Observation Scale Research Articles

Remote sensing-based maize growth process parameters revel the maize yield: a comparison of field- and regional-scale

The accurate estimation of regional crop yields holds significant importance for optimizing subsequent resource allocation and maximizing economic returns in agriculture. Crop yield can be effectively estimated by assessing the overall growth status through long-term remote sensing observations. However, most previous studies have relied on remote sensing data from one or a few periods for yield estimation, thus lacking a comprehensive description of entire crop growth. Furthermore, past algorithms have not considered their applicability across different observational scales (e.g., unmanned aerial vehicle (UAV)- and satellite-observed). Considering this, we extracted four maize growth process parameters using Leaf Area Index (LAI) obtained from UAV (equipped with multispectral sensor, centimeter-level) and satellite (MODIS, 1 km) observations: PP_a (representing the duration of the crop growth period), PP_b (representing the peak growth stage of the crop), PP_c (representing the initial state of the crop), and LAImax (maximum LAI). These parameters were used to construct a maize yield estimation model applicable at both regional and field scales. The results indicate that the four process parameters extracted in this study can accurately estimate crop yields, with rRMSE = 14.08% at the field-scale and rRMSE = 17.75% at the regional-scale. Among these parameters, PP_a, representing the duration of the crop growth period, and the maximum LAI, are the parameters that individually contribute the most to the estimation accuracy. Moreover, the proposed method exhibited good spatial applicability (field-scale: Moran Index (MI) = -0.18; regional-scale: MI = 0.19). In conclusion, the parameters describing maize growth process derived from long-term-series observations can effectively estimate maize yield across different observation scales. This method not only facilitates the optimization of agronomic practices based on UAV observations but also supports the decision of regional agricultural policies based on satellite observations. Furthermore, crop yield estimation utilizing process-based parameters provides a new perspective for related studies.

Optimalisatie en validatie van de Vlaamse Observationele Pijnschaal bij Meervoudige Beperkingen (VOPS-MB) voor personen met een Meervoudige Beperking: een multidisciplinaire benadering

Optimization and validation of the Flemish Observational Pain Scale for Multiple Disabilities (VOPS-MB) for individuals with multiple disabilities: a multidisciplinary approach Introduction: People with severe cognitive impairments and multiple disabilities often experience pain, but this pain frequently goes unrecognized or untreated, negatively impacting their quality of life. Pain management in this group is challenging due to limited communication abilities and the lack of validated pain assessment tools. Aim: This study aims to optimize and validate the VOPS-MB pain scale of the Leieborg Care Center in Deinze for use with individuals with multiple disabilities. Methods: Optimization was carried out through a systematic literature review, an expert focus group, and a Delphi study. The scale's validation was tested through observations of 50 care recipients at the center, with inter-rater reliability measured using Pearson's r correlation coefficient and Cohen's kappa. Results: The optimized pain scale demonstrated high inter-rater reliability, with a Pearson's r of 0.947 and a Kappa value of 0.867. These results indicate that the scale provides reliable results, even when observations are conducted by individuals unfamiliar with the care recipient. Conclusion: This study shows that the pain scale is useful, practical and adequate to use in practice. Furthermore, the findings suggest that this pain scale can also be used in other contexts. The scale enables accurate pain measurement in people with intellectual disabilities, regardless of the observer's knowledge of the patient. Further validation, including digitization and testing for responsiveness, is recommended to enhance the scale's usability.

Study to Evaluate the Effectiveness of Acute Illness Observation Scale (AIOS) in Predicting the Severity of the Illness and Determining the Management Among Children of 2‐60 Months of Age with Acute Respiratory Illness

Study to Evaluate the Effectiveness of Acute Illness Observation Scale (AIOS) in Predicting the Severity of the Illness and Determining the Management Among Children of 2‐60 Months of Age with Acute Respiratory Illness

Three-dimensional imaging of topologically protected strings in a multiferroic nanocrystal

Multiferroic materials can host a plethora of intriguing phenomena due to the presence of multiple ferroic properties that break both spatial inversion symmetry and time reversal symmetry at an observable scale. Hexagonal manganite multiferroics are of particular interest as the properties of their symmetry-lowering phase transition can be described by a Mexican-hat-like potential energy surface. The early universe is proposed to have undergone a symmetry-lowering phase transition that is described by a similar Mexican-hat-like potential that gives rise to the formation of one-dimensional topologically protected defects known as cosmic strings. According to the Kibble-Zurek mechanism, hexagonal manganite multiferroics can host the crystallographic equivalent of cosmic strings and can therefore serve as a testing ground for exploration of concepts in cosmology. To date, however, direct imaging of 1D topological defects in a condensed matter material system has not been achieved. Here we report on robust three-dimensional imaging of topologically protected strings in a single hexagonal manganite nanocrystal, enabled by advances in experimental techniques. Our findings reveal multiferroic strings with a preferred phase vortex winding direction and average separation of ~93 nm.

Standardisation of the Brazilian version of Lucerne ICF-based multidisciplinary observational scale (LIMOS) into a patient-reported outcome measure (PROM)

Purpose The LIMOS is a validated observational tool designed to assess stroke rehabilitation within hospital settings. To enable its application in outpatient settings in Brazil and similar low- and middle-income countries, it is necessary to adapt LIMOS into a Patient-Reported Outcome Measure (PROM). Accordingly, this study aimed to translate, cross-culturally adapt, and standardise LIMOS for the Brazilian context (LIMOS-Br) and transform it into a PROM. Material and methods The adaptation process included translation, synthesis, expert evaluation, back-translation, target population evaluation and re-evaluation by experts. The study involved 100 adult stroke survivors. We assessed content validity, reliability, internal consistency, Criterion-related validity with the Functional Independence Measure (FIM), item and participant calibration, and accuracy. Results The LIMOS-Br demonstrated good internal consistency (Cronbach’s alpha = 0.8), and excellent intra- and inter-rater reliability (ICC2.1=0.97; 95%CI = 0.94–0.98 and ICC2.1=0.85; 95%CI = 0.74–0.91, respectively). Criterion-related validity with FIM was high (rho = 0.85; p < 0.01). Rasch analyses indicated high reliability indices (item: 0.96, people: 0.94), good item and person variance (separation indices: items 5.18, people 4.06), and adequate performance deviations. Accuracy for functional independence was optimal with a cut-off score of 180 points (sensitivity 83.3% and specificity 88.9%). Conclusions The LIMOS-Br maintained its clinimetric integrity, validating its use as a PROM.

Evaluation of the impact of refined nursing care on schizophrenia patients.

This study evaluates the impact of refined nursing interventions on patients with schizophrenia, focusing on disease severity, cognitive function, medication adherence, quality of life, and medication-related complications. The aim is to provide evidence for enhancing future clinical treatments. From January 2022 to January 2024, 201 schizophrenia patients were enrolled based on specific inclusion and exclusion criteria. Patients were allocated into 2 groups using propensity score matching: an experimental group that received refined nursing care and a control group that received routine care. Outcome measures included Positive and Negative Syndrome Scale scores, cognitive assessments (Mini-Mental State Examination and Nurses' Observation Scale for Inpatient Evaluation), medication adherence, quality of life, relapse rates, and medication-related side effects. After propensity score matching, baseline characteristics of the experimental and control groups were comparable. Following nursing interventions, the experimental group demonstrated significant improvements in Positive and Negative Syndrome Scale scores, cognitive assessments (Mini-Mental State Examination and Nurses' Observation Scale for Inpatient Evaluation), medication adherence, and quality of life compared to the control group. The experimental group also showed lower relapse rates and fewer medication side effects, confirming the enhanced effectiveness of refined nursing interventions. Refined nursing care significantly improved disease outcomes, cognitive function, medication adherence, and quality of life in schizophrenia patients, while reducing relapse rates and medication-related complications, highlighting its clinical value in psychiatric care.

An Ontology‐Augmented Digital Twin for Fiber‐Reinforced Polymer Structures at the Example of Wind Turbine Rotor Blades

A methodology for establishing a structural digital twin is proposed to facilitate the lifetime prediction of fiber‐reinforced polymer (FRP) structures, in this case, a wind turbine rotor blade. The digital twin incorporates production peculiarities and imperfections occurring during the manufacturing process of the FRP component. The methodology involves the computation of process‐defined effective elastic properties and residual stresses through numerical simulation of the resin cure cycle. The results are then transferred to a structural finite‐element model. By applying local wind conditions to this model, a comprehensive state of stress is obtained. This serves as a basis for a practical evaluation of material fatigue within the composite, leading to the prediction of the component's lifetime. The entire workflow is implemented in a Jupyter‐based application that uses an ontology with an appertaining knowledge graph to facilitate the transfer of intermediate results between the observation scales and process steps of the digital twin. In line with the principles of open science, the methodology utilizes open‐source software.

Integrating wide-swath altimetry data into Level-4 multi-mission maps

Abstract. Real-time observation of ocean surface topography is essential for various oceanographic applications. Historically, these observations have mainly relied on satellite nadir altimetry data, which were limited to observation scales greater than approximately 60 km. However, the recent launch of the wide-swath Surface Water Ocean Topography (SWOT) mission in December 2022 marks a significant advancement, enabling the two-dimensional global observation of finer-scale oceanic scales (∼ 15 km). While the direct analysis of the two-dimensional content of these swaths can provide valuable insights into ocean surface dynamics, integrating such data into mapping systems presents several challenges. This study focuses on integrating the SWOT mission into multi-mission mapping systems. Specifically, it examines the contribution of the SWOT mission to both the current nadir altimetry constellation (six/seven nadirs) and a reduced nadir altimetry constellation (three nadirs). Our study indicates that within the current nadir altimetry constellation, SWOT's impact is moderate, as existing nadir altimeters effectively constrain surface dynamics. However, in a hypothetical scenario where a reduced nadir altimetry constellation is envisioned to be operational by 2030, the significance of wide-swath data in mapping becomes more pronounced. Alternatively, we found that data-driven and dynamical mapping systems can significantly participate in refining the resolution of the multi-mission gridded products. Consequently, integrating high-resolution ocean surface topography observations with advanced mapping techniques can enhance the resolution of satellite-derived products, providing promising solutions for studying and monitoring sea-level variability at finer scales. However, to fully exploit SWOT's capabilities, future research will need to focus on innovations in data gridding and assimilation to extend mapping beyond geostrophically balanced flows.

Reducing children’s anxiety and pain in dental environment using an eye massage device combined with natural sounds—a randomized controlled trial

This study evaluated the efficacy of an eye massage device that uses acupressure points combined with natural sounds to reduce anxiety and pain in children receiving dental anesthesia for the first time. A total of 105 children aged between 8 and 10 years whose dental treatment required inferior alveolar nerve block (IANB) injection participated in this randomized controlled clinical trial. The participants were randomly divided into three groups: Group A: eye massage with natural sounds; Group B: eye massage only; and Group C (control group): traditional behavior management techniques. Anxiety and pain were assessed before, during, and after anesthesia using the Children’s Fear Scale (CFS), Wong-Baker pain rating scale (WBS), the Face-Legs-Activity-Cry-Consolability (FLACC) observational pain assessment scale, and pulse rate as a physiological scale. Anxiety and pain significantly decreased in groups A and B compared with those in the control group (p < 0.05), with group A showing a greater decrease in pulse rate and objective pain assessed during injection via the FLACC scale than group B (p < 0.05); however, no significant difference was noted between groups A and B regarding the data recorded after anesthesia using the WBS and CFS (p > 0.05). Changes in pulse rate and anxiety levels (CFS) measured before and after the procedure in each group revealed a significant decrease in fear and pulse rate in group A and no significant change in group B, whereas group C showed a significant increase in pulse rate and fear at the end of the procedure. Eye massage with natural sounds can effectively alleviate children’s anxiety in the dental setting and reduce pain related to anesthesia, and the combination of these two interventions has the best relaxation effect on children.

Effects of instructional therapeutic play in the behavior of children during the first attempt at intravenous catheterization.

To verify the effects of instructional therapeutic play on the behavior of children during the first attempt at peripheral intravenous catheterization. This is a quasi-experimental post hoc analysis with a non-equivalent control group, secondary to a randomized clinical trial. The convenience sample comprised 193 children, allocated for convenience into an intervention group (preparation for catheterization with a therapeutic play; n=101 children) and a control group (preparation with structured conversation supported by the use of a booklet; n=92 children). The Observation Scale of Behavior Distress was used to evaluate opposing behavior (attacking the professional, whining, crying, getting nervous, screaming, moving until being immobilized, and protesting) and non-opposing behavior (helping and asking for information. We conducted descriptive and inferential analyses of the data. Statistically significant differences were observed between the intervention and control groups in the variables: nervousness, moving to immobilization, protest and assistance during venipuncture. The use of therapeutic play reduced the risk of being nervous during the procedure by 43%, the risk of moving did so by 51%, and the risk of not protesting by 51%. Furthermore, assistive behavior during the procedure increased by 27%. The instructional therapeutic play was effective in reducing behaviors competing with intravenous catheterization and favored the child's collaboration in their first attempt.

A field-level emulator for modified gravity

Abstract Stage IV surveys like LSST and Euclid present a unique opportunity to shed light on the nature of dark energy. However, their full constraining power cannot be unlocked unless accurate predictions are available at all observable scales. Currently, only the linear regime is well understood in models beyond ΛCDM: on the nonlinear scales, expensive numerical simulations become necessary, whose direct use is impractical in the analyses of large datasets. Recently, machine learning techniques have shown the potential to break this impasse: by training emulators, we can predict complex data fields in a fraction of the time it takes to produce them. In this work, we present a field-level emulator capable of turning a ΛCDM N-body simulation into one evolved under f(R) gravity. To achieve this, we build on the map2map neural network, using the strength of modified gravity $|f_{R_0}|$ as style parameter. We find that our emulator correctly estimates the changes it needs to apply to the positions and velocities of the input N-body particles to produce the target simulation. We test the performance of our network against several summary statistics, finding $1{{\%}}$ agreement in the power spectrum up to k ∼ 1 h Mpc−1, and $1.5{{\%}}$ agreement against the independent boost emulator eMantis. Although the algorithm is trained on fixed cosmological parameters, we find it can extrapolate to models it was not trained on. Coupled with available field-level emulators and simulation suites for ΛCDM, our algorithm can be used to constrain modified gravity in the large-scale structure using full information available at the field level.

Scale dependence of bird diversity in London

ContextUnderstanding drivers of biodiversity in cities can be mutually beneficial for ecosystems and people. Crowd-sourced bird observations provide an opportunity to assess how patterns of bird diversity change across observation scales and suggest driving processes.ObjectivesWe assessed the scale dependence of bird diversity within a 128 × 128 km extent over London’s urban–rural gradient to suggest scales at which key drivers may be operating.MethodsWe quantified scale variance of bird diversity across scales from 500 m to 64,000 m for three groups of species (All, Passeriformes, and Anseriformes and Charadriiformes combined). We estimated diversity by aggregating observations into a series of grids and computed comparable diversity estimates within each cell using interpolation and rarefaction. We calculated the variance explained by each scale for common diversity metrics.ResultsThe results show that bird diversity patterns around London vary by scale, and that the location of high variance shifts across the study area depending on both scale and species group. The variance of Passeriformes diversity gradually shifted from the urban core to the periphery, while variance of Anseriformes and Charadriiformes diversity occurred near water features.ConclusionsThe results suggest that the urban–rural gradient and location of water are two properties of the study extent around London influencing the scale dependance of bird diversity that could be used to ground scale considerations of further modeling efforts.

Nasal High Flow to Modulate Dyspnea in Orally Intubated Patients.

High flow therapy reduces dyspnea in acute respiratory failure but the underlying mechanisms are not fully elucidated. To compare dyspnea, airway occlusion pressure (P0.1) and inspiratory work with and without nasal high flow (NHF, FiO2 21%, temperature 31°C) in intubated patients under pressure support ventilation and during a spontaneous breathing trial (SBT). Dyspnea (numerical rating scale, NRS and Mechanical Ventilation - Respiratory Distress Observational Scale, MV-RDOS), P0.1, esophageal pressure, respiratory muscles EMG, arterial blood gas were compared in intubated patients on pressure support ventilation presenting a dyspnea-NRS > 3 during two sequences: 1) pressure support ventilation with NHF at 0 L/min followed by 30, 50 and 60 L/min (the last three were randomized) and 2) a SBT with NHF at 0 and 50 L/min (randomized). Twenty patients were included. During pressure support ventilation, as compared to dyspnea-NRS that was 5 (4 - 6) at NHF 0 L/min, dyspnea-NRS was 3 (2 - 6) and 3 (2 - 5) at NHF 30L/min and NHF 50L/min, respectively (p<0.05). However, there was no change in MV-RDOS, P0.1, esophageal pressure, respiratory muscles EMG and gas exchange. During the SBT, at NHF 50 L/min, dyspnea-NRS and P0.1 were lower than during the SBT at NHF 0 L/min (p<0.01 and p=0.04 respectively) whereas MV-RDOS, esophageal pressure, respiratory muscles EMG did not change as compared to SBT with NHF 0 L/min. In orally intubated patients, nasal high flow was associated with lower dyspnea and lower respiratory drive without affecting the inspiratory work.

Improving Leadership in the Digital Era: A Case Study from Rural Mexico

The development of leadership competencies is a current topic in the scientific community. The weaknesses detected in our study reflect the limited treatment offered to this area of work and the current struggle of rural elementary school directors in navigating the challenges of the digital era. The following methods and techniques were used at the theoretical and empirical levels: analytical–synthetic, historical–logical, inductive–deductive, systemic, documentary analysis, observation, surveys, interviews, and self-assessment scales. The systematized theory is based on the process of development of leadership competence in school directors as a dimension of educational quality. This research introduced a professional development strategy for the development of leadership competence in primary school directors consisting of three stages, with their objectives and actions contributing to raising the scientific methodological level of these management teams, including workshops, consultancies, accompaniments, and case studies, as well as monitoring their transformation. The proposed strategy improves the educational leadership skills of school principals, encourages mastery of content, and increases the degree of motivation and interest in management work. It is based on the diagnosis of their reality, and it includes the combination of improvement, methodological, and self-improvement actions to stimulate reflection and the active involvement of participants in their own transformation process.

Impact of Neglect on the Relationship Between Upper Limb Motor Function and Upper Limb Performance in the (Hyper)acute Poststroke Phase.

Visuospatial neglect (VSN) is a negative, strong, and independent predictor of poor outcome after stroke, and is associated with poorer upper limb (UL) motor recovery in terms of function or capacity (ie, in standardized, lab-based testing). Although the main aim of stroke rehabilitation is to re-establish optimal functioning in daily life, the impact of VSN on UL performance (ie, in unstructured, everyday environments) is largely unknown. In this proof of principle study, the impact of VSN on the strength of the association between UL motor function (Jamar Hand Dynamometer) and UL performance (Upper Limb Lucerne ICF-based Multidisciplinary Observation Scale) was investigated in 65 (hyper)acute first-ever stroke patients. In a moderator analysis, the interaction term was negative and significant, showing that VSN suppresses the use of UL motor function in daily life (ie, performance). This finding suggests that, when considering UL performance in the (hyper)acute phase after stroke, interventions aimed to reduce deficits in both UL motor function and visuospatial function should already be started in the acute stroke unit setting.

A prospective, observational study of a pediatric affect and cooperation scale (HRAD±) for vascular access procedures.

Anxiety is common in pediatric patients, especially during vascular access procedures. Most well-studied affect and anxiety scales, including the Observation Scale of Behavioral Distress-Revised (OSBD-r), the modified Yale Preoperative Anxiety Scale (mYPAS), and the modified Induction Compliance Checklist (mICC), are too cumbersome for clinical use outside of research settings. HRAD± (Happy, Relaxed, Anxious, Distressed with yes/no to cooperation) is a clinically-efficient observational scale that evaluates pediatric procedural affect and cooperation. This study examined the clinical utility of HRAD± during vascular access procedures in children. The aims were to investigate the correlation of HRAD± to highly reliable, research-based affect and cooperation scales and to assess inter-rater reliability (IRR) between observers in this setting. This was a prospective, observational study conducted at Lucile Packard Children's Hospital Stanford. Inpatient participants were 1 month to 25 years old and undergoing a peripheral intravenous insertion or phlebotomy. Two trained research assistants (RAs) scored each patient independently during the vascular access procedure using HRAD±, OSBD-r, mYPAS, and mICC. Correlation analyses computed the associations between HRAD± and reference scales. IRR between RAs and vascular access providers was calculated using Fleiss' Kappa. A total of 234 patients were included. HRAD± scores strongly correlated with OSBD-r and mYPAS (p < 0.0001, p < 0.0001, respectively). The cooperation assessment of HRAD± demonstrated strong correlation to mICC (p < 0.0001). IRR of HRAD± between research assistants and vascular access providers showed moderate agreement (p < 0.0001). HRAD± demonstrated strong correlation to the reference affect and cooperation scales. This study supports the utility of HRAD± for rapid assessment of pediatric procedural anxiety and cooperation during vascular access procedures. HRAD± can serve as a practical tool for facilitating clinical decisions, and its wider incorporation into healthcare settings would importantly guide targeted interventions to reduce patient anxiety.

A preliminar study on RVE homogenization for phase-field multiscale analysis

Despite the phenomenological approach presents excellent results in material behavior analysis, real-world materials are inherently heterogeneous. A material is considered heterogeneous when, at a particular observation scale, it becomes feasible to discern multiple mixture phases within it. This level of observation is commonly referred to as the microscale, where interactions between constituents occur, ultimately leading to the emergence of cracks.Modeling a material at the microscale begins with defining a Representative Volume Element (RVE), which is the smallest part of the material that is large enough to statistically represent the entire mixture. This ensures that other samples of the same size exhibit similar properties with minor variations. The analysis of the RVE leads to obtaining the effective properties of a portion of the material. That process is called homogenization.Modeling a RVE can be a challenging task, as it requires the use of highly refined meshes to accurately capture the geometric representation of all mixture components. Therefore, phase-field models present themselves as a suitable choice for this type of modeling, once due to the intrinsic features of its variational formulation, they already need refined meshes and do not present localization effects.Thus, the objective of this work is to model a heterogeneous RVE and obtain its homogenized properties. This homogenization of the material parameters is fundamental for the upscaling operation of multiscale analyses.All implementation were done in INSANE, an opensource software developed by the Engineering Structures Department (DEES) of Federal University of Minas Gerais (UFMG).

Multiscale Wettability of Microtextured Irregular Surfaces.

Surface microgeometry created by the energy of electric discharges is related to surface wetting behavior. These relationships change depending on the scale of observation. In this work, contact angles correlated with the surface complexity of AA 6060 after electro-discharge machining were analyzed at different observation scales. This research focuses on the methodology of selecting the best scales for observing wetting phenomena on irregular surfaces, as well as indicating the topographic characterization parameters of the surface in relation to the scales. Additionally, the geometric features of the surface that determine the contact angle were identified. In this study, the surfaces of an aluminum alloy are rendered using focus variation 3D microscopy and described by standardized ISO, area-scale, and length-scale parameters. The research also confirms that it is possible to design surface wettability, including its hydrophilicity and hydrophobicity, using electrical discharge machining parameters. The static and dynamic behavior of liquids on surfaces relevant to contact mechanics was also determined.

(Dis)Order in Submarine Fans at Different Observational Scales: An Example From Unit a of the Laingsburg Formation, Karoo Basin

Perceived order in submarine fans is traditionally used to support simple sequence stratigraphic interpretation of allogenic forcing but evidence is typically limited to qualitative evaluation of the geological dataset. Quantitative analysis of the well-studied ‘Unit A’ basin-floor fan from the Laingsburg Formation, Karoo Basin, South Africa suggests a more complex interpretation. We use Markov facies analysis to test for order in the facies successions, and runs tests and power spectral analyses to assess order in the succession of bed thicknesses. Some bed-by-bed order is detectable in the facies successions, but thickness successions are more complex; no order is detectable as simple consistent bed-by-bed runs of thickening or thinning-upwards. Spectral analysis does detect some significant periodicities, but the periods are different in each vertical section analysed, ranging from 35-45 beds, 50-55 beds and from 60-70 beds in respective vertical sections. This perhaps indicates that complex autogenic compensational stacking processes control the details of how patterns emerge at specific locations, even when larger-scale trends do occur in regional stacking of lobes and lobe complexes and there is no evidence for a single, dominant allogenic control the Karoo submarine fan strata. More comprehensively, this analysis suggests that sequence stratigraphic interpretations of outcrop and core deep-water strata will be more robust with integrated quantitative bed thickness and facies trend analysis as a standard approach. Sequence stratigraphic interpretations of deep-water strata should avoid a model-driven single dominant control approach, and instead use the quantitative analysis to more fully explore the typical complexity of these strata.

Effects of Positive Expiratory Pressure Device on Gas Exchange, Atelectasis, Hemodynamics, and Dyspnea in Spontaneously Breathing Critically Ill Subjects.

EzPAP Positive Airway Pressure System (EzPAP) is a noninvasive positive expiratory pressure (PEP) device designed to promote lung expansion. The aim of this study was to evaluate the effects of PEP on gas exchange. Secondary objectives included assessing the early effects of PEP on radiological atelectasis score (RAS), hemodynamics, and dyspnea. These outcomes were compared between spontaneously breathing subjects with and without tracheostomy. This observational single-center study was conducted at a university hospital. Inclusion criteria were spontaneously breathing adult subjects with RAS ≥ 2 and a worsened PaO2 /FIO2 . Exclusion criteria included life-threatening conditions, intracranial hypertension, hemodynamic instability, and pneumothorax. Gas-exchange, hemodynamic parameters, and dyspnea measured with the Respiratory Distress Observation Scale (RDOS) were assessed at 3 time points: T0 (before PEP), T1 (immediately after PEP), and T2 (2 h after PEP). RAS was assessed at T0 and 1-week post treatment (T3). Of 213 patients assessed for eligibility, 186 were excluded for various reasons, leaving 27 subjects (19 without and 8 with tracheostomy) enrolled in the study. The median [interquartile range] age was 65 [58-74] y, with 66.7% being male. In the overall sample and in subjects without tracheostomy, PaO2 /FIO2 did not differ significantly between T1 and T0 (P = .52 and P = .54, respectively) or between T2 and T0 (P = .47 and P = .85, respectively). In subjects with tracheostomy, PaO2 /FIO2 was higher at T1 compared to T0 (P = .039) but not between T2 and T0 (P = .58). Arterial PaO2 and hemodynamic parameters remained unchanged in the overall cohort. The RAS improved within 1 week of treatment in the overall cohort (T3 vs T0, P < .001) and in subjects without tracheostomy (T3 vs T0, P = .001). However, PEP therapy did not improve RDOS. In critically ill, spontaneously breathing subjects, PEP therapy significantly improved RAS without affecting hemodynamic stability or respiratory symptoms.