DRG Category: 216
Mean LOS: 15.9 days
Description: Surgical: Cardiac Valve and Other Major Cardiothoracic Procedures With Cardiac Catheterization With Major Complication or Comorbidity
DRG Category: 218
Mean LOS: 6.7 days
Description: Surgical: Cardiac Valve and Other Major Cardiothoracic Procedures With Cardiac Catheterization Without Complication or Comorbidity or Major Complication or Comorbidity
DRG Category: 219
Mean LOS: 10.9 days
Description: Surgical: Cardiac Valve and Other Major Cardiothoracic Procedures Without Cardiac Catheterization With Major Complication or Comorbidity
DRG Category: 221
Mean LOS: 4.7 days
Description: Surgical: Cardiac Valve and Other Major Cardiothoracic Procedures Without Cardiac Catheterization Without Complication or Comorbidity or Major Complication or Comorbidity
DRG Category: 307
Mean LOS: 3.1 days
Description: Medical: Cardiac Congenital and Valvular Disorders Without Major Complication or Comorbidity
Infective endocarditis (IE) is an inflammatory process of the endocardial lining of the heart. It typically affects a deformed or previously damaged valve, which is usually the focus of the infection, or a septal defect. Typically, endocarditis occurs when an invading organism enters the bloodstream and attaches to a sterile fibrin clot already present on the leaflets of the valves or the endocardium. The bacteria “innoculate” the clot, multiply, and form a projection of tissue that includes bacteria, fibrin, red blood cells, and white blood cells on the valves of the heart including the valve leaflets. This clump of material, called vegetation, may eventually cover the entire valve surface, leading to ulceration and tissue necrosis. Vegetation may even extend to the chordae tendineae, causing them to rupture and the valve to become incompetent. Approximately 10% to 20% of the infections occur with prosthetic valves. Most commonly, the mitral or aortic valve is involved. The tricuspid valve is mainly involved in IV drug abusers but is otherwise rarely infected. Infections of the pulmonary valve are rare.
IE can occur as an acute or a subacute condition. Generally, acute IE is a rapidly progressing infection, whereas subacute IE progresses more slowly. Acute endocarditis usually occurs on a normal heart valve and is rapidly destructive and fatal in 6 weeks if it is left untreated. Subacute endocarditis usually occurs in a heart already damaged by congenital or acquired heart disease on damaged valves and takes up to a year to cause death if it is left untreated. Complications include thromboembolic phenomenon such as stroke, myocardial infarction, cardiac valvular insufficiency, heart failure, sepsis, myocardial abscesses, arthritis, and myositis.
Since the 1960s, the most common causes of IE have been nosocomial infections from IV catheters, IV drug abuse, and prosthetic valve endocarditis. IVs become infected at the insertion site, on the catheter itself, from another site in the body, or from the IV infusate. IE can result from injected drug use and abuse as well.
The etiology of acute IE is predominantly bacterial. The two most common causes of bacterial endocarditis are staphylococcal and streptococcal infections (Box 1), and Staphylococcus aureus is the primary pathogen of endocarditis. Subacute IE occurs in people with acquired cardiac lesions. Possible ports of entry for the infecting organism include lesions or abscesses of the skin and genitourinary (GU) or gastrointestinal (GI) infections. Surgical or invasive procedures such as tooth extraction, tonsillectomy, bronchoscopy, endoscopy, colonoscopy, cystoscopy, transesophageal echocardiography, and prosthetic valve replacement also place the patient at risk.
Box 1 Conditions Predisposing to Endocarditis
- Rheumatic heart disease
- Congenital heart disease (CHD; patent ductus arteriosus, ventricular septal defect, bicuspid aortic valve, Fallot tetralogy)
- Prosthetic valve surgery
- Parenteral drug abuse
- Placement of intravascular foreign bodies (IV catheters, dialysis shunts, pacemakers, hyperalimentation catheters)
- Mitral valve prolapse
- Asymmetric septal hypertrophy
- Marfan syndrome
- Previous episodes of endocarditis
- Skin, bone, and pulmonary infections
Heritable immune responses could be protective or increase susceptibility.
The incidence of IE in infancy and childhood is low. Nearly all children infected have an identifiable predisposing lesion. Men over age 45 years are at highest risk, as males are affected three times more than females. More than half the cases occur in people older than age 60 years.
Ethnicity, race, and sexual/gender minority status have no known effect on the risk for IE.
The incidence of IE in the United States, Western Europe, and other developed regions is approximately 13 cases per 100,000 persons per year. Less is known about the incidence in developing countries, but because many of their healthcare systems are underresourced and medical procedures are less frequent, rates of IE are likely lower than in developed countries.
PLANNING AND IMPLEMENTATION
Collaborative
Antibiotics are the mainstay of the treatment for IE. Antibiotics are chosen depending on the infecting organisms and are traditionally given intravenously for 4 to 6 weeks. Some physicians are prescribing oral step-down antibiotics after 3 weeks of IV antibiotics rather than the longer IV course (Spellberg et al., 2020 [see Evidence-Based Practice and Health Policy]). For persons at high risk for contracting IE, most physicians prescribe antibiotic therapy to prevent episodes of bacteremia before, during, and after invasive procedures. Procedures that are particularly associated with endocarditis are manipulation of the teeth and gums or GU and GI systems and surgical procedures or biopsies that involve respiratory mucosa.
Supportive treatment with oxygen, treatment of congestive heart failure, or management of acute renal failure with dialysis may be necessary. If the patient has developed endocarditis as a result of IV drug abuse, an addiction consultation is essential, with a possible referral to an appropriate treatment program. Surgical replacement of the infected valve is needed in those patients who have an infecting microorganism that does not respond to available antibiotic therapy and for patients who have developed infectious endocarditis in a prosthetic heart valve. (See Coronary Heart Disease for a full discussion of the collaborative and independent management of a patient following open heart surgery.)
| Medication or Drug Class | Dosage | Description | Rationale |
|---|
| Penicillin G | 2 million units IV daily 4 hr for 4 wk | Antibiotic | Treats penicillin-susceptible streptococcal infections in subacute bacterial endocarditis; patients who are allergic to penicillin may receive vancomycin |
| Oxacillin; ceftriaxone, gentamicin, vancomycin, or tobramycin; cefazolin | Varies with drug | Antibiotic | Treats acute bacterial endocarditis; S aureus and gram-negative bacilli are the most likely bacteria |
| Acetaminophen (Tylenol) | 650 mg as needed daily 4–6 hr | Nonnarcotic analgesic; antipyretic | Relieves joint and muscle achiness; controls fever |
Other Drugs: Ceftriaxone at 2 g/day IV for 4 weeks; may also be given intramuscularly if problems occur with venous access and can be given once a day as an outpatient if the patient is stable. Other antibiotics are cefepime and nafcillin.
Independent
During the acute phase of the disease, provide adequate rest by assisting the patient with daily hygiene. Use strategies to increase the patient's comfort during the acute phase of the illness, during which symptoms such as fever, diaphoresis, and shortness of breath are uncomfortable. Space all nursing care activities and diagnostic tests to provide the patient with adequate rest. During the first few days of hospital admission, encourage the family to limit visitation.
Emphasize patient education. Individualize a standardized plan of care and adapt it to meet the patient's needs. Areas for discussion include the cause of the disease and its course, medication regimens, technique for administering IV antibiotics, and practices that help avoid and identify future infections.
If the patient is to continue parenteral antibiotic therapy at home, make sure that before the patient is discharged from the hospital, the patient has all the appropriate equipment and supplies that will be needed. Make a referral to a home health nurse as needed, and provide the patient and family with a list of information that describes when to notify the primary healthcare provider about complications.
Evidence-Based Practice and Health Policy
Spellberg, B., Chambers, H., Musher, D., Walsh, T., & Bayer, A. (2020). Evaluation of a paradigm shift from intravenous antibiotics to oral step-down therapy for the treatment of infective endocarditis: A narrative review. JAMA Internal Medicine, 180, 769–777.
- While prolonged IV antibiotic courses have long been used to treat IE, they are associated with high rates of adverse events. Recent studies have shown that oral step-down antibiotic treatment may be an alternative. The authors reviewed electronic databases to determine whether evidence supports the notion that oral step-down antibiotic therapy for IE is associated with inferior outcomes compared with IV-only therapy. They found 21 observational studies evaluating oral antibiotics for treating IE, typically after an initial course of IV therapy.
- None of the observational studies found oral step-down therapy to be inferior to IV-only therapy. Three randomized clinical trials also demonstrated that oral step-down antibiotic therapy is at least as effective as IV-only therapy in IE. In the largest trial, patients who received oral step-down antibiotic therapy had a significantly improved cure rate and reduced mortality rate compared with those who received only IV antibiotic therapy.