LEARN STEP #2
Make the connections to key topics.
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Unit VI Promoting Health in Patients With Circulatory or Perfusion Disorders
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Chapter 30 Coordinating Care for Patients With Cardiac Disorders
Pathophysiology Infective endocarditis is defined as an infection of the innermost layer of the heart, the endocardium, most typ- ically affecting the heart valves. Infective endocarditis begins with damage to the endocardial lining of the heart, which can occur as a result of turbulent blood flow. Tur- bulent blood flow is often caused by valve dysfunction. Platelet and fibrin deposit onto the injured area, forming what is known as a nonbacterial thrombotic endocardial lesion . Microorganisms introduced into the bloodstream through patient exposures circulate and can become trapped under the layers of platelet and fibrin deposits. These microor- ganisms and deposits grow into clumps known as vegeta- tion . This vegetation can severely damage the valves of the heart (Fig. 30.4). The etiology of IE is generally of bacterial origin, although other pathogens have been reported. The most common causative microorganisms are Staphylococcus aureus and Streptococcus . Infective endocarditis can also be caused by other bacteria, viruses, and fungi. The source of expo- sure to microorganisms in the blood has been historically linked to dental and other invasive procedures. However, it has been suggested that repeated exposures to microor- ganisms are more likely to cause IE than random exposure during a single dental or other invasive procedure. Clinical Manifestations Clinical manifestations of IE include red, painful nodes in the pads of the fingers and toes—Osler’s nodes—and red, painless spots on the palms and soles, called Janeway lesions. Splinter hemorrhages, tiny blood clots that run vertically under nails, may also be present . Most patients have a heart murmur , the sound heard when there is turbulent blood flow across a heart valve. They can also experience heart
failure (HF), arrhythmias, weight loss, or night sweats. Other symptoms are similar to those of any infectious pro- cess, such as the following: l Fever l Fatigue l Confusion (in older adults) Interprofessional Management Medical Management Diagnosis Diagnostic Tests Tests used to confirm the diagnosis of IE are blood cul- tures, two sets from different sites, and transthoracic echo- cardiogram (TTE) or transesophageal echocardiogram (TEE). Echocardiography can identify valve dysfunction, vegetative growth, abscesses, and changes in heart size and pumping ability that can occur with IE. Echocardiogra- phy is described in more detail in Chapter 28. An elevated white blood cell count may also be indicative of infection. Medications Medication management consists primarily of IV antibi- otic therapy. The increasing trend of microbial resistance has led to the use of combination therapy. The standard duration of treatment is 4 to 6 weeks but may be longer for prosthetic valves. Patients are often discharged to home on IV antimicrobial therapy. Shorter duration is recom- mended for some combination therapies. Oral antimicro- bial agents are rarely used as initial treatment. Repeated blood cultures may be obtained until results are negative, indicative of adequate bactericidal effects. Prophylactic use of oral antibiotics is not routinely recommended but is used for patients at high risk (see Safety Alert). The choice of antimicrobial agents is complex and based on the organism cultured and the sensitivity report,
right-sided versus left-sided IE, native versus prosthetic valve involvement, patient comorbidity, and other factors. Infectious disease specialists are often consulted. Penicillin G, ceftriaxone, vancomycin, ampicillin, daptomycin, and gentamicin may be considered in various combinations for the treatment of IE. Supportive treatment for the common complications of IE, especially HF, is also indicated to optimize cardiac output and tissue perfusion.
typically seen in the hands and feet, are due to infection. Sepsis can occur in conjunction with IE. Septic emboli can alter CNS and systemic perfusion. The damage to the heart valves can cause a new murmur and heart failure. Nursing Diagnoses/Problem List l Infection related to an invading organism secondary to IE l Ineffective tissue perfusion related to emboli l Decreased cardiac output related to valve dysfunc- tion, altered rhythm, and/or altered stroke volume l Fever l Fatigue Nursing Interventions ■ Assessments l Vital signs Fever is indicative of ongoing acute infection. Hypotension, tachycardia, tachypnea, and low SpO 2 can be signs of sepsis or heart failure. l Auscultate breath sounds. Crackles may be a sign of heart failure related to valve dysfunction. l Auscultate heart sounds. A new or worsening murmur may occur due to valve damage. l Assess neurological function. Neurological changes or deficits in pupils, grips, foot pushes, facial droop, and speech may be signs of CNS embolization. l Assess extremities. Cyanosis or pallor, delayed capillary refill, and decreased peripheral pulses may indicate peripheral embolization. Edema could be a sign of heart failure related to valve dysfunction. l Skin assessment Osler’s nodes, Janeway lesions, and splinter hemorrhages are indicative of IE. l Monitor diagnostic test results. Repeated culture reports are used to evaluate the effective treatment of IE. White blood cell (WBC) counts can indicate responsiveness to infection. Echocardiograms can evaluate the size of vegetation and valve function and can be used to predict the risk of complications. l History of drug use, invasive procedures, implanted vascular or cardiac devices, or valve replacement surgery Common risk factors for IE ■ Actions l Administer antibiotics as prescribed. Treatment for IE is long-term IV antibiotic treatment. l Maintain IV access for antibiotic administrations. Intravenous access is essential for antibiotic administration. Long-term venous access, such as a peripherally inserted central catheter (PICC), may be considered. l Administer heart failure medications as needed. Heart failure treatment optimizes cardiac output and tissue perfusion.
Safety Alert
Routine antibiotic prophylaxis is no longer recommended for patients who
have mechanical or bioprosthetic valves for the pre- vention of IE because this contributes to antimicrobial resistance and has not been proven to reduce infection risk. Prophylactic antibiotics are recommended before genitourinary procedures or in high-risk patients such as those with active infections or who may be immunosup- pressed. Meticulous oral hygiene should be encouraged for patients at highest risk, such as those with a history of IE, intracardiac prosthetic material such as valves and defect closure devices, cardiac transplant, and congenital heart disease. Surgical Management The surgical treatment options for IE include valve repair or replacement. Surgery can remove infected tissue and reduce mortality and complications, but it also has sig- nificant risk. Recent evidence suggests that early surgery within the first 7 days has reduced mortality, embolisms, and recurrence when compared to delayed surgery. Complications Embolic events are the major complication of IE and occur in 22% to 50% of cases. Embolization occurs when frag- ments of vegetation break free from the valve and travel to other parts of the body through the bloodstream. Embolic events are often a complication of left-sided IE and are rarely seen in right-sided IE. The emboli can travel ran- domly to any organ or tissue, resulting in obstructed blood flow and potential spreading of infection. Emboli from left-sided IE typically travel to the central nervous system (CNS; 65%) but can also affect the kidneys, spleen, bowel, and extremities. Emboli traveling to the CNS cause tran- sient ischemic attacks or strokes. Right-sided IE is associ- ated with pulmonary emboli. Heart failure and dysrhythmias can also occur due to valvular dysfunction and abscesses in the conduction sys- tem. Strokes, heart failure, and dysrhythmias can be a part of the presenting symptoms of IE because they compel
Vegetation
Left atrium
Mitral valve
patients to seek treatment. Nursing Management Assessment and Analysis
Left ventricle
The clinical manifestations of IE, such as positive blood cultures combined with fever, fatigue, and the lesions
FIGURE 30.4 Mitral valve vegetation in infective endocarditis.
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