Can advanced edge enhancement software improve image quality to visualise tubes, catheters and wires in digital chest radiographs?

INTRODUCTION: This study aimed to test whether Advanced Edge Enhancement (AEE) software could improve the localisation of tubes, catheters or wires, while also affecting the overall image quality in chest x-rays (CXR). METHODS: In total, 50 retrospective CXRs were included. All images were obtained utilising the Canon X-ray system (CANON/Arcoma Precision T3 DR System, Canon Europe, Amsterdam, NL) with a CXDI-810C wireless detector. A clinical image, plus three additional AEE algorithms were applied using post processing (two intensity variations 1 and 4) on all CXRs totalling 350 different images. Three radiologists evaluated the images using a subjective Absolute Visual Grading Analysis (VGA). The clinical images used in post processing were not applied as reference in the analysis. Each radiologist graded the images separately in a randomized order, with a score of three indicating suitability for diagnostic assessment. RESULTS: The three AEE algorithms contributed to an overall improvement (average 16-49%) in visualisation of tube, catheter or wire on CXR images. The Mann-Whitney U tests showed a statistically significant (p < 0.05) improvement in contrast resolution and sharpness, indicating an increased ability to differentiate tubes, wires or catheters tips from surrounding tissues. For the noise criterion, not applying any AEE algorithm showed a significantly higher homogeneity in soft tissue (p < 0.001), reducing the ability to visualise soft tissue. The high-intensity catheter algorithm was the only algorithm to achieve a statistically significant (p = 0.017) increase in the ability to differentiate pulmonary tissues of similar density. CONCLUSION: An overall improvement in the visualisation of tube, catheter and wire placement was obtained using the three AEE-algorithms. The bone and catheter algorithms showed the highest consistency, with the small structure algorithm underperforming in resolution and low contrast resolution. In general, image noise increased regardless of algorithm type or applied intensity. The AEE-algorithms should therefore be seen as a supplementary tool to the clinical image protocol, while having the potential to improve image quality to specific clinical situations. IMPLICATIONS FOR PRACTICE: AEE filtered images appear to be a supplement to the current practice of using CXRs in the diagnosis in placement of catheters, tubes and wires in the chest region. The use of AEE-algorithms has the potential to improve the daily work in clinical practice, which serves the basis for further investigation of its effect on radiographic practices.

Brote nosocomial de COVID-19 en una planta de medicina interna: probable transmisión aérea / Nosocomial outbreak of COVID-19 in an internal medicine ward: Probable airborne transmission

Antecedentes y objetivos A pesar de los datos cada vez mayores que respaldan la importancia de la transmisión aérea en la infección por el SARS-CoV-2, en la inmensa mayoría de los brotes nosocomiales descritos de COVID-19 no se ha considerado relevante. El objetivo de este estudio consiste en describir un brote nosocomial de infección por el SARS-CoV-2 cuyas características indican que la transmisión por aerosoles desempeñó un papel importante. Métodos Se trata de un análisis descriptivo de un brote nosocomial de infección por el SARS-CoV-2 en una planta de medicina interna que tuvo lugar en diciembre de 2020. Todos los casos se confirmaron mediante una PCR positiva para SARS-CoV-2. Resultados Entre el 5 y el 17 de diciembre, 21 pacientes y 44 profesionales sanitarios contrajeron una infección nosocomial por el SARS-CoV-2. De los 65 casos, 51 (78,5%) se diagnosticaron entre el 6 y el 9 de diciembre. La tasa de afectación en los pacientes fue del 80,8%. Entre los profesionales sanitarios, la tasa fue mayor en los que habían trabajado al menos una jornada laboral completa en la planta (56,3%) que en los que habían estado ocasionalmente en ella (25,8%; p=0,005). Tres días antes de detectar el primer caso positivo se identificó una avería en 2extractores de aire, que afectó a la ventilación de 3habitaciones. Dieciséis casos cursaron de forma asintomática, 48 manifestaron síntomas leves y 2 precisaron ingreso en la unidad de cuidados intensivos. Todos los casos se recuperaron finalmente. Conclusiones La elevada tasa de afectación, la naturaleza explosiva del brote y la coincidencia en el tiempo con la avería de los extractores de aire en algunas habitaciones de la planta indican que la transmisión aérea desempeñó un papel fundamental en el desarrollo del brote (AU)

Background and objectives Despite the increasing evidence supporting the importance of airborne transmission in SARS-CoV-2 infection, it has not been considered relevant in the vast majority of reported nosocomial outbreaks of COVID-19. The aim of this study is to describe a nosocomial outbreak of SARS-CoV-2 infection whose features suggest that aerosol transmission had an important role. Methods This is a descriptive analysis of a nosocomial outbreak of SARS-CoV-2 infection in an internal medicine ward that occurred in December 2020. All cases were confirmed by a positive PCR test for SARS-CoV-2. Results From December 5 to December 17, 21 patients and 44 healthcare workers developed a nosocomial SARS-CoV-2 infection. Fifty-one of the 65 cases (78.5%) were diagnosed between December 6 and 9. The attack rate in patients was 80.8%. Among workers, the attack rate was higher in those who had worked at least one full working day in the ward (56.3%) than in those who had occasionally been in the ward (25.8%, p=0.005). Three days before the first positive case was detected, 2extractor fans were found to be defective, affecting the ventilation of 3rooms. Sixteen cases were asymptomatic, 48 cases had non-severe symptoms, and 2 cases required admission to the intensive care unit. All patients eventually recovered. Conclusion The high attack rate, the explosive nature of the outbreak, and the coincidence in time with the breakdown in air extractors in some rooms of the ward suggest that airborne transmission played a key role in the development of the outbreak (AU)

Nosocomial outbreak of COVID-19 in an internal medicine ward: Probable airborne transmission.

BACKGROUND AND OBJECTIVES: Despite the increasing evidence supporting the importance of airborne transmission in SARS-CoV-2 infection, it has not been considered relevant in the vast majority of reported nosocomial outbreaks of COVID-19. The aim of this study is to describe a nosocomial outbreak of SARS-CoV-2 infection whose features suggest that aerosol transmission had an important role. METHODS: This is a descriptive analysis of a nosocomial outbreak of SARS-CoV-2 infection in an internal medicine ward that occurred in December 2020. All cases were confirmed by a positive PCR test for SARS-CoV-2. RESULTS: From December 5 to December 17, 21 patients and 44 healthcare workers (HCWs) developed a nosocomial SARS-CoV-2 infection. Fifty-one of the 65 cases (78.5%) were diagnosed between December 6 and 9. The attack rate in patients was 80.8%. Among HCWs, the attack rate was higher in those who had worked at least one full working day in the ward (56.3%) than in those who had occasionally been in the ward (25.8%; p = 0.005). Three days before the first positive case was detected, two extractor fans were found to be defective, affecting the ventilation of three rooms. Sixteen cases were asymptomatic, 48 cases had non-severe symptoms, and 2 cases required admission to the intensive care unit. All patients eventually recovered. CONCLUSION: The high attack rate, the explosive nature of the outbreak, and the coincidence in time with the breakdown in air extractors in some rooms of the ward suggest that airborne transmission played a key role in the development of the outbreak.

[Nosocomial outbreak of COVID-19 in an internal medicine ward: Probable airborne transmission]. / Brote nosocomial de COVID-19 en una planta de medicina interna: probable transmisión aérea.

Background and objectives: Despite the increasing evidence supporting the importance of airborne transmission in SARS-CoV-2 infection, it has not been considered relevant in the vast majority of reported nosocomial outbreaks of COVID-19. The aim of this study is to describe a nosocomial outbreak of SARS-CoV-2 infection whose features suggest that aerosol transmission had an important role. Methods: This is a descriptive analysis of a nosocomial outbreak of SARS-CoV-2 infection in an internal medicine ward that occurred in December 2020. All cases were confirmed by a positive PCR test for SARS-CoV-2. Results: From December 5 to December 17, 21 patients and 44 healthcare workers developed a nosocomial SARS-CoV-2 infection. Fifty-one of the 65 cases (78.5%) were diagnosed between December 6 and 9. The attack rate in patients was 80.8%. Among workers, the attack rate was higher in those who had worked at least one full working day in the ward (56.3%) than in those who had occasionally been in the ward (25.8%, p = 0.005). Three days before the first positive case was detected, 2 extractor fans were found to be defective, affecting the ventilation of 3 rooms. Sixteen cases were asymptomatic, 48 cases had non-severe symptoms, and 2 cases required admission to the intensive care unit. All patients eventually recovered. Conclusion: The high attack rate, the explosive nature of the outbreak, and the coincidence in time with the breakdown in air extractors in some rooms of the ward suggest that airborne transmission played a key role in the development of the outbreak.

The influence of a novel edge enhancement software on image quality of DR hand images of patients with rheumatoid arthritis.

INTRODUCTION: This study aimed to evaluate the effects of a newly developed Advanced Edge Enhancement software (AEE) (Canon Europe, Amsterdam, NL) on image quality (IQ) of Digital Radiography (DR) hand images focusing on rheumatoid arthritis (RA). METHODS AND MATERIALS: Fifty posterior-anterior hand images with or suspected for RA were collected. For each of the 50 images, six copies were made with each their AEE algorithm settings. A total of 330 images (30 images iterated) were evaluated using relative Visual Grading Analysis (VGA) by three observers and combined into a VGA Score (VGAS). Second, 50 images of a technical Contrast Detail Radiography Phantom (CDRAD) was produced with three different AEE software settings, each at level 1,5 and without the AEE software yielding 350 CDRAD images. All images was analysed by the CDRAD Analyser and included for an objective analysis of the AEE software. RESULTS: The VGA study showed a significant difference in image quality between a standard image and images with AEE software applied. The average VGA score of the AEE software was better than the standard images (interval between 0.2 and 0.9). The AEE algorithms at level 5 scored significantly lower for noise but significantly higher for spatial resolution, sharpness and contrast in the VGA. The CDRAD images showed that all AEE algorithms had a statistically significant improvement for level 1 and deterioration for level 5 compared to the standard image. CONCLUSION: Overall the AEE algorithm: small structure level 1 showed an improvement of all IQ criteria in the VGA and a better technical IQ. IMPLICATIONS FOR PRACTICE: The AEE software ought to be considered as a useful addition to the current software, possibly enabling visualisation of structures currently visible.

Cirugía Mayor Ambulatoria en España. ¿Dónde estamos? / Outpatient surgery in Spain. Where are we?

Muchos profesionales del mundo de la sanidad estamos convencidos de que el futuro de la asistencia hospitalaria pasa necesariamente por una apuesta decidida por la ambulatorización. En efecto, recursos asistenciales como son el Hospital de Día, el Hospital a Domicilio y la Cirugía Ambulatoria serán esenciales para conseguir que nuestro sistema sanitario sea viable y sostenible. Es evidente que los recursos mencionados consiguen un producto sanitario más eficiente, pero no podemos olvidar que la eficiencia se basa en combinar el mantenimiento de la calidad asistencial con el ahorro de costes, y uno de los puntales de la calidad asistencial es la seguridad de los pacientes. (AU)

Fluticasone in mild to moderate atopic dermatitis relapse: a randomized controlled trial

BACKGROUND: The long-term efficacy of corticosteroids to prevent atopic dermatitis (AD) relapses has partially been addressed in children. This study compared an intermittent dosing regimen of fluticasone propionate (FP) cream 0.05% with its vehicle base in reducing the risk of relapse in children with stabilized AD. METHODS: A randomized controlled, multicentric, double-blind trial was conducted. Children (2-10 years) with mild/moderate AD (exclusion criteria: >30% affected body surface area and/or head) were enrolled into an Open-label Stabilization Phase (OSP) of up to 2 weeks on twice daily FP. Those who achieved treatment success entered the Double-blind Maintenance Phase (DMP). They were randomly allocated to receive FP or vehicle twice-weekly on consecutive days for 16 weeks. The primary study endpoint was relapse rate; time to relapse and severity of disease were also studied. Kaplan-Meier estimates were calculated. RESULTS: Fifty-four patients (29 girls) entered the OSP (23 mild AD) and 49 (26 girls) continued into the DMP. Mean age was 5.5 (SD: 2.8) and 5.1 (SD: 2.3) yrs for FP and vehicle groups, respectively. Four patients withdrew from the DMP (two in every group). Patients treated with FP twice weekly had a 2.7 fold lower risk of experiencing a relapse than patients treated with vehicle (relative risk 2.72, SD: 1.28; p = 0.034). FP was also superior to vehicle for delaying time to relapse. Both treatment therapies were well tolerated. CONCLUSION: This long-term study shows that twice weekly FP provides an effective maintenance treatment to control the risk of relapse in children with AD

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Fluticasone in mild to moderate atopic dermatitis relapse: A randomized controlled trial.

BACKGROUND: The long-term efficacy of corticosteroids to prevent atopic dermatitis (AD) relapses has partially been addressed in children. This study compared an intermittent dosing regimen of fluticasone propionate (FP) cream 0.05% with its vehicle base in reducing the risk of relapse in children with stabilized AD. METHODS: A randomized controlled, multicentric, double-blind trial was conducted. Children (2-10 years) with mild/moderate AD (exclusion criteria: >30% affected body surface area and/or head) were enrolled into an Open-label Stabilization Phase (OSP) of up to 2 weeks on twice daily FP. Those who achieved treatment success entered the Double-blind Maintenance Phase (DMP). They were randomly allocated to receive FP or vehicle twice-weekly on consecutive days for 16 weeks. The primary study endpoint was relapse rate; time to relapse and severity of disease were also studied. Kaplan-Meier estimates were calculated. RESULTS: Fifty-four patients (29 girls) entered the OSP (23 mild AD) and 49 (26 girls) continued into the DMP. Mean age was 5.5 (SD: 2.8) and 5.1 (SD: 2.3) yrs for FP and vehicle groups, respectively. Four patients withdrew from the DMP (two in every group). Patients treated with FP twice weekly had a 2.7 fold lower risk of experiencing a relapse than patients treated with vehicle (relative risk 2.72, SD: 1.28; p=0.034). FP was also superior to vehicle for delaying time to relapse. Both treatment therapies were well tolerated. CONCLUSION: This long-term study shows that twice weekly FP provides an effective maintenance treatment to control the risk of relapse in children with AD.

Selective non-antibiotic treatment in sigmoid diverticulitis: is it time to change the traditional approach?

BACKGROUND: A growing body of knowledge is calling into question the use of antibiotics in acute diverticulitis (AD). Moreover, recent studies provide evidence regarding the security of treating patients with AD as outpatients. The aim of this study was to evaluate a restrictive antibiotic outpatient protocol for the treatment of mild-to-moderate episodes of AD. METHODS: All patients with symptoms of AD presenting to our emergency department were assigned a modified Neff stage. Patients with mild AD received outpatient treatment without antibiotics. Patients with mild AD and comorbidities were admitted to receive the same treatment. Patients with moderate AD were admitted for 48 h and were then managed as outpatients until they had completed 10 days of antibiotic treatment. RESULTS: Between April 2013 and November 2014, we attended 110 patients with a diagnosis of AD, 77 of whom we included in the study: 45 patients with mild AD and 32 with moderate AD. Of the patients with mild AD, 88.8 % successfully completed the non-antibiotic, non-admission treatment regime and 95.5 % benefited from a non-antibiotic regime, whether as outpatients or inpatients. A total of 88 % of patients with mild AD and 87.5 % of patients with moderate AD who met the inclusion criteria completed treatment as outpatients without incident. No major complications (abscess, emergency surgery) or deaths were recorded. CONCLUSIONS: Outpatient treatment without antibiotics for patients with mild AD is safe and effective. Patients with moderate AD can be safely treated with antibiotics in a mixed regime as inpatients and outpatients.

Effect of horizontal wave barriers on ground vibration propagation.

The aim of this article is to introduce a method to mitigate ground surface vibration through a flexural plate coupled to the ground and acting as a horizontal wave barrier. Using the thin plate hypothesis, two flexural plates are coupled to the ground, the first plate being the excited plate and the second plate the horizontal wave barrier. For instance, the first plate may represent a slab track and be excited by the tramway wheels. A solution to the problem can be found using a spatial two-dimensional Fourier transform of the elastodynamics equation for the ground and a modal decomposition for the flexural plate vibration. The authors show that vibration is substantially mitigated by the horizontal wave barrier and depends on its thickness and width. When the top surface wavelength becomes smaller than twice the plate width, the horizontal wave barrier acts as a wave barrier in the frequency range of interest, i.e., from 20 Hz.

Ground cross-modal impedance as a tool for analyzing ground/plate interaction and ground wave propagation.

An analytical approach is investigated to model ground-plate interaction based on modal decomposition and the two-dimensional Fourier transform. A finite rectangular plate subjected to flexural vibration is coupled with the ground and modeled with the Kirchhoff hypothesis. A Navier equation represents the stratified ground, assumed infinite in the x- and y-directions and free at the top surface. To obtain an analytical solution, modal decomposition is applied to the structure and a Fourier Transform is applied to the ground. The result is a new tool for analyzing ground-plate interaction to resolve this problem: ground cross-modal impedance. It allows quantifying the added-stiffness, added-mass, and added-damping from the ground to the structure. Similarity with the parallel acoustic problem is highlighted. A comparison between the theory and the experiment shows good matching. Finally, specific cases are investigated, notably the influence of layer depth on plate vibration.

Does stapled anopexy for bleeding haemorrhoids cure associated anaemia?

AIM: The aim of this study was to evaluate the effectiveness of stapled anopexy (SA) in patients with chronic bleeding haemorrhoids and secondary anaemia. METHOD: Our department performed 340 SA procedure per patient for haemorrhoids between January 1999 and December 2011. Fifty (14.7%) of these patients (25 male patients and 25 female patients) had anaemia (haemoglobin concentration < 13 g/dl in male patients and < 12 g/dl in female patients) secondary to chronic haemorrhoidal bleeding. Patients with colorectal bleeding and anaemia not caused by haemorrhoids were excluded. The mean (SD) age was 56.4 (13.9) years and the mean (SD) haemoglobin concentration was 9.2 (1.6) g/dl for male patients and 10.4 (1.2) g/dl for female patients. Five (10%) patients with anaemia had Grade II, 22 (44%) had Grade III and 23 (46%) had Grade IV haemorrhoids. The median (range) duration of postoperative follow-up was six (1-12) years. RESULTS: None of the patients required early postoperative admission or experienced early or late complications related to SA. The procedure was successful (normal haemoglobin concentration and no bleeding at 6 months postsurgery) in 45 (90%) patients. Of the five (10%) patients in whom SA was ineffective, one had Grade II, three had Grade III and one had Grade IV haemorrhoids. All these patients underwent Milligan-Morgan haemorrhoidectomy 3 months after SA. CONCLUSION: SA is an effective treatment for patients with bleeding haemorrhoids and subsequent anaemia. In our experience, the success rate was satisfactory and there were no serious complications.

Síndrome de Lemierre, secundario a otitis media aguda: revisión a partir de un caso / Lemierre syndrome secondary to acute otitis media: review from a case

El síndrome de Lemierre (SL), una grave complicación, generalmente de las infecciones orofaríngeas. Se caracteriza por una inflamación agresiva del espacio parafaríngeo lateral, aparición de tromboflebitis de la vena yugular interna y el desarrollo de émbolos sépticos a distancia. Con un diagnóstico clínico y radiológico para su confirmación y posterior seguimiento, debe ser tratado con antibioterapia precoz y parenteral, además de debridación, drenaje quirúrgico de las posibles colecciones purulentas que presente y eventual anticoagulació. En el siguiente trabajo, reportamos el caso de un paciente con esta rara, pero nuevamente emergente entidad, en donde se profundiza su estudio y se resume la literatura.

Lemierre's syndrome (SL), generally, a serious complication of the oropharyngeal infections.Its characterized by an aggressive inflammation of the lateral parapharyngeal space, thrombophlebitis of the yugular internal vein and metastasic abscesses in different organs. With a clinical and radiological diagnosis for his confirmation and later follow-up, it must be treatedwith iv antibiotics and surgical drainage of the possible purulent collections that he presentsand eventual anticoagulation. In the following work, we bring the case of a patient with this rare, but again emergent entity, where his study is deepened and the literature is summarized.

Síndrome de Lemierre: reporte de un caso / Lemierre syndrome: a case report / Lemierre syndrome: A case report

El síndrome de Lemierre es una complicación muy poco frecuente de una infección orofaríngea, que progresa con tromboflebitis séptica secundaria e infecciones embólicas frecuentes. Presentamos el caso de una mujer de 20 años que inició un cuadro de odinofagia y fiebre, el cual progresó rápidamente a un absceso periamigdalino con trombosis de la vena yugular interna ipsilateral, embolias sépticas pulmonares y meningitis. Se manejó con drenaje del absceso por punción, terapia antibiótica de amplio espectro y anticoagulación respondiendo favorablemente, siendo dada de alta en buenas condiciones luego de 35 días de hospitalización. Con la terapia antimicrobiana, casos como éste son poco frecuentes, incluso a veces olvidados, pero dado su gravedad deben considerarse en cuadros faríngeos de evolución tórpida o ante la aparición de signos neurológicos o sépticos.

Lemierre syndrome is a rare complication of oropharyngeal infection which progresses with secondary septic thrombophlebitis and embolic infections. A 20 years-old woman started with odynophagia and fever, which progressed rapidly to a peritonsillar abscess with thrombosis of the ipsilateral internal jugular vein, septic pulmonary emboli and meningitis. She was managed with abscess drainage puncture, broad-spectrum antibiotic therapy and anticoagulant responding favorably, and was discharged in good condition after 35 days of hospitalization. Since the use of antimicrobial therapy, cases like these are rare, sometimes forgotten, but given its severity should be considered in pharyngeal torpid illness or at the onset of neurological signs or sepsis.

[Postoperative unilateral acute glaucoma after abdominal surgery]. / Glaucoma agudo unilateral en el postoperatorio de cirugía abdominal.

An early and correct diagnosis substantially improves the post-operative prognosis of acute angle closure glaucoma (AACG). A 90 year-old woman was operated on for a right colon tumour by laparotomy, under combined anaesthesia without any adverse events. Twelve hours after the operation, the patient described recurrent periorbital pain in her right eye, with ocular hyperaemia, blurred vision, and unresponsive mydriasis. A diagnosis of AACG was made, but although conservative treatment was started YAG laser iridotomies were required to reduce the intraocular pressure. In the AACG postoperative period, as well as with an eye with several predisposed local factors including genetic predisposition, female gender, hypermetropia, increased lens thickness and small corneal diameter, can be added a pupillary block induced by adrenergic and anticholinergic drugs used in anaesthetic procedures. An acute and intensive periorbital or ocular pain, with or without visual disturbance, must aware the doctor. A differential diagnosis with other postoperative ocular diseases and cranial pain causes must be done.

Day case stapled anopexy for the treatment of haemorrhoids and rectal mucosal prolapse.

AIM: Stapled anopexy (SA) gives better early postoperative results than classical haemorrhoidectomy. The aim of this study is to demonstrate that SA is a safe and effective procedure for the treatment of haemorrhoids and rectal mucose prolapse in a day-case surgery programme. METHOD: From January 2000 to December 2008, 297 SA procedures were performed; 230 (77.4%) were performed in the Day Surgery Unit (DSU). Third- and fourth-degree haemorrhoids, second-degree haemorrhoids with no response to conservative treatment and several cases of rectal prolapse were included. The mean age of the patients in the series was 48.1 years (range 21-85). Preoperative preparation included phosphate enemas and antibiotic prophylaxis. Patients were operated on mainly under spinal anaesthesia. Day-case rate, postoperative pain (measured by a visual analogic scale, 1-10), admissions, re-admissions, early postoperative situation and recurrence were evaluated in the study. RESULTS: The overall DSU rate was 78%, with a progressive increase from 46% to 99% in 2008. One hundred and eighty-five patients (80%) had pain scores under 2; no patient had a pain score over 7. Eighteen (8%) patients required admission on the day of surgery. Late admission was needed for 3 (3%) patients. Thirty-three patients reported their situation as excellent, 174 as good, 20 as acceptable and three as bad when they answered a phone questionnaire 24 h after surgery. Overall, 20 (9%) patients had recurrence of symptoms. CONCLUSION: SA is a safe and effective procedure for prolapsing haemorrhoids in the day case setting. The recurrence rate is higher than that observed in classical haemorrhoidectomy. Most patients can be managed as day-cases.

Prevalence, characteristics, and predictors of police training initiatives by US SEPs: building an evidence base for structural interventions.

BACKGROUND: Community-based prevention initiatives such as syringe exchange programs (SEPs) are proven to curb injection-related HIV transmission. Policing targeting injection drug users (IDUs) can interfere with SEP functioning. Efforts to maximize the public health benefit of SEPs have included police trainings designed to reduce such interference. METHODS: We surveyed US SEP managers to assess prevalence, content, and correlates of SEP police trainings. Multivariate analyses were utilized to identify predictors of training participation. RESULTS: Of 107 SEPs (57% of all US programs), 20% reported participating in trainings during the previous year. Covered topics included the public health rationale behind SEPs (71%), police occupational health (67%), needle stick injury (62%), SEPs' legal status (57%), and harm reduction philosophy (67%). On average, trainings were seen as moderately effective, but only four programs reported conducting any formal evaluation. In multivariate modeling, training participation was independently associated with state law authorizing syringe possession by clients (aOR=3.71, 95%CI=1.04-13.23), higher frequency of client arrest (aOR=2.07, 95%CI=1.0-4.7), and systematic monitoring of adverse client-police encounters (aOR=4.02, 95%CI=1.14-14.17). Assistance with police trainings was identified by 72% of respondents as the key to improving police relations. CONCLUSION: At a time when collaboration with police may become requisite for SEPs to receive federal funding, most program managers in the US perceive police trainings as a key to improved SEP-police relations. Robust evaluation is needed to better understand the impact of these trainings on law enforcement practices, SEP operations, and community health. Such research will inform technical assistance, policy design, and resource allocation.