Oxygen Delivery Devices in Postoperative Patients: Proper Selection of Patients Matters!

How to cite this article: Bhattacharya D, Esquinas AM, Mandal M. Oxygen Delivery Devices in Postoperative Patients: Proper Selection of Patients Matters! Indian J Crit Care Med 2024;28(8):802.

Sparsity-Independent Lyapunov Exponent in the Sachdev-Ye-Kitaev Model.

The saturation of a recently proposed universal bound on the Lyapunov exponent has been conjectured to signal the existence of a gravity dual. This saturation occurs in the low-temperature limit of the dense Sachdev-Ye-Kitaev (SYK) model, N Majorana fermions with q body (q>2) infinite-range interactions. We calculate certain out-of-time-order correlators (OTOCs) for N≤64 fermions for a highly sparse SYK model and find no significant dependence of the Lyapunov exponent on sparsity up to near the percolation limit where the Hamiltonian breaks up into blocks. This provides strong support to the saturation of the Lyapunov exponent in the low-temperature limit of the sparse SYK. A key ingredient to reaching N=64 is the development of a novel quantum spin model simulation library that implements highly optimized matrix-free Krylov subspace methods on graphical processing units. This leads to a significantly lower simulation time as well as vastly reduced memory usage over previous approaches, while using modest computational resources. Strong sparsity-driven statistical fluctuations require both the use of a much larger number of disorder realizations with respect to the dense limit and a careful finite size scaling analysis. The saturation of the bound in the sparse SYK points to the existence of a gravity analog that would enlarge substantially the number of field theories with this feature.

Applications of spatial transcriptomics and artificial intelligence to develop integrated management of pancreatic cancer.

Cancer is a complex disease intrinsically associated with cellular processes and gene expression. With the development of techniques such as single-cell sequencing and sequential fluorescence in situ hybridization (seqFISH), it was possible to map the location of cells based on their gene expression with more precision. Moreover, in recent years, many tools have been developed to analyze these extensive datasets by integrating machine learning and artificial intelligence in a comprehensive manner. Since these tools analyze sequencing data, they offer the chance to analyze any tissue regardless of its origin. By applying this to cancer settings, spatial transcriptomic analysis based on artificial intelligence may help us understand cell-cell communications within the tumor microenvironment. Another advantage of this analysis is the identification of new biomarkers and therapeutic targets. The integration of such analysis with other omics data and with routine exams such as magnetic resonance imaging can help physicians with the earlier diagnosis of tumors as well as establish a more personalized treatment for pancreatic cancer patients. In this review, we give an overview description of pancreatic cancer, describe how spatial transcriptomics and artificial intelligence have been used to study pancreatic cancer and provide examples of how integrating these tools may help physicians manage pancreatic cancer in a more personalized approach.

Sequencing of Checkpoint or BRAF/MEK Inhibitors on Brain Metastases in Melanoma.

BACKGROUND: The impact of the order of treatment with checkpoint inhibitors or BRAF/MEK inhibitors on the development of brain metastases in patients with metastatic unresectable BRAFV600-mutant melanoma is unknown. The SECOMBIT trial examined the impact of the order of receipt of these treatments in such patients. METHODS: In this three-arm trial, we reviewed patients without brain metastases who received the BRAF/MEK inhibitors encorafenib and binimetinib until they had progressive disease followed by the immune checkpoint inhibitors ipilimumab and nivolumab (arm A); or treatment with ipilimumab and nivolumab until they had progressive disease followed by encorafenib and binimetinib (arm B); or treatment with encorafenib and binimetinib for 8 weeks followed by ipilimumab and nivolumab until they had progressive disease followed by retreatment with encorafenib arm binimetinib (arm C). RESULTS: Brain metastases were discovered during the trial in 23/69 patients in arm A, 11/69 in arm B, and 9/68 in arm C. At a median follow-up of 56 months, the 60-month brain metastases-free survival rates were 56% for arm A, 80% for arm B (hazard ratio [HR] vs. A: 0.40, 95% confidence interval [CI] 0.23 to 0.58), and 85% for arm C (HR vs. A: 0.35, 95% CI 0.16 to 0.76). CONCLUSIONS: In patients with unresectable metastatic melanoma, the treatment sequence of immune checkpoint inhibition followed by BRAF/MEK inhibitors was associated with longer periods of new brain metastases-free survival than the reverse sequence. A regimen in which immune checkpoint inhibition was sandwiched between BRAF/MEK inhibition also appeared to be protective against brain metastases. (ClinicalTrials.gov number NCT02631447.).

Control, bi-stability, and preference for chaos in time-dependent vaccination campaign.

In this work, effects of constant and time-dependent vaccination rates on the Susceptible-Exposed-Infected-Recovered-Susceptible (SEIRS) seasonal model are studied. Computing the Lyapunov exponent, we show that typical complex structures, such as shrimps, emerge for given combinations of a constant vaccination rate and another model parameter. In some specific cases, the constant vaccination does not act as a chaotic suppressor and chaotic bands can exist for high levels of vaccination (e.g., >0.95). Moreover, we obtain linear and non-linear relationships between one control parameter and constant vaccination to establish a disease-free solution. We also verify that the total infected number does not change whether the dynamics is chaotic or periodic. The introduction of a time-dependent vaccine is made by the inclusion of a periodic function with a defined amplitude and frequency. For this case, we investigate the effects of different amplitudes and frequencies on chaotic attractors, yielding low, medium, and high seasonality degrees of contacts. Depending on the parameters of the time-dependent vaccination function, chaotic structures can be controlled and become periodic structures. For a given set of parameters, these structures are accessed mostly via crisis and, in some cases, via period-doubling. After that, we investigate how the time-dependent vaccine acts in bi-stable dynamics when chaotic and periodic attractors coexist. We identify that this kind of vaccination acts as a control by destroying almost all the periodic basins. We explain this by the fact that chaotic attractors exhibit more desirable characteristics for epidemics than periodic ones in a bi-stable state.

Monitoring the psychopathological profile of inflammatory bowel disease patients treated with biological agents: a pilot study.

BACKGROUND: Biological agents were found to alter the psychopathological profile of a small subgroup of patients treated for a variety of conditions, including inflammatory bowel disease (IBD) and psychiatric disorders. The association between the administration of biological agents and psychopathology needs to be further investigated. METHODS: In this naturalistic prospective cohort study, patients with IBD were assigned to two treatment groups, i.e., a biological agent (which also included tofacitinib) or conventional therapy. Clinician-administered scales were used to assess psychosomatic symptoms (Hamilton Depression Rating Scale [Ham-D], Hamilton Anxiety Rating Scale [Ham-A], Young Mania Rating Scale [YMRS], and Brief Psychiatric Rating Scale [BPRS]) and disease activity (Mayo Score and Harvey-Bradshaw Index [HBI]) at baseline, after one, three, and six months of treatment. Each group was assessed for the course of their scores during the observation period at each assessment point. RESULTS: Patients on biological drugs who completed three months of treatment (N.=32) and six months of treatment (N.=20) scored significantly lower on the Mayo compared to baseline. Patients on conventional treatment obtained significant drops from baseline on the HBI after one and three months of treatment (N.=30) and also at the six-month endpoint (N.=11). Both groups showed no improvement or worsening on the psychiatric rating scales. CONCLUSIONS: In this study, we found no evidence of psychiatric symptom worsening, as some literature would suggest. Our data suggest that the use of biological agents in IBD is safe.

Development and optical characterisation of agarose-based phantoms mimicking biological tissues for studies of light penetration in the brain.

Searching for materials that accurately mimic the optical properties of biological tissues is essential, particularly for transcranial photobiomodulation (PBM) research, where it is necessary to comprehend how light propagates through the head tissues. In this research, we characterised, in the 500-1200 nm range, the transmittance spectra of porcine tissues (skin, muscle, cranium, brain, and cerebellum) and different agarose-based phantoms. These phantoms were developed using different combinations of titanium dioxide (TiO2), India ink, organometallic compounds, and laser-ablated gold and zinc oxide nanoparticles. The surface and mechanical properties of these phantoms were also characterized. The results showed that an increased TiO2 concentration decreased the optical transmittance of the phantoms. However, when TiO2 was added to the India ink and laser-ablated nanoparticles' phantoms, not only did it reduce transmittance amplitude, but it also flattened its spectra. Comparing the phantoms and biological tissues' results, the spectral profiles of TiO2 samples appeared similar to those of muscle, skin, and brain/cerebellum; organometallic compounds replicated the skin and muscle curves; India ink emulated skin and cranium; and the laser-ablated nanoparticles mimicked the muscle. Although it was possible to establish qualitative similarities between the phantoms and the biological tissues' optical transmittance spectra, there is a need for further studies with different components' combinations to ascertain curves that more closely mimic the biological tissues.

Clinical outcomes and complications of a new high-density polyethylene-based spherical integrated porous orbital implant.

PURPOSE: To describe our experience over 6 years using a new high-density polyethylene-based spherical integrated porous orbital implants (Oculfit). METHODS: This is an observational retrospective case series study analyzing all cases requiring Oculfit implants between February 2015 and September 2021. Clinical information regarding the population included, the characteristics of the implant, and the outcomes and complications during the follow-up were noted. The success of the implant was defined according to anatomical and functional parameters. RESULTS: The study analyzed 90 cases of anophthalmic patients. The main causes for enucleation or evisceration were ocular decompensations (36.7%) and neoplasms (27.8% uveal melanoma and 7.8% retinoblastoma). Anatomical success was identified in 63 (70.0%) cases, functional success in 79 (87.8%) and complete success (anatomical + functional) in 61 (67.7%) cases. Factors associated with the functional success were age and exposure of the primary orbital implant. Complications appeared in 11 (12.2%) cases, which were completely resolved without sequelae in 4 (4.4%). Orbital explant was required in 5 (5.6%) cases. CONCLUSION: In our experience, Oculfit can be considered a useful alternative among the currently available options for orbital implants and has a good efficacy/safety profile.

Analysis and relationship between the volume of upper limb lymphoedema and pressure pain threshold, neural range of motion, pain intensity, kinesiophobia, pain hypervigilance and catastrophizing in breast cancer survivors.

BACKGROUND: Lymphedema of the upper limbs and persistent pain are frequent sequelae after surgical treatment of breast cancer. AIM: The aim of this paper was to analyze the upper limb volume, pressure pain threshold, neural range of motion, pain intensity, kinesiophobia, pain hypervigilance and catastrophizing in patients with and without lymphoedema after breast cancer surgery. Secondly, we aimed to investigated the association between upper limb volume and these variables. DESIGN: Descriptive observational study. SETTING: Faculty of Health Sciences of the University of Granada. POPULATION: Fifty-eight post-surgical breast cancer survivors, 29 with upper limb lymphoedema and 29 without lymphoedema. METHODS: We measured upper limb volume (perimetric method). Also, pressure pain thresholds were assessed with a digital algometer, neural range of motion (neurodynamic test for radial, ulnar and median nerves), pain intensity (visual analogue scale), kinesiophobia, pain hypervigilance and catastrophizing (validated tests). To detect differences between the groups for the measurement variables we performed a t-test for independent samples analysis. A simple linear regression analysis adjusting for age and body mass index was performed to check the association among upper limb volume and pain variables in the group with lymphoedema. RESULTS: The analysis showed that lymphoedema group had lower pressure pain threshold bilaterally in the masseter (origin P≤0.036; insertion P≤0.046), temporalis (insertion P≤0.021), suboccipitalis (P≤0.036); second (P≤0.014), third (P≤0.001) and tenth rib (P≤0.001); affected side of the temporalis (origin P=0.025); temporomandibular joint (P=0.024); neural range of motion in the median nerve (P=0.047), ulnar (P=0.042) on the affected side and radial (P=0.039) on the unaffected side; and greater kinesiophobia (P=0.042). Linear regression analysis only showed a significant association between upper limb volume and neural range of motion in the radial nerve (P=0.020) in the lymphedema group. No significant associations were obtained for the rest of variables. CONCLUSIONS: These findings suggest that the presence of lymphoedema may contribute to an increased level of generalized mechanosensitivity and fear to movement in this population. CLINICAL REHABILITATION IMPACT: Upper limb lymphedema can lead to heightened mechanosensitivity and movement-related fear in breast cancer survivors. Therefore, fast track rehabilitation approach should be focus in screening and rehabilitation methods for detection and control this sequalae.

Left atrial function in patients with rheumatic mitral stenosis: addressing prognostic insights beyond atrial fibrillation prediction.

Aims: Rheumatic mitral stenosis (MS) frequently leads to impaired left atrial (LA) function because of pressure overload, highlighting the underlying atrial pathology. Two-dimensional speckle tracking echocardiography (2D-STE) offers early detection of LA dysfunction, potentially improving risk assessment in patients with MS. This study aims to evaluate the predictive value of LA function assessed by 2D-STE for clinical outcomes in patients with MS. Methods and results: Between 2011 and 2021, patients with MS underwent LA function assessment using 2D-STE, with focus on the reservoir phase (LASr). Atrial fibrillation (AF) development constituted the primary outcome, with death or valve replacement as the secondary outcome. Conditional inference trees were employed for analysis, validated through sample splitting. The study included 493 patients with MS (mean valve area 1.1 ± 0.4 cm2, 84% female). At baseline, 166 patients (34%) had AF, with 62 patients (19%) developing AF during follow-up. LASr emerged as the primary predictor for new-onset AF, with a threshold of 17.9%. Over a mean 3.8-year follow-up, 125 patients (25%) underwent mitral valve replacement, and 32 patients (6.5%) died. A decision tree analysis identified key predictors such as age, LASr, severity of tricuspid regurgitation (TR), net atrioventricular compliance (C n), and early percutaneous mitral valvuloplasty, especially in patients aged ≤49 years, where LASr, with a threshold of 12.8%, significantly predicted adverse outcomes. Conclusion: LASr emerged as a significant predictor of cardiovascular events in this MS cohort, validated through a decision tree analysis. Patients were stratified into low- or high-risk categories for adverse outcomes, taking into account LASr, age, TR severity, and C n.

Early science and colossal stone engineering in Menga, a Neolithic dolmen (Antequera, Spain).

Megaliths represent the earliest form of monumental stone architecture. The earliest megalithic chambers in Europe appeared in France in the fifth millennium BCE. Menga is the oldest of the great dolmens in Iberia (approximately 3800 to 3600 BCE). Menga's capstone #5 weighing 150 tons is the largest stone ever moved in Iberia as part of the megalithic phenomenon and one of the largest in Europe. The research presented here proposes a completely innovative interpretation of how this colossal monument was built. It comprises a geoarchaeological analysis encompassing three major components: (i) the angles of the planes of each stone, (ii) the stratigraphic polarity of each structural element, and (iii) the depth of the foundations. Our results show that Menga is a unique example of creative genius and early science among Neolithic societies. It was designed as a completely original engineering project, for which we know of no precedents in Iberia.

Long-term sex differences in atherosclerotic cardiovascular disease in individuals with heterozygous familial hypercholesterolaemia in Spain: a study using data from SAFEHEART, a nationwide, multicentre, prospective cohort study.

BACKGROUND: Sex differences in atherosclerotic cardiovascular disease (ASCVD) in familial hypercholesterolaemia have been reported but are not fully established. We aimed to assess sex differences in the risk of ASCVD and life-time burden of ASCVD in patients with heterozygous familial hypercholesterolaemia. METHODS: SAFEHEART is a nationwide, multicentre, long-term prospective cohort study conducted in 25 tertiary care hospitals and one regional hospital in Spain. Participants in the SAFEHEART study aged 18 years or older with genetically confirmed familial hypercholesterolaemia were included in our analysis. Data were obtained between Jan 26, 2004, and Nov 30, 2022. ASCVD and age at onset were documented at enrolment and at follow-up. Our aim was to investigate the differences by sex in the risk and burden of ASCVD in patients with heterozygous familial hypercholesterolaemia, over the study follow-up and over the life course. The SAFEHEART study is registered with ClinicalTrials.gov, NCT02693548. FINDINGS: Of the 5262 participants in SAFEHEART at the time of analysis, 3506 (1898 [54·1%] female and 1608 [45·9%] male participants) met the inclusion criteria and were included in the current study. Mean age was 46·1 years (SD 15·5) and median follow-up was 10·3 years (IQR 6·4-13·0). Mean on-treatment LDL-cholesterol at follow-up was 3·1 mmol/L (SD 1·4) in females and 3·0 mmol/L (1·5) in males. LDL-cholesterol reductions over time were similar in both sexes (1·39 mmol/L [95% CI 1·30-1·47] absolute reduction in females vs 1·39 mmol/L [1·29-1·48] in males; p=0·98). At enrolment, 130 (6·8%) females and 304 (18·9%) males (p<0·0001) had cardiovascular disease. During follow-up, 134 (7·1%) females and 222 (13·8%) males (p<0·0001) had incident cardiovascular events. Median age at first ASCVD event (mostly due to coronary artery disease) was 61·6 years (IQR 50·0-71·4) in females and 50·6 years (42·0-58·6) in males (p<0·0001). The adjusted hazard ratio for ASCVD in males compared with females during follow-up was 1·90 (95% CI 1·49-2·42) and for cardiovascular death was 1·74 (1·11-2·73). Major adverse cardiovascular disease event (MACE)-free survival from birth was lower in males than females (hazard ratio 3·52 [95% CI 2·98-4·16]; p<0·0001). Median MACE-free survival time was 90·1 years (95% CI 86·5-not estimable) in females and 71·0 years (69·2-74·6) in males. The age at which 25% of female participants have had a MACE event was 74·9 years, this figure was 55·5 years in male participants. INTERPRETATION: Our findings suggest that the burden and risk of ASCVD are markedly lower in females than males with familial hypercholesterolaemia. The impact of sex needs to be considered to improve risk stratification and personalised management in patients with heterozygous familial hypercholesterolaemia. FUNDING: Fundación Hipercolesterolemia Familiar, the Instituto de Salud Carlos III, and Next Generation EU funds from the Recovery and Resilience Mechanism Program. TRANSLATION: For the Spanish translation of the abstract see Supplementary Materials section.

Use of a new aiming compression device and technique for the repair of navicular bone fractures in horses: A cadaveric study.

OBJECTIVE: To assess the use of a newly developed aiming compression device (ACD) for screw insertion in non-fractured navicular bones (NB) in cadavers. STUDY DESIGN: Cadaveric study. SAMPLE POPULATION: A total of 10 cadaveric front limbs of adult horses. METHODS: Placement of a 3.5 mm cortical screw in non-fractured NB under radiographic guidance was performed in 10 cadaver limbs in a standing position. An ACD was used to stabilize the NB and to guide the drilling process. Preparation and surgical time as well as the number of radiographic images were noted. A postoperative scoring system was used to assess screw placement by cone beam computed tomography (CBCT) and gross examination by two evaluators. RESULTS: The total procedure time was 25-62 min (median 33.5). During the procedure, 11-21 radiographs (median 18.5) were taken. The postoperative gross examination revealed an excellent screw placement in nine NB and poor in one. This could not be reliably assessed with post-procedure CBCT. CONCLUSION: The described technique achieves an excellent screw placement in 9/10 bones without disrupting the articular or flexural surface of the NB and with no protrusion of the screw head or tip, in a median procedure time of under 35 min. CLINICAL SIGNIFICANCE: Adequate screw placement is paramount for NB fracture repair. The described approach under radiographic guidance allows adequate screw placement using the ACD to stabilize the NB by lateral to medial compression. This technique facilitates adequate screw placement within the NB without the use of advanced imaging techniques.

Fetal growth restriction and placental defects in obese mice are associated with impaired decidualisation: the role of increased leptin signalling modulators SOCS3 and PTPN2.

Decidualisation of the endometrium is a key event in early pregnancy, which enables embryo implantation. Importantly, the molecular processes impairing decidualisation in obese mothers are yet to be characterised. We hypothesise that impaired decidualisation in obese mice is mediated by the upregulation of leptin modulators, the suppressor of cytokine signalling 3 (SOCS3) and the protein tyrosine phosphatase non-receptor type 2 (PTPN2), together with the disruption of progesterone (P4)-signal transducer and activator of transcription (STAT3) signalling. After feeding mice with chow diet (CD) or high-fat diet (HFD) for 16 weeks, we confirmed the downregulation of P4 and oestradiol (E2) steroid receptors in decidua from embryonic day (E) 6.5 and decreased proliferation of stromal cells from HFD. In vitro decidualised mouse endometrial stromal cells (MESCs) and E6.5 deciduas from the HFD showed decreased expression of decidualisation markers, followed by the upregulation of SOCS3 and PTPN2 and decreased phosphorylation of STAT3. In vivo and in vitro leptin treatment of mice and MESCs mimicked the results observed in the obese model. The downregulation of Socs3 and Ptpn2 after siRNA transfection of MESCs from HFD mice restored the expression level of decidualisation markers. Finally, DIO mice placentas from E18.5 showed decreased labyrinth development and vascularisation and fetal growth restricted embryos. The present study revealed major defects in decidualisation in obese mice, characterised by altered uterine response to E2 and P4 steroid signalling. Importantly, altered hormonal response was associated with increased expression of leptin signalling modulators SOCS3 and PTPN2. Elevated levels of SOCS3 and PTPN2 were shown to molecularly affect decidualisation in obese mice, potentially disrupting the STAT3-PR regulatory molecular hub.

Correction: Borges et al. The Roles of Potassium and Calcium Currents in the Bistable Firing Transition. Brain Sci. 2023, 13, 1347.

Funding Updated [...].

Dendrochronological Analysis of Pinus pinea in Central Chile and South Spain for Sustainable Forest Management.

Pinus pinea is an important Mediterranean species due to its adaptability and tolerance to aridity and its high-quality pine nuts. Different forest types located in Mediterranean native and non-native environments provide the opportunity to perform comparative studies on the species' response to climate change. The aims of this study were to elucidate growth patterns of the species growing in native and exotic habitats and to analyze its response to climatic fluctuations, particularly drought, in both geographical contexts. Understanding stone pine (Pinus pinea) growth responses to climate variability in native and exotic habitats by comparing natural stands and plantations may provide useful information to plan adequate management under climate change. By doing so, we enhance the understanding of P. pinea's adaptability and provide practical approaches to its sustainable management. In this study, we reconstructed and compared the stem radial growth of seven stone pine stands, two in southern Spain and five in central-southern Chile, growing under different climatic conditions. We quantified the relationships between growth variability and climate variables (total rainfall, mean temperature, and SPEI drought index). Growth was positively correlated with autumn rainfall in plantations and with autumn-winter rainfall in natural stands. Growth was also enhanced by high autumn-to-spring rainfall in the driest Chilean plantation, whereas in the wettest and coolest plantation, such correlation was found in winter and summer. A negative impact of summer temperature was found only in one of the five Chilean plantations and in a Spanish site. The correlation between SPEI and tree-ring width indices showed different patterns between and within countries. Overall, exotic plantations showed lower sensitivity to climate variability than native stands. Therefore, stone pine plantations may be useful to assist in mitigating climate change.

Acid Mine Drainage Precipitates from Mining Effluents as Adsorbents of Organic Pollutants for Water Treatment.

Acid mine drainage (AMD) is one of the main environmental problems associated with mining activity, whether the mine is operational or abandoned. In this work, several precipitates from this mine drainage generated by the oxidation of sulfide minerals, when exposed to weathering, were used as adsorbents. Such AMD precipitates from abandoned Portuguese mines (AGO, AGO-1, CF, and V9) were compared with two raw materials from Morocco (ClayMA and pyrophyllite) in terms of their efficiency in wastewater treatment. Different analytical techniques, such as XRD diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR), N2 adsorption isotherms, and Scanning Electron Microscopy (SEM) with Energy Dispersive X-ray (EDX) were used to characterize these natural materials. The adsorption properties were studied by optimizing different experimental factors, such as type of adsorbent, adsorbent mass, and dye concentration by the Box-Behnken Design model, using methylene blue (MB) and crystal violet (CV) compounds as organic pollutants. The obtained kinetic data were examined using the pseudo-first and pseudo-second order equations, and the equilibrium adsorption data were studied using the Freundlich and Langmuir models. The adsorption behavior of the different adsorbents was perfectly fitted by the pseudo-second order kinetic model and the Langmuir isotherm. The most efficient adsorbent for both dyes was AGO-1 due to the presence of the cellulose molecules, with qm equal to 40.5 and 16.0 mg/g for CV and MB, respectively. This study confirms the possibility of employing AMD precipitates to adsorb organic pollutants in water, providing valuable information for developing future affordable solutions to reduce the wastes associated with mining activity.

Development of machine learning models for fractional flow reserve prediction in angiographically intermediate coronary lesions.

BACKGROUND: Fractional flow reserve (FFR) represents the gold standard in guiding the decision to proceed or not with coronary revascularization of angiographically intermediate coronary lesion (AICL). Optical coherence tomography (OCT) allows to carefully characterize coronary plaque morphology and lumen dimensions. OBJECTIVES: We sought to develop machine learning (ML) models based on clinical, angiographic and OCT variables for predicting FFR. METHODS: Data from a multicenter, international, pooled analysis of individual patient's level data from published studies assessing FFR and OCT on the same target AICL were collected through a dedicated database to train (n = 351) and validate (n = 151) six two-class supervised ML models employing 25 clinical, angiographic and OCT variables. RESULTS: A total of 502 coronary lesions in 489 patients were included. The AUC of the six ML models ranged from 0.71 to 0.78, whereas the measured F1 score was from 0.70 to 0.75. The ML algorithms showed moderate sensitivity (range: 0.68-0.77) and specificity (range: 0.59-0.69) in detecting patients with a positive or negative FFR. In the sensitivity analysis, using 0.75 as FFR cut-off, we found a higher AUC (0.78-0.86) and a similar F1 score (range: 0.63-0.76). Specifically, the six ML models showed a higher specificity (0.71-0.84), with a similar sensitivity (0.58-0.80) with respect to 0.80 cut-off. CONCLUSIONS: ML algorithms derived from clinical, angiographic, and OCT parameters can identify patients with a positive or negative FFR.

The effect of cycloplegia in the accuracy of autorefraction, keratometry and axial length using the Myopia Master.

BACKGROUND: Assessing refractive errors under cycloplegia is recommended for paediatric patients; however, this may not always be feasible. In these situations, refraction has to rely on measurements made under active accommodation which may increase measurements variability and error. Therefore, evaluating the accuracy and precision of non-cycloplegic refraction and biometric measurements is clinically relevant. The Myopia Master, a novel instrument combining autorefraction and biometry, is designed for monitoring refractive error and ocular biometry in myopia management. This study assessed its repeatability and agreement for autorefraction and biometric measurements pre- and post-cycloplegia. METHODS: A prospective cross-sectional study evaluated a cohort of 96 paediatric patients that underwent ophthalmologic examination. An optometrist performed two repeated measurements of autorefraction and biometry pre- and post-cycloplegia. Test-retest repeatability (TRT) was assessed as differences between consecutive measurements and agreement as differences between post- and pre-cycloplegia measurements, for spherical equivalent (SE), refractive and keratometric J0/J45 astigmatic components, mean keratometry (Km) and axial length (AL). RESULTS: Cycloplegia significantly improved the SE repeatability (TRT, pre-cyclo: 0.65 D, post-cyclo: 0.31 D). SE measurements were more repeatable in myopes and emmetropes compared to hyperopes. Keratometry (Km) repeatability did not change with cycloplegia (TRT, pre-cyclo: 0.25 D, post-cyclo:0.27 D) and AL repeatability improved marginally (TRT, pre-cyclo: 0.14 mm, post-cyclo: 0.09 mm). Regarding pre- and post-cycloplegia agreement, SE became more positive by + 0.79 D, varying with refractive error. Myopic eyes showed a mean difference of + 0.31 D, while hyperopes differed by + 1.57 D. Mean keratometry, refractive and keratometric J0/J45 and AL showed no clinically significant differences. CONCLUSIONS: Refractive error measurements, using the Myopia Master were 2.5x less precise pre-cycloplegia than post-cycloplegia. Accuracy of pre-cycloplegic refractive error measurements was often larger than the clinically significant threshold (0.25 D) and was refractive error dependent. The higher precision compared to autorefraction measurements, pre- and post-cycloplegia agreement and refractive error independence of AL measurements emphasize the superiority of AL in refractive error monitoring.

Perceptions and Behaviors of Nurses and Physicians During Bedside Rounds in Medical-Surgical Units.

BACKGROUND: Communication and collaboration among health care professionals during bedside rounds improve patient outcomes and nurses' and physicians' satisfaction. OBJECTIVES: To determine barriers to nurse-physician communication during bedside rounds and identify opportunities to improve nurse-physician collaboration at an academic medical center. METHODS: A survey with Likert-scale and open-ended questions regarding professional attitudes toward nurse-physician communication was administered to 220 nurses and physicians in medical-surgical units to assess perceptions of participation in bedside rounds. After the survey was given, observational data from 1007 bedside rounds were collected via a standardized data collection tool. RESULTS: Nurses and physicians perceived different barriers to including nurses in bedside rounds. Nurses most often cited being unaware that bedside rounds were occurring (38 of 46 nurses [83%]); physicians most often cited nurse unavailability (43 of 52 physicians [83%]). Of 1007 observed rounds, 602 (60%) involved in-person contact of nurses and physicians; 418 (69%) of the 602 included a conversation between the nurse and physician about the nurse's concerns. Of 355 rounds with no in-person or telephone contact between nurses and physicians, the medicine team did not contact the nurse in 284 (80%). Conversations about nurses' concerns occurred more often after physician-initiated contacts (73% of 369 contacts) and nurse-initiated contacts (74% of 93 contacts) than after chance encounters (57% of 140 contacts). CONCLUSION: Initiating discussions of care between nurses and physicians and discussing nurses' concerns during bedside rounds have multiple benefits.