Harnessing a real-time location system for contact tracing in a busy emergency department

BACKGROUND

With the persistent threat of emerging infectious diseases (EIDs), digital contact tracing (CT) tools can augment conventional CT for the prevention of healthcare-associated infectious disease transmission. However, their performance has yet to be evaluated comprehensively in the fast-paced emergency department (ED) setting.

OBJECTIVE

This study compared the CT performance of a radiofrequency identification (RFID)-based real-time location system (RTLS) with conventional electronic medical record (EMR) review against continuous direct observation of close contacts ('gold standard') in a busy ED during the coronavirus disease 2019 pandemic period.

METHODS

This cross-sectional study was conducted at the ED of a large tertiary care hospital in Singapore from December 2020 to April 2021. CT performance [sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and kappa] of the RTLS, EMR review and a combination of the two approaches (hybrid CT) was compared with direct observation. Finally, the mean absolute error (MAE) in the duration of each contact episode found via the RTLS and direct observation was calculated.

RESULTS

In comparison with EMR review, both the RTLS and the hybrid CT approach had higher sensitivity (0.955 vs 0.455 for EMR review) and a higher NPV (0.997 vs 0.968 for EMR review). The RTLS had the highest PPV (0.777 vs 0.714 for EMR review vs 0.712 for hybrid CT). The RTLS had the strongest agreement with direct observation (kappa=0.848). The MAE between contact durations of 80 direct observations and their respective RTLS contact times was 1.81 min.

CONCLUSION

The RTLS was validated to be a high-performing CT tool, with significantly higher sensitivity than conventional CT via EMR review. The RTLS can be used with confidence in time-strapped EDs for time-sensitive CT for the prevention of healthcare-associated transmission of EIDs.

Multimodality imaging results of TAP versus novel modified TAP stenting in coronary bifurcation: From bench testing to first-in-man investigation

OBJECTIVES

We investigated the results of T and small protrusion (TAP) versus a novel modification of TAP (mTAP) stenting by multimodality imaging in bench testing and in patients with coronary bifurcation lesions (CBL).

BACKGROUND

TAP stenting is a suboptimal technique for bailout side branch (SB) stenting.

METHODS

In a bench model, optical coherence tomography (OCT), microscopic examinations (ME), and computational fluid dynamics (CFD) were performed after TAP and mTAP stenting. In 20 patients with CBL, 80 intravascular ultrasound (IVUS) examinations were performed during mTAP stenting in which the SB stent was pulled-back to indent the inflated main vessel (MV) balloon and deployed while deflating it. For TAP stenting, the tip of the SB stent was positioned in the MV and deployed.

RESULTS

In bench testing, OCT showed neocarina length (NL) was shorter and minimum stent area (MSA) was larger after mTAP versus TAP stenting (2.84 ± 0.70 vs. 4.80 ± 020 mm; 6.75 ± 1.50 vs. 4.5 ± 2.2 mm² ; respectively; p < 0.05). By ME, NL was shorter and shear rate trended lower after mTAP versus TAP stenting. In patients, IVUS showed MSA was larger after versus before mTAP stenting (6.32 ± 0.58 vs. 5.21 ± 0.56 mm² ; p < 0.01); NL was 1.43 ± 0.22 mm with SB ostium coverage. The Seattle Angina questionnaire (SAQ) score was higher at 6 months versus baseline (85 ± 4.0 vs. 48 ± 6.0, respectively; p < 0.001).

CONCLUSIONS

This multimodality imaging study showed, for the first time, mTAP stenting resulted in larger stent area and shorter neocarina than TAP stenting in bench testing. In patients with CBL, mTAP stenting led to larger stent area, short neocarina with complete SB ostium coverage, and improved the SAQ score at follow-up.

Determinants of antibiotic over-prescribing for upper respiratory tract infections in an emergency department with good primary care access: a quantitative analysis

BACKGROUND

Upper respiratory tract infections (URTI) account for the highest proportion of non-urgent visits to the emergency department (ED), resulting in unnecessary antibiotic use.

AIM

This study sought to understand the determinants of antibiotic prescribing for URTI among 130 junior physicians in a busy adult ED in Singapore.

METHODS

Forty-four Likert-scale statements were developed with reference to a prior qualitative study, followed by an anonymous cross-sectional survey among ED junior physicians. Data analysis was performed with factor reduction and multivariable logistic regression.

FINDINGS

One-in-six (16.9%) physicians were high antibiotic prescribers (self-reported antibiotic prescribing rate of >30% of URTI patients). After adjusting for place of medical education and years of practice as a physician, perceived over-prescribing of antibiotics in the ED (adjusted odds ratio (OR) 2.37, 95% confidence interval (CI) (1.15, 4.86), P=0.019) and perceived compliance with the antibiotic prescribing practices in the ED (adjusted OR 2.10, 95% CI (1.02, 4.30), P=0.043) were positively associated with high antibiotic prescribing. In contrast, high antibiotic prescribers were 6.67 times (95% CI (1.67, 25.0), P=0.007) less likely to treat and manage patients with URTI symptomatically and 7.12 times (95% CI (1.28, 39.66), P=0.025) more likely to depend on diagnostic tests to prescribe antibiotics than the regular antibiotic prescribers.

CONCLUSION

Organizational-related factors (organizational norms and culture) were strong determinants of antibiotic prescribing practices for uncomplicated URTI in the ED. Other contributing factors include diagnostic uncertainty and knowledge gaps. Role-modelling of institutional best practice norms and clinical decision support tools based on local epidemiology can optimize antibiotic prescribing in the ED.

T and Small Protrusion (TAP) vs Double-Kissing Crush Technique: Insights From In Vitro Models

BACKGROUND

Percutaneous coronary interventions on complex bifurcation lesions may require implantation of two stents to appropriately treat diffuse side-branch (SB) disease. Comparisons among different bifurcation stenting techniques are continuously attempted by various study designs (bench tests, computer simulations, clinical studies). Among different techniques, double kissing crush (DKC) represents the last evolution for "crushing" while T and small Protrusion (TAP) represents the evolution of "T stenting". Both techniques are actually gaining popularity, but head-to-head comparisons are lacking.

METHODS AND RESULTS

Two last generation drug-eluting stents (Synergy™, Boston Scientific, MA, USA and Ultimaster™,Terumo Corp., Japan) were implanted in left main bifurcation bench models using TAP (n = 6 sets) and DKC (n = 6 sets) techniques. A peristaltic pump with fresh porcine blood was used to perfuse the blood through the silicone model at a flow rate of 200 ml/min for 4 min. Optical coherence tomography (OCT) was used to assess stent struts geometry and thrombus formation. SB cross sectional area as well as SB obstruction did not significantly differ between the two techniques. Numerical (but not statistically significant) differences were found in terms of malapposed struts (fewer with TAP) and floating struts (fewer with DKC). Thrombus formation after blood perfusion was similar between TAP and DKC technique (1.53 ± 1.12 vs. 1.20 ± 1.01 mm², p = 0.6).

CONCLUSION

The result of the present in-vitro study shows the absence of significant difference between TAP and DKC in terms of stent struts apposition and acute thrombus formation potential. Despite the completely different technical steps required, both techniques have similar performance according to such articulated pre-clinical evaluation. WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT?: Due to its limited complexity, T and Protrusion (TAP) technique is considered the to-go technique for bifurcation lesions with good long-term results. Recently, double kissing crush (DKC) technique has been gaining popularity and demonstrated promising results in randomized clinical trials. WHAT DOES THIS STUDY ADD?: This in-vitro bench test study provides a unique detailed OCT comparison and local hemodynamic environment analysis of the two techniques. HOW MIGHT THIS IMPACT ON CLINICAL PRACTICE?: New insights of acute thrombogenicity and computational flow model simulation may guide percutaneous therapeutic strategies of bifurcation lesions.

Drug-coated balloons: Technical and clinical progress

The advancement of drug-coated balloons (DCB) presents an alternative nonstent method in the percutaneous treatment of atherosclerotic lesions. While the current generation of drug-eluting stents (DES) are the device of choice, especially in coronary artery disease (CAD), DCB has potential applications in the treatment of de novo lesions, in-stent restenosis (ISR), bifurcations, and in peripheral artery disease (PAD). In terms of coronary clinical experience, DCB is used most in ISR scenarios and more data are collected to support the use of DCB in de novo lesions compared to best-in-class DES. The use of DCB in bifurcation side branch treatment has demonstrated safety, and with good angiographic and clinical outcomes, but more data from randomized trials will be required to assess its clinical value. For PAD, the clinical outcomes of DCB with and without debulking devices in diseased femoropopliteal arteries and treatment of below-the-knee (BTK) vessels with DCB are discussed. Current data demonstrated conflicting long-term safety outcomes in the use of paclitaxel devices in the femoral and/or popliteal arteries, while the role of DCB in BTK disease remains uncertain due to a lack of randomized controlled trial data. In summary, this review provides an overall view of current DCB technologies and progress, followed by an update on DCB clinical data in the treatment of CAD and PAD.

Drug-Coated Balloons: Technologies and Clinical Applications

The progress and development of drug-coated balloons (DCBs) represents an emerging alternative treatment in peripheral and coronary artery diseases, particularly when a non-stent approach is necessary. Several studies and meta-analyses have evaluated the clinical outcomes of DCBs in different lesions and this review aims to compile the progress and updated clinical data of DCB strategy in both peripheral artery diseases (PAD) and coronary artery diseases (CAD). The review highlights that clinical data has encouraged the use of DCB for applications in PAD and in the treatment of coronary in-stent restenosis (ISR). The employment of DCB in side branch treatment of bifurcation lesions has been reported to be feasible and safe, with good angiographic and clinical outcome. The use of DCB for arteriovenous fistula and grafts stenoses is a promising strategy, but more clinical data is required to draw reliable conclusions. The limitations and impact of the current generation of DCBs will be discussed and the clinical development of newer generation of the device is also covered in this review.

Proliferation dynamics of acute myeloid leukaemia and haematopoietic progenitors competing for bone marrow space

Leukaemia progressively invades bone marrow (BM), outcompeting healthy haematopoiesis by mechanisms that are not fully understood. Combining cell number measurements with a short-timescale dual pulse labelling method, we simultaneously determine the proliferation dynamics of primitive haematopoietic compartments and acute myeloid leukaemia (AML). We observe an unchanging proportion of AML cells entering S phase per hour throughout disease progression, with substantial BM egress at high levels of infiltration. For healthy haematopoiesis, we find haematopoietic stem cells (HSCs) make a significant contribution to cell production, but we phenotypically identify a quiescent subpopulation with enhanced engraftment ability. During AML progression, we observe that multipotent progenitors maintain a constant proportion entering S phase per hour, despite a dramatic decrease in the overall population size. Primitive populations are lost from BM with kinetics that are consistent with ousting irrespective of cell cycle state, with the exception of the quiescent HSC subpopulation, which is more resistant to elimination.

How leukaemia cells invade the bone marrow by outcompeting haematopoietic cells is still unclear. Here, the authors used detailed cell number measurements in conjunction with a dual pulse labelling method to determine proliferation rates and followed the in vivo dynamics of AML disease progression.

Early MRI in term infants with perinatal hypoxic-ischaemic brain injury: interobserver agreement and MRI predictors of outcome at 2 years

AIM

To compare diffusion-weighted imaging (DWI) and non-DWI magnetic resonance imaging (MRI), proton MR spectroscopy (1H-MRS), and clinical biomarkers for prediction of 2 year developmental outcome in term infants with perinatal hypoxic-ischaemic encephalopathy (HIE).

MATERIALS AND METHODS

Nineteen infants ≥36 weeks gestation with HIE were recruited and MRI performed day 3-7 (mean = 5). MRI was scored independently by three radiologists using a standardized scoring system. Lactate-to-N-acetylaspartate ratio (Lac:NAA) in the lentiform nucleus was calculated. Developmental assessment was performed at 2 years using the Bayley Scales of Infant and Toddler Development (BSID-III). Interobserver agreement about abnormality in 10 brain regions was measured. Univariate analysis was performed to determine variables associated with adverse outcome (i.e., death or Bayley score for any domain <70).

RESULTS

Good interobserver agreement (kappa = 0.61-0.69) on scores for DWI was obtained for the cortex, putamen, and brainstem, but not for any region on non-DWI. A significant association was found between outcome and Lac:NAA (p < 0.003) and DWI scores for lentiform nucleus, thalamus, cortex, posterior limb of the internal capsule (PLIC), and paracentral white matter (p = 0.001-0.013), but for non-DWI score only in the vermis or brainstem. A combination of Lac:NAA ≥0.25 or DWI/apparent diffusion coefficient (ADC) signal abnormality in the PLIC had 100% specificity and sensitivity for poor outcome.

CONCLUSION

Interobserver agreement for non-DWI performed during the first week is poor. Agreement by three radiologists about the presence of abnormal signal within the PLIC on ADC/DWI images or elevation of Lac:NAA above 0.25 improved sensitivity without reducing the prognostic specificity of MRS in the 19 patients, but this requires validation in a larger group of infants with HIE who have been treated with hypothermia.

Neuroprotective effects of LBP on brain ischemic reperfusion neurodegeneration

AIM

The present study was conducted to investigate whether LBP had a protective effect on cerebral ischemic reperfusion injury and to determine the possible mechanisms.

MATERIALS AND METHODS

Male Kunming (KM) mice were used to make the model cerebral artery occlusion/reperfusion (MCAO/R). The behavioral test was used to measure neurological deficit scores for evaluation of ischemic reperfusion damage of brain. The change of electroencephalograph (EEG) was monitored by Model SMUP-E Bio-electric Signals Processing System. The infarction area of brain was assessed in brain slices with 2% solution of 2,3,5-triphenyl tetrazolium chloride (TTC). Spectrophotometric assay was used to determine the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT) and lactate dehydrogenase (LDH), contents of malondialdehyde (MDA) and adenosine triphosphate (ATP) of the brain.

RESULTS

The results showed that LBP at doses of 20 and 40 mg/kg markedly decreased the neurological deficit scores and the infarction area in MCAO/R mice. At the same time, LBP significantly decreased MDA content, and increased SOD, GSH-Px, CAT, LDH activities in ischemic reperfusion brain.

CONCLUSIONS

These suggest that LBP might act as a potential neuroprotective agent against the cerebral reperfusion-induced injury in the brain through reducing lipid peroxides, scavenging free radicals, and improving the energy metabolism.