patient admitted with heart failure appears very anxious and complains of shortness of breath. Which nursing actions would be appropriate to alleviate this patient's anxiety (select all that apply)?
- Administer ordered morphine sulfate. - Position patient in a semi-Fowler's position. - Instruct patient on the use of relaxation techniques. - Use a calm, reassuring approach while talking to patient. Rationale: Morphine sulfate reduces anxiety and may assist in reducing dyspnea. The patient should be positioned in semi-Fowler's position to improve ventilation that will reduce anxiety. Relaxation techniques and a calm reassuring approach will also serve to reduce anxiety.
NCLEX review questions: The patient has heart failure (HF) with an ejection fraction of less than 40%. What core measures should the nurse expect to include in the plan of care for this patient (select all that apply)?
- Left ventricular function is documented. - Prescription for angiotensin-converting enzyme (ACE) inhibitor at discharge - Education materials about activity, medications, weight monitoring, and what to do if symptoms worsen Rationale: The Joint Commission has identified these three core measures for heart failure patients. Although controlling dysrhythmias will improve CO and workload, it will not eliminate HF. Prescribing digoxin for all HF patients is no longer done because there are newer effective drugs and digoxin toxicity occurs easily related to electrolyte levels and the therapeutic range must be maintained.
What are three effects of ventricular failure?
- Low blood pressure (BP) - Low CO - Poor renal perfusion
Name the five complications of heart failure
- Pleural effusion - Dysrhythmias: atrial and ventricular - Left ventricular thrombus - Hepatomegaly - Renal failure
What are common clinical manifestations of pulmonary edema?
- anxious, pale, and possibly cyanotic - clammy and cold skin (from vasoconstriction caused by stimulation of the SNS) - dyspnea - orthopnea - RR > 30 w/accessory muscle use - productive cough with frothy, blood-tinged sputum - diffuse crackles, wheezes, and rhonchi - tachycardia - BP may be elevated or decreased depending on the severity of the HF
In what conditions is mixed heart failure present?
-disease states such as dilated cardiomyopathy (DCM) - Poor EFs (<35%) - High pulmonary pressures - Biventricular failure (both may be dilated and have poor filling and emptying capacity)
NCLEX review questions: The nurse is administering a dose of digoxin (Lanoxin) to a patient with heart failure (HF). The nurse would become concerned with the possibility of digitalis toxicity if the patient reported which symptom(s)?
Anorexia and nausea Rationale: Anorexia, nausea, vomiting, blurred or yellow vision, and cardiac dysrhythmias are all signs of digitalis toxicity. The nurse would become concerned and notify the health care provider if the patient exhibited any of these symptoms.
NCLEX review questions: A stable patient with acute decompensated heart failure (ADHF) suddenly becomes dyspneic. Before positioning the patient on the bedside, what should the nurse assess first?
Blood pressure Rationale: The nurse should evaluate the blood pressure before dangling the patient on the bedside because the blood pressure can decrease as blood pools in the periphery and preload decreases. If the patient's blood pressure is low or marginal, the nurse should put the patient in the semi-Fowler's position and use other measures to improve gas exchange.
NCLEX review questions: A male patient with a long-standing history of heart failure has recently qualified for hospice care. What measure should the nurse now prioritize when providing care for this patient?
Choose interventions to promote comfort and prevent suffering Rationale: The central focus of hospice care is the promotion of comfort and the prevention of suffering. Patient education should continue, but providing comfort is paramount. Medications should be continued unless they are not tolerated. Experimental therapies and surgeries are not commonly used in the care of hospice patients.
Precipitating causes of heart failure: Thyrotoxicosis
Changes the tissue metabolic rate, ↑HR and workload of the heart
ADHF: Drug Therapy
Diuretics: Decrease volume overload (preload) [Furosemide (Lasix), bumetanide (Bumex)] Vasodilators: Reduce circulating blood volume and improve coronary artery circulation [IV nitroglycerin, Sodium nitroprusside (Nipride)] [Nesiritide (Natrecor): studies showed this doesn't work)] Morphine: Reduces preload and afterload, relieves dyspnea (dilates pulmonary blood vessels, improving gas exchange), pain and anxiety Positive inotropes: increases myocardial contractility β-adrenergic agonists (dopamine [Intropin], dobutamine [Dobutrex]-IDEAL) Phosphodiesterase inhibitors (inamrinone [Inocor], milrinone [Primacor]) Digitalis (not recommended for initial tx)
Compare the positive inotropes dopamine and dobutamine. What are main differences?
Dopamine: increases myocardial contractility and SVR, dilates the renal blood vessels and enhances urine output Dobutamine: SELECTIVE β-adrenergic agonist and works primarily on the β1-receptors in the heart. Dobutamine does not increase SVR and is preferred for short-term treatment of ADHF
NCLEX review questions: A patient with a diagnosis of heart failure has been started on a nitroglycerin patch by his primary care provider. What should this patient be taught to avoid?
Drugs to treat erectile dysfunction Rationale: The use of erectile drugs concurrent with nitrates creates a risk of severe hypotension and possibly death. High-potassium foods, NSAIDs, and H2-receptor blockers do not pose a risk in combination with nitrates.
Heart failure complications: Left ventricular thrombus
Enlarged LV and decreased CO combine to increase the chance of thrombus formation in the LV The thrombus itself can decrease left ventricular contractility, decrease CO, and further worsen the patient's perfusion Risk for stroke due to possible emboli
Heart failure complications: dysrhythmias
Enlargement (stretching of the atrial and ventricular walls) can cause changes in the normal electrical pathways Risk of thrombus formation in atrial fibrillation
Compensatory mechanisms: Dilation
Enlargement of the chambers of the heart; occurs when pressure in the heart chambers (usually the LV) is elevated over time Initially effective (increased stretch=increased contractility due to Frank-Starling law), but the elastic elements of the muscle fibers are overstretched and can no longer contract effectively, thereby decreasing the CO
What are common clinical manifestations of chronic heart failure?
F atigue A ctivities are limited C hest congestion/cough E dema (weight gain of >3 lb (1.4 kg) in 2 days may indicate ADHF) S hortness of breath (including paroxysmal nocturnal dyspnea) as well as: tachycardia, nocturia (supine: fluid moves from the interstitial spaces back into the circulatory system AND cardiac workload is decreased during rest so increased renal blood flow and diuresis), Skin changes (dusky, brown/brawny, shiny/swollen), behavioral changes (decreased cerebral perfusion/poor gas exchange), chest pain, weight changes
Compensatory mechanisms: SNS
First and least effective mechanism - releases catecholamines (epinephrine and norepinephrine) - Increased heart rate - Increased myocardial contractility - Peripheral vasoconstriction - Initially helpful but then harmful
Compensatory mechanisms: Ventricular Remodeling
Hypertrophy of ventricular myocytes Caused by: Activation of SNS, neurohormonal and pro-inflammatory cytokines increasing cardiac workload Results in: increased ventricular mass, increased wall tension, increased oxygen consumption, and impaired contractility RISK FACTOR for SCD and life-threatening dysrhythmias
Diastolic Heart Failure: Pathophysiology
Impaired ability of the ventricles to relax and fill during diastole Caused by: left ventricular hypertrophy from hypertension, MI, valve disease, or cardiomyopathy Results in: decreased stroke volume and CO Heart failure with normal EF
NYHA Functional Classification of Heart Disease Class IV
Inability to carry on any physical activity without discomfort. Symptoms of cardiac insufficiency or of angina may be present even at rest. If any physical activity is undertaken, discomfort is increased.
Systolic Heart Failure: Pathophysiology
Inability to pump blood forward Caused by: - Impaired contractile function - Increased afterload - Cardiomyopathy - Mechanical abnormalities Results in: Decreased left ventricular ejection fraction (EF) - generally have an EF less than 45%. It can be as low as 10%.
Clinical manifestations of acute decompensated heart failure (ADHF) in early stage
Increased pulmonary venous pressure --> Mild increase in the respiratory rate --> Decrease in Pao2
Precipitating causes of heart failure: Hypothyroidism
Indirectly predisposes to ↑ atherosclerosis; severe hypothyroidism decreases myocardial contractility
Bridge to NCLEX questions: Patients with a heart transplantation are at risk for which complications in the first year after transplantation (select all that apply)?
Infection Rejection Sudden cardiac death Rationale: A variety of complications can occur after heart transplantation. In the first year after transplantation, the major causes of death are acute rejection and infection. Heart transplant recipients also are at risk for sudden cardiac death. Later, malignancy (especially lymphoma) and cardiac vasculopathy (accelerated CAD) are major causes of death.
Precipitating causes of heart failure: Bacterial endocarditis
Infection: ↑metabolic demands and O2 requirements Valvular dysfunction: causes stenosis and regurgitation
Clinical manifestations of acute decompensated heart failure (ADHF) in later stage
Interstitial edema: the increase in intravascular pressure causes more fluid to move into the interstitial space than the lymphatics can remove --> Tachypnea --> patient is symptomatic (SOB)
What is unique about BiDil?
It is the only drug approved for use in African Americans
What is flash pulmonary edema?
Lung alveoli become filled with serosanguineous fluid - Flash pulmonary edema is another way acute decompensated heart failure can manifest - Most common cause: left-sided HF secondary to CAD
NYHA Functional Classification of Heart Disease Class III
Marked limitation of physical activity but usually comfortable at rest. Less than ordinary physical activity causes fatigue, dyspnea, palpitations, or anginal pain.
Precipitating causes of heart failure: Dysrhythmias
May ↓CO and ↑ workload and O2 requirements of myocardial tissue
Precipitating causes of heart failure: Nutritional deficiencies
May↓ cardiac function by ↑ myocardial muscle mass and myocardial contractility
Heart failure drug therapy: Diuretics Loop Diuretics • furosemide (Lasix) • bumetanide (Bumex) Thiazide Diuretics (*Chronic HF ONLY*) • hydrochlorothiazide (HCTZ) • metolazone (Zaroxolyn) Potassium-Sparing Diuretics • spironolactone (Aldactone) • eplerenone (Inspra)
Mechanism of action: • Decrease fluid volume • Decrease preload • Decrease pulmonary venous pressure • Relieve symptoms of heart failure (e.g., edema)
ACCF/AHA Stages of Heart Failure: Stage A
Patients at high risk for HF (e.g., patients with hypertension, diabetes, metabolic syndrome) but without structural heart disease or symptoms of HF.
ACCF/AHA Stages of Heart Failure: Stage B
Patients with structural heart disease (e.g., patients with history of MI, valve disease) but who have never shown signs or symptoms of HF
What's the difference between primary and precipitating causes of heart failure?
Primary causes: Conditions that directly damage the heart Precipitating causes: Conditions that increase the workload of ventricles
NCLEX review questions: A patient with a recent diagnosis of heart failure has been prescribed furosemide (Lasix) in an effort to physiologically do what for the patient?
Reduced preload Rationale: Diuretics such as furosemide are used in the treatment of HF to mobilize edematous fluid, reduce pulmonary venous pressure, and reduce preload. They do not directly influence afterload, contractility, or vessel tone.
NCLEX pre-test questions: The nurse prepares to administer digoxin (Lanoxin) 0.125 mg to an 82-year-old man admitted with influenza and a history of chronic heart failure. What should the nurse assess before giving the medication?
Serum potassium level Rationale: Serum potassium should be monitored because hypokalemia increases the risk for digoxin toxicity. Changes in prothrombin time, urine specific gravity, and hemoglobin or hematocrit would not require holding the digoxin dose.
NCLEX pre-test questions: The home care nurse visits a 73-year-old Hispanic woman with chronic heart failure. Which clinical manifestations, if assessed by the nurse, would indicate acute decompensated heart failure (pulmonary edema)?
Severe dyspnea and blood-streaked, frothy sputum Rationale: Clinical manifestations of pulmonary edema include anxiety, pallor, cyanosis, clammy and cold skin, severe dyspnea, use of accessory muscles of respiration, a respiratory rate > 30 breaths per minute, orthopnea, wheezing, and coughing with the production of frothy, blood-tinged sputum. Auscultation of the lungs may reveal crackles, wheezes, and rhonchi throughout the lungs. The heart rate is rapid, and blood pressure may be elevated or decreased.
NYHA Functional Classification of Heart Disease Class II
Slight limitation of physical activity. No symptoms at rest. Ordinary physical activity results in fatigue, dyspnea, palpitations, or anginal pain.
What is complication of the vasodilator sodium nitroprusside (Nipride)?
Thiocyanate toxicity, which can develop 48 hours after use
Compensatory mechanisms: Neurohormonal responses
When blood flow is decreased to... Kidneys: Release renin and initiate RAAS Brain: Posterior pituitary gland secretes antidiuretic hormone (ADH)/vasopressin, which increases water reabsorption in the kidneys --> increasing blood volume is increased (but the person is already volume overloaded) When catecholamines, angiotensin II and ADH are released... Vascular endothelial cells: release endothelin, which results in further arterial vasoconstriction and an increase in cardiac contractility and hypertrophy Proinflammatory cytokines released by injured cardiac tissue depress cardiac function by causing cardiac hypertrophy, contractile dysfunction, and cardiac cell death
NCLEX review questions: The nurse is preparing to administer digoxin to a patient with heart failure. In preparation, laboratory results are reviewed with the following findings: sodium 139 mEq/L, potassium 5.6 mEq/L, chloride 103 mEq/L, and glucose 106 mg/dL. What should the nurse do next?
Withhold the dose and report the potassium level Rationale: The normal potassium level is 3.5 to 5.0 mEq/L. The patient is hyperkalemic, which makes the patient more prone to digoxin toxicity. For this reason, the nurse should withhold the dose and report the potassium level. The physician may order the digoxin to be given once the potassium level has been treated and decreases to within normal range.
Bridge to NCLEX questions: You are caring for a patient with ADHF who is receiving IV dobutamine (Dobutrex). You know that this drug is ordered because it (select all that apply)
improves contractility. works on the β1-receptors in the heart. Rationale: Dobutamine (Dobutrex) has a positive chronotropic effect and increases heart rate and improves contractility. It is a selective β-adrenergic agonist and works primarily on the β1-adrenergic receptors in the heart. It is frequently used in the short-term management of acute decompensated heart failure (ADHF).
Left sided heart failure: pathophysiology
left ventricular dysfunction causes blood to back up into left atrium and pulmonary veins Increased pulmonary pressure causes fluid leakage from the pulmonary capillary bed into the interstitium and then the alveoli manifestation: PULMONARY CONGESTION AND EDEMA
Bridge to NCLEX questions: A compensatory mechanism involved in HF that leads to inappropriate fluid retention and additional workload of the heart is
neurohormonal response Rationale: The following mechanisms in heart failure lead to inappropriate fluid retention and additional workload of the heart: activation of the renin-angiotensin-aldosterone system (RAAS) cascade and release of antidiuretic hormone from the posterior pituitary gland in response to low cerebral perfusion pressure that results from low cardiac output.
Heart failure drug therapy: Renin-Angiotensin-Aldosterone System Inhibitors ACE Inhibitors • captopril (Capoten) • benazepril (Lotensin) • enalapril (Vasotec) Angiotensin II Receptor Blockers • losartan (Cozaar) • valsartan (Diovan)
• Dilate venules and arterioles • Improve renal blood flow • Decrease fluid volume • Relieve symptoms of heart failure • Promote reverse remodeling • Decrease morbidity and mortality ACE INHIBITORS: can reduce the level of albuminuria and the rate of progression of renal disease to a greater degree than other antihypertensive agents
Heart failure drug therapy: Vasodilators • hydralazine (Apresoline) (*Chronic HF ONLY*) • isosorbide dinitrate/ hydralazine (BiDil) (*Chronic HF ONLY*) • nitrates (e.g., nitroglycerin [Nitro-Bid], isosorbide dinitrate [Isordil]) • nesiritide (Natrecor) (*ADHF ONLY*) • nitroprusside (Nipride) (*ADHF ONLY*)
• Reduce cardiac afterload, leading to increased CO • Dilate the arterioles of the kidneys, leading to increased renal perfusion and fluid loss • Decrease BP • Decrease preload • Relieve symptoms of heart failure (e.g., dyspnea)
What are examples of collaborative therapies that are used in both ADHF and chronic heart failure?
• Treatment of underlying cause • Circulatory assist devices (e.g., ventricular assist device: performs pumping action of a heart that cannot effectively contract by itself) • Daily weights • Sodium- and, possibly, fluid-restricted diet
Precipitating causes of heart failure: Pulmonary embolism
↑ Pulmonary pressure resulting from obstruction, leads to pulmonary hypertension ↓CO
Precipitating causes of heart failure: Infection
↑O2 demand of tissues, stimulating↑CO
Precipitating causes of heart failure: Paget's disease
↑Workload of the heart by ↑vascular bed in the skeletal muscle
Bridge to NCLEX questions: The nurse recognizes that primary manifestations of systolic failure include
↓ EF and ↑ PAWP Rationale: Systolic heart failure results in systolic failure in the left ventricle (LV). The LV loses its ability to generate enough pressure to eject blood forward through the aorta. This results in increased pulmonary artery wedge pressure (PAWP). The hallmark of systolic failure is a decrease in the left ventricular ejection fraction (EF).
Precipitating causes of heart failure: Anemia
↓O2-carrying capacity of the blood stimulating ↑ in CO to meet tissue demands, leading to increase in cardiac workload and increase in size of LV