Current practice in prevention of bacterial endocarditis

Knowledge of General Dentists and Senior Dental Students in Iran about Prevention of Infective Endocarditis

Infective endocarditis (IE) is an infection of the endothelial surface of the heart and heart valves with serious, even fatal, complications and that often requires long-term and expensive treatment. Dental procedures may lead to IE in high-risk patients. The aim of this study was to evaluate and compare the knowledge of general dentists and dental students concerning the prevention of IE in Hamadan, Iran. In this cross-sectional study, the awareness of general dentists and dentistry students concerning the prevention of IE was evaluated during 2010. A questionnaire was prepared and administered to 58 final-year dental students and 96 general dental practitioners in Hamadan. A total of 154 persons completed the questionnaire. The questionnaire consisted of some demographic questions and questions about awareness of IE in three sections. The gathered data were analyzed by using descriptive statistics, Pearson's chi-square test, Mann-Whitney test, and independent t-tests. The gathered data showed that dentistry students answered the questions about awareness of the prevention of IE more correctly than did general dentists. The overall knowledge of endocarditis prophylaxis among students and dentists was about 65% and 56%, respectively. The students' knowledge was better because 94.9% of the students had desired (acceptable) and relatively desired knowledge; this result for dentists, however, was 82.3%. In our study, the overall awareness level of the study population was moderate. Dentist and students believed that patients with prosthetic valves and previous IE were the most common cardiac disease cases that required prophylaxis. The most common prophylactic regimen was in accordance with the guidelines of the American Heart Association and was a single dose of 2 g amoxicillin 1 hour before treatment. The results indicated that gender had no effect on the level of knowledge; however, there was a statistically significant relationship between age and level of knowledge.

An update on the controversies in bacterial endocarditis of oral origin

OBJECTIVES

The aim of this review was to evaluate the evidence implicating dental procedures in bacterial endocarditis (BE) development and the basis for antimicrobial prophylaxis (AP).

STUDY DESIGN

In this article, the literature is reviewed and meaningful findings about epidemiology, pathogenesis, and AP guidelines for BE of oral origin are highlighted. Available results are used to formulate clinical recommendations for the dental practitioner.

RESULTS

The nature of dental procedures that cause bacteremia, patients at risk for BE, and the effectiveness of AP guidelines, continue to be points of controversy. There appears to be further evidence to support the important role of oral health status in the prevention of BE of dental origin.

CONCLUSIONS

One objective of the dental practitioner in caring for patients at risk for BE should be to promote oral health care. There are no hard data on which to scientifically base the need for AP in patients at risk for BE. However, it would appear prudent, at least from the medicolegal perspective, to provide AP, at least to persons with previous BE or prosthetic heart valves and to those undergoing oral surgery, periodontal treatment, or implant placement.

Assessment of knowledge of guidelines for the prevention of infective endocarditis amongst clinicians in a teaching hospital

A significant minority of instances of endocarditis appear to be the result of invasive procedures performed in susceptible patients with underlying cardiac conditions. Absence, or inappropriate administration, of antimicrobial prophylaxis could expose the patient to the development of a potentially lethal infection. This study was formulated, therefore, to assess the knowledge of guidelines for the prevention of infective endocarditis among hospital-based physicians and surgeons. A multiple choice test was developed, including: (1) cardiac conditions at increased risk for development of infection; (2) procedures more likely to be associated with bacteraemia and endocarditis; and (3) type and route of antimicrobials prescribed when endocarditis prophylaxis is indicated. The quality of the test was determined in several ways. Success was defined as a pass rate of 11 of 18 questions (61%). The test was taken by 153 of 251 (60%) physicians employed by the hospital; 95 (62%) passed the test. No significant difference in success rates was found according to sex, professional status or medical school. Internists performed substantially better (with a pass rate of 41 of 53, 77%) than both paediatricians (13 of 26, 50%, P<0.05) and surgeons (41 of 74, 55%, P<0.01). The range of success varied from 100% to 36% according to specialty (P<0.001). The mean score was 69+/-21 in the study group and 94+/-10 in a control group of 20 infectious disease physicians (P<0.001). In conclusion, this study demonstrates the need for improved education of hospital-based clinicians regarding endocarditis prophylaxis recommendations.

Greek physicians' and dentists' compliance with the British society for antimicrobial chemotherapy (BSAC) guidelines for preventing bacterial endocarditis

Two thousand questionnaires inquiring about applied prophylaxis for bacterial endocarditis were sent to practicing doctors in Greece. Two hundred and ninety-nine questionnaires were completed and returned (15% response rate) and were subsequently divided into two groups: Group A (163) consisting of responses from dentists, chest physicians and ear, nose and throat (ENT) specialists and group B (136) including responses from gastroenterologists, gynecologists, urologists and radiologists. The percentage of correct answers given in response by clinicians in Groups A and B to the main questions and in accordance with the 1992 guidelines of the British Society for Antimicrobial Chemotherapy (BSAC) were respectively: (a) 53% vs 35% asked patients their previous history pertaining to valve disease, rheumatic fever or prosthetic valve surgery; (b) 55% vs 33% administered prophylaxis to patients with relevant history prior to medical procedures; (c) 67% vs 0% of prescribing doctors administered the appropriate antibacterials; (d) 33% vs 31% initiated prophylaxis in proper timing prior to medical procedure; (e) 14% vs 13% administered antibiotics in correct time/route/duration of infusion where applicable, prior to medical procedure; (f) 7% of group A doctors administering recommended antibiotics, implemented prophylaxis with correct time/route/dosage while, although none of group B doctors administered recommended antibiotics, 7% implemented prophylaxis with correct time/route recommendations; (g) an overall 2% of doctors from both groups met the BSAC recommendations. In conclusion, it is imperative that the appropriate training of doctors in all subspecialties regarding prophylaxis of bacterial endocarditis and according to current recommendations be carried out.

Bacteremia during extracorporeal shock wave lithotripsy of renal calculi

An increasing incidence of bacterial endocarditis has been observed since the beginning of the last decade. An explanation for this fact is the expansion of diagnostic and therapeutic procedures in diverse medical disciplines. In a clinical study performed on 49 consecutive patients undergoing extracorporeal shock wave lithotripsy a 14.3% rate of bacteremia was detected during treatment. The bacterial spectrum consisted of gram-positive cocci, gram-negative cocci, Bacteroides capillosus and Proteus mirabilis. In principle, these results do not call for an antibiotic prophylaxis. Nevertheless, according to the recommendations of the American Heart Association and the Deutsche Gesellschaft für Herz- und Kreislaufforschung, patients with a cardiac risk predisposing to bacterial endocarditis must receive perioperative antibiotic prophylaxis.

Dental procedures and endocarditis prophylaxis: experiences from 108 dental practices

In a previous survey, we analyzed a questionnaire to 220 patients, who underwent cardiac surgery with insertion of prosthetic heart valves in the period 1978-1982. Of the 147 patients with their own natural teeth, 136 gave us permission to contact their regular or casual dentists. Of the 108 dentists (79%), who responded to a questionnaire, two thirds were well aware that their patients had prosthetic heart valve and the vast majority of dentists believed that antibiotic prophylaxis is justified in connection with (certain) dental procedures. However, only 15 dentists (14%) prescribed prophylactic antibiotics, i.e. before scaling. The dosage route, frequency and duration of antibiotic administration used by more than half of the dentists was not in accordance with modern principles of antibiotic prophylaxis to prevent bacterial endocarditis. Proposals for antibiotic regimens have to be linked to better education/information of the patients, doctors and dentists and should be linked to recommendations to ensure the highest level of dental care in risk patients.

'Usual and customary' practice versus the recommendations of experts: clinician noncompliance in the prevention of bacterial endocarditis

Data were collected from a representative sample of American general practitioners to ascertain adherence to the recommendations by the American Heart Association (AHA) concerning management of patients at risk for bacterial endocarditis. Inconsistencies were found in the prescribing of appropriate risk-related therapies such as proper timing, selection of antibiotics, and associated dosages. It is suggested that clinicians' compliance level with these recommendations may be raised by a careful reading of the AHA's latest findings.

Dental procedures and endocarditis prophylaxis in patients with prosthetic heart valves: results of a questionnaire to 220 patients

220 patients with prosthetic heart valves were surveyed regarding dental status, dental health, patient-dentist relationship, information on dental procedures and antimicrobial prophylaxis at the last visit to the dentist. The vast majority of these patients were on life-long anticoagulant treatment because of mechanical heart valve prostheses. Half of the patients had a regular dentist and customarily visited a dentist one or more times a year. One third of the patients were edentulous and 26.5% of the patients indicated dental disease, including chronic periodontitis. Only 30.4% of the patients received antimicrobial prophylaxis in connection with dental extraction and only 13.8% in connection with scaling. Maintenance of good oral health, routine dental checks and better information to the patients and the dentist are called for.

Hospital survey of antimicrobial prophylaxis to prevent endocarditis in patients with prosthetic heart valves

The American Heart Association (AHA) has published guidelines for use of prophylactic antibiotics to prevent bacterial endocarditis, but few data are available about physician compliance with these guidelines. A retrospective review was conducted of the use of prophylactic antibiotics in patients with prosthetic heart valves who were undergoing diagnostic or operative procedures or heart catheterization at three hospitals. Compliance with AHA recommendations was only 30 percent (14 of 46) for procedures considered high risk for patients with prosthetic heart valves. Six (23 percent) of 26 patients who underwent right or left heart catheterization received prophylactic antibiotics (not recommended by AHA). Antibiotics were given to 42 (74 percent) of 57 patients who underwent surgical procedures considered at low risk of bacteremia, but only 33 (58 percent) received antibiotics that cover organisms commonly present at the site of the procedure. The results indicate that clinicians frequently do not administer prophylactic antibiotics in patients with prosthetic heart valves who are undergoing invasive procedures or do not follow published AHA guidelines when antibiotics are administered.

New concept in chemoprophylaxis of bacterial endocarditis resulting from dental treatment

Bacteremia following dental procedures may lead to bacterial endocarditis in susceptible patients. Traditional methods of chemoprophylaxis with a parenteral loading dose of penicillin followed by oral penicillin have proved impractical outside the hospital. In 1978, it was suggested in England that amoxicillin be substituted as the drug of choice in the prophylaxis of bacterial endocarditis. The recommended mode of treatment was a single oral dose of 3 g amoxicillin administered 1 hour before onset of the dental procedure. Amoxicillin is absorbed to a greater extent and more rapidly than penicillin V. It maintains its effectiveness throughout the critical postoperative period at concentrations well over the minimum necessary to combat Streptococcus viridans. Amoxicillin has two mechanisms of protection: bactericidal and inhibition of bacterial adherence to the thrombotic vegetation on injured heart valves. Data obtained from 206 susceptible patients undergoing dental treatment under chemoprophylaxis with amoxicillin showed that in no case did infective endocarditis occur. Only in 13.1% of the patients could very mild side effects of this drug be observed. With this new method, there is a higher incidence of patient compliance and administration is easier to supervise.

Clinician compliance and the prevention of bacterial endocarditis

Analysis of our data indicates confusion about, and lack of compliance with, the AHA recommendations. Clinician level of knowledge varies with issues of risk management and by specialty group membership. Patient groups that are particularly problematic include children and all patients with congenital heart disease, those receiving a continuing antibiotic regimen for secondary prevention of rheumatic fever, those with a penicillin allergy, and those with prosthetic heart valves. Another area of clinician uncertainty concerns dental procedures which may or may not be associated with the possible causation of bacterial endocarditis. The biodynamic principles involved in endocarditis are central to the structure of the AHA recommendations. These principles, as well as those which provide theoretical support for the loading dose, timing, sequence, and duration recommended by the AHA, have been presented with the hope that clinician compliance with these recommendations will be increased.

The teeth and infective endocarditis

During 1981 and 1982 544 cases of infective endocarditis were investigated retrospectively by means of a questionnaire. Only 13.7% had undergone any dental procedure within three months of the onset of the illness, and in 42.5% there was no known cardiac abnormality before the onset of the disease. Furthermore, the number of cases occurring annually was about the same as or more than it was before the introduction of penicillin. The mouth and nasopharynx were the most likely sources of the commonest organism, Streptococcus viridans, and it is suggested that it is not dental extractions themselves which are of importance but good dental hygiene. In most patients with infective endocarditis the portal of entry of the organism whatever its nature cannot be identified. If this is so antibiotics are being given to only a small proportion of those at risk, and this would explain why the number of cases is much the same as it was before the introduction of penicillin. Furthermore, the large proportion of patients with no known previous cardiac abnormality adds to the difficulty of providing effective prophylaxis. The evidence suggests that antibiotic prophylaxis should still be given before dental procedures, and a schedule is appended. Much more importance should be given, however, to encouraging people to seek better routine dental care. We also believe that doctors and dentists should appreciate that the pattern of the disease has changed considerably in the past 50 years and that the information given here warrants a revised approach to the problem.

Acupuncture needles as a cause of bacterial endocarditis

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Antibiotic prophylaxis of subacute bacterial endocarditis for adult patients by dentists in Dade County, Florida

To determine compliance with 1977 American Heart Association (AHA) recommendations for antibiotic prophylaxis (AbP) of subacute bacterial endocarditis (SBE), we mailed a questionnaire to 1019 licensed dentists from Dade County, Florida. Of the 614 practicing dentists who responded, 97.7% believe that AbP prevents SBE and 94.2% always obtain a cardiac history from new patients. AbP is given to patients with known rheumatic or other valvular heart disease by 98.9% of responders and to patients with known prosthetic heart valves by 81.5%. The majority of dentists prescribe the antibiotics recommended by the AHA, but the dosage, route, frequency and duration of therapy are usually not according to AHA guidelines. AbP completely consistent with these guidelines is prescribed by 15.4% of dentists for patients with heart disease and by only 6.7% of dentists for patients with prosthetic heart valves. The AHA recommends parenteral AbP for most patients with prosthetic heart valves, but approximately 80% of dentists use only oral agents for these patients. We conclude that most dental patients predisposed to SBE receive AbP, but not in accordance with AHA guidelines. The widest deviation occurs among patients with prosthetic heart valves.

Infectious complications of gastrointestinal endoscopy

The relationships of infectious disease and fiberoptic gastrointestinal endoscopy have been reviewed. After a decade of burgeoning fiberoptic use, endoscopically related infections have occurred, but with remarkable rarity, despite lack of uniformity in endoscopic cleansing techniques. Transmission of viral disease has not been demonstrated. Reported bacterial cross infections have occurred under variable cleansing conditions which did not include disinfection. Transient low level bacteremia occurs following gastrointestinal endoscopy, and is generally inconsequential. Prophylactic antibiotics against gram negative organisms are to be considered in the patient with a prosthetic valve, because of theoretical risks which have not been clinically observed. Problems of cross infection and bacteremia can be generally avoided by various measures, but can most certainly be precluded by use of disinfectants, which maximally suppress microorganisms. Endogenous infection, chiefly evident as aspiration pneumonia, is likely underreported but uncommon, and prevention is probably related in part to good endoscopic technique. Infections are not an important complication of gastrointestinal endoscopy.

Prosthetic valve endocarditis: a review of 24 cases

Petheram, I. S. and Boyce, J. M. H. (1977).Thorax, 32, 478-485. Prosthetic valve endocarditis: a review of 24 cases. Twenty-four episodes of prosthetic valve endocarditis occurred in 23 patients in a 10-year period. Fifteen patients presented within four months and nine from 14 months to seven years after surgery. The commonest pathogens in the early group were Candida albicans (five), but in three of these patients other organisms were found; diphtheroid species in five and Staphylococcus aureus in three. Four patients in the late group had Streptococcus viridans infection. Antistaphylococcal operative prophylaxis has been successful, but opportunist organisms of low virulence in health have emerged as pathogens. Continuous monitoring of antibiotic prophylaxis may reduce the incidence of early cases, and antibiotic cover for dental procedures should be as meticulous after valve replacement as before operation. The most frequent cause of death in both groups was delayed or inadequate treatment because of failure to isolate the pathogens from blood cultures with consequent severe haemodynamic upset or uncontrolled infection. Previous courses of antibiotics were the usual reason for negative blood cultures. Successful management requires close liaison with an interested clinical bacteriologist and aggressive surgery for haemodynamic faults or failure to control infection.