Isotropic finishing of austempered iron casting cylindrical parts by roller burnishing

Roller burnishing technique to achieve isotropic surface topography on cylindrical components made of austempered ductile iron (ADI) casting is presented in this paper. In the last years, ADI casting components are used in many mechanical applications, due to their enhanced mechanical properties. ADI castings are difficult-to-cut materials; therefore, advanced techniques to improve manufacturing productivity are necessary and under research. On the other hand, spiral roughness pattern produced by turning operation is a common source of unconformities in several applications. Turning produces a defined kinematic pattern, similar to a thread. This work presents a theoretical and experimental validation using different burnishing conditions. Roughness and surface topography and surface integrity were checked. Results show that the technique greatly improves surface roughness, and eliminates the kinematic-driven roughness pattern of turning, leading to a more isotropic finishing. A comparison between roller burnishing and ball burnishing is also presented in this paper.

Accuracy of the clinical pulmonary infection score to differentiate ventilator-associated tracheobronchitis from ventilator-associated pneumonia

BACKGROUND

Differentiating Ventilator-Associated Tracheobronchitis (VAT) from Ventilator-Associated Pneumonia (VAP) may be challenging for clinicians, yet their management currently differs. In this study, we evaluated the accuracy of the Clinical Pulmonary Infection Score (CPIS) to differentiate VAT and VAP.

METHODS

We performed a retrospective analysis based on the data from 2 independent prospective cohorts. Patients of the TAVeM database with a diagnosis of VAT (n = 320) or VAP (n = 369) were included in the derivation cohort. Patients admitted to the Intensive Care Centre of Lille University Hospital between January 1, 2016 and December 31, 2017 who had a diagnosis of VAT (n = 70) or VAP (n = 139) were included in the validation cohort. The accuracy of the CPIS to differentiate VAT from VAP was assessed within the 2 cohorts by calculating sensitivity and specificity values, establishing the ROC curves and choosing the best threshold according to the Youden index.

RESULTS

The areas under ROC curves of CPIS to differentiate VAT from VAP were calculated at 0.76 (95% CI [0.72-0.79]) in the derivation cohort and 0.67 (95% CI [0.6-0.75]) in the validation cohort. A CPIS value ≥ 7 was associated with the highest Youden index in both cohorts. With this cut-off, sensitivity and specificity were respectively found at 0.51 and 0.88 in the derivation cohort, and at 0.45 and 0.89 in the validation cohort.

CONCLUSIONS

A CPIS value ≥ 7 reproducibly allowed to differentiate VAT from VAP with high specificity and PPV and moderate sensitivity and NPV in our derivation and validation cohorts.

Aspiration Risk Factors, Microbiology, and Empiric Antibiotics for Patients Hospitalized With Community-Acquired Pneumonia

BACKGROUND

Aspiration community-acquired pneumonia (ACAP) and community-acquired pneumonia (CAP) in patients with aspiration risk factors (AspRFs) are infections associated with anaerobes, but limited evidence suggests their pathogenic role.

RESEARCH QUESTION

What are the aspiration risk factors, microbiology patterns, and empiric anti-anaerobic use in patients hospitalized with CAP?

STUDY DESIGN AND METHODS

This is a secondary analysis of GLIMP, an international, multicenter, point-prevalence study of adults hospitalized with CAP. Patients were stratified into three groups: (1) ACAP, (2) CAP/AspRF+ (CAP with AspRF), and (3) CAP/AspRF- (CAP without AspRF). Data on demographics, comorbidities, microbiological results, and anti-anaerobic antibiotics were analyzed in all groups. Patients were further stratified in severe and nonsevere CAP groups.

RESULTS

We enrolled 2,606 patients with CAP, of which 193 (7.4%) had ACAP. Risk factors independently associated with ACAP were male, bedridden, underweight, a nursing home resident, and having a history of stroke, dementia, mental illness, and enteral tube feeding. Among non-ACAP patients, 1,709 (70.8%) had CAP/AspRF+ and 704 (29.2%) had CAP/AspRF-. Microbiology patterns including anaerobes were similar between CAP/AspRF-, CAP/AspRF+ and ACAP (0.0% vs 1.03% vs 1.64%). Patients with severe ACAP had higher rates of total gram-negative bacteria (64.3% vs 44.3% vs 33.3%, P = .021) and lower rates of total gram-positive bacteria (7.1% vs 38.1% vs 50.0%, P < .001) when compared with patients with severe CAP/AspRF+ and severe CAP/AspRF-, respectively. Most patients (>50% in all groups) independent of AspRFs or ACAP received specific or broad-spectrum anti-anaerobic coverage antibiotics.

INTERPRETATION

Hospitalized patients with ACAP or CAP/AspRF+ had similar anaerobic flora compared with patients without aspiration risk factors. Gram-negative bacteria were more prevalent in patients with severe ACAP. Despite having similar microbiological flora between groups, a large proportion of CAP patients received anti-anaerobic antibiotic coverage.

Ceftolozane and tazobactam for the treatment of hospital acquired pneumonia

INTRODUCTION

Patients admitted to hospitals are at risk of developing nosocomial infections. These types of infections typically occur in immune-compromised patients. Furthermore, nosocomial infections are frequently caused by resistant organisms, including nonfermenting gram-negative bacilli such as Pseudomonas aeruginosa.

AREAS COVERED

P. aeruginosa is a hazardous pathogen. It can resist numerous antibiotics, due to several resistance mechanisms. It is associated with serious illnesses, particularly hospital-acquired infections including ventilator-associated pneumonia. In the past, only a limited number of anti-pseudomonal drugs were available. However, several therapeutic advancements have been made, in recent years, to target P. aeruginosa, including the development of the new cephalosporin: ceftolozane-tazobactam.

EXPERT OPINION

Ceftolozane-tazobactam is a combination of a novel semi-synthetic fifth-generation cephalosporin with a well-established beta-lactamase inhibitor. From a structural perspective, ceftolozane-tazobactam has attested increased stability to AmpC β-lactamases. Additionally, ceftolozane-tazobactam is less affected by changes in efflux pumps and porin permeability due to an enhanced affinity to certain penicillin-binding proteins (PBPs). This enables the molecule to overcome the most common anti-drug resistant mechanisms of bacteria. According to previous clinical trials conducted, ceftolozane-tazobactam must be considered when treating patients with confirmed or suspected P. aeruginosa respiratory tract infections, either nosocomial pneumonia or ventilator-associated pneumonia.

Comparison of two different oocyte vitrification methods: a prospective, paired study on the same genetic background and stimulation protocol

STUDY QUESTION

Can two different methods for oocyte vitrification, one using an open tool and the other a closed tool, result in similar oocyte survival rates?

SUMMARY ANSWER

The oocyte survival rate was found to be higher in the closed method.

WHAT IS KNOWN ALREADY

Open vitrification is performed routinely in oocyte donation cycles. Closed oocyte vitrification may result in slower cooling rates and thus it is less used, even though it has been recommended in order to avoid the risk of cross-contamination between material from different patients.

STUDY DESIGN, SIZE, DURATION

This is a prospective cohort study with sibling oocytes carried out in a fertility center between July 2014 and January 2016. The study included 83 oocyte donors each providing a minimum of 12 mature oocytes (metaphase II: MII) at oocyte retrieval. Oocyte survival rate and fertilization rate, as well as reproductive outcomes (biochemical, clinical, ongoing pregnancy and live birth rates) per embryo transfer and also cumulatively between the two methods were compared by Chi2 tests.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Donor oocytes were denuded and six MII oocytes from each donor were vitrified using an open method and later assigned to one recipient, while another six MII oocytes were vitrified using a closed method and assigned to a different recipient (paired analysis). ICSI was used in all cases and embryo transfer was performed on Day 2-3 in all cases.

MAIN RESULTS AND THE ROLE OF CHANCE

Oocyte donors were 24.8 years old on average (SD 4.7). Recipient age (average 41.2 years, SD 4.7) and BMI (mean 23.8 kg/m2, SD 4.0) were similar between recipient groups. Oocytes vitrified using the closed method had higher survival rate (94.5% versus 88.9%, P = 0.002), but lower fertilization rate (57.1% versus 69.8%, P < 0.001) compared to the open method. The number of fresh embryos transferred in the two groups was 1.8 on average (SD 0.4). Biochemical (45% closed versus 50% open), clinical (40% versus 50%) and ongoing (37.5% versus 42.5%) pregnancy rates were not different between groups (P > 0.05) and neither were live birth rates (37.5% versus 42.5%, P > 0.05). Cumulative reproductive results (obtained after the transfer of all the embryos) were also similar between groups.

LIMITATIONS, REASONS FOR CAUTION

The participants of this study were oocyte donors, i.e. young women in good health, and care should be exerted in extending our results to other populations such as infertility patients, oncofertility patients and women freezing oocytes to delay childbearing.

WIDER IMPLICATIONS OF THE FINDINGS

Our results suggest that, in spite of different survival and fertilization rates, closed and open oocyte vitrification methods should offer similar reproductive outcomes up to cumulative live birth rates.

STUDY FUNDING/COMPETING INTEREST(S)

The authors report no conflict of interest. Vitrolife provided the media and the closed method tool needed for the study at no cost.

Complex Destabilization in the Mitochondrial Chaperonin Hsp60 Leads to Disease

Several neurological disorders have been linked to mutations in chaperonin genes and more specifically to the HSPD1 gene. In humans, HSPD1 encodes the mitochondrial Heat Shock Protein 60 (mtHsp60) chaperonin, which carries out essential protein folding reactions that help maintain mitochondrial and cellular homeostasis. It functions as a macromolecular complex that provides client proteins an environment that favors proper folding in an ATP-dependent manner. It has been established that mtHsp60 plays a crucial role in the proper folding of mitochondrial proteins involved in ATP producing pathways. Recently, various single-point mutations in the mtHsp60 encoding gene have been directly linked to neuropathies and paraplegias. Individuals who harbor mtHsp60 mutations that negatively impact its folding ability display phenotypes with highly compromised muscle and neuron cells. Carriers of these mutations usually develop neuropathies and paraplegias at different stages of their lives mainly characterized by leg stiffness and weakness as well as degeneration of spinal cord nerves. These phenotypes are likely due to hindered energy producing pathways involved in cellular respiration resulting in ATP deprived cells. Although the complete protein folding mechanism of mtHsp60 is not well understood, recent work suggests that several of these mutations act by destabilizing the oligomeric stability of mtHsp60. Here, we discuss recent studies that highlight key aspects of the mtHsp60 mechanism with a focus on some of the known disease-causing point mutations, D29G and V98I, and their effect on the protein folding reaction cycle.

Clinical risk factors for early mortality in patients with community-acquired septic shock. The importance of adequate source control

OBJECTIVE

To evaluate the incidence and risk factors for early mortality (EM) in the ICU in patients with community-acquired septic shock (CASS).

DESIGN

A retrospective cohort study of patients with CASS admitted to the ICU (2003-2016).

SETTING

ICU at a University Hospital in Spain.

PATIENTS

All consecutive patients admitted to the ICU with CASS.

INTERVENTIONS

None.

MAIN VARIABLES OF INTEREST

CASS was defined according to the Sepsis-3 definitions. EM were defined as occurring within of 72h following ICU admission. A multinomial logistic regression analysis was performed to identify the risk factors associated with early deaths.

RESULTS

During the study period, 625 patients met the Sepsis-3 criteria and admitted with CASS. 14.4% of all patients died within the first 72h. Of 161 patients who died in the ICU, 90 (55.9%) died within the first 72h. The percentage of early and late mortality did not vary significantly during the study period. The need and adequacy of source control were significantly lower in patients with EM. In the multivariate analysis, ARDS, non-respiratory infections, bacteremia and severity at admission were variables independently associated with EM. The only factor that decreased EM was adequate source control in patients with infections amenable to source control.

CONCLUSIONS

The incidence of EM has remained stable over time, which means that more than half of the patients who die from CASS do so within the first 72h. Infections where adequate source control can be performed have lower EM.

Validation of Delphi procedure consensus criteria for defining fetal growth restriction

OBJECTIVE

Recently, a Delphi procedure was used to establish new criteria for defining fetal growth restriction (FGR). These criteria require clinical validation. We sought to validate the Delphi consensus criteria by comparing their performance with that of our current definition (estimated fetal weight (EFW) < 10^th percentile) in predicting adverse neonatal outcome (ANO).

METHODS

This was a secondary analysis of data from a prospective cohort study of women referred for fetal growth assessment between 26 and 36 weeks' gestation. The current standard definition of FGR used in our clinical practice is EFW < 10^th percentile using Hadlock's fetal growth standard. The Delphi consensus criteria for FGR include either a very small fetus (abdominal circumference (AC) or EFW < 3^rd percentile) or a small fetus (AC or EFW < 10^th percentile) with additional abnormal Doppler findings or a decrease in AC or EFW by two quartiles or more. The primary outcome was the prediction of a composite of ANO including one or more of: admission to the neonatal intensive care unit, cord pH < 7.1, 5-min Apgar score < 7, respiratory distress syndrome, intraventricular hemorrhage, neonatal seizures or neonatal death. The discriminatory capacities of the two definitions of FGR for composite ANO and delivery of a small-for-gestational-age (SGA) neonate, defined as birth weight < 10^th percentile, were compared using area under the receiver-operating-characteristics curve (AUC). The sensitivity, specificity and predictive values of the methods were also compared.

RESULTS

Of 1055 pregnancies included in the study, composite ANO occurred in 139 (13.2%). There were only two cases of early FGR (before 32 weeks); therefore, the study focused on late FGR. Our current FGR diagnostic criterion of EFW < 10^th percentile was not associated significantly with composite ANO (relative risk (RR), 1.1 (95% CI, 0.6-1.8)), while the Delphi FGR criteria were (RR, 2.0 (95% CI, 1.2-3.3)). Our current definition of FGR showed higher discriminatory ability in the prediction of a SGA neonate (AUC, 0.69 (95% CI, 0.65-0.73)) than did the Delphi definition (AUC, 0.64 (95% CI, 0.60-0.67)) (P = 0.001). The AUCs of both definitions were poor for the prediction of composite ANO, despite slightly improved performance using the Delphi consensus definition of FGR (AUC, 0.53 (95% CI, 0.50-0.55)) compared with that of our current definition (AUC, 0.50 (95% CI, 0.48-0.53)) (P = 0.02).

CONCLUSION

The newly postulated criteria for defining FGR based on a Delphi procedure detects fewer cases of neonatal SGA than does our current definition of EFW < 10^th percentile, but is associated with a slight improvement in predicting ANO. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

Update of the treatment of nosocomial pneumonia in the ICU

In accordance with the recommendations of, amongst others, the Surviving Sepsis Campaign and the recently published European treatment guidelines for hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP), in the event of a patient with such infections, empirical antibiotic treatment must be appropriate and administered as early as possible. The aim of this manuscript is to update treatment protocols by reviewing recently published studies on the treatment of nosocomial pneumonia in the critically ill patients that require invasive respiratory support and patients with HAP from hospital wards that require invasive mechanical ventilation. An interdisciplinary group of experts, comprising specialists in anaesthesia and resuscitation and in intensive care medicine, updated the epidemiology and antimicrobial resistance and established clinical management priorities based on patients' risk factors. Implementation of rapid diagnostic microbiological techniques available and the new antibiotics recently added to the therapeutic arsenal has been reviewed and updated. After analysis of the categories outlined, some recommendations were suggested, and an algorithm to update empirical and targeted treatment in critically ill patients has also been designed. These aspects are key to improve VAP outcomes because of the severity of patients and possible acquisition of multidrug-resistant organisms (MDROs).

Exploring the pros and cons of new approaches for gamete cross-border donation based on fresh and vitrified oocytes

As highlighted by European statistics, the employment of donor oocytes is a growing option for women who cannot make use of their own gametes. As the potential recipients are continuously increasing in number, a donor programme which satisfies this demand is mandatory. Improvements in cryopreservation techniques, like oocyte and embryo vitrification, have led to the overcoming of the sequence of stimulation-retrieval-transfer both from a spatial and a temporal point of view, with the development of cryobanks of oocytes permitting crossborder donation. However, while some studies report comparable success when using vitrified and fresh oocytes we still need to investigate whether the use of fresh oocytes give higher live birth rate than cryopreserved ones, when the same number of oocytes are given. The performance of embryo cryopreservation, conversely, seems to be more reliable. A novel approach based on the shipment of frozen sperm from the recipient's country to the oocyte donor's one, where fresh oocytes are inseminated and the resulting embryos frozen and transported back to the referring IVF centre to perform a frozen embryo transfer may be a good strategy. We believe that the use of frozen embryos from fresh oocytes could be associated with a higher cumulative live birth rate per cycle, while favouring personalised oocyte recipient care with a flexible number of oocytes assigned and limiting the burden of travelling abroad.

THU0517 THE ROLE OF ULTRASOUND-DEFINED SYNOVITIS GRADE I IN PATIENTS PRESENTING WITH INFLAMMATORY ARTHRALGIA, A RETROSPECTIVE STUDY

Background:

Musculoeskeletal ultrasound (MSUS) is frequently used in several rheumatology units to detect subclinical inflammation in patients with joint symptoms suspected for progression to inflammatory arthritis (IA). Synovitis grade I (EULAR-OMERACT combined score) is known to be a casual finding in healthy individuals, but studies headed to unravel its possible role on rheumatic diseases are sparse.

Objectives:

To investigate the correlation between synovitis grade I, and the diagnosis of IA made after a year follow-up period since MSUS findings, in patients of an MSUS-specialized unit of a Rheumatology Department.

Methods:

We conducted a descriptive, retrospective and unicentric study. 30 patients were selected from the MSUS-specialized unit of our Rheumatology Department from July-18 to January-19. Patients presenting synovitis grade 0 (exclusively), 2 and/or 3 on combined score were excluded. Data collection at baseline included age, sex, immunological profile and previous physical examination to the MSUS findings, as well as the diagnosis made by the rheumatologist in 1-year visit follow-up: dividing the patient sample into two groups: those who were diagnosed with IA and those not. Non-parametric statistical tests for comparing means were used.

Results:

The mean age was 51,6 years and 70% were females. 6 (20%) patients were diagnosed with inflammatory arthritis after a year follow-up: 2 (4,8%) psoriatic arthritis, 1 (3,3%) undifferentiated arthritis, 1 (3,3%) rheumatoid arthritis, 1 (3,3%) Sjögren’s syndrome. Non-inflammatory arthropathies were also found 24 (80%), of which, 12 (40%) were non-specific arthralgias and 8 (19%) osteoarthritis.

In the group of patients who did not developed an IA the mean C-reactive protein (CPR) value was 3,12 mg/L and erythrocyte sedimentation rate (ESR) was 8,2 mm; all of them were rheumatoid factor (RF) positive and ACPA-negative except one patient. 5 (31,3%) patients presented low antinuclear antibodies (ANAs) levels. In those who HLA B-27 and Cw6 were tested (4,25%); both were negative except for one that was HLA B-27 positive. The median number of swollen and painful joint count was 0, and the mean of joints with MSUS involvement was 3,5; the mean involved metacarpophalangeal (MCP) joints was 1,83; proximal interphalangeal (PIP) joints was 1,48 and distal interphalangeal (DIP) joints 0,21.

Among the group of patients that developed an IA the mean of CPR and ESR was 9,27 mg/L and 14,17 mm respectively; 2 (33%) patients were RF- positive, and 1 ACPA-positive. ANAs were positive in 3 cases (50%). The median of swollen joint count was 2 and for painful joint count was 0, the median of joints with MSUS involvement was 4,5. The mean of MSUS involvement was for MCP, PIP and DIP joints: 1,67, 2 and 0. Comparing the means of CPR values in the two groups with Student’s t-test we obtained a statistically significant difference (p=0,023). No other significant differences were found.

Conclusion:

Despite the limitations and possible statistical bias, the presence of MSUS-defined synovitis grade I and elevated CRP levels could be related to further diagnoses of inflammatory arthropathy. Besides, the absence of synovitis in DIP joints might have a diagnostic role. Normal physical exploration and normal levels of CRP might suggest low MSUS value. However, further research is needed to clarify the role of MSUS-defined synovitis grade I.

References:

[1]D’Agostino MA et al. Scoring ultrasound synovitis in rheumatoid arthritis: a EULAR-OMERACT ultrasound taskforce-Part 1: definition and development of a standardized, consensus-based scoring system. RMD Open. 2017;3(1):e000428.

[2]Van den Berg R et al. What is the value of musculoskeletal ultrasound in patients presenting with arthralgia to predict inflammatory arthritis development? A systematic literature review. Arthritis Research & Therapy (2018) 20:228.

Disclosure of Interests:

None declared

Community-based oral health interventions for people experiencing homelessness: a scoping review

OBJECTIVE

To determine the characteristics of community-based oral health interventions for people experiencing homelessness.

BASIC RESEARCH DESIGN

A scoping review was conducted, adhering to the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses: Scoping Reviews) checklist. A search strategy was developed using MeSH terms and key words, and used to search the following electronic databases: Medline/PubMed, CINAHL, ProQuest Assia, Scopus, Web of Science and PsychNet. Key journals and reference lists were also hand-searched. Two reviewers then read the abstracts of all papers, excluding duplicates and papers that did not meet the eligibility criteria. The reviewers then read to full-texts of the studies to be included in the review.

RESULTS

Eighteen studies met the inclusion criteria and were included in the study. These studies were predominantly evaluations of community-based dental services or other oral health interventions. Several recommendations were extracted. Interventions should involve co-design with homeless service users; multidisciplinary working, collaboration with dental practitioners, and working with educational establishments. The location of community-based services was also found to be of importance.

CONCLUSION

This review has highlighted several recommendations, as well as gaps in the literature. These gaps suggest a need for more non-clinical oral health interventions for the homeless population, and a closer look at the role that non-dental practitioners can play in the delivery of oral health care.

Serum levels of neutrophil Gelatinase associated Lipocalin (NGAL) predicts hemodialysis after coronary angiography in high risk patients with acute coronary syndrome

Background

Contrast-induced nephropathy (CIN) following a percutaneous coronary intervention (PCI) is the third most common cause of acute kidney injury (AKI) worldwide. Patients who require hemodialysis secondary to CIN have an elevated mortality rate as high as 55%. The current definition of CIN is based on an elevation of creatinine and decrease in urinary output. Creatinine typically increases 48 h after the contrast exposure, which delays the diagnosis and treatment of CIN. The neutrophil gelatinase associated lipocalin (NGAL) has emerged as a sensitive and specific biomarker of renal injury. Limited data exists about the effectiveness of NGAL to predict CIN in high-risk patients with acute coronary syndrome (ACS) that underwent PCI. The primary aim of this study was to determine the association of serum NGAL levels and the need for hemodialysis after PCI.

Methods

This is a prospective, observational study. NGAL levels were measured using ELISA. Blood samples were obtained within the first 6 h of hospital admission, and 12 and 24 h after contrast exposure from angiography. The primary outcome was the requirement of hemodialysis. The non-parametric Mann-Whitney U test was used to test for differences in median serum levels of NGAL. A receiver operating characteristic (ROC) curve was developed to assess the accuracy of NGAL to predict the need for hemodialysis after PCI.

Results

A total of 2875 were screened; however, 45 patients with ACS that underwent PCI were included. All patients were at high risk of developing CIN defined by Mehran score > 11 points. The median (IQR) serum concentration of NGAL was significantly higher in patients that required versus did not require hemodialysis (340 [83–384] vs. 169 [100–210], p = 0.01). Elevated serum levels of NGAL with a cut-off at 6 h post PCI of 281 mg/dL predicted the need for hemodialysis with an area under the curve of 0.86 (95% CI, 0.66–1.00).

Conclusions

In patients with ACS undergoing PCI; and high risk of developing CIN, an elevated serum level of NGAL 6 h after contrast exposure predicts the development of acute kidney injury requiring hemodialysis.

P772 Percutaneous transcatheter patent foramen ovale closure: does size really matter?

Introduction

Patent foramen ovale (PFO) has been associated with cryptogenic stroke. Percutaneous transcatheter PFO closure has been in development for the last years. In recent studies, it has shown a reduction of recurrent ischemic stroke events. Several manufactures of PFO device closure have developed guidelines for selection of device size based on anatomic measurements obtained through echocardiography. A study showed that according to the guidelines few patients had adequate tissue rim to allow device implantation, and yet almost all the patients had an effective closure.

Purpose and methods

The aim of this study was to evaluate the characteristics of PFO with transesophageal echocardiogram (TEE) (size, distance between foramen ovale-superior vena cava (FO-SVC) and distance between FO-aortic annulus (FO-AoAn)) and to determinate the correlation between the size of PFO device implanted and the theoretical device size according to the guidelines.

We performed a retrospective study among patients who underwent a PFO closure procedure between 2006 and 2018.

Results

42 patients were included, 55% male, mean age 56 years and mean BSA 1,83 m². The PFO mean diameter and length were 3 and 13 mm respectively. The majority of PFO were complex: 91% of patients had defects larger than 8mm and 36% had atrial septum aneurism. Characteristic of PFO were measured (Table). In older patients the distance between PFO-SVC and PFO-AoAn was larger and the septum secundum was thicker (p 0.02). The right-to-left shunt was moderated or severe in most cases (75%). The PFO closure device was successfully implanted in all patients. The majority of them received an Amplatzer PFO device (45%) followed by an Hyperion PFO device. The size of the device was 25mm in half of the patients followed by 30mm device. According to the guidelines, in 67% of the cases the wrong size was chosen and the mean size of the device should had been 30mm (SD ±5,2). TEE examination during follow up showed no residual or mild residual shunt in 80% of the patients. Residual shunt was more prevalent with larger devices (p 0.008)

Conclusions

These results showed that the size of PFO closure device implanted in our population differed from the size recommended by guidelines. Smaller devices have been used. According to our results, larger devices are associated with more residual shunt, which suggests that a different approach may be necessary to establish new protocols for PFO device closure

Table Minimal Maximal Mean SD SVC (mm) 10 30 17.55 ±3,7 AoAn (mm) 9 23 14.1 ±3,5 Minimal and maximal distance between PFO-SVC and AoAn

Determining the Efficacy of Liquid Sporicides Against Spores of Bacillus subtilis on a Hard Nonporous Surface Using the Quantitative Three Step Method: Collaborative Study

A collaborative study was conducted to validate the quantitative Three Step Method (TSM), a method designed to measure the performance of liquid sporicides on a hard nonporous surface. Ten laboratories agreed to participate in the collaborative study; data from 8 of 10 participating laboratories were used in the final statistical analysis. The TSM uses 5 5 1 mm glass coupons (carriers) upon which spores have been inoculated and which are introduced into liquid sporicidal agent contained in a microcentrifuge tube. Following exposure to a test chemical and a neutralization agent, spores are removed from carriers in 3 fractions: passive removal (Fraction A), sonication (Fraction B), and gentle agitation (Fraction C). Liquid from each fraction is serially diluted and plated on a recovery medium for spore enumeration. Control counts are compared to the treated counts, and the level of efficacy is determined by calculating the log10 reduction (LR) of spores. The main statistical goals were to evaluate the repeatability and reproducibility of the LR values, to estimate the components of variance for LR, and to assess method responsiveness. AOAC Method 966.04Method II was used as a reference method. The scope of the validation was limited to testing liquid formulations against spores of Bacillus subtilis, a surrogate for virulent strains of B. anthracis, on a hard nonporous surface (glass). The test chemicals used in the study were sodium hypochlorite, a combination of peracetic acid and hydrogen peroxide, and glutaraldehyde. Each test chemical was evaluated at 3 levels of presumed efficacy: high, medium, and low. Three replications were required. The TSM was validated as it successfully met the statistical parameters for quantitative test methods. Satisfactory validation parameters, such as the repeatability standard deviation (Sr) and reproducibility standard deviation (SR), were obtained for control carrier counts and LR values. Both the TSM and the reference method were responsive to the efficacy levels of the test chemicals. For the 72 total TSM tests conducted, the mean ( standard error of the mean) log density of spores per control carrier was 6.86 ( 0.08); the Sr and SR were low at 0.15 and 0.27, respectively. Across the range of test chemicals, the Sr and SR estimates associated with LR were also acceptably low. The Sr rangedfrom 0.17 to 0.72 and the SR ranged from 0.34 to 1.43. Overall, the Sr and SR estimates associated with the efficacy data were within the ranges published for other quantitative methods and meet the performance characteristics necessary for validation.

Modification to the AOAC Sporicidal Activity of Disinfectants Test (Method 966.04): Collaborative Study

In an effort to improve AOAC Method 966.04, the Sporicidal Activity of Disinfectants Test, selected modifications to the procedure were evaluated in a collaborative study. Method 966.04 is used to generate efficacy data to support the product registration of sporicides and sterilants. The method is a carrier-based test that provides a qualitative measure of product efficacy against spores of Bacillus subtilis and Clostridium sporogenes. The use of garden soil extract and the lack of standard procedures for the enumeration of spores and neutralization of the test chemicals have been considered problematic for many years. The proposed modifications were limited to the B. subtilis and hard surface carrier (porcelain penicylinder) components of the method. The study included the evaluation of a replacement for soil extract nutrient broth and an establishment of a minimum spore titer per carrier, both considered crucial for the improvement and utilization of the method. Additionally, an alternative hard surface material and a neutralization confirmation procedure were evaluated. To determine the equivalence of the proposed alternatives to the standard method, 3 medium/carrier combinations, (1) soil extract nutrient broth/porcelain carrier (current method), (2) nutrient agar amended with 5 g/mL manganese sulfate/porcelain carrier, and (3) nutrient agar amended with 5 g/mL manganese sulfate/stainless steel carrier were analyzed for carrier counts, HCl resistance, efficacy, quantitative efficacy, and spore wash-off. The test chemicals used in the study represent 3 chemical classes and are commercially available antimicrobial liquid products: sodium hypochlorite (bleach), glutaraldehyde, and a combination of peracetic acid and hydrogen peroxide. Four laboratories participated in the study. The results of the spore titer per carrier, HCl resistance, efficacy, and wash-off studies demonstrate that amended nutrient agar in conjunction with the porcelain is comparable to the current method, soil extract nutrient broth/porcelain. The nutrient agar method is simple, inexpensive, reproducible, and provides an ample supply of high quality spores. Due to the current use of porcelain carriers for testing C. sporogenes, it is advisable to retain the use of porcelain carriers until stainless steel can be evaluated as a replacement carrier material for Clostridium. The evaluation of stainless steel for Clostridium has been initiated by the Study Director. Study Director recommendations for First Action revisions are provided in a modified method.

Urbanisation and asthma in low-income and middle-income countries: a systematic review of the urban-rural differences in asthma prevalence

BACKGROUND

Urbanisation has been associated with temporal and geographical differences in asthma prevalence in low-income and middle-income countries (LMICs). However, little is known of the mechanisms by which urbanisation and asthma are associated, perhaps explained by the methodological approaches used to assess the urbanisation-asthma relationship.

OBJECTIVE

This review evaluated how epidemiological studies have assessed the relationship between asthma and urbanisation in LMICs, and explored urban/rural differences in asthma prevalence.

METHODS

Asthma studies comparing urban/rural areas, comparing cities and examining intraurban variation were assessed for eligibility. Included publications were evaluated for methodological quality and pooled OR were calculated to indicate the risk of asthma in urban over rural areas.

RESULTS

Seventy articles were included in our analysis. Sixty-three compared asthma prevalence between urban and rural areas, five compared asthma prevalence between cities and two examined intraurban variation in asthma prevalence. Urban residence was associated with a higher prevalence of asthma, regardless of asthma definition: current-wheeze OR:1.46 (95% CI:1.22 to 1.74), doctor diagnosis OR:1.89 (95% CI:1.47 to 2.41), wheeze-ever OR:1.44 (95% CI:1.15 to 1.81), self-reported asthma OR:1.77 (95% CI:1.33 to 2.35), asthma questionnaire OR:1.52 (95% CI:1.06 to 2.16) and exercise challenge OR:1.96 (95% CI:1.32 to 2.91).

CONCLUSIONS

Most evidence for the relationship between urbanisation and asthma in LMICs comes from studies comparing urban and rural areas. These studies tend to show a greater prevalence of asthma in urban compared to rural populations. However, these studies have been unable to identify which specific characteristics of the urbanisation process may be responsible. An approach to understand how different dimensions of urbanisation, using contextual household and individual indicators, is needed for a better understanding of how urbanisation affects asthma.

PROSPERO REGISTRATION NUMBER

CRD42017064470.

Positive-pressure needleless connectors did not increase rates of catheter hub colonization respecting the use of neutral-pressure needleless connectors in a prospective randomized trial

INTRODUCTION

The aim of this study was to compare the colonization rates of central venous catheter (CVC) and arterial catheter (ArtC) hubs fitted with two types of needleless connectors (NCs).

METHODS

We designed a prospective randomized study to compare rates of catheter hub colonization of CVC and ArtC hubs fitted with two types of needleless connectors: neutral-pressure NCs (NP-NCs) and positive-pressure NCs (PP-NCs) in critically ill patients. All NCs were replaced every 7 days of use.

RESULTS

We obtained 326 cultures from 146 catheters (81 CVC and 65 ArtC) in 70 patients. The total cumulative days of risk were 1250 catheter-days. Global swab cultures were positive in NP-NCs in 29/198 (14.6%) versus 17/128 (13.3%) in PP-NCs during catheter use. We did not observe any cases of CRBSI.

CONCLUSIONS

In our experience, the use of PP-NCs did not result in significantly more frequent hub colonization with respect to NP-NCs.

The association of cardiovascular failure with treatment for ventilator-associated lower respiratory tract infection

PURPOSE

Ventilator associated-lower respiratory tract infections (VA-LRTIs), either ventilator-associated pneumonia (VAP) or tracheobronchitis (VAT), accounts for most nosocomial infections in intensive care units (ICU) including. Our aim was to determine if appropriate antibiotic treatment in patients with VA-LRTI will effectively reduce mortality in patients who had cardiovascular failure.

METHODS

This was a pre-planned subanalysis of a large prospective cohort of mechanically ventilated patients for at least 48 h in eight countries in two continents. Patients with a modified Sequential Organ Failure Assessment (mSOFA) cardiovascular score of 4 (at the time of VA-LRTI diagnosis and needed be present for at least 12 h) were defined as having cardiovascular failure.

RESULTS

VA-LRTI occurred in 689 (23.2%) out of 2960 patients and 174 (25.3%) developed cardiovascular failure. Patients with cardiovascular failure had significantly higher ICU mortality than those without (58% vs. 26.8%; p < 0.001; OR 3.7; 95% CI 2.6-5.4). A propensity score analysis found that the presence of inappropriate antibiotic treatment was an independent risk factor for ICU mortality in patients without cardiovascular failure, but not in those with cardiovascular failure. When the propensity score analysis was conducted in patients with VA-LRTI, the use of appropriate antibiotic treatment conferred a survival benefit for patients without cardiovascular failure who had only VAP.

CONCLUSIONS

Patients with VA-LRTI and cardiovascular failure did not show an association to a higher ICU survival with appropriate antibiotic treatment. Additionally, we found that in patients without cardiovascular failure, appropriate antibiotic treatment conferred a survival benefit for patients only with VAP.

TRIAL REGISTRY

ClinicalTrials.gov, number NCT01791530.