Study protocol: infectious diseases consortium (I3D) for study on integrated and innovative approaches for management of respiratory infections: respiratory infections research and outcome study (RESPIRO).

BACKGROUND: Community-acquired respiratory infections are a leading cause of illness and death globally. The aetiologies of community-acquired pneumonia remain poorly defined. The RESPIRO study is an ongoing prospective observational cohort study aimed at developing pragmatic logistical and analytic platforms to accurately identify the causes of moderate-to-severe community-acquired pneumonia in adults and understand the factors influencing disease caused by individual pathogens. The study is currently underway in Singapore and has plans for expansion into the broader region. METHODS: RESPIRO is being conducted at three major tertiary hospitals in Singapore. Adults hospitalised with acute community-acquired pneumonia or lower respiratory tract infections, based on established clinical, laboratory and radiological criteria, will be recruited. Over the course of the illness, clinical data and biological samples will be collected longitudinally and stored in a biorepository for future analysis. DISCUSSION: The RESPIRO study is designed to be hypothesis generating, complementary to and easily integrated with other research projects and clinical trials. The detailed clinical database and biorepository will yield insights into the epidemiology and outcomes of community-acquired lower respiratory tract infections in Singapore and the surrounding region and offers the opportunity to deeply characterise the microbiology and immunopathology of community-acquired pneumonia.

Association between Bilateral Infarcts Pattern and Detection of Occult Atrial Fibrillation in Embolic Stroke of Undetermined Source (ESUS) Patients with Insertable Cardiac Monitor (ICM).

BACKGROUND AND AIMS: Increasingly, insertable cardiac monitors (ICM) have been used to detect Atrial Fibrillation (AF) in patients with cryptogenic stroke or embolic strokes of undetermined source (ESUS). We aim to examine the characteristics of these patients who were subsequently found to have AF. METHODS: We studied 83 consecutive patients who were comprehensively evaluated using neuroimaging and vessel imaging (computed tomography angiography, magnetic resonance angiography, or transcranial and extracranial Doppler sonography) to have met the previously established ESUS criteria. All 83 patients had ICM implanted between 2015 and 2017. All patients were followed up for at least 1 year, with a median follow-up period of 1.5 ± .5 years. We compared the baseline clinical, laboratory, echocardiographic, neuro-imaging profiles, and clinical outcomes in terms of functional recovery, recurrent stroke, and mortality in patients with and without detected AF. RESULTS: AF detection rate in this ESUS cohort was 12% over the study period. Patients with detected AF were associated with bilateral infarcts pattern at presentation (30% versus 5.5%, P = .035). Infarcts involving multiple vascular territories was not significantly associated with the detection of AF. There were no significant differences in the other clinical characteristics and outcomes between the AF group compared to the group without detected AF. Echocardiographic parameters including left ventricular ejection fraction and left atrial diameter were also not shown to be significantly different. CONCLUSION: Our study found that a neuroimaging profile of bilateral infarcts was associated with AF detection using insertable cardiac monitor in ESUS patients. Larger prospective studies are needed to validate our findings.

A new non-invasive index for prognosis evaluation in patients with aortic stenosis.

The global left ventricular (LV) contractility index, dσ*/dtmax measures the maximal rate of change in pressure-normalized LV wall stress. We aim to describe the trend of dσ*/dtmax in differing severity of aortic stenosis (AS) with preserved left ventricular ejection fraction (LVEF) and the association of dσ*/dtmax with clinical outcomes in moderate AS and severe AS. We retrospectively studied a total of 1738 patients with AS (550 mild AS, 738 moderate AS, 450 severe AS) and preserved LVEF ≥ 50% diagnosed from 1st January 2001 to 31st December 2015. dσ*/dtmax worsened with increasing severity of AS despite preserved LVEF (mild AS: 3.69 ± 1.28 s-1, moderate AS: 3.17 ± 1.09 s-1, severe AS: 2.58 ± 0.83 s-1, p < 0.001). Low dσ*/dtmax < 2.8 s-1 was independently associated with a higher composite outcome of aortic valve replacement, congestive cardiac failure admissions and all-cause mortality (adjusted hazard ratio 1.48, 95% CI: 1.25-1.77, p < 0.001). In conclusion, dσ*/dtmax declined with worsening AS despite preserved LVEF. Low dσ*/dtmax < 2.8 s-1 was independently associated with adverse clinical outcomes in moderate AS and severe AS with preserved LVEF.

Effectiveness of near-peer simulation for managing the acutely deteriorating patient among residents of an internal medicine junior residency programme.

INTRODUCTION: Near-peer teaching is gaining popularity as a teaching modality, as it improves the learner's understanding, is targeted at an appropriate level and promotes familiarisation. This study was initiated to evaluate the effectiveness of incorporating near-peer instruction into simulation-based training within a junior residency programme. METHODS: 42 first-year residents from an internal medicine junior residency programme were recruited. Participants underwent a simulation-based training programme conducted over five weeks. Each week involved either an emergency or acute clinical scenario. A structured questionnaire was administered prior to and after the course to compare participants' perceived knowledge, experience and confidence in managing the clinical scenarios. RESULTS: In our study, 83% of participants agreed/strongly agreed that the scenarios were realistic. There were improvements in perceived knowledge, experience and confidence after the course. The greatest improvement was seen for experience (post-simulation: median 7.00 [interquartile range (IQR) 6.00‒8.00] vs. pre-simulation: median 5.00 [IQR 3.00-6.25]). 65% of participants were keen to help with future training. CONCLUSION: Near-peer simulation training was found to be a viable and valuable method of instruction for first-year residents for increasing experience, instilling confidence and improving perceived knowledge. Integration of such programmes within medical education curricula shows good promise of continuity, with many first-year residents inspired to organise subsequent sessions.

Comparison of Clinical and Echocardiographic Features of Asymptomatic Patients With Stenotic Bicuspid Versus Tricuspid Aortic Valves.

The clinical and imaging differences between bicuspid aortic valve (BAV) and tricuspid aortic valve (TAV) patients with medically managed asymptomatic moderate-to-severe aortic stenosis (AS) have not been studied previously. We aim to characterize these differences and their clinical outcomes in this study. A retrospective observational study was conducted on 836 consecutive cases of isolated asymptomatic moderate-to-severe AS, with median follow-up of 3.4 years. Clinical and echocardiographic characteristics were compared between BAV and TAV patients. Subgroup analysis stratified by AS severity were performed. Survival analysis of all-cause mortality was performed using Kaplan-Meier curves and Cox proportional hazards model. Compared to BAV patients, TAV patients were older (76 ± 11 vs 55 ± 16 years, p <0.001) and had more co-morbidities including hypertension (78% vs 56%; p <0.001), diabetes (41% vs 24%; p <0.001), and chronic kidney disease (20% vs 3%; p = 0.001). TAV patients had less severe aortic valve disease than BAV patients, with a higher aortic valve area index (0.71 ± 0.20 cm2/m2 vs 0.61 ± 0.18 cm2/m2, p <0.001) and less aortic dilation (sinotubular junction: 23.7 ± 4.0 mm vs 26.9 ± 4.8 mm, p <0.001; mid-ascending aorta: 31.4 ± 4.7 mm vs 36.3 ± 6.3 mm, p <0.001). TAV patients were more likely to have eccentric left ventricular hypertrophy and less likely to have a normal geometry (p = 0.003). Competing risk analysis identified increased age (hazard ratio 1.03, 95% confidence interval 1.02 to 1.05, p <0.001) and LVEF (hazard ratio 0.98, 95% confidence interval 0.97 to 0.99, p <0.001) as independent risk factors of all-cause mortality. Valve morphology was not a significant independent risk factor for aortic valve replacement or mortality. In conclusion, asymptomatic TAV patients had more cardiovascular risk factors, less severe aortic valve disease, less sinotubular and mid-ascending aortic dilation, more severe LV remodeling.

Acute Health Impacts of the Southeast Asian Transboundary Haze Problem-A Review.

Air pollution has emerged as one of the world's largest environmental health threats, with various studies demonstrating associations between exposure to air pollution and respiratory and cardiovascular diseases. Regional air quality in Southeast Asia has been seasonally affected by the transboundary haze problem, which has often been the result of forest fires from "slash-and-burn" farming methods. In light of growing public health concerns, recent studies have begun to examine the health effects of this seasonal haze problem in Southeast Asia. This review paper aims to synthesize current research efforts on the impact of the Southeast Asian transboundary haze on acute aspects of public health. Existing studies conducted in countries affected by transboundary haze indicate consistent links between haze exposure and acute psychological, respiratory, cardiovascular, and neurological morbidity and mortality. Future prospective and longitudinal studies are warranted to quantify the long-term health effects of recurrent, but intermittent, exposure to high levels of seasonal haze. The mechanism, toxicology and pathophysiology by which these toxic particles contribute to disease and mortality should be further investigated. Epidemiological studies on the disease burden and socioeconomic cost of haze exposure would also be useful to guide policy-making and international strategy in minimizing the impact of seasonal haze in Southeast Asia.

Perceptions of a night float system for intern doctors in an internal medicine program: an Asian perspective.

Long duty hours have been associated with significant medical errors, adverse events, and physician "burn-out". An innovative night float (NF) system has been implemented in our internal medicine program to reduce the negative effects of long duty hours associated with conventional full-call systems. However, concerns remain if this would result in inadequate training for interns. We developed a structured questionnaire to assess junior doctors' perceptions of the NF system compared to full calls, in areas of patient safety, medical training, and well-being. Ninety-seven (71%) of the 137 doctors polled responded. Ninety-one (94%) felt the NF system was superior to the full call system. A strong majority felt NF was beneficial for patient safety compared to full call (94% vs. 2%, p<0.001). The NF system was also perceived to reduce medical errors (94% vs. 2%, p<0.001) and reduce physician "burn-out" (95% vs. 5%, p<0.001). Beyond being a practical solution to duty-hour limitations, there was a significant perceived benefit of the NF system compared to the full call in terms of overall satisfaction, patient safety, reducing medical errors and physician "burn-out".

Effect of Renin-Angiotensin Blockers on Left Ventricular Remodeling in Severe Aortic Stenosis.

Studies have shown that medical therapy with renin-angiotensin blockers (RABs) may benefit patients with aortic stenosis (AS). However, its use and efficacy remains controversial, including in patients with low flow (LF) with preserved left ventricular ejection fraction (LVEF). We examined the effects of RAB use on LV remodeling in patients with severe AS with preserved LVEF, analyzing the differential effects in patients with LF compared with normal flow (NF). This is a retrospective study of 428 consecutive subjects from 2005 to 2014 with echocardiographic diagnosis of severe AS and preserved LVEF. Clinical and echocardiographic parameters were systematically collected and analyzed. Two hundred forty-two (57%) patients had LF. Sixty-four LF patients (26%) were treated with RAB. Patients on RAB treatment had a higher incidence of hyperlipidemia (69% vs 44%) and diabetes mellitus (53% vs 34%). Severity of AS in terms of valve area, transvalvular mean pressure gradient, and aortic valve resistance were similar between both groups as was the degree of LV diastolic function. The RAB group demonstrated significantly lower LV mass index with a correspondingly lower incidence of concentric LV hypertrophy. Regardless of the duration of RAB therapy, patients had increased odds of having a preserved LV mass index compared with those without RAB therapy. In conclusion, RAB therapy may be associated with less LV pathological remodeling and have a role in delaying patients from developing cardiovascular complications of AS.