Search Results (19)

Accurate and rapid prediction of sensor responses is critical for real-time measurement systems, digital twin implementations, and sensor design optimization. Traditional numerical methods such as Finite Element Method (FEM) and Computational Fluid Dynamics (CFD) provide high-fidelity solutions but suffer from prohibitive computational costs, limiting their applicability in time-sensitive applications. This paper presents a novel framework utilizing Fourier Neural Operators (FNO) as surrogate models for fast multi-physics sensor response prediction across thermal, acoustic, and flow measurement domains. Unlike conventional neural networks that learn finite-dimensional mappings, FNO learns operators between infinite-dimensional function spaces by parameterizing the integral kernel in Fourier space, enabling resolution-invariant predictions with remarkable computational efficiency. We demonstrate the framework’s efficacy through three comprehensive case studies: (1) thermal sensor response prediction achieving $R^2>0.98$ with 8300× speedup over FEM, (2) acoustic sensor array modeling with mean absolute error below 0.5 dB and 4000× speedup over BEM, and (3) flow sensor characterization with velocity field prediction accuracy exceeding 97% and 31,000× speedup over CFD. The proposed FNO-based surrogate models are trained on simulation datasets generated from high-fidelity numerical solvers and validated against simulation holdout data for all three case studies, with additional experimental validation conducted for the thermal sensor case. Results indicate that FNO architectures effectively capture the underlying physics governing sensor behavior while reducing inference time from minutes to milliseconds. The framework enables real-time sensor calibration, uncertainty quantification, and design optimization, opening new possibilities for intelligent measurement systems and Industry 4.0 applications. We also investigate the spectral characteristics of FNO predictions, addressing the inherent low-frequency bias through a hybrid architecture combining FNO with local convolutional layers. The primary contributions of this work include: (1) the first systematic application of FNO-based surrogate modeling specifically tailored for sensor response prediction across multiple physics domains, (2) a novel H-FNO architecture that combines spectral operators with local convolutions to mitigate spectral bias in sensor applications, and (3) comprehensive validation including both simulation and experimental data for practical deployment. This work establishes FNO as a powerful tool for accelerating sensor simulation and advancing the field of AI-enhanced instrumentation and measurement. Full article

Background: Weaning failure remains a major challenge in intensive care practice, often reflecting the interplay between systemic catabolism and skeletal muscle wasting. The blood urea nitrogen-to-creatinine (BUN/Cr) ratio is a routinely available biochemical index influenced by renal handling, hemodynamic status, protein metabolism, and muscle mass, and has been associated with adverse outcomes in critical illness. This study aimed to evaluate the association between BUN/Cr ratio, weaning outcomes, and ultrasound-based rectus femoris thickness. Methods: This retrospective observational study included 42 mechanically ventilated adults admitted to the medical ICU of Marmara University between December 2024 and September 2025. Rectus femoris thickness was measured via bedside ultrasonography at the time of the spontaneous breathing trial (SBT). Weaning success was defined as extubation without reintubation, death, or need for NIV/HFNO due to respiratory distress within 7 days. Laboratory and clinical variables—including BUN/Cr ratio, SOFA, APACHE II, mNUTRIC, and albumin—were recorded. Multivariable logistic regression and receiver operating characteristic (ROC) analyses were performed. Results: Weaning failure occurred in 13 patients (31.0%). These patients had higher BUN/Cr ratios (58.7 [44.6–76.9] vs. 39.7 [23.8–49.2], p = 0.007) and lower rectus femoris thickness (6.2 [5.4–7.0] vs. 7.8 [6.9–8.6] mm, p = 0.021). The BUN/Cr ratio independently predicted weaning failure (OR 1.07; 95% CI 1.01–1.14; p = 0.024). ROC analysis identified a BUN/Cr cut-off of 44.6 (AUC = 0.76) for weaning failure. An exploratory composite metabolic–muscle indicator (MMI), combining BUN/Cr ratio and rectus femoris thickness, demonstrated higher discriminative performance in this cohort (AUC = 0.81). Conclusions: An elevated BUN/Cr ratio was independently associated with weaning failure and lower rectus femoris thickness in this cohort. Given the observational design and potential confounding, these findings should be interpreted as hypothesis-generating. Combined biochemical and ultrasound-based assessment highlights the potential value of integrating metabolic and morphologic information when characterizing patients at risk for weaning failure. However, whether incorporation of such markers into clinical decision-making improves weaning outcomes requires prospective validation. Full article

Background: Data on high flow nasal oxygenation (HFNO) efficacy in hypoxia prevention in transcatheter aortic valve replacement (TAVR) are conflictive. We aimed to determine the benefit of HFNO in preventing the occurrence of desaturations during TAVR. Methods: An investigator-initiated, proof of concept, single-centre, randomised, and controlled trial on 132 adult patients who were scheduled to undergo transfemoral TAVR was conducted. Patients were randomised (1:1) to HFNO (H-group) with a flow rate of 50 L min⁻¹ and FiO₂ 0.6 or standard of care oxygen therapy (S-group). The primary endpoint was the number of patients with a desaturation episode (SpO₂ < 93%) for >10 s during TAVR. Secondary outcomes included arterial partial pressure of oxygen (pO₂) 45 min from sedation start and changes in glomerular filtration rate from baseline to 12 h post-procedure. Results: Between 23 November and 24 July, a per-protocol analysis was performed in a total of 125 patients (H-group n = 64; S- group n = 61; 49 females). The number of patients with any desaturation episode was significantly lower in the H-group [13/64 (20%, 95% CI: 12–32%)] than in the S-group [31/61 (51%, 95% CI: 39–63%), RR: 0.39 (95%CI: 0.23–0.68)]. At 45 min, mean (SD) pO₂ was higher in the H-group (24(9.8) kPa vs. 16.7(7.5) kPa; p < 0.005). A significant improvement in delta median (IQR) difference on glomerular filtration rate was observed in the H-group [1.6(−1–7.9) mL min⁻¹ 1.73 m⁻²] with respect to the S-group [0.2(−6.1–3.1) mL min⁻¹ 1.73 m⁻²; p-value: 0.013]. Conclusions: This trial demonstrated that HFNO provides a better oxygenation pattern than standard oxygen therapy during TAVR. Larger studies focusing on long-term clinical outcomes are warranted to evaluate the benefit of HFNO during sedation for TAVR procedures. Full article

Background/Objectives: At Fiona Stanley Hospital’s pulmonary rehabilitation program, people awaiting lung transplantation (LTx), whose exertional oxygen requirements are unable to be met with traditional oxygen interfaces, utilize high-flow nasal oxygen (HFNO) to exercise. In this paper, we aim to: (i) describe the characteristics of our service and of the people who have utilized HFNO; and (ii) explore differences between those who survived vs. did not survive whilst awaiting LTx. Methods: We conducted a description of the service and a retrospective analysis (from January 2021 to April 2024). The service description included: facility, equipment/cost, staffing/patient ratio, exercise program characteristics, and safety. Inclusion criteria for the analysis were: people actively listed for LTx and completion of three or more exercise sessions on HFNO. Data extracted included patient characteristics, comorbidities, 6-min walk distance (6MWD) prior to commencing HFNO, and survival pre-LTx. Differences between those who survived vs. did not survive whilst awaiting LTx were explored. Results: Nineteen patients were included (13 males; age 60 ± 12 yr; 18 with interstitial lung disease). The median [IQR] number of exercise sessions on HFNO was 15 [9; 25]. Eight (42%) patients died whilst awaiting LTx. In those who survived, the median time to LTx was 46 [25; 268] days. Compared to those who died, those who underwent LTx had fewer comorbidities (median: 2 [1; 4] vs. 4 [3; 5], p = 0.03). They also tended to be younger and have greater absolute 6MWD prior to commencing HFNO (mean difference, 95%CI: age −8.6 yr, −19.3 to 2.1; 6MWD 55 m, −74 to 185). Associations between dyspnea or body mass index with survival were not demonstrated. This analysis is hypothesis-generating rather than inferential, given the limited sample size. Conclusions: Our unique service of high-flow nasal oxygen (HFNO) use in patients participating in pulmonary rehabilitation whilst awaiting lung transplantation is described. Preliminary analysis suggests that, in people utilizing HFNO whilst awaiting LTx, those who underwent LTx had fewer comorbidities than those who did not survive the waitlist period. Larger studies are needed to explore further differences between those who survive vs. those who do not survive whilst awaiting LTx. Full article

Background and Objectives: a “vicious vortex” model was proposed to explain the pathophysiology of bronchiectasis, incorporating abnormal mucus, altered mucociliary clearance and chronic inflammation. Evidently, airway clearance needs to be implemented in the patient’s daily routine for a protracted period in order to ameliorate the clinical outcomes. High Flow therapy (HFT) has several physiologic effects and represents a valid therapy for various respiratory diseases. The aim of this study is to assess clinical and radiologic effects of long-term HFT in adult non-CF bronchiectasis. Materials and Methods: This is a retrospective observational cohort study including adult patients affected by bronchiectasis and frequent exacerbations and hospitalizations. A chest HRCT was performed, and a quantitative evaluation of the scans was conducted applying a modified Bhalla score of five items. A total of 44 patients completed the follow up, 23 in the HF-group and 21 in the controls (No-HF group). Results: The median follow up was 41 months (range 36–48 months). The mean age was 65 years, 45% were females. After treatment the annual rate of exacerbations was significantly lower in the HF group (1.2 ± 0.95 versus 3.5 ± 1.0 per year, p < 0.0001). The annual rate of hospitalizations was significantly lower in the HF group (0.4 ± 0.52 versus 1 ± 0.93 per year, p = 0.01). The total score of the modified Bhalla improved after treatment in the HF group with a mean score of 5.32 versus 8.38, p = 0.034. The difference was substantially due to the lower score of mucoid impactions in the HF group. Conclusions: Bronchiectasis is an evolutive disease. Long-term HFT reduces the annual rate of exacerbation and hospitalization. In addition, HFT prevents mucoid impaction and potentially influences the radiological evolution of the disease. Full article

Over time, endoscopic retrograde cholangiopancreatography (ERCP) evolved into the preferred method for both diagnosing and treating diseases of the biliary, pancreatic, and ampullary systems. Traditionally performed under “conscious” sedation, anesthesiological management during ERCP increasingly involves the use of general anesthesia (GA) due to the complexity of procedures and patient comorbidities. This narrative review aims to underscore the current absence of definitive evidence supporting a single airway management strategy during ERCP. In each section, we examine the strengths and limitations of various airway management strategies, including spontaneous breathing, endotracheal intubation, and newer techniques such as high-flow nasal oxygen (HFNO) and supraglottic airway devices (SGAs), tailored for endoscopic procedures. We explore and discuss the multifactorial determinants that influence clinical decision-making, including patient-specific risk factors, procedural complexity, resource availability, and potential complications. Any anesthesiological choice must guarantee the immobility of the patient and the versatility of the position and must be integrated with the preferences and skills of the endoscopist, the available means in the endoscopic suite, and the internal protocols. Spontaneous breathing with sedation may be appropriate for low-risk, short-duration procedures but carries risks of hypoventilation and aspiration, while GA with a device to manage airways improves procedural conditions and perioperative risks. Still, it is resource-intensive and may delay recovery. Transitions between different strategies are inherently fluid, reflecting the need for a flexible, patient-centered approach tailored to the specific clinical context. Rigorous future research is essential to establish evidence-based guidelines that enhance both safety and efficiency of airway management in this setting. Full article

Background: Airway management in otolaryngology presents unique challenges due to shared airway access, altered anatomy, and specific procedural requirements. This article examines current techniques and oxygenation strategies across various ENT procedures to provide a guide for otolaryngologists. Methods: A narrative review was performed of the contemporary literature, focusing on airway techniques in ENT surgery, including laryngeal surgery, pediatric bronchoscopy, transoral surgery, and trauma and emergency scenarios. A systematic search for difficult airway guidelines was performed using the EMBASE, Pubmed, and Cochrane databases to examine where guidelines are published. Results: The key areas for specialist airway management included laryngeal surgery in the tubeless field and adjuncts for emergency situations. High-flow nasal oxygen (HFNO), jet ventilation, video laryngoscopy, and specialized tubes emerged as key technological advances, improving safety and outcomes. A systematic search identified 947 difficult airway articles across 82 publishers. These were predominantly in anesthetic journals (n = 301), with limited representation in the otolaryngology literature (n = 8) and limited guidance concerning awake surgical tracheostomies under local anesthetic. Awake tracheal intubation and emergency front-of-neck access were identified as key techniques across multiple publications. Conclusions: Modern ENT airway management requires multidisciplinary planning, advanced equipment familiarity, and procedure-specific techniques. Despite having the expertise to perform the gold standard, the limited otolaryngology literature on difficult airways suggests that guidelines are primarily developed by the anesthetic community. Full article

Acute hypoxemic respiratory failure (ARF) is a common cause for hospital admission. High-flow nasal oxygen (HFNO) is increasingly used as a first-line treatment for patients with ARF, including in medical wards. Clinical guidance is crucial when providing HFNO, and health services use local health guidance documents (LHGDs) to achieve this. It is unknown what hospital LHGDs recommend regarding ward administration of HFNO. This study examined Australian hospitals’ LHGDs regarding ward-based HFNO administration to determine content that may affect safe delivery. A scoping review was undertaken on 2 May 2022 and updated on 29 January 2024 to identify public hospitals’ LHGDs regarding delivery of HFNO to adults with ARF in medical wards in two Australian states. Data were extracted and analysed regarding HFNO initiation, monitoring, maintenance and weaning, and management of clinical deterioration. Of the twenty-six included LHGDs, five documents referenced Australian Oxygen Guidelines. Twenty LHGDs did not define a threshold level of hypoxaemia where HFNO use was recommended over conventional oxygen therapy. Thirteen did not provide target oxygen saturation ranges whilst utilising HFNO. Recommendations varied regarding maximal levels of inspired oxygen and flow rates in the medical ward. Eight LHGDs did not specify any system to identify and manage deteriorating patients. Five LHGDs did not provide guidance for weaning patients from HFNO. There was substantial variation in the LHGDs regarding HFNO care for adult patients with ARF in Australian hospitals. These findings have implications for the delivery of high-quality, safe clinical care in hospitals. Full article

Introduction: The pandemic instigated by the SARS-CoV-2 virus has led to over 7 million deaths globally, primarily attributable to viral pneumonia. Identifying fundamental markers associated with an elevated risk of mortality can aid in the early identification of patients prone to disease progression to a severe state, enabling prompt intervention. Methods: This was a single-center, retrospective study. Results: In this study, we examined 299 patients admitted to the Department of Infectology and Travel Medicine in Košice, Slovakia, with PCR-confirmed COVID-19 pneumonia. Patients were monitored from 1 January 2021 to 31 March 2021, with the endpoint being discharge from the hospital or death. All patient-related data were retrospectively collected from medical records. This study identified several risk factors significantly associated with an increased risk of mortality, including the requirement of HFNO (p < 0.001), age over 60 years (p < 0.001), Ne/Ly values of >6 (p < 0.001), as well as certain lymphocyte subtypes—CD4+ < 0.2 × 10⁹/L (p = 0.035), CD8+ < 0.2 × 10⁹/L (p < 0.001), and CD19+ < 0.1 × 10⁹/L (p < 0.001)—alongside selected biochemical inflammatory markers—IL-6 > 50 ng/L (p < 0.001) and lactate > 3 mmol/L (p < 0.001). Conclusions: We confirmed that the mentioned risk factors were significantly associated with the death of patients from viral pneumonia in the hospital. Full article

The use of the Ratio of Oxygen Saturation (ROX) index to predict the success of high-flow nasal oxygenation (HFNO) is well established. The ROX can also predict the need for intubation, mortality, and is easier to calculate compared with APACHE II. In this prospective study, the primary aim is to compare the ROX (easily administered in resource limited setting) to APACHE II for clinically relevant outcomes such as mortality and the need for intubation. Our secondary aim was to identify thresholds for the ROX index in predicting outcomes such as the length of ICU stay and failure of non-invasive respiratory support therapies and to assess the effectiveness of using the ROX (day 1 at admission, day 2, and day 3) versus Acute physiology and chronic health evaluation (APACHE) II scores (at admission) in patients with Coronavirus Disease 2019 (COVID-19) pneumonia and Acute Respiratory Distress Syndrome (ARDS) to predict early, late, and non-responders. After screening 208 intensive care unit patients, a total of 118 COVID-19 patients were enrolled, who were categorized into early (n = 38), late (n = 34), and non-responders (n = 46). Multinomial logistic regression, receiver operating characteristic (ROC), Multivariate Cox regression, and Kaplan–Meier analysis were conducted. Multinomial logistic regressions between late and early responders and between non- and early responders were associated with reduced risk of treatment failures. ROC analysis for early vs. late responders showed that APACHE II on admission had the largest area under the curve (0.847), followed by the ROX index on admission (0.843). For responders vs. non-responders, we found that the ROX index on admission had a slightly better AUC than APACHE II on admission (0.759 vs. 0.751). A higher ROX index on admission [HR (95% CI): 0.29 (0.13–0.52)] and on day 2 [HR (95% CI): 0.55 (0.34–0.89)] were associated with a reduced risk of treatment failure. The ROX index can be used as an independent predictor of early response and mortality outcomes to HFNO and NIV in COVID-19 pneumonia, especially in low-resource settings, and is non-inferior to APACHE II. Full article

Introduction: The objective of this study is to assess the failure of therapies with HFNO (high-flow nasal oxygen), CPAP, Bilevel, or combined therapy in patients with hypoxemic acute respiratory failure due to SARS-CoV-2 during their hospitalization. Methods: This was a retrospective and observational study of SARS-CoV-2-positive patients who required non-invasive respiratory support (NIRS) at the Reina Sofía General University Hospital of Murcia between March 2020 and May 2021. Results: Of 7355 patients, 197 (11.8%) were included; 95 of them failed this therapy (48.3%). We found that during hospitalization in the ward, the combined therapy of HFNO and CPAP had an overall lower failure rate and the highest treatment with Bilevel (p = 0.005). In the comparison of failure in therapy without two levels of airway pressure, HFNO, CPAP, and combined therapy of HFNO with CPAP, (35.6% of patients) presented with 24.2% failure, compared to those who had two levels of pressure with Bilevel and combined therapy of HFNO with Bilevel (64.4% of patients), with 75.8% associated failure (OR: 0, 374; CI 95%: 0.203–0.688. p = 0.001). Conclusions: The use of NIRS during conventional hospitalization is safe and effective in patients with respiratory failure secondary to SARS-CoV-2 infection. The therapeutic strategy of Bilevel increases the probability of failure, with the combined therapy strategy of CPAP and HFNO being the most promising option. Full article

Patients with systemic autoimmune rheumatic disease (SARD) have increased susceptibility to viral infections, including SARS-CoV-2. The aim of this study was to analyse the SARD patient population with COVID-19 (coronavirus disease 2019) in terms of baseline characteristics, severity, course and outcomes of the disease compared with the non-SARD group, and to identify factors associated with prognosis, including remdesivir therapy efficacy. Retrospective study comprised 8220 COVID-19 cases from the SARSTer database, including 185 with SARD. Length of hospitalisation, duration of oxygen therapy, mortality and the need for HFNO (high-flow nasal oxygen) and/or NIV (noninvasive ventilation) were significantly higher in the SARD versus non-SARD group. There was no difference in clinical features on admission to hospital. Patients with SARD were older and more likely to have cardiovascular, pulmonary and chronic kidney diseases. Age, the presence of cardiovascular disease, more severe conditions on admission and higher inflammatory marker values were found to be risk factors for death in the SARD group. In patients with SARD treated with remdesivir, there was a trend towards improved mortality but without statistical significance. Length of hospitalisation, 28-day mortality and the need for HFNO and/or NIV were higher in the SARD group. These patients often had other chronic diseases and were older. Full article

Older individuals have an increased risk for severe coronavirus disease 2019 (COVID-19) and a higher risk for complications and death. The aim of this study was to investigate the clinical characteristics of older patients admitted with COVID-19 and describe their outcomes. This was a retrospective cohort study of patients older than 65 years admitted to the COVID-19 Department of the University Hospital of Heraklion. Data recorded and evaluated included age, gender, Infectious Diseases Society of America (IDSA) severity score, Charlson comorbidity index (CCI), high-flow nasal oxygen (HFNO) use, admission to the Intensive Care Unit (ICU), laboratory exams, treatment administered, and outcome. In total, 224 patients were evaluated in the present study. The median age was 75 years and 105 (46.9%) were female. In 50 patients (22.7%), HFNO was used and 23 (10.3%) were admitted to the ICU. Mortality was 13.4% (30 patients). Patients that died had higher age, were more likely to be male, had an IDSA severity score of 3, had prior HFNO use, had been admitted to the ICU, and were also more likely to have a higher white blood cell (WBC) count, CRP, ferritin, procalcitonin, d-dimers, and troponin. A multivariate logistic regression analysis identified age and the need for HFNO use to be independently positively associated with mortality. To conclude, COVID-19 carries significant mortality in hospitalized older patients, which increases with age, while the need for HFNO also increased the likelihood of worse outcomes. Clinicians caring for patients with COVID-19 should bear in mind these two factors. Future studies could elaborate on the effect of new variants on the dynamics of mortality in older patients. Full article

Obese patients are predisposed to rapid oxygen desaturation during tracheal intubation. We aimed to compare the risk of desaturation between high-flow nasal oxygenation (HFNO) and classical facemask oxygenation (FMO) during rapid sequence intubation for elective surgery in obese patients. Adults with a body mass index ≥30 kg·m⁻² undergoing laparoscopic sleeve gastrectomy at a medical center were randomized into the HFNO group (n = 40) and FMO group (n = 40). In the HFNO group, patients used a high-flow nasal cannula to receive 30 to 50 L·min⁻¹ flow of heated and humidified 100% oxygen. In the FMO group, patients received a fitting facemask with 15 L·min⁻¹ flow of 100% oxygen. After 5-min preoxygenation, rapid sequence intubation was performed. The primary outcome was arterial desaturation during intubation, defined as a peripheral capillary oxygen saturation (SpO₂) <92%. The risk of peri-intubation desaturation was significantly lower in the HFNO group compared to the FMO group; absolute risk reduction: 0.20 (95% confidence interval: 0.05–0.35, p = 0.0122); number needed to treat: 5. The lowest SpO₂ during intubation was significantly increased by HFNO (median 99%, interquartile range: 97–100) compared to FMO (96, 92–100, p = 0.0150). HFNO achieved a higher partial pressure of arterial oxygen (PaO₂) compared to FMO, with medians of 476 mmHg (interquartile range: 390–541) and 397 (351–456, p = 0.0010), respectively. There was no difference in patients’ comfort level between groups. Compared with standard FMO, HFNO with apneic oxygenation reduced arterial desaturation during tracheal intubation and enhanced PaO₂ among patients with obesity. Full article

High-flow nasal oxygen (HFNO) is recommended as a first-line treatment in patients with acute hypoxemic respiratory failure due to COVID-19. We assessed the effectiveness of HFNO and predictors of failure and death. The medical records of 200 consecutive adult patients treated with HFNO were analysed. Ninety-two patients (46%) were successfully cured, 52 (26%) required noninvasive ventilation, and 61 (30.5%) received intubation. Overall mortality was 40.5%. Risk factors of HFNO ineffectiveness were: SpO₂ ≤ 90% with conventional oxygen therapy (HR 0.32, 95% CI 0.19–0.53, p < 0.001), SpO₂ ≤ 74% without oxygen therapy (HR 0.44, 95% CI 0.27–0.71, p < 0.001), an age ≥ 60, comorbidities, biomarkers (C-reactive protein, procalcitonin, creatinine, lactate dehydrogenase), duration of symptoms before admission to hospital ≤ 9 days, start of treatment with HFNO ≤ 4 days. The multivariate logistic regression models (age ≥ 60, comorbidities, C-reactive protein concentration and SpO₂ with oxygen therapy) revealed a high predictive value of death and HFNO failure (AUC 0.851, sensitivity 0.780, specificity 0.802; AUC 0.800, sensitivity 0.776, specificity 0.739, respectively). HFNO is a safe method for treating acute hypoxemic respiratory failure, with effectiveness reaching nearly 50%. Low values of SpO₂ without and during oxygen therapy seem to be good diagnostic tools for predicting death and HFNO failure. Full article