Clinical Research Directory

High-flow Nasal Oxygen Therapy in Obese Patients Undergoing Sedativegastrointestinal Endoscopy

Obese patients often have fat accumulation in the head and neck, increased soft tissue in the oropharynx, decreased lung compliance, decreased lung volume and residual volume, and some obese patients also suffer from obstructive sleep apnea. Therefore, obese patients may experience hypoxemia during sedative gastroscopy. High-flow nasal cannula oxygen therapy (HFNC) can provide patients with high-flow (20-70 L/min) and adjustable oxygen concentration (21%-100%) through a special nasal prong catheter. It has the function of warming and humidifying the air, relieving pressure on the nasal mucosa, maintaining airway patency and moisture, reducing the risk of nasal bleeding. In addition, HFNC can generate positive airway pressure (3-7 cmH2O), increase end-expiratory volume, help with alveolar recruitment, prevent atelectasis, and reduce shunts. The flow rate of HFNC is positively correlated with the nasopharyngeal pressure. At a flow rate of 50 L/min, the nasopharyngeal pressure can exceed 3 cmH2O. Obese patients are prone to upper airway obstruction under sedation or anesthesia. The use of HFNC at 70 L/min perioperatively can reduce hypoxemia in patients, but discomfort in the nasopharynx may occur at this flow rate. The optimal flow rate for clinical use of HFNC has not been established. Meta-analysis shows that when the oxygen flow rate during painless esophagogastroduodenoscopy is greater than 30 L/min, it can significantly reduce the incidence of hypoxemia in patients. Therefore, for obese patients undergoing painless esophagogastroduodenoscopy, the investigators propose using HFNC at three different flow rates: 30 L/min, 50 L/min, and 70 L/min, to provide guidance on the optimal flow rate for clinical use of HFNC.

Spectroscopic Assessment of Tissue Oxygenation Changes in Plastic Surgical Flap Reconstructions

This study is a single-center, observational study designed to collect tissue spectrometric data.

Optimizing Care in Critically Ill at UCHealth by Liberalizing the Target O2 in Mechanically-ventilated ICU Patients

A multimodal educational intervention to target an oxygen saturation target range (SpO2 90-96%) will reduce ventilator length of stay and reduce occult hypoxemia by increased awareness and adherence to a designated oxygen saturation target range.

ICU-SUCCEED for Survivors of Acute Respiratory Failure and Their Caregivers

This study will investigate whether a family-centered intervention that has been adapted for patients with critical illness and their caregivers is possible, acceptable, and helpful

Influence of HFNO on Respiratory Stability in Patients of Different ASA Risk During Moderate Multimodal Analgo-sedation for Pars Plana Vitrectomy

Pars plana vitrectomy is minimally invasive endoscopic procedure which is usually performed in moderate analgo-sedation given by anesthesiologist combined with topical anesthesia and regional eye anesthesia (retrobulbar or SubTenon block) performed by a surgeon. Intravenously applied anesthetics can often lead to slower breathing rate or cessation of breathing which introduces risk of low blood oxygen level despite careful adjustment of anesthetics' dose and application of standard low-flow nasal oxygenation (LFNO). Respiratory instability is often accompanied by circulatory instability manifested by disturbances of heart rate and blood pressure. LFNO provides maximally 40% inspired fraction of oxygen and can cause discomfort of a patient due to coldness and dryness of inspired gas. On the other hand, high-flow nasal oxygenation (HFNO) can bring up to 100% of inspired oxygen fraction to patient, providing noninvasive pressure support of 3-7 cmH2O in patients' upper airway which ensures better oxygenation especially in higher anesthesia risk patients. Because of carrying warmed and humidified air/oxygen mixture via soft nasal cannula, HFNO is better tolerated by patients. In this trial investigators will compare effect of HFNO to LFNO during intravenously applied standardized analgo-sedation given for vitrectomy in normal weight patients of low and high anesthesia risk. Investigators hypothesize that normal weight patients of low and high anesthesia risk, whose breathing pattern is preserved, receiving HFNO vs. LFNO during standardized analgo-sedation for vitrectomy will be more respiratory stable using equal FiO2, preserving normal blood O2 and CO2 level, breathing pattern, heart rate and blood pressure.

Novel Hypoxia Imaging for Head and Neck Cancer: Imaging Phenotype for Personalized Treatment

Tumor hypoxia is one of the physiological factors for treatment resistance and likely contributes to poor overall survival among patients with head and neck cancer (HNC). Identifying hypoxic features of HNC may allow the personalizing treatment plan. The investigators propose multiparametric Hypoxia MR (HMR) imaging using diffusion, perfusion, and oxygenation as non-invasive, in-vivo imaging components of a hypoxia phenotype. Assessing the hypoxia phenotypes' expression will be critically important for characterizing and predicting CRT response among patients with advanced HNC. A prospective cohort study will be conducted used multiparametric MR (MPMR) imaging correlated with treatment response assessed by 3 months fluorodeoxyglucose-positron emission tomography (FDG-PET). The image analysis approach will be developed to incorporate FDG-PET and quantitative MRI characteristics of tumor (ADC, oxygen-enhanced T1 and T2\* maps, and volume transfer constant (Ktrans) to facilitate 3D visualization of multiparametric information. This proposed study's overarching goal is to develop and validate multiparametric HMR imaging using 18F - (fluoromisonidazole) FMISO-PET and immunohistochemistry (IHC) as the standard of references.

Effects of Bicarbonate Spring Water Immersion on Cognitive Reliability and Post-Maximal Exercise Recovery in Adolescent Rowers During Altitude Training: A Sex-Stratified Three-Arm Randomized Controlled Trial

This randomized controlled trial aims to investigate the effects of hot spring bath therapy on cognitive function recovery, cerebral hemodynamics, and athletic performance in athletes undergoing altitude training. Participants will be randomly assigned to either a hot spring intervention group, a hot water control group, or a blank control group. The hot spring intervention group receives hot spring baths (38°C, 20 minutes) combined with altitude training; the hot water control group receives hot water baths (38°C, 20 minutes) combined with altitude training; and the blank control group receives standard recovery procedures combined with altitude training. Primary outcome measures include cognitive performance assessments (Stroop test, psychomotor vigilance test) and cerebral hemodynamic indicators (functional near-infrared spectroscopy, transcranial Doppler ultrasound). Secondary outcomes included exercise capacity (maximal oxygen uptake, triathlon performance, 500-meter test), blood lactate, and hematological parameters (white blood cells, neutrophils, platelets). These findings may provide evidence for non-pharmacological interventions to enhance cognitive recovery and brain adaptation during altitude training.

Hypoxia and Heart Rate Variability

The purpose of this study is to evaluate how variations in oxygen demands may change heart electrical activity in individuals with and without oxygen dependence.

Clinical Validation of Vital-PICASO for Predicting Hypoxia Within 24 Hours in General Ward Inpatients

The purpose of this retrospective study is to evaluate the clinical performance of Vital-PICASO, an artificial intelligence-based biological signal analysis software designed to predict the risk of hypoxia within 24 hours using vital-sign data from adult general ward inpatients. Electronic medical record data from patients aged 19 years or older who were admitted to a general ward at Seoul National University Hospital will be retrospectively reviewed. Hypoxia will be evaluated using two separate reference-standard criteria: oxygen saturation below 94% and administration of oxygen at 4 L/min or more. Eligible hypoxia-positive and hypoxia-negative datasets will be randomly selected. The selected vital-sign datasets will be analyzed using Vital-PICASO while the device operator is blinded to the reference-standard classification. The software-generated hypoxia risk scores will be compared with the reference-standard classifications to evaluate predictive performance. Because the study uses previously collected medical records, there is no direct participant contact and the software results will not affect patient care.

Effects of Intermittent Hypoxia Training With Iron Supplementation on Red Blood Cells and Iron Levels in Trained Athletes

This study investigates how training under conditions of reduced oxygen (intermittent hypoxia) affects the body's ability to produce red blood cells and manage iron levels, compared to training under normal oxygen conditions. Red blood cells are essential for transporting oxygen throughout the body, and their production depends on having enough available iron. Thirty-two physically trained participants completed a 3-week training program, either in low-oxygen conditions or in normal oxygen conditions. All participants followed the same diet and received daily supplements of iron and vitamins to ensure adequate nutritional support. The main hypothesis of this study is that training in low-oxygen conditions stimulates the production of red blood cells more strongly than training in normal oxygen conditions, and that this increased production requires the body to use stored iron, potentially lowering iron reserves. Results showed that participants training in low-oxygen conditions experienced a greater increase in red blood cells and related markers compared to those training in normal conditions. At the same time, their stored iron levels decreased, suggesting that the body was using its iron reserves to support the increased production of red blood cells. In contrast, participants training in normal oxygen conditions showed smaller changes and maintained or slightly increased their iron stores. These findings suggest that low-oxygen training can enhance the body's capacity to produce red blood cells but may also reduce iron reserves. This highlights the importance of monitoring iron levels during such training programs, especially in athletes or individuals with conditions related to low oxygen availability, such as anemia. Overall, this study aims to improve understanding of how oxygen availability influences blood health and may help guide future strategies that combine hypoxia training and iron supplementation to support performance and treat certain medical conditions.

Methodological Study of Exercise and Hypoxic Conditions in Healthy Subjects

The aim of this protocol is to assess physiological responses during various physical exercise protocols (whole-body exercise such as cycling or treadmill running, or localised exercise such as knee extension) and during inhalation of a gas mixtures with various oxygen contents (similar to exposure at high altitude).

Fetal Cerebrovascular Autoregulation in Congenital Heart Disease and Association With Neonatal Neurobehavior

Determine 1) the impact of abnormal fetal cerebrovascular physiology with neurodevelopmental delay (ND) outcomes and 2) how this relationship is modified by patient and environmental factors such as chronic congenital heart disease (CCHD) lesion, maternal-fetal environment, and social determinants of heath (SDOH) in a diverse population using a multicenter design. Pregnant women will be approached during one of their fetal cardiology clinic visits.

The Effects of Endotracheal Suctioning on Pain and Serum Markers

The goal of this experimental study is to understand if endotracheal tube (ETT) suctioning increases pain and causes stress on the body in intubated adult ICU patients. These patients are already on ventilators, which means they need suctioning to keep their airways clear, but this procedure may be uncomfortable and cause stress. The main questions this study aims to answer are: Does ETT suctioning raise pain levels as measured by the Critical-Care Pain Observation Tool (CPOT)? Does ETT suctioning increase certain chemicals in the blood (hypoxanthine, xanthine, and uric acid) that show stress and lack of oxygen in the body? Researchers will compare patients who have ETT suctioning (intervention group) with those who do not have suctioning during the study period (control group) to see if there are differences in pain and blood markers of stress. Participants will: Have pain measured before and after suctioning using the CPOT. Have blood samples taken from an existing line at three time points: 5 minutes before, 5 minutes after, and 30 minutes after suctioning. Provide demographic information (like age, gender, and diagnosis) from medical records. This research will help improve how pain is managed for ICU patients who cannot speak for themselves, potentially leading to better pain relief methods in the future.

A Study Using 18F-FAZA and PET Scans to Study Hypoxia in Pancreatic Cancer

This is a diagnostic study to look for low levels of oxygen (hypoxia) in pancreatic cancer using an imaging test called positron emission tomography (PET). Hypoxia can influence how pancreatic cancer grows and responds to treatments such as chemotherapy and radiotherapy. The use of PET scans to measure hypoxia may be better and simpler than the approaches used previously. This study will assess whether or not PET scans using a tracer called 18F-FAZA (18F-Fluoroazomycin Arabinoside) can provide useful information about hypoxia in pancreatic cancer. Also as part of the study, a blood sample will be taken to study biomarkers (substances in the body that may be important indicators of hypoxia and/or pancreatic cancer) that may be useful in studying pancreatic cancer and hypoxia.

Effect of Acute Hypoxia on RIght VEntRicular Function in Asthma.

More and more people are engaging in sports in the mountains, including individuals with heart or lung diseases. At the same time, such diseases are becoming more common in Switzerland. At high altitude, less oxygen is available, which places stress on the body-particularly on the heart, which has to pump blood through the lungs. How the heart, especially the right ventricle, in people with asthma responds to this stress is still not well understood. Therefore, this study investigates how the heart responds to simulated altitudes of 2,500 m and 4,000 m, both at rest and during light physical activity in patients with asthma. The primary objective is to assess how right ventricular function changes under conditions of reduced oxygen availability. In addition, vital signs, changes in blood gases, oxygen levels in blood and tissue and shortness of breath are assessed. The "altitude" is simulated using a special gas mixture that participants inhale. Participants undergo three altitude conditions (490, 2,500, and 4,000 m above sea level). The order of the altitude conditions is assigned at random. The aim is to better understand how the right ventricle and other parameters respond to low-oxygen conditions and how affected patients can be better supported in the future.

Outpatient Pediatric Pulse Oximeters in Africa

The primary objective of this clinical trial is to evaluate the performance of three pulse oximeters during outpatient care within Cape Town, South Africa. This objective will be achieved through generating evidence on how, why, for whom, to what extent and at what cost can paediatric pulse oximetry devices improve the management of hypoxemic children. This will be done with two inter-linked studies: * Aim 1: Determine the impact of two novel paediatric pulse oximeter devices on the correct management of hypoxaemia. * Aim 2: Describe the burden of hypoxaemia and risks for mortality amongst children presenting with acute respiratory infections in a low-resource setting in Cape Town.

OM2 Abbreviated Sensor Verification

The verification of an investigational pulse oximetry board to verify pulse rate and saturation accuracy over a specified saturation range in diverse populations.

OM2 Motion Verification Study

The verification of an investigational pulse oximetry board to verify pulse rate and saturation accuracy over a specified saturation range in diverse populations.

Virtual Reality-Based Simulation Versus High-Fidelity Simulation for Emergency Management Training in Medical Interns

This study is a two-arm parallel randomized controlled non-inferiority trial designed to compare the educational effectiveness of virtual reality (VR)-based simulation with high-fidelity simulation (HFS) for emergency management training in medical interns. Participants will be randomized 1:1 to either VR-based training or HFS-based training for managing desaturation and anaphylaxis scenarios. After training and structured debriefing, all participants will undergo objective structured clinical examinations (OSCEs) and complete pre- and post-training surveys. The primary outcome is OSCE performance score. Secondary outcomes include confidence improvement, participant satisfaction, usability (UEQ-S).

Study of the Effects of Acute Exposure to Moderate Altitude Hypoxia on Prospective Memory.

The goal of this study is to investigate whether prospective memory, i.e., memory for delayed intentions, is impaired at moderate altitude (4,000m). It will also allow to study the effect of air and oxygen administration during hypoxia exposure. The main questions it aims to answer are: * Does moderate acute hypoxia impair prospective memory ? * If so, does air or oxygen adminsitration induce a restoration of prospective memory? Researchers will compare cognitive performance during normobaric hypoxia exposure to cognitive performance during normoxia (control situation). Participants will: * Session S0. Perform a battery of neuropsychological tests and questionnaires). EEG will be recorded during tests. A cheek swab will be performed. * Sessions S1 and S2. Perform several cognitive tasks while exposed to hypoxia and to normoxia (2 different sessions, randomized order) in a normobaric chamber. These are standardized cognitive tests administered on a computer and cognitive tests embedded in a flight simulator scenario. Various questionnaires will be performed on a regular basis. Several physiological measurements will be performed continuously: EEG, ECG, SpO2 and breathing rate. Blood pressure will be measured at the beginning and at the end of hypoxia/normoxia exposure. A blood sample will also be performed. At last, participants will inhale air or oxygen through a mask while making a cognitive task in the chamber.

Effect of Hypoxic Conditioning on Cerebrovascular Health in the Elderly

In line with the ever-growing aging of Western populations, the development of preventive strategies to slow down the effects of aging on cardiovascular health represents a major challenge in order to preserve functional capacities and a sufficient quality of life in the elderly. The alteration of vascular function (at the cerebral and systemic level) with aging is an important feature in the clinical picture including a decrease in physical and cognitive capacities. Although physical activity is recognized as an essential means of combating the effects of aging, optimizing its effects by defining the most effective strategies of practice remains a key objective. Offering alternative interventions to exercise training is also necessary for people who are unwilling or unable to engage in a physical activity program. In this context, hypoxic conditioning, alone or in conjunction with rehabilitative exercise training, is a new therapeutic modality with strong preclinical validity, in particular from a cardiovascular standpoint, and used in other pathologies to improve cardiovascular function and exercise performance and quality of life. Our aim is, therefore, to investigate the effect of hypoxic conditioning (alone or in conjunction with exercise training) on cerebrovascular health in the elderly.

Structural Modification In Supraglottic Airway Device

The proposed A/Z modification of a supraglottic airway (SGA) incorporates an opening in the SGA body that enables access to the endotracheal tube (ETT) through the body of the SGA without the need of using an exchange catheter, thus enabling an ETT to move in the body of the SGA and convert a supraglottic to endotracheal ventilation. In its original form an adaptor made from same material currently used in the endotracheal tubes can make ventilation through the proposed airway device possible in exactly the same manner of a conventional SGA currently used. This adapter also known as the R-piece can be replaced with an ETT. The modification also allows placement of SGA over an existing ETT to convert and endotracheal (ET) to supraglottic (SG) mode of ventilation without the need to use an exchange catheter.

Nocturnal Hypoxia in Geriatric Patients After Hip Fracture

Delirium is a common complication following hip fracture surgery (HFS) in older people. Postoperative hypoxia has also been associated with delirium, but not specifically in geriatric patients. The aim of the study is to demonstrate that post-operative hypoxia is associated with in-hospital complications in patients with HFS.

High-Flow Nasal Cannula for Preventing Hypoxia During Sedated Endoscopy in High-Risk Obstructive Sleep Apnea Patients

Hypoxia represents the most frequent adverse event during propofol-sedated gastrointestinal endoscopy. The STOP-BANG questionnaire serves as a widely adopted, straightforward tool for screening obstructive sleep apnea (OSA) risk, with a score ≥5 identifying high-risk OSA patients who are particularly susceptible to hypoxia under sedation. Although preliminary research from our team suggests that High-Flow Nasal Cannula (HFNC) may lower the incidence of hypoxemia, evidence remains limited and inconsistent in studies specifically targeting high-risk OSA populations. Therefore, this multicenter randomized controlled trial aims to evaluate whether HFNC can effectively reduce the occurrence of hypoxia during sedated gastrointestinal endoscopy in patients identified as high-risk for OSA.