Prevention of bacterial endocarditis: recommendations by the American Heart Association

Endothelial-to-Mesenchymal Transition in Cardiovascular Pathophysiology

Under different pathophysiological conditions, endothelial cells lose endothelial phenotype and gain mesenchymal cell-like phenotype via a process known as endothelial-to-mesenchymal transition (EndMT). At the molecular level, endothelial cells lose the expression of endothelial cell-specific markers such as CD31/platelet-endothelial cell adhesion molecule, von Willebrand factor, and vascular-endothelial cadherin and gain the expression of mesenchymal cell markers such as α-smooth muscle actin, N-cadherin, vimentin, fibroblast specific protein-1, and collagens. EndMT is induced by numerous different pathways triggered and modulated by multiple different and often redundant mechanisms in a context-dependent manner depending on the pathophysiological status of the cell. EndMT plays an essential role in embryonic development, particularly in atrioventricular valve development; however, EndMT is also implicated in the pathogenesis of several genetically determined and acquired diseases, including malignant, cardiovascular, inflammatory, and fibrotic disorders. Among cardiovascular diseases, aberrant EndMT is reported in atherosclerosis, pulmonary hypertension, valvular disease, fibroelastosis, and cardiac fibrosis. Accordingly, understanding the mechanisms behind the cause and/or effect of EndMT to eventually target EndMT appears to be a promising strategy for treating aberrant EndMT-associated diseases. However, this approach is limited by a lack of precise functional and molecular pathways, causes and/or effects, and a lack of robust animal models and human data about EndMT in different diseases. Here, we review different mechanisms in EndMT and the role of EndMT in various cardiovascular diseases.

Oral Health Clearance Outcomes for Cardiovascular Surgery

Objective

To determine the risk of morbidity and mortality in patients receiving dental extractions before planned cardiovascular surgery (CVS) and examine factors that may affect the chance of oral health clearance.

Patients and Methods

A retrospective medical record review was performed of patients who underwent dental screening before CVS from January 1, 2015, to December 31, 2021, at a major medical institution. A total of 496 patients met the inclusion criteria and were divided into 2 groups. Group 1 patients were cleared to advance to planned CVS (n=390). Group 2 patients were not cleared for surgery and subsequently underwent dental extractions before planned CVS (n=106).

Results

Six patients (5.7%) experienced postoperative complications after dental extraction that resulted in an emergency room visit. No deaths occurred after dental extraction before CVS. However, 4 patients died within 30 days of CVS, 3 from Group 1 (0.77%) and 1 from Group 2 (0.94%). Dental extraction before planned CVS showed a borderline significant association with death based on unadjusted (P=.06) and age-adjusted analysis (P=.05). Patients who reported seeing a dentist routinely had a significantly higher chance of oral health clearance (P <.001). No differences were noted between the 2 groups with regard to age, sex, or 30-day hospital readmission rate.

Conclusion

Patients who had dental extractions completed before planned CVS may be at an increased risk of mortality. Further studies are needed to examine this relationship. Emphasis should be on prioritization of routine dental visits before planned CVS.

Role of Prophylactic Dose of Oral Amoxicillin Trihydrate in Prevention of Bacteremia Post Surgical Removal of Impacted Mandibular Third Molar: A Clinical Study

The current study is designed to evaluate the efficacy of pre-operative prophylactic antibiotic for prevention of bacteremia after surgical removal of impacted mandibular third molar SRIMTM. The study was carried out as an open clinical trial. Fifty patients who fulfilled the criteria were included. Twenty five randomly selected patients (study group) were administered two grams oral dose of amoxicillin trihydrate, one hour prior to the procedure. Twenty five patients (control group) were not administered any antibiotic prior to the procedure. All patients underwent surgical removal of impacted mandibular third molar through intraoral approach under local anesthesia. Blood culture for detection of aerobic and anaerobic micro-organisms was done for all 50 patients. Eleven out of the twenty five patients (44%) in the control group showed positive growth, including mixed growth (aerobic and anaerobic). Seven patients showed purely anaerobic, 2 patients purely aerobic and two mixed growth. In the study (antibiotic) group, 7 out of the 25 patients (28%) showed positive growth, including mixed growth. Three patients showed purely anaerobic, 2 patients purely aerobic and 2 mixed type of growth. The study suggests that the judicious use of antibiotic prophylaxis, in conjunction with optimal oral health care serves to minimize the adverse effects of antibiotic therapy; and at the same time reduce the significant morbidity and mortality associated with systemic infections that might occur due to bacteremia resulting from surgical procedures of the oral cavity.

Antimicrobial Mouthwashes: An Overview of Mechanisms-What Do We Still Need to Know?

This narrative literature review is the first in a 6-section supplement on the role of mouthwashes in oral care. This introduction briefly summarises current knowledge on antimicrobial mechanisms, relating to some of the most common over-the-counter mouthwash products available worldwide: chlorhexidine, hydrogen peroxide, cetylpyridinium chloride, povidone iodine, and essential oils. The aim of this first article is to describe how mouthwashes "kill" pathogenic microbes when used adjunctively and thus provide a basis for their widespread use to manage key oral diseases, namely caries, gingivitis, and periodontal disease. This article therefore sets the scene for subsequent, more detailed exploration of mouthwashes regarding their clinical effectiveness, impact on the oral microbiome, and possible effects on systemic health as well as natural alternatives and future directions. Other than the clinical effectiveness (for certain agents) of mouthwashes, on many topics there remains insufficient evidence for systematic review or formulation of robust national guidelines. The supplement, therefore, compiled by an international task team, is aimed at general dental practitioners across the globe, as an easy-to-read guide for helping to advise patients on mouthwash use based on the current best available evidence.

Predictors of mortality of Staphylococcus aureus bacteremia among patients hospitalized in a Swiss University Hospital and the role of early source control; a retrospective cohort study

S. aureus bacteremia is associated with high mortality. The aim was to identify predictors of mortality among patients with S. aureus bacteremia and evaluate the role of early source control. This retrospective study was conducted at the Lausanne University Hospital, Switzerland. All episodes of S. aureus bacteremia among adult patients from 2015 to 2021 were included. During the study period, 839 episodes of S. aureus bacteremia were included, of which 7.9% were due to methicillin-resistant isolates. Bacteremias were related to bone or joint infections (268; 31.9%), followed by bacteremia of unknown origin (158; 18.8%), proven endocarditis (118; 14.1%) and lower-respiratory tract infections (79; 9.4%). Overall 28-day mortality was 14.5%. Cox multivariate regression model showed that Charlson comorbidity index > 5 (P < 0.001), nosocomial bacteremia (P 0.019), time to blood culture positivity ≤ 13 h (P 0.004), persistent bacteremia for ≥ 48 h (P 0.004), sepsis (P < 0.001), bacteremia of unknown origin (P 0.036) and lower respiratory tract infection (P < 0.001) were associated with 28-day mortality, while infectious diseases consultation within 48 h from infection onset (P < 0.001) was associated with better survival. Source control was warranted in 575 episodes and performed in 345 episodes (60.0%) within 48 h from infection onset. Results from a second multivariate analysis confirmed that early source control (P < 0.001) was associated with better survival. Mortality among patients with S. aureus bacteremia was high and early source control was a key determinant of outcome. Infectious diseases consultation within 48 h played an important role in reducing mortality.

Value of diagnosing immunological phenomena in patients with suspected endocarditis

Purpose

Immunological phenomena are a minor criteria in the modified Duke Criteria for endocarditis. Given the changes in epidemiology and diagnostics, the added value of determining these phenomena in today’s patients with suspected endocarditis is unknown.

Methods

In a retrospective cohort study of all patients with suspected endocarditis admitted to our hospital and discussed in our endocarditis team, we determined the proportion of patients classified as definite endocarditis because of either positive IgM rheumatoid factor (IgM RF), haematuria, or Roth’s spots on ophthalmology consultation. We also determined diagnostic accuracy of each of these immunological phenomena separately and combined.

Results

Of 285 patients included, 138 (48%) had definite endocarditis and at least one immunological test was performed in 222 patients (78%). Elevated IgM RF was found in 22 of 126 patients tested (17%), haematuria in 78 of 196 tested (40%) and Roth’s spots in six of 120 tested (5%). Eighteen of 138 patients with definite IE (13%) were classified as such because of a positive IgM RF, haematuria or Roth’s spots. Haematuria had the highest sensitivity: 50.5% (95% CI 40.4–60.6) and Roth’s spots the highest specificity: 98.3% (95% CI 90.8–99.9). The diagnostic accuracy results were robust in a sensitivity analysis aimed at avoiding incorporation bias.

Conclusion

Among patients with a clinical suspicion of endocarditis, recommended systematic testing for immunological phenomena helped classify more patients as definite IE and is useful to confirm the diagnosis of endocarditis.

Review of the Current Antibiotic Guidelines used in Dermatologic Surgery

Antibiotics have been used as a prophylaxis for dermatologic procedures. We will review the various procedures that specific antibiotics with dosages are used for, depending on the procedure, diagnosis, and circumstance of the patient. We will examine the current and updated guidelines used in dermatologic surgery and the overlapping guidelines across other fields. Physicians must consider the side effects of antibiotics and the resistance that may occur as a result before using the class or level of prophylaxis. Initial evaluation for alcohol, chlorhexidine or iodine should be measured as well. Updated guidelines aim to address the contraindications of antibiotics, yet further research is needed to avoid antibiotic resistance and to explore alternative methods of antibiotic application, such as intranasal and intravenous. This article is protected by copyright. All rights reserved.

The LAUsanne STAPHylococcus aureus ENdocarditis (LAUSTAPHEN) score: A prediction score to estimate initial risk for infective endocarditis in patients with S. aureus bacteremia

Introduction

Infective endocarditis (IE) is a common complication of Staphylococcus aureus bacteremia (SAB). The study aimed to develop and validate a prediction score to determine IE risk among SAB.

Methods

This retrospective study included adults with SAB (2015-2021) and divided them into derivation and validation cohorts. Using the modified 2015 European Society of Cardiology modified Duke Criteria for definite IE, the LAUSTAPHEN score was compared to previous scores.

Results

Among 821 SAB episodes, 419 and 402 were divided into derivation and validation cohorts, respectively. Transthoracic and transoesophageal echocardiography (TOE) were performed in 77.5 and 42.1% of episodes, respectively. Definite IE was diagnosed in 118 episodes (14.4%). Derivation cohort established that cardiac predisposing factors, such as cardiac implantable electronic devices, prolonged bacteremia ≥48 h, and vascular phenomena were independently associated with IE. In addition to those parameters, native bone and joint infections were used to constitute the LAUSTAPHEN score. LAUSTAPHEN and VIRSTA scores misclassified <4% of IE cases as low risk. Misclassification using POSITIVE and PREDICT scores was >10%. The number of TOEs required to safely exclude IE were 66.9 and 51.6% with VIRSTA and LAUSTAPHEN, respectively.

Discussion

LAUSTAPHEN and VIRSTA scores exhibited the lowest misclassification rate of IE cases to the low-risk group. However, the number of patients requiring TOE was higher for VIRSTA than for LAUSTAPHEN.

Prediction rules for ruling out endocarditis in patients with Staphylococcus aureus bacteremia

Background

Staphylococcus aureus bacteremia (SAB) is in 10% to 20% of cases complicated by infective endocarditis. Clinical prediction scores may select patients with SAB at highest risk for endocarditis, improving the diagnostic process of endocarditis. We compared the accuracy of the Prediction Of Staphylococcus aureus Infective endocarditiseTime to positivity, Iv drug use, Vascular phenomena, preExisting heart condition (POSITIVE), Predicting Risk of Endocarditis Using a Clinical Tool (PREDICT), and VIRSTA scores for classifying the likelihood of endocarditis in patients with SAB.

Methods

Between August 2017 and September 2019, we enrolled consecutive adult patients with SAB in a prospective cohort study in 7 hospitals in the Netherlands. Using the modified Duke Criteria for definite endocarditis as reference standard, sensitivity, specificity, negative predictive (NPV), and positive predictive values were determined for the POSITIVE, PREDICT, and VIRSTA scores. An NPV of at least 98% was considered safe for excluding endocarditis.

Results

Of 477 SAB patients enrolled, 33% had community-acquired SAB, 8% had a prosthetic valve, and 11% a cardiac implantable electronic device. Echocardiography was performed in 87% of patients, and 42% received transesophageal echocardiography (TEE). Eighty-seven (18.2%) had definite endocarditis. Sensitivity was 77.6% (65.8%–86.9%), 85.1% (75.8%–91.8%), and 98.9% (95.7%–100%) for the POSITIVE (n = 362), PREDICT, and VIRSTA scores, respectively. NPVs were 92.5% (87.9%–95.8%), 94.5% (90.7%–97.0%), and 99.3% (94.9%–100%). For the POSITIVE, PREDICT, and VIRSTA scores, 44.5%, 50.7%, and 70.9% of patients with SAB, respectively, were classified as at high risk for endocarditis.

Conclusions

Only the VIRSTA score had an NPV of at least 98%, but at the expense of a high number of patients classified as high risk and thus requiring TEE.

Clinical Trials Registration

Netherlands Trial Register code 6669.

Infective Endocarditis: A Contemporary Review

Infective endocarditis (IE), initially described more than 350 years ago, involves infection of the endocardial surface of the heart. The clinical manifestations of IE can involve every organ system, and the cardiac manifestations can include valvular vegetation, abscess, periannular extension of infection, and myopericarditis. Echocardiography is crucial in the diagnosis of IE, but alternative imaging modalities are playing an increasing role in the diagnosis and management of IE. Multidisciplinary care is imperative to the management of IE, often requiring the expertise of cardiologists, cardiothoracic surgeons, infectious diseases specialists, radiologists, and neurologists. We performed a literature search of the PubMed database from January 1st, 2000, to September 30th, 2019, using the terms infective endocarditis, diagnosis, and management to find the most pertinent and highest-quality evidence. This review summarizes key aspects of IE, with a focus on emerging advances in diagnosis. We also highlight growing patient populations at risk for IE, including patients with intracardiac devices and congenital heart disease.

Is antibiotic prophylaxis to prevent infective endocarditis worthwhile?

Infective endocarditis (IE) is a rare condition which is associated with considerable morbidity and mortality. Almost 100 years ago, the links between endocarditis and procedures, particularly dental procedures, were postulated. Over 50 years ago the first guidelines recommending antibiotic prophylaxis (AP), with the aim of preventing IE developing after procedures, were proposed. However, there has only ever been circumstantial evidence in humans that AP prevents IE. The rarity of IE has made a randomised controlled clinical trial impractical to date. This article outlines the history of AP and reviews the evidence base for the use of AP to prevent IE.

Antibiotic prophylaxis is not indicated prior to dental procedures for prevention of periprosthetic joint infections

Background and purpose - To minimize the risk of hematogenous periprosthetic joint infection (HPJI), international and Dutch guidelines recommended antibiotic prophylaxis prior to dental procedures. Unclear definitions and contradictory recommendations in these guidelines have led to unnecessary antibiotic prescriptions. To formulate new guidelines, a joint committee of the Dutch Orthopaedic and Dental Societies conducted a systematic literature review to answer the following question: can antibiotic prophylaxis be recommended for patients (with joint prostheses) undergoing dental procedures in order to prevent dental HPJI? Methods - The Medline, Embase, and Cochrane databases were searched for randomized controlled trials (RCTs), reviews, and observational studies up to July 2015. Studies were included if they involved patients with joint implants undergoing dental procedures, and either considered HPJI as an outcome measure or described a correlation between HPJI and prophylactic antibiotics. A guideline was formulated using the GRADE method and AGREE II guidelines. Results - 9 studies were included in this systematic review. All were rated "very low quality of evidence". Additional literature was therefore consulted to address clinical questions that provide further insight into pathophysiology and risk factors. The 9 studies did not provide evidence that use of antibiotic prophylaxis reduces the incidence of dental HPJI, and the additional literature supported the conclusion that antibiotic prophylaxis should be discouraged in dental procedures. Interpretation - Prophylactic antibiotics in order to prevent dental HPJI should not be prescribed to patients with a normal or an impaired immune system function. Patients are recommended to maintain good oral hygiene and visit the dentist regularly.

A prospective multicenter evaluation of direct molecular detection of blood stream infection from a clinical perspective

BACKGROUND

Rapid diagnosis and appropriate antimicrobial therapy are of major importance to decrease morbidity and mortality in patients with blood stream infections (BSI). Blood culture, the current gold standard for detecting bacteria in blood, requires at least 24-48 hours and has limited sensitivity if obtained during antibiotic treatment of the patient. The aim of this prospective multicenter study was to clinically evaluate the application of a commercial universal 16S/18S rDNA PCR, SepsiTest™ (PCR-ST), directly on whole blood.

METHODS

In total 236 samples from 166 patients with suspected sepsis were included in the study. PCR-ST results were compared to blood culture, the current gold standard for detecting BSI. Because blood cultures can give false-negative results, we performed an additional analysis to interpret the likelihood of bloodstream infection by using an evaluation based on clinical diagnosis, other diagnostic tests and laboratory parameters.

RESULTS

Clinical interpretation of results defined the detected organism to be contaminants in 22 of 43 positive blood cultures (51.2 %) and 21 of 47 positive PCR-ST results (44.7 %). Excluding these contaminants resulted in an overall sensitivity and specificity of the PCR-ST of 66.7 and 94.4 % respectively. Of the 36 clinically relevant samples, 11 BSI were detected with both techniques, 15 BSI were detected with PCR-ST only and 10 with blood culture only. Therefore, in this study, SepsiTest™ detected an additional 71 % BSI compared to blood culture alone.

CONCLUSIONS

More clinically relevant BSI were diagnosed by molecular detection, which might influence patient treatment. An improved SepsiTest™ assay suited for routine use can have additional value to blood culture in diagnosing bacteremia in septic patients.

Bacteremia after Endoscopic Submucosal Excavation for Treating the Gastric Muscular Layer Tumors

Background. The bacteremia is reported as being infrequent and transient in gastric EMR and ESD for treating gastric mucosa lesions or superficial gastric neoplastic lesion. There was no report of it being investigated in ESD for treating gastric muscular layer tumors (endoscopic submucosal excavation, ESE). This study aimed to determine the frequency of bacteremia in gastric ESE. Patients and Methods. A prospective study, in 122 consecutive patients who underwent gastric ESE for treating gastric muscular layer tumors, investigated the frequency of bacteremia before and 15 minutes after the procedure. Results. The median time for the total ESE procedure was 29 min (range from 8 to 62 min). The mean size of the biggest diameter of each resected specimen was 10 ± 2.7 mm (range from 5 mm to 30 mm). Blood cultures obtained before ESE were positive in 0% (0/122) of cases. Blood cultures obtained 15 min after ESE were positive in 2.5% (3/122) of cases. Six blood samples contained Staphylococcus with coagulase negative, which was considered contaminant. No signs of sepsis were seen in all patients. Conclusions. The frequency of bacteremia after gastric ESE was low. ESE for treating gastric lesions is thought to have a low risk of infectious complications; therefore, prophylactic administration of antibiotics may not be warranted.

Avaliação do conhecimento de Cirurgiões-Dentistas e acadêmicos de Odontologia na cidade de Aracaju, Sergipe, a respeito da adequada prescrição de antimicrobianos

INTRODUÇÃO: Os antimicrobianos são caracterizados como um dos mais notáveis exemplos do avanço da Medicina moderna. Contudo, a adaptabilidade dos microrganismos propicia resistência a determinados antimicrobianos.OBJETIVO: Apresentar, por meio de pesquisa realizada com alunos do curso de Odontologia e Cirurgiões-Dentistas na cidade de Aracaju-SE, um perfil do conhecimento destes sobre antibioticoterapia, propondo oferecer uma oportunidade de identificar e reconhecer os riscos relacionados à administração incorreta destes fármacos.MATERIAL E MÉTODO: Investigação observacional, transversal, com base em um questionário respondido por 80 alunos do curso de Odontologia e 50 Cirurgiões-Dentistas, escolhidos de forma aleatória, para verificar o conhecimento sobre o tema proposto.RESULTADO: Dentre os entrevistados, aproximadamente 40% eram profissionais e 60% acadêmicos de Odontologia; destes, cerca de 40% relataram que prescrevem utilizando como critério de seleção que o antimicrobiano seja seletivo e bactericida, enquanto que 90% dos entrevistados afirmam prescrever antibiótico somente quando necessário, como forma de evitar a resistência bacteriana.CONCLUSÃO: De acordo com a metodologia empregada, pode-se concluir que os dois grupos mostraram desconhecimento sobre a diferença entre antibioticoterapia, profilaxia antimicrobiana e terapêutica medicamentosa.

Dental disease and periprosthetic joint infection

➤ The number of patients with end-stage osteoarthritis is increasing, and treatment with hip and knee arthroplasty is expected to increase over the next several decades. ➤ Dental disease has long been anecdotally associated with increased periprosthetic joint infections, although case-control studies do not support this relationship. ➤ While most recent guidelines for the prevention of endocarditis have favored treatment of fewer patients, the most recent recommendations for prevention of periprosthetic joint infection have increased the number of patients who would receive antibiotics before a dental procedure. ➤ Antibiotics given before a dental procedure decrease the risk of bacteremia from the oral cavity, but this is of uncertain clinical importance. ➤ The number of patients who would require antibiotics before dental procedures to prevent one periprosthetic joint infection greatly outnumbers the number of patients who would experience an adverse event associated with antibiotics given before a dental procedure.

Strategies for the prevention of infection after solid organ transplantation

Infection is a frequent complication of organ transplantation and is associated with significant morbidity and mortality. Preventative antimicrobial strategies are a key component of the care received by transplant patients. This review summarizes the evidence supporting anti-infective prophylaxis in this setting. Specific recommendations for the prevention of bacterial, fungal, viral and parasitic infection after transplant are made, with a focus on recent developments in the field of transplant infectious diseases.

Protective effects of human lactoferrin during Aggregatibacter actinomycetemcomitans-induced bacteremia in lactoferrin-deficient mice

Aggregatibacter actinomycetemcomitans, a periodontopathogen, has been associated with several systemic diseases. Herein, we report the protective effect of human lactoferrin (hLF) during A. actinomycetemcomitans bacteremia in lactoferrin knockout (LFKO(-/-)) mice. The prophylactic, concurrent, and therapeutic intravenous (i.v.) administrations of hLF significantly cleared the bacteria from blood and organs. Nevertheless, all modes of hLF administration significantly decreased the concentrations of serum proinflammatory cytokines, such as interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), IL-6, IL-10, and IL-12p70. Additionally, hLF administration significantly decreased hepatic and splenic proinflammatory cytokine expression levels compared to those in the non-hLF-treated group. Furthermore, administration of hLF decreased the serum C-reactive protein level, inducible nitric oxide synthase (iNOS) and myeloperoxidase (MPO) gene expression levels in liver and spleen. hLF treatment has also resulted in a 6-fold decrease in spleen weight with the migration of typical inflammatory cells in infected mice as a result of decreased inflammatory response. These results reveal that hLF protects against A. actinomycetemcomitans bacteremia, as indicated by rapid bacterial clearance and decreased host proinflammatory mediators.

Indications of antibiotic prophylaxis in dental practice- review

Antibiotics are frequently used in dental practice. Clinical and bacteriological epidemiological factors determine the indications of antibiotics in dentistry. Antibiotics are used in addition to appropriate treatment to aid the host defences in the elimination of remaining bacteria. It is indicated when there is evidence of clinical sign involvement and spread of infection. Antibiotics are prescribed in dental practice for treating odontoge nic infections, non-odontogenic infections, as prophylaxis against focal and local infection. Special care needs to be addressed to patients with organ transplants, poorly controlled diabetes and pregnancy. Antibiotics should be used only as an adjunct to dental treatment and never alone as the first line of care. The present paper reviews the indications of antibiotics in dental practice.

Odontostomatologic management of patients receiving oral anticoagulant therapy: a retrospective multicentric study

Introduction

Today, we frequently find patients taking oral anticoagulant therapy (OAT), a prophylaxis against the occurrence of thromboembolic events. An oral surgeon needs to know how to better manage such patients, in order to avoid hemorrhagic and thromboembolic complications.

Materials and methods

A group of 193 patients (119 men aged between 46 and 82 and 74 women aged between 54 and 76) undergoing OAT for more than 5 years were managed with a standardized management protocol and a 2-months follow-up. The aim of the present study was to apply a protocol, which could provide a safe intra- and postoperative management of patients on OAT.

Results

Among the 193 patients, only 2 had postoperative complications.

Conclusions

We think that the protocol used in the present study can be used for complete safety in the treatment of this type of patients.

Induction of experimental endocarditis by continuous low-grade bacteremia mimicking spontaneous bacteremia in humans

Transient high-grade bacteremia following invasive procedures carries a risk of infective endocarditis (IE). This is supported by experimental endocarditis. On the other hand, case-control studies showed that IE could be caused by cumulative exposure to low-grade bacteremia occurring during daily activities. However, no experimental demonstration of this latter possibility exists. This study investigated the infectivity in animals of continuous low-grade bacteremia compared to that of brief high-grade bacteremia. Rats with aortic vegetations were inoculated with Streptococcus intermedius, Streptococcus gordonii or Staphylococcus aureus (strains Newman and P8). Animals were challenged with 10(3) to 10(6) CFU. Identical bacterial numbers were given by bolus (1 ml in 1 min) or continuous infusion (0.0017 ml/min over 10 h). Bacteremia was 50 to 1,000 times greater after bolus than during continuous inoculation. Streptococcal bolus inoculation of 10(5) CFU infected 63 to 100% vegetations compared to 30 to 71% infection after continuous infusion (P > 0.05). When increasing the inoculum to 10(6) CFU, bolus inoculation infected 100% vegetations and continuous infusion 70 to 100% (P > 0.05). S. aureus bolus injection of 10(3) CFU infected 46 to 57% valves. This was similar to the 53 to 57% infection rates produced by continuous infusion (P > 0.05). Inoculation of 10(4) CFU of S. aureus infected 80 to 100% vegetations after bolus and 60 to 75% after continuous infusion (P > 0.05). These results show that high-level bacteremia is not required to induce experimental endocarditis and support the hypothesis that cumulative exposure to low-grade bacteremia represents a genuine risk of IE in humans.

Long-term effect of an oral healthcare programme on oral hygiene in a nursing home

This article reports on the long-term effect of an oral healthcare programme aimed at improving and maintaining the oral hygiene of elderly residents in a nursing home. The method was based on (i) motivation and oral-care training of the nursing staff, (ii) production of picture-based oral-care procedure cards, (iii) distribution of adequate oral-care equipment, (iv) practical implementation of new routines, and (v) assessment of results attained. The level of oral hygiene in the nursing home was assessed using the mucosal-plaque score (MPS) index. Overall evaluation was made before the start of the study, after 3 months, and eventually after 6 yr. Before implementation of the oral healthcare programme, 36% of the residents had an acceptable score. Six years later, the proportion was 70%. The evaluation showed that the introduction of such an oral healthcare programme significantly improved the oral hygiene of the residents on a long-term basis. However, 30% of the residents did not achieve an acceptable score because they were very ill or dying, aggressive or wanted to brush their teeth themselves.

The use of povidone-iodine and hydrogen peroxide mixture as an adjunct to non-surgical treatment of slight to moderate chronic periodontitis

OBJECTIVE

The aim of this study was to evaluate the clinical effects of the adjunctive use of povidone-iodine with or without hydrogen peroxide as coolant and disinfectant during ultrasonic scaling and root planing in the treatment of chronic periodontitis.

MATERIALS AND METHODS

Sixteen patients initially participated in the study. Thirteen patients (8 males and 5 females) completed the 3-month follow-up period. Their mean (±SD) age was 42.92 ± 7.55 years. In each experimental subject, the mouth was split into four quadrants. A randomly selected quadrant was chosen to receive one of the three treatment group modalities which were: Group 1 - ultrasonic scaling and root planing plus irrigation with 1% povidone-iodine and 3.0% hydrogen peroxide mixture; Group 2 - ultrasonic scaling and root planing plus irrigation with 1% povidone-iodine; Group 3 - ultrasonic scaling and root planing plus irrigation with normal saline. The fourth quadrant served as a control group.

RESULTS

At the 3-month evaluation, there was no significant difference between the three treatment groups in terms of probing depth reduction, clinical attachment gain, gingival recession increase, reduction in the bleeding upon probing or plaque score reduction (P > 0.05). However, the three treatment groups had statistically significant higher mean reduction in the probing depth, gain in the clinical attachment level and reduction in the bleeding upon probing than the control group (P < 0.05).

CONCLUSION

There were no added benefits of using a mixture of povidone-iodine and hydrogen peroxide or povidone-iodine as disinfectants during ultrasonic scaling and root planing in the treatment of chronic periodontitis.

Anesthetic Considerations in the Patient With Valvular Heart Disease Undergoing Noncardiac Surgery

Valvular heart disease can be an important finding in patients presenting for noncardiac surgery. Valvular heart disease and resulting comorbidity, such as heart failure or atrial fibrillation, significantly increase the risk for perioperative adverse events. Appropriate preoperative assessment, adequate perioperative monitoring, and early intervention, should hemodynamic disturbances occur, may help prevent adverse events and improve patient outcome. This review article aims to guide the practitioner in the various aspects of anesthetic management in the perioperative care of patients with valvular heart disease. The pharmacological approach to optimization of patient outcome with drugs, such as βblockers and lipid-lowering medications (statins), is an evolving field, and recent developments are discussed in this article.

Clinically Compressed Digital Echocardiography: A Patient-safe Alternative to Videotape Review

Introduction: Digital storage of echocardiographic data offers logistical advantages over videotape archival. However, limited information is available on the accuracy of clinically compressed digitised examinations, an important consideration for patient safety. Materials and Methods: Transthoracic echocardiograms of 520 consecutive patients were prospectively acquired digitally and on videotape. Two echocardiologists, in consensus, reported studies in both formats sequentially. Using the videotape as a reference, the significance of any reported differences was graded from both imaging and clinical standpoints, and the reasons for these differences identified. Results: From an imaging perspective, differences between digital and videotaped studies were absent or minor in 459 cases (88%), fairly significant in 55 (11%) and very significant in 6 (1%). The main reasons for the observed differences were inadequate acquisition of optimal views (59%), an insufficient number of acquired cardiac cycles (25%) and suboptimal image quality (9%). These differences were considered to be of possible or definite clinical importance in 21 (4%) and 8 (2%) cases, respectively. In multinominal logistic regression models, the only independent predictor of significant difference between digitised and videotaped images was study complexity. Regardless of case complexity, most diagnostic errors arising from digital review were attributable to technical failure rather than observer error. Conclusions: The potential for important errors arising from exclusive reporting of clinically compressed digital echocardiograms is small. Digital echocardiography, as practiced in a routine clinical setting, offers a patient-safe alternative to videotape review. Key words: Clinical implications, Digital echocardiography, Patient safety, Videotape

Oral Surgery in Patients on Anticoagulant Treatment Without Therapy Interruption

PURPOSE

Conflicting opinions exist in literature concerning the management of oral surgery in patients on oral anticoagulants because no consensus on perioperative protocols is available, including precise guidelines regarding the need for therapy modification or withdrawal. The aim of this study was to evaluate bleeding complications associated with oral surgery performed on patients on oral anticoagulants without therapy modification or withdrawal but following a standardized comprehensive perioperative management protocol.

PATIENTS AND METHODS

Patients on oral anticoagulant therapy with warfarin and in need of oral surgery underwent a thorough general and oral clinical evaluation to assess thromboembolic and bleeding risk; 255 subjects who, on the morning of surgery, had INR values <or=5.5 were included in the study. An atraumatic surgical technique was carried out and all patients received postoperative careful instructions.

RESULTS

Five cases (1.96%) of bleeding complication were observed in patients with moderate to high thromboembolic and bleeding risk.

CONCLUSION

The findings from this study suggest that a comprehensive perioperative management protocol for oral surgery in patients on oral anticoagulants including 1) thromboembolic and bleeding risk assessment, 2) an atraumatic surgical technique, and 3) postoperative careful instructions, can lead to safe and successful results with minimal complications.

Prospective study of bacteremia and complications With EUS FNA of rectal and perirectal lesions

BACKGROUND & AIMS

Recent studies showed that endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) is a low-risk procedure for causing bacteremia and infectious complications when sampling solid lesions of the upper gastrointestinal (GI) tract. As a result, antibiotics are not recommended for prophylaxis against endocarditis. Our aim was to prospectively evaluate the risk of bacteremia and other infectious complications in patients undergoing EUS FNA of lower GI tract lesions.

METHODS

Patients referred for EUS FNA of lower GI tract lesions were considered for enrollment. Patients were excluded if there was an indication for preprocedure antibiotic administration based on American Society for Gastrointestinal Endoscopy guidelines, had taken antibiotics within the prior 7 days, or if they had a cystic lesion. Blood cultures were obtained immediately before the procedure, after flexible sigmoidoscopy/radial EUS, and 15 minutes after EUS FNA.

RESULTS

One hundred patients underwent a total of 471 FNAs (mean, 4.7 FNAs/patient; range, 1-10 FNAs/patient). Blood cultures were positive in 6 patients. Cultures from 4 patients (4.0%, 95% confidence interval, 1.6%-9.8%) grew coagulase-negative Staphylococcus (n = 2), Peptostreptococcus stomatis (n = 1), or Moraxella (n = 1), which were considered contaminants. Two patients (2.0%, 95% confidence interval, 0.6%-7%) developed bacteremia: Bacteroides fragilis (n = 1) and Gemella morbillorum (n = 1). No signs or symptoms of infection developed in any patient.

CONCLUSIONS

EUS FNA of solid lesions in the lower GI tract should be considered a low-risk procedure for infectious complications that does not warrant prophylactic administration of antibiotics for the prevention of bacterial endocarditis.

Evaluating and minimizing cardiac risk in surgical patients

Cardiovascular complications are a major cause of postoperative morbidity and mortality. Proper assessment of risk and subsequent interventions can help diminish these complications. Assessing the patient's risk is based on the type of surgery performed and on individual patient characteristics. The latter can be established with a thorough history and physical, laboratory testing, risk indices, and cardiology studies.

Necessity of surgical dental foci treatment prior to organ transplantation and heart valve replacement

Diagnosis and surgical treatment of septic foci (e.g., apical or marginal and profound periodontitis, cysts, unrestorable teeth, or abscesses) in patients awaiting organ transplants and heart valve replacement (HVR) have become a recommended, yet controversial standard procedure. This study aims to evaluate the numerical extent of the required oral surgical procedures removing septic foci in these patients. Data of 204 patients (115 males/89 females) of the Department of Oral- and Maxillofacial Surgery with an average age of 58 years were evaluated in terms of necessary oral surgical procedures before HVR or kidney (K), heart (H), or liver (L) transplant (T) and were compared with data from patients not undergoing transplantation or HVR, who were referred for other reasons such as oral surgery. The number of tooth extractions or apicoectomies per patient averaged two to five for each of the four patient groups (KT, 0-7 affected teeth; HT, 0-5; LT, 1-5; and HVR, 1-10). Treatment of periodontitis was necessary in 64% of patients. A total of 70% of patients required oral surgical procedures before HT, LT, and HVR, while 84% needed before KT. Removal of oral septic foci is necessary to avoid jeopardizing the success of transplantations. With regard to the surprisingly high need for surgical treatment in this patient population, assessment of these patients by the appropriate specialist and continuation with a follow-up program is still highly recommended.

Single-dose oral amoxicillin or linezolid for prophylaxis of experimental endocarditis due to vancomycin-susceptible and vancomycin-resistant Enterococcus faecalis

Endocarditis prophylaxis following genitourinary or gastrointestinal procedures targets Enterococcus faecalis. Prophylaxis recommendations advocate oral amoxicillin (2 g in the United States and 3 g in the United Kingdom) in moderate-risk patients and intravenous amoxicillin (2 g) or vancomycin (1 g) plus gentamicin in high-risk patients. While ampicillin-resistant (or amoxicillin-resistant) E. faecalis is still rare, there is a concern that these regimens might fail against vancomycin-resistant and/or aminoglycoside-resistant isolates. The present study tested oral linezolid as an alternative. Rats with catheter-induced aortic vegetations were given prophylaxis simulating human pharmacokinetics of oral amoxicillin (2- to 3-g single dose), oral linezolid (600 mg, single or multiple oral doses every 12 h), or intravenous vancomycin (1-g single dose). Rats were then inoculated with the minimum inoculum infecting 90% of the animals (90% infective dose [ID(90)]) or with 10 times the ID(90) of the vancomycin-susceptible E. faecalis strain JH2-2 or the vancomycin-resistant (VanA phenotype) E. faecalis strain UCN41. Amoxicillin was also tested with two additional vancomycin-susceptible E. faecalis strains, 309 and 1209. Animals were sacrificed 3 days later. All the tested bacteria were susceptible to amoxicillin and gentamicin. Single-dose amoxicillin provided 100% protection against all four isolates at both the ID(90) and 10 times the ID(90). In contrast, linezolid required up to four consecutive doses to provide full protection against the vancomycin-resistant isolate. Vancomycin protected only against the vancomycin-susceptible strain. The high efficacy of single-dose oral amoxicillin suggests that this regimen could be used for prophylaxis in both moderate-risk and high-risk patients without additional aminoglycosides. Linezolid appears to be less reliable, at least against the vancomycin-resistant strain.

Infective endocarditis of native valve after anterior nasal packing

We present a case report of a patient who was previously treated for spontaneous epistaxis with a petroleum jelly gauze (0.5 in x 72 in) anterior nasal packing filled with an antibiotic ointment, along with prophylactic oral clindamycin. The patient presented with fever and hypotension 3 days after the nasal packing. Her blood cultures grew methicillin-resistant Staphylococcus aureus and the transesophageal echocardiography showed vegetation on the atrial surface of the posterior mitral valve leaflet, confirming the diagnosis of bacterial endocarditis attributable to nasal packing. Several case reports discuss toxic shock syndrome after nasal packing, but none describe endocarditis of the native heart valves subsequent to anterior nasal packing. Current guidelines on endocarditis prophylaxis produced by the American Heart Association, European Cardiac Society, and British Cardiac Society together with published evidence do not recommend endocarditis prophylaxis for patients with native heart valves undergoing anterior nasal packing.

Knowledge of prescribing antimicrobials among Yemeni general dentists

OBJECTIVE

Overuse of antimicrobial agents is closely related to an increase in bacterial resistance. A sound knowledge of appropriate prescribing of antimicrobials among health professionals is thus critical in combating the resistance. The objectives of this study were to assess the rationale for and patterns of antimicrobial prescriptions by general dental practitioners in Yemen.

MATERIAL AND METHODS

A questionnaire containing 65 closed questions was used for this cross-sectional study and distributed to 280 dentists in the three major governorates in Yemen. The anonymously completed questionnaires sought answers to demographic questions and to questions on the therapeutic and prophylactic use of antimicrobial agents in dentistry. Correct and incorrect answers were defined according to information available in the current authoritative literature. Each correct answer was given a score of 1 while an incorrect answer scored 0. Thus, the total score had an attainable range from 0 to 65. Frequencies, means, and associations were assessed statistically.

RESULTS

Out of 181 collected forms (response rate 64.6%), 150 were appropriately completed and used for data analyses. Penicillins were the most frequently prescribed drugs (72%), followed by spiramycin (10%). It was found that up to 84% of practitioners were likely to prescribe an antimicrobial agent when there was no clinical indication for such a medication. Many respondents (70%) would consider antibiotics for at least one of the given non-clinical factors.

CONCLUSIONS

The results suggest that dental practitioners in Yemen lack uniformity in the rationale for appropriate prescribing of antimicrobials to their patients. Consequently, to reduce overuse, there is an urgent need for the dental community in the country to be informed about evidence-based guidelines and the appropriate use of antimicrobial agents in clinical dental practice.

Infective endocarditis: diagnosis and management

Despite advances in antimicrobial therapy, diagnostic imaging and cardiac surgery, infective endocarditis (IE) remains challenging clinically and is associated with high morbidity and mortality. Diagnosis relies on several factors: initial clinical suspicion, microbiological data and echocardiographic findings. The use of an integrated diagnostic schema, such as the modified Duke criteria, is useful. Transthoracic or transesophageal echocardiography should be performed promptly for all suspected IE cases. Although the choice of investigation might be influenced by availability, the approach to imaging should be tailored to the individual's clinical situation. Promptly administered intravenous antimicrobial therapy is essential, while the use of antiplatelet or antithrombin therapy to prevent embolic complications is not supported by clinical data. Deciding whether to undertake cardiac surgery for the treatment of IE can be extremely difficult. The principal indications are the development of heart failure from acute, severe aortic or mitral regurgitation, or perivalvular extension of infection. The timing of surgery following central nervous system embolization is problematic because of the risk of hemorrhagic transformation. Prophylactic surgery to prevent embolization is currently advocated only for the management of large, mobile vegetations, when undertaken at centers performing high volumes of heart valve surgery. In this review, we describe diagnostic approaches for IE, particularly echocardiography, and provide recommendations for treatment, paying particular attention to surgery in the acute setting.

Linezolid in prophylaxis against experimental aortic valve endocarditis due to Streptococcus oralis or Enterococcus faecalis

There are no experimental studies regarding the prophylactic efficacy of linezolid against infective endocarditis. Nonbacterial thrombotic endocarditis of the aortic valve was induced in rabbits by the insertion of a polyethylene catheter. Twenty-four hours later, animals were randomly assigned to a control group, and groups receiving either ampicillin (two doses of 40 mg/kg of body weight each, given intravenously, 2 h apart) or linezolid (a single per os dose of 75 mg/kg). The first dose of ampicillin and the single dose of linezolid were administered 0.5 and 1 h, respectively, prior to the intravenous inoculation of approximately 10(7) CFU of Streptococcus oralis or Enterococcus faecalis. Linezolid peak levels in rabbit serum were similar to the peak serum levels in humans following a 600-mg oral dose of linezolid. Linezolid prevented endocarditis in 87% of S. oralis-challenged rabbits (P < 0.001 versus controls; P = 0.026 versus ampicillin). In rabbits challenged with E. faecalis, linezolid prevented endocarditis in 73% (P = 0.003 versus controls; P = 0.049 versus ampicillin). Ampicillin prevented endocarditis due to S. oralis or due to E. faecalis in 47% (P = 0.005 versus controls) and in 30% (P = not significant versus controls) of the challenged animals, respectively. In conclusion, linezolid was effective as prophylaxis against endocarditis caused by a strain of S. oralis and to a lesser degree against that caused by a strain of E. faecalis. Its prophylactic efficacy was superior to that of ampicillin.

Atrioventricular block after transcatheter closure of perimembranous ventricular septal defects

OBJECTIVE

To look at the presentation, treatment and outcome of patients who developed atrioventricular block after transcatheter closure of a perimembranous ventricular septal defect (PMVSD) with the Amplatzer PMVSD device.

SETTING

Three tertiary referral centres for paediatric cardiology in two countries.

RESULTS

All three patients presented within 10 days of the procedure. All three patients were treated with intravenous steroids. A permanent pacemaker was inserted in all patients but no pacemaker required activation after two months.

CONCLUSION

Complete atrioventricular block occurring in the weeks after device occlusion of a PMVSD appears to resolve quickly. Continued involvement in multicentre device databases is required to monitor safety.