1. Clinical presentations
Infective endocarditis is an infection that involves both the endothelial surface of the heart and the valves. The clinical presentations however involve other systems as well and include:
General manifestations whereby patients may complain of cough, weight loss, anorexia, general malaise, back and joint pains. Other general signs include fever which is intermittent in nature, petechiae especially in the conjuctiva and mucous membranes, Osler’s nodes that is, small but painful nodes which appear in the pads of the fingers or toes and splinter hemorrhages under toenails or fingernails which may at times be present (Sabharwal et al. 354).
Cardiac manifestations normally include heart murmurs although they may be absent in the early stages of the infection, enlargement of the heart with or without development of heart failure. Valvular damages either due to the presence of vegetations on the valves or perforation of the valves manifest as progressive changes in the murmurs (Smeelter and Brunner 781).
Central nervous system manifestations are normally attributed to embolization of the cerebral arteries and present as headaches, transient cerebral ischemia and cerebral vascular accidents/strokes (Sabharwal et al. 355).
Patients with prosthetic heart valves, congenital heart malformations, previous history of endocarditis, surgically constructed systemic or pulmonary shunts are at a higher risk for infective endocarditis. Others at high risk for the condition include those with rheumatic heart disease and/or mitral valve prolapse. Patients at the greatest risk for hospital-acquired infective endocarditis include those with debilitating illnesses, indwelling catheters, those on immunosuppressive therapies like corticosteroids and finally those receiving prolonged IV medications and/or antibiotic therapies (Smeelter and Brunner 781).
Infective endorcarditis most oftenly occurs due to the direct invasion of the innermost layer of the heart that is the endocardium by microbes. The microbes normally involved include those of the genus streptococci, pneumococci, enterococci or staphylococci. In a minority of cases of infective endorcarditis, fungi and ricketssiae have been found to be the causative organisms. The infection normally causes deformities of the leaflets of the heart valves although it may involve the other cardiac structures for example, the chordae tendineae. Valvular deformities occur because of the destruction or perforations of the valves or chordae tendineae as well as due to bulky vegetations which inhibit the proper coaptation of the valve leaflets .These vegetations are composed of fibrin, platelets, clusters of bacteria and leucocytes. Presence of vegetations is normally termed the hallmark of infective endocarditis. Upon healing, some endocarditis become perforated with smooth borders or develops aneurysms. The most commonly affected valves are the aortic and/or mitral valves (Gattuso 962).
3. Differential diagnosis
Influenza because both conditions present with aneroxia, cough, fever, weight loss, back and joint pains (Smeelter and Brunner 782).
Non-bacterial thrombotic endocarditis (Gattuso 962).
Encephalopathy, epilepsy and stroke due to the [presence of central nervous system symptoms.
Rheumatoid and oncological processes due to the presence of symptoms like joint and back pains, malaise, weight loss and fatigue (Zaoutis and Chiang 549).
4. Work up
Diagnosis is done by performing serial blood cultures so as to identify the infective organism. Normally, three sets of blood cultures are done with each and every set including both an aerobic and anaerobic culture. A definitive diagnosis of infective endocarditis is made when any of the causative microbes is found to be present in two separate blood cultures.
Echocardiograms either transoesophageal or transthoracic, done by Doppler color flow mapping are also indicated in the diagnosis of infective endocarditis due to their ability to demonstrate any moving masses on the surface of normal and prosthetic valves, new regurgitation and the development of heart failure.
Other work ups done include full blood counts, coagulation profile, urea and electrolytes, liver function tests, C-reactive protein and the erythrocyte sedimentation rates (Sabharwal et al. 353).
5. Management of the disease
Antimicrobial therapy is the mainstay of medical management of infective endocarditis. The choice of drug depends on the microorganism isolated from the blood cultures. Penicillins are the most commonly used antibiotics in the management of bacterial infective endocarditis and they are administered parenterally as continuous IV infusions for durations of two to six weeks. Chosen antibiotics are administered in adequate doses so as to one, achieve a high serum concentration and two, ensure the length of duration of action of the drugs is adequate to allow for the complete eradication of the infective organism even in the dense vegetations. Continuous monitoring of the serum levels of the antibiotics, the patient’s body temperature and repeat blood cultures is done so as to monitor the effects of the therapy. Antifungal agents like Amphotericin B are used in the management of infective endocarditis caused by fungi (Zaoutis and Chiang 549).
Supportive management for patients with infective endocarditis include nutritional support because these patients are normally catabolic and thus easily lose weight as well as muscle bulk, educational and emotional support. In addition, prophylaxis against deep venous thrombosis and subsequent formation of pulmonary emboli by giving prophylaxis heparin or using compression stockings is necessary because these patients are frequently bedbound (Sabharwal et al. 364).
Surgical therapy is indicated in patients who develop signs of congestive heart failure, experience more than one episode of systemic emboli, have fungal or prosthetic valve endocarditis and recurrent or uncontrolled infections. The aim of surgical therapy is to replace damaged heart valves and in effect improve the prognosis of the patient (Smeelter and Brunner 782).
Gattuso, Paolo, et al. Differential Diagnosis in Surgical Pathology. Philadelphia: Elsevier Health Sciences, 2010. Print.
Sabharwal, Nikant, et al. Valvular Heart Disease. New York: Oxford University Press, 2011.Print.
Smeelteer, and Brunner, B.G. Brunner & Suddarth’s textbook of medical-surgical nursing. Philadelphia: Lippincott, Williams and Wilkins, 2004. Print.
Zaoutis, and Chiang, Vincent. Comprehensive Pediatric Hospital Medicine. Philadelphia: Mosby Elsevier, 2007. Print.