Intravenous amoxicillin/clavulanate for the prevention of bacteraemia following dental procedures: a randomized clinical trial

Smoking Impacts Alzheimer's Disease Progression Through Oral Microbiota Modulation

Alzheimer's disease (AD) is an important public health challenge with a limited understanding of its pathogenesis. Smoking is a significant modifiable risk factor for AD progression, and its specific mechanism is often interpreted from a toxicological perspective. However, microbial infections also contribute to AD, with oral microbiota playing a crucial role in its progression. Notably, smoking alters the ecological structure and pathogenicity of the oral microbiota. Currently, there is no systematic review or summary of the relationship between these three factors; thus, understanding this association can help in the development of new treatments. This review summarizes the connections between smoking, AD, and oral microbiota from existing research. It also explores how smoking affects the occurrence and development of AD through oral microbiota, and examines treatments for oral microbiota that delay the progression of AD. Furthermore, this review emphasizes the potential of the oral microbiota to act as a biomarker for AD. Finally, it considers the feasibility of probiotics and oral antibacterial therapy to expand treatment methods for AD.

Use or abuse of antibiotics as prophylactic therapy in oral surgery: A systematic review

BACKGROUD

Antibiotics are a type of medication routinely prescribed by dental professionals; however, it is very common that the administration is not justified. Around 15% of dentists admit that they have administered antibiotics unnecessarily more than once a week. The objective of this project is to identify the effectiveness of the use of antibiotics as prophylactic therapy in oral surgery, and to carry out an analysis of the alternatives to pharmacological therapy.

METHODS

The search strategy was carried out in the PubMed, Scopus, and ScienceDirect databases. For study selection, a first filter was carried out by title and abstract, which mentioned the use of prophylactic antibiotics in some type of oral surgery. To establish the risk of bias, the JBI Critical Appraisal Checklist for Randomized Controlled Trials was utilized.

RESULTS

The type of antibiotics most prescribed as prophylactic therapy were beta-lactams, which were indicated in 100% of the studies. Penicillins predominated, observing amoxicillin as the most indicated drug in 54.1% of the studies (n = 13) followed by the use of amoxicillin in conjunction with clavulanic acid in 33.3% of the studies (n = 8). Of the 21 studies included, 17 mention that there is insufficient evidence to support the use of antibiotics as prophylactic therapy in patients who will undergo some type of oral surgery.

CONCLUSIONS

Without a doubt, the biggest challenge is to develop academic update strategies aimed at dentists with active clinical practice and dental students from educational and government institutions to provide updated information about the correct use of prescription drugs.

Myeloperoxidase: A Circulating Marker of Inflammation and Tooth Infection

BACKGROUND

Atherosclerotic cardiovascular disease and tooth infection are common in primary care, and both significantly reduce quality of life. Our study aimed to examine signs of vascular inflammation associated with loss of tooth vitality before and after a single tooth extraction.

METHODS

An observational cohort study was performed with adults who had a nonvital tooth and an indicated desire for tooth extraction. Concentrations of total cholesterol, high-density lipoprotein-cholesterol, high-sensitivity C-reactive protein (hs-CRP), myeloperoxidase (MPO), and troponin T were measured in venous blood serum or plasma at baseline and 6-weeks after tooth extraction.

RESULTS

Circulating hs-CRP levels were > 3 mg/dL in 15 participants (68.2%) and MPO levels were > 350 pmol/L in 9 (40.9%) of 22 participants at baseline. After tooth extraction (n = 18), MPO levels decreased significantly compared with baseline (P < .00006) and hs-CRP levels moved directionally downward. The response rate for MPO was 88.9% (confidence interval: 65.1%-98.6%) from visit 1 to visit 2. Those with high MPO levels at baseline demonstrated larger reductions in MPO levels by visit 2 than those with lower baseline MPO levels (r = .81; P < .0001). A total of 13 individuals (72.2%) achieved MPO levels < 350 pmol/L and 11 (61.1%) achieved hs-CRP levels < 3 mg/dL at visit 2. Total cholesterol, high-density lipoprotein-cholesterol, and troponin T levels did not significantly change from visit 1 to visit 2.

CONCLUSION

A link between dental infection and circulating levels of inflammation was observed, suggesting that oral infection could be a risk factor for atherosclerotic cardiovascular disease.

Antibiotic prophylaxis before dental procedures to prevent infective endocarditis: a systematic review

PURPOSE

Infective endocarditis (IE) is a severe bacterial infection. As a measure of prevention, the administration of antibiotic prophylaxis (AP) prior to dental procedures was recommended in the past. However, between 2007 and 2009, guidelines for IE prophylaxis changed all around the word, limiting or supporting the complete cessation of AP. It remains unclear whether AP is effective or not against IE.

METHODS

We conducted a systematic review whether the administration of AP in adults before any dental procedure, compared to the non-administration of such drugs, has an effect on the risk of developing IE. We searched for studies in the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE via OVID, and EMBASE. Two different authors filtered articles independently and data extraction was performed based on a pre-defined protocol.

RESULTS

The only cohort study meeting our criteria included patients at high-risk of IE. Analysis of the extracted data showed a non-significant decrease in the risk of IE when high-risk patients take AP prior to invasive dental procedures (RR 0.39, p-value 0.11). We did not find other studies including patients at low or moderate risk of IE. Qualitative evaluation of the excluded articles reveals diversity of results and suggests that most of the state-of-the-art articles are underpowered.

CONCLUSIONS

Evidence to support or discourage the use of AP prior to dental procedures as a prevention for IE is very low. New high-quality studies are needed, even though such studies would require big settings and might not be immediately feasible.

Update on pulmonary arteriovenous malformations

This review aimed to provide an overview of pulmonary arteriovenous malformations, including the major clinical and radiological presentations, investigation, and treatment algorithm of the condition. The primary etiology of pulmonary arteriovenous malformations is hereditary hemorrhagic telangiectasia (HHT), also known as Rendu-Osler-Weber syndrome, with mutations in the ENG gene on chromosome 9 (HHT type 1) or in the ACVRL1/ALK1 complex (HHT type 2). Epistaxis should always be evaluated when repeated, when associated with anemia, and in some cases of hypoxemia. In the investigation, contrast echocardiography and chest CT are essential for evaluating this condition. Embolization is the best treatment choice, especially for correction in cases of hypoxemia or to avoid systemic infections. Finally, disease management was addressed in special conditions such as pregnancy. CT follow-up should be performed every 3-5 years, depending on the size of the afferent and efferent vessels, and antibiotic prophylactic care should always be oriented. Ultimately, knowledge of the disease by health professionals is a crucial point for the early diagnosis of these patients in clinical practice, which can potentially modify the natural course of the disease.

Impact of the COVID-19 Pandemic on Antibiotic Prescribing by Dentists in Galicia, Spain: A Quasi-Experimental Approach

BACKGROUND

Antibiotic resistance is one of the most pressing public health problems. Health authorities, patients, and health professionals, including dentists, are all involved in its development. COVID-19 pandemic restrictions on dental care may have had repercussions on antibiotic prescribing by dentists. The aim of this study was to assess the impact of the COVID-19 pandemic on antibiotic prescribing by dentists, and to review antibiotic consumption according to the WHO Access, Watch, Reserve classification. We conducted a natural, before-and-after, quasi-experimental study, using antibiotic prescription data covering the period from January 2017 to May 2021. A segmented regression analysis with interrupted time series data was used to analyse the differences between the numbers of defined daily doses (DDD) of antibiotics prescribed monthly. The outcomes showed an immediate significant decrease in overall antibiotic prescribing by primary-care dentists during lockdown, followed by a non-significant upward trend for the next year. This same pattern was, likewise, observed for Access and Watch antibiotics. COVID-19 pandemic restrictions on dental care influenced the prescription of antibiotics. During confinement, an initial decrease was observed, this trend changed when in person consultations were recovered. It might be beneficial to analyse the prescription of antibiotics using the WHO AWaRe classification, in order to monitor their appropriate use.

Whole genome sequences discriminate hereditary hemorrhagic telangiectasia phenotypes by non-HHT deleterious DNA variation

The abnormal vascular structures of hereditary hemorrhagic telangiectasia (HHT) often cause severe anemia due to recurrent hemorrhage, but HHT causal genes do not predict the severity of hematological complications. We tested for chance inheritance and clinical associations of rare deleterious variants in which loss-of-function causes bleeding or hemolytic disorders in the general population. In double-blinded analyses, all 104 patients with HHT from a single reference center recruited to the 100 000 Genomes Project were categorized on new MALO (more/as-expected/less/opposite) sub-phenotype severity scales, and whole genome sequencing data were tested for high impact variants in 75 HHT-independent genes encoding coagulation factors, or platelet, hemoglobin, erythrocyte enzyme, and erythrocyte membrane constituents. Rare variants (all gnomAD allele frequencies <0.003) were identified in 56 (75%) of these 75 HHT-unrelated genes. Deleteriousness assignments by Combined Annotation Dependent Depletion (CADD) scores >15 were supported by gene-level mutation significance cutoff scores. CADD >15 variants were identified in 38/104 (36.5%) patients with HHT, found for 1 in 10 patients within platelet genes; 1 in 8 within coagulation genes; and 1 in 4 within erythrocyte hemolytic genes. In blinded analyses, patients with greater hemorrhagic severity that had been attributed solely to HHT vessels had more CADD-deleterious variants in platelet (Spearman ρ = 0.25; P = .008) and coagulation (Spearman ρ = 0.21; P = .024) genes. However, the HHT cohort had 60% fewer deleterious variants in platelet and coagulation genes than expected (Mann-Whitney test P = .021). In conclusion, patients with HHT commonly have rare variants in genes of relevance to their phenotype, offering new therapeutic targets and opportunities for informed, personalized medicine strategies.

Is clindamycin effective in preventing infectious complications after oral surgery? Systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

To determine the effect of clindamycin in the prevention of infection after oral surgery.

MATERIAL AND METHODS

This systematic review and meta-analysis followed the PRISMA statement, the PICO-framework and included only randomized controlled clinical trials. In all studies clindamycin was administered to prevent infections in patients who underwent oral surgery. Two independent researchers conducted the search, data extraction and risk of bias assessment. Included studies were classified by the type of oral surgery. Besides, data of patients, procedures and outcome variables were collected. Risk ratios (RR) and 95% confidence intervals (CI) were calculated by using Mantel-Haenszel model and the number needed to treat (NNT). Finally, any potential sources of heterogeneity were estimated.

RESULTS

Seven trials of 540 articles met the inclusion criteria and were included in the qualitative synthesis. Four articles assessing the effect of oral clindamycin in third molar surgery were quantitatively analyzed. The overall RR was 0.66 (95% CI = 0.38-1.16), being non-statistically significant (p = 0.15). There was no heterogeneity between the studies I² = 0, p = 0.44. The NNT was 29 (95% CI = 12- -57).

CONCLUSIONS

The effectiveness of clindamycin could not be evaluated except in third molar extraction. Oral clindamycin is ineffective in preventing infection in third molar surgery.

CLINICAL RELEVANCE

There is a lack of high-quality evidence supporting the prescription of clindamycin to prevent infections after oral surgery, despite being frequently prescribed as an alternative for penicillin-allergic patients. Oral clindamycin has not been shown to be effective after third molar extractions.

The European Rare Disease Network for HHT Frameworks for management of hereditary haemorrhagic telangiectasia in general and speciality care

Hereditary haemorrhagic telangiectasia (HHT) is a complex, multisystemic vascular dysplasia affecting approximately 85,000 European Citizens. In 2016, eight founding centres operating within 6 countries, set up a working group dedicated to HHT within what became the European Reference Network on Rare Multisystemic Vascular Diseases. By launch, combined experience exceeded 10,000 HHT patients, and Chairs representing 7 separate specialties provided a median of 24 years' experience in HHT. Integrated were expert patients who focused discussions on the patient experience. Following a 2016-2017 survey to capture priorities, and underpinned by more than 40 monthly meetings, and new data acquisitions, VASCERN HHT generated position statements that distinguish expert HHT care from non-expert HHT practice. Leadership was by specialists in the relevant sub-discipline(s), and 100% consensus was required amongst all clinicians before statements were published or disseminated. One major set of outputs targeted all healthcare professionals and their HHT patients, and include the new Orphanet definition; Do's and Don'ts for common situations; Outcome Measures suitable for all consultations; COVID-19; and anticoagulation. The second output set span aspects of vascular pathophysiology where greater understanding will assist organ-specific specialist clinicians to provide more informed care to HHT patients. These cover cerebral vascular malformations and screening; mucocutaneous telangiectasia and differential diagnosis; anti-angiogenic therapies; circulatory interplays between anaemia and arteriovenous malformations; and microbiological strategies to counteract loss of normal pulmonary capillary function. Overall, the integrated outputs, and documented current practices, provide frameworks for approaches that augment the health and safety of HHT patients in diverse health-care settings.

Postextraction infection and antibiotic prescribing among veterans receiving dental extractions

OBJECTIVE

To characterize postextraction antibiotic prescribing patterns, predictors for antibiotic prescribing and the incidence of and risk factors for postextraction oral infection.

DESIGN

Retrospective analysis of a random sample of veterans who received tooth extractions from January 1, 2017 through December 31, 2017.

SETTING

VA dental clinics.

PATIENTS

Overall, 69,610 patients met inclusion criteria, of whom 404 were randomly selected for inclusion. Adjunctive antibiotics were prescribed to 154 patients (38.1%).

INTERVENTION

Patients who received or did not receive an antibiotic were compared for the occurrence of postextraction infection as documented in the electronic health record. Multivariable logistic regression was performed to identify factors associated with antibiotic receipt.

RESULTS

There was no difference in the frequency of postextraction oral infection identified among patients who did and did not receive antibiotics (4.5% vs 3.2%; P = .59). Risk factors for postextraction infection could not be identified due to the low frequency of this outcome. Patients who received antibiotics were more likely to have a greater number of teeth extracted (aOR, 1.10; 95% CI, 1.03-1.18), documentation of acute infection at time of extraction (aOR, 3.02; 95% CI, 1.57-5.82), molar extraction (aOR, 1.78; 95% CI, 1.10-2.86) and extraction performed by an oral maxillofacial surgeon (aOR, 2.29; 95% CI, 1.44-3.58) or specialty dentist (aOR, 5.77; 95% CI, 2.05-16.19).

CONCLUSION

Infectious complications occurred at a low incidence among veterans undergoing tooth extraction who did and did not receive postextraction antibiotics. These results suggest that antibiotics have a limited role in preventing postprocedural infection; however, future studies are necessary to more clearly define the role of antibiotics for this indication.

Endodontic implications of a patient with arteriovenous malformation: a case report and literature review

AIM

To present the endodontic management of a patient diagnosed with a high-flow arteriovenous malformation (AVM) requiring root canal treatment and to discuss the relevant endodontic literature for this rare but significant problem.

SUMMARY

AVM is a complex communication of an artery and a vein in which the oxygenated blood is forced away from the intended tissue. The incidence of its occurrence in the face and neck is rare, and when present, the most common sign is gingival bleeding. Arteriovenous malformation is both a diagnostic and therapeutic challenge for dentists. Also, there is ambiguity regarding the precautions to be taken whilst doing endodontic procedures in such cases. Hence, there is a need to understand the disease process and its implications in order to prevent life-threatening complications during treatment. This case report highlights the successful endodontic management of a cariously exposed right maxillary second premolar in a patient diagnosed with high-flow AVM. On an orthopantomogram, the AVM was spreading in the left submandibular space involving the left ramus area. The clinical findings of limited mouth opening with inter-appointment swelling and trismus during treatment made the case unusual and challenging. This paper addresses the current understanding of the classification, diagnosis, clinical features and endodontic management, together with specific guidelines and recommendations whilst performing endodontic procedures in AVM cases.

KEY LEARNING POINTS

The classification and oral manifestations of AVM must be known and understood. Practitioners should be aware of the radiographic appearance of AVM. Recommended precautions should be taken when carrying out restorative and endodontic procedures in a patient with AVM. Antibiotic prophylaxis may be considered before endodontic treatment in a patient with AVM. Multidisciplinary treatment planning may be required.

Prevalence of bacteraemia following dental extraction - efficacy of the prophylactic use of amoxicillin and clindamycin

OBJECTIVES

To evaluate the efficacy of single-dose antibiotic prophylaxis (AP) in the prevention of bacteraemia following tooth extractions at our clinic.

MATERIAL AND METHODS

Fifty patients undergoing tooth extractions were enrolled. The need of AP was determined according to the health status and possible allergies of the patients. Blood culture samples were collected at baseline, 5 min after the first tooth extraction and 20 min after the last extraction.

RESULTS

The majority (76%) received prophylactic oral amoxicillin or intravenous ampicillin (AMX/AMP) (2 g), 12% received clindamycin (CLI) (600 mg) and 12% received no prophylaxis (NO AP). All baseline blood cultures were reported negative. The prevalence of bacteraemia was significantly higher in the CLI and NO AP groups compared to the AMX/AMP group 5 min after the first tooth extraction (p < .0001 and p = .015, respectively). Twenty minutes after the last extraction positive blood cultures were reported only for CLI (p = .0015) and NO AP groups. There was no significant difference in the prevalence of positive blood cultures between CLI and NO AP groups.

CONCLUSIONS

Appropriately administered AMX/AMP proved its efficacy in reducing both the prevalence and duration of bacteraemia following tooth extractions whereas CLI was not effective in preventing bacteraemia following tooth extractions.

Infection of Human Dental Pulp Stromal Cells by Streptococcus mutans: Shedding Light on Bacteria Pathogenicity and Pulp Inflammation

Cariogenic Streptococcus mutans (S. mutans) is implicated in the dental pulp necrosis but also in cardiovascular tissue infections. Herein, the purpose was to elucidate how human dental pulp derived stromal cells (DPSCs) react toward a direct interaction with S. mutans. DPSCs were challenged with S. mutans. Following 3 h of interaction, DPSCs were able to internalize S. mutans (rate < 1%), and F-actin fibers played a significant role in this process. S. mutans persisted in the DPSCs for 48 h without causing a cytotoxic effect. S. mutans was, however, able to get out of the DPSCs cytoplasm and to proliferate in the extracellular environment. Yet, we noticed several adaptive responses of bacteria to the extracellular environment such as a modification of the kinetic growth, the increase in biofilm formation on type I collagen and polyester fabrics, as well as a tolerance toward amoxicillin. In response to infection, DPSCs adopted a proinflammatory profile by increasing the secretion of IL-8, lL-1β, and TNF-α, strengthening the establishment of the dental pulp inflammation. Overall, these findings showed a direct impact of S. mutans on DPSCs, providing new insights into the potential role of S. mutans in infective diseases.

Executive summary of the 12th HHT international scientific conference

Hereditary hemorrhagic telangiectasia is an autosomal dominant trait affecting approximately 1 in 5000 people. A pathogenic DNA sequence variant in the ENG, ACVRL1 or SMAD4 genes, can be found in the majority of patients. The 12th International Scientific HHT Conference was held on June 8-11, 2017 in Dubrovnik, Croatia to present and discuss the latest scientific achievements, and was attended by over 200 scientific and clinical researchers. In total 174 abstracts were accepted of which 58 were selected for oral presentations. This article covers the basic science and clinical talks, and discussions from three theme-based workshops. We focus on significant emergent themes and unanswered questions. Understanding these topics and answering these questions will help to define the future of HHT research and therapeutics, and ultimately bring us closer to a cure.

Impact of antibiotic prophylaxis on the incidence, nature, magnitude, and duration of bacteremia associated with dental procedures: A systematic review

BACKGROUND

Antibiotic prophylaxis (AP) is used routinely in high-risk groups of patients to reduce bacteremia and the risk of developing infective endocarditis (IE). In this systematic review, the authors evaluated the efficacy of AP on the incidence, nature, magnitude, and duration of post-dental procedure bacteremia.

METHODS

The authors conducted a systematic search of the literature using MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials up to and including May 2019. They included randomized clinical trials in which researchers compared antibiotics with a placebo or no treatment (as the control). They undertook random-effects meta-analyses to evaluate the incidence of bacteremia after dental procedures.

RESULTS

The authors included 12 studies in the review. The studies evaluated the incidence of bacteremia after AP with American Heart Association (AHA) protocol antibiotics (amoxicillin, clindamycin, cephalosporin, and azithromycin) or non-AHA protocol antibiotics (moxifloxacin and intravenous [IV] amoxicillin-clavulanic acid). The pooled analysis revealed that antibiotics significantly reduced the bacteremia incidence, but their effectiveness was moderate (risk ratio, 0.50; 95% confidence interval, 0.38 to 0.67). IV amoxicillin-clavulanic acid promoted a considerable reduction in bacteremia. However, in patients with penicillin allergies, antibiotics (that is, clindamycin and cephalosporin) had lower efficacy.

PRACTICAL IMPLICATIONS

Oral amoxicillin is still the antibiotic of choice to reduce bacteremia. IV amoxicillin-clavulanic acid could be used for patients at high risk of developing IE who require invasive dental procedures, have high levels of dental infection, and are to be treated under general anesthesia. In patients with penicillin allergies, oral azithromycin showed a higher efficacy for the reduction of bacteremia and the use of clindamycin should be reviewed. Antibiotic premedication should be limited to patients at high risk of developing IE, according to the indications of the AHA guide.

Prevention of Postdental Procedure Bacteremia: A Network Meta-analysis

Postdental procedure bacteremia is common and troublesome. The comparative efficacy of multiple prophylactic interventions is unclear. We compared the efficacy of interventions for the prevention of postdental procedure bacteremia. We conducted a review of ClinicalKey, Cochrane CENTRAL, Embase, ProQuest, PubMed, ScienceDirect, Web of Science, and ClinicalTrials.gov from inception to December 4, 2018. Randomized controlled trials that evaluated prophylactic interventions for the prevention of postdental procedure bacteremia were eligible. The primary outcome was the incidence of postdental procedure bacteremia. A total of 24 trials were included with 2,147 participants. Our network meta-analysis demonstrated that intravenous administration of 1,000/200 mg of amoxicillin/clavulanate provided the least incidence of postdental procedure bacteremia among all the prophylactic interventions (odds ratio = 0.03, 95% CI = 0.00 to 0.63) as compared with the placebo/controls. Oral 3 g of amoxicillin had the least incidence of postdental procedure bacteremia among all oral or topical forms of prophylactic interventions (odds ratio = 0.10, 95% CI = 0.02 to 0.44) as compared with the placebo/controls. No serious adverse events, such as anaphylactic shock, mortality, and the development of antibiotic-resistant bacteria, were reported. None of the included subjects were of high risk of infectious endocarditis. Our network meta-analysis demonstrates that intravenous amoxicillin/clavulanate and oral amoxicillin might be the best prophylactic interventions in preventing postdental procedure bacteremia among all the oral/topical forms of interventions for the overall populations.

Prevention of infective endocarditis and bacterial resistance to antibiotics: A brief review

The purpose of this statement is to debate the recommendations of the American Heart Association (AHA) for the prevention of infective endocarditis through an antibiotic prophylaxis protocol and its relation with bacterial resistance to antibiotics. Since dental infections involve biofilms that include several bacterial species (Gram-negative and Gram-positive), it is essential, from the dental point of view, to consider the frequency, magnitude, and duration of bacteremia associated with active dental infections before applying antibiotic prophylaxis. The actual guidelines for antibiotic prophylaxis should be revised according to recent evidence of bacterial resistance. Amoxicillin/clavulanic acid and moxifloxacin should be considered due to their effectiveness against bacteria associated with oral, GU, and GI infections and the low rates of antibiotic resistance associated with these antibiotics, instead of the actual protocol, which includes amoxicillin (2 g) or clindamycin (600 mg) administered an hour before the dental procedures. The breaking point to test the antibiotic bacterial resistance (ABR) had a wide range in the different studies that were analyzed, which could explain the widely varied ABR percentages reported for the various antibiotics used for antibiotic prophylaxis.

Microbial stability of syringes of anesthetic drugs prepared in the operating room

STUDY OBJECTIVE

To determine whether microbial contamination of anesthesia syringes prepared in the operating room (OR) become contaminated in a time-dependent fashion.

DESIGN

Observational.

SETTING

Operating suite in a major university hospital.

PATIENTS

None (in vitro study). 400 syringes were studied for microbial contamination.

INTERVENTIONS

Syringes prepared in the OR by anesthesia personnel were sampled at 1, 2, 3, or 4 h in a sterile fashion and sent to the microbiology laboratory for quantitative culture of any bacteria.

MEASUREMENTS

Colony forming units (CFU) per mL of drug were calculated and any identified positive cultures were identified by Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry. Logistic regression was used to test the effect of time since preparation on prevalence of positive culture, as was the effect of number of accesses of the syringe and identity of the drug.

MAIN RESULTS

Overall, 9/400 (2.25%) syringes were positive for bacteria. The median (interquartile range [IQR]) concentration of bacteria among positive cultures was 100 (100,100) CFU. All cultured species were generally nonpathogenic common contaminants. There was no effect of time since preparation, number of accesses of the syringe at the time of sampling, or drug identity (propofol vs. other).

CONCLUSIONS

Contamination of anesthesia syringes is uncommon and occurs at a low overall concentration of bacteria. Contamination does not appear to be time related, and thus calls into question the reasonableness of USP Chapter 797's one-hour requirement.

European Reference Network For Rare Vascular Diseases (VASCERN) Outcome Measures For Hereditary Haemorrhagic Telangiectasia (HHT)

Hereditary haemorrhagic telangiectasia (HHT) is a multisystemic vascular dysplasia that leads to nosebleeds, anaemia due to blood loss, and arteriovenous malformations (AVMs) in organs such as the lungs, liver and brain. HHT is estimated to affect 85,000 European citizens, but most health care providers have limited prior HHT exposure or training.

Outcome Measures were developed and implemented by the HHT Working Group of the European Reference Network for Rare Vascular Diseases (VASCERN), in order to maximise the number of patients receiving good care. The measures specifically target areas where optimal management reduces morbidity and mortality in HHT patients, and were designed to be robust to emerging new evidence. Thresholds are the percentage of patients in particular settings who have been recommended screening, or provided with written advice. The 5 Outcome Measures cover (1) pulmonary AVM screening; (2) written nosebleed advice, (3) assessment of iron deficiency; (4) antibiotic prophylaxis prior to dental and surgical procedures for patients with pulmonary AVMs, and (5) written advice on pregnancy. They are not a blueprint for detailed HHT management, but are suitable for all clinicians to be aware of and implement.

In summary, these 5 Outcome Measures provide metrics to identify healthcare providers of good care, and encourage care improvement by all healthcare providers.

Cerebral Abscess Associated With Odontogenic Bacteremias, Hypoxemia, and Iron Loading in Immunocompetent Patients With Right-to-Left Shunting Through Pulmonary Arteriovenous Malformations

Background

Cerebral abscess is a recognized complication of pulmonary arteriovenous malformations (PAVMs) that allow systemic venous blood to bypass the pulmonary capillary bed through anatomic right-to-left shunts. Broader implications and mechanisms remain poorly explored.

Methods

Between June 2005 and December 2016, at a single institution, 445 consecutive adult patients with computed tomography–confirmed PAVMs (including 403 [90.5%] with hereditary hemorrhagic telangiectasia) were recruited to a prospective series. Multivariate logistic regression was performed and detailed periabscess histories were evaluated to identify potential associations with cerebral abscess. Rates were compared to an earlier nonoverlapping series.

Results

Thirty-seven of the 445 (8.3%) patients experienced a cerebral abscess at a median age of 50 years (range, 19–76 years). The rate adjusted for ascertainment bias was 27 of 435 (6.2%). Twenty-nine of 37 (78.4%) patients with abscess had no PAVM diagnosis prior to their abscess, a rate unchanged from earlier UK series. Twenty-one of 37 (56.7%) suffered residual neurological deficits (most commonly memory/cognition impairment), hemiparesis, and visual defects. Isolation of periodontal microbes, and precipitating dental and other interventional events, emphasized potential sources of endovascular inoculations. In multivariate logistic regression, cerebral abscess was associated with low oxygen saturation (indicating greater right-to-left shunting); higher transferrin iron saturation index; intravenous iron use for anemia (adjusted odds ratio, 5.4 [95% confidence interval, 1.4–21.1]); male sex; and venous thromboemboli. There were no relationships with anatomic attributes of PAVMs, or red cell indices often increased due to secondary polycythemia.

Conclusions

Greater appreciation of the risk of cerebral abscess in undiagnosed PAVMs is required. Lower oxygen saturation and intravenous iron may be modifiable risk factors.

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.

The Lung in Hereditary Hemorrhagic Telangiectasia

Hereditary hemorrhagic telangiectasia (HHT) is a dominantly inherited genetic vascular disorder with an estimated prevalence of 1 in 6,000, characterized by recurrent epistaxis, cutaneous telangiectasia, and arteriovenous malformations (AVMs) that affect many organs including the lungs, gastrointestinal tract, liver, and brain. Its diagnosis is based on the Curaçao criteria, and is considered definite if at least 3 of the 4 following criteria are fulfilled: (1) spontaneous and recurrent epistaxis, (2) telangiectasia, (3) a family history, and (4) pulmonary, liver, cerebral, spinal, or gastrointestinal AVMs. The focus of this review is on delineating how HHT affects the lung.