Hypoxia

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).

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.

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.

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.

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.

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.

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.

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.

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 past HAPE 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 past HAPE. 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.

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.

The purpose of this study is to determine if taking iron supplement pills improves exercise performance in low-oxygen conditions.

This study will collect physiological measurements in healthy adult volunteers under controlled hypoxia and hemodilution conditions.

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 healthy heart, especially the right ventricle, 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. The present investigation focuses on healthy individuals in order to establish a reference for future comparisons with patients suffering from cardiopulmonary diseases. 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. Healthy 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.

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.

Bronchoscopy is now widely used for the diagnosis and treatment of various respiratory diseases. However, the procedure is highly stimulating and provokes a strong stress response; because the airway is shared, patients are prone to hypoxia. With the growing emphasis on comfortable care, demand for anesthesia during bronchoscopy has increased. Deep sedation is the most common approach, but when administered in the supine position it often causes the tongue base to fall back. Both nasopharyngeal and oropharyngeal airways can relieve this obstruction, yet neither connects seamlessly to an oxygen supply line, resulting in insufficient oxygen delivery.We therefore replaced the nasopharyngeal airway with a wired endotracheal tube (size 4.0 or 4.5) inserted via the nose. This thinner tube couples easily to an oxygen line or ventilator circuit, partially relieves airway obstruction, and allows ample supraglottic oxygenation. The present study was designed to evaluate the feasibility and safety of this modified oxygen-delivery method in patients undergoing deep sedation for bronchoscopy.

The goal of this study is to determine whether omitting tracheal suctioning immediately prior to extubation is non-inferior to routine tracheal suctioning with respect to early postoperative oxygenation among adult surgical patients (aged 18-90 years, American Society of Anesthesiologists \[ASA\] physical status I-III) undergoing elective surgery under general anesthesia with endotracheal intubation. The study addresses the following questions: * Primary outcome (non-inferiority): * Is the risk of postoperative desaturation (oxygen saturation \[SpO₂\] \<92% within 60 minutes after extubation) in the no-suction group not worse than in the routine-suction group by more than 10 percentage points? * Secondary outcomes (superiority): * Does omitting tracheal suctioning reduce postoperative cough severity and sore throat? * Does omitting tracheal suctioning avoid increasing extubation-related adverse events? Participants will be randomly assigned (1:1) to one of two groups: * Routine suctioning (SUC): Endotracheal suctioning plus oropharyngeal suctioning immediately before extubation * No suctioning (NON-SUC): Oropharyngeal suctioning only, without endotracheal suctioning All participants will receive standard anesthetic care and postoperative monitoring in the post-anesthesia care unit (PACU) for 60 minutes. Follow-up for airway symptoms and patient satisfaction will be conducted at 24 hours after surgery.

Hypoxia is the most common adverse reaction during sedation outside the operating room.Exploring novel drug combinations to reduce the incidence of hypoxia during sedation in patients undergoing transvaginal oocyte retrieval procedures enhances patient safety and lowers perioperative adverse event rates. This multicenter, prospective, randomized, controlled clinical study will compare the hypoxia incidence rate of the remimazolam-alfentanil combination against the commonly used propofol-alfentanil combination.

Introduction: Currently, there is a lack of international guidelines or clinical recommendations for individuals with mental illnesses (i.e., bipolar disorder, posttraumatic stress disorder) going on high altitude sojourns. However, these guidelines would be important considering that mental illnesses are among the most common disorders worldwide and millions of people are hiking at high altitudes in the Alps, being granted easy access up to 3800m by cable cars. Before conceptualizing these guidelines, it seems necessary to study the physiological and psychological effects of ambient pressure changes leading to oxygen deficiency (hypoxia) in individuals with mental illnesses when being exposed to hypoxic conditions. The investigators hypothesize a shift towards negative affective responses and state anxiety as well as increased levels of neurotransmitter precursor amino acids (PHE/TYR and KYN/TRP) in individuals with mental illnesses when being exposed to hypoxic conditions. Methods and Analysis: The investigators plan to perform a double-blind randomized controlled trial in a safe laboratory environment by using a normobaric hypoxic chamber. Participants suffering from depression and anxiety symptoms will be included as well as age and sex-matched healthy controls. They will attend a six-hour exposure equivalent to 3800m of altitude as well as a six-hour exposure to sham hypoxic conditions. Recruited participants will be screened by the Beck Anxiety and Depression Inventory, the Symptom Checklist (SCL-90) as well as an interview assessment. Affective responses in state anxiety will be assessed before, and during each hour of exposure by using the Feeling Scale (FS), Felt Arousal Scale (FAS), Positive and Negative Affect Schedule (PANAS), State-Anxiety Inventory (STAI) and subjective mental stress levels (Visual Analogue Scale; VAS). Physiological parameters will be assessed by venous blood sampling, pulse oximetry and oxidative stress level measurement before entering the chamber, after three and six hours of exposure. Additionally, symptoms of acute mountain sickness will be assessed by the Lake Louise Score before, after three and six hours of exposure. Follow-up measurements are planned one and seven days after the chamber visit, consisting of venous blood sampling, the Beck Anxiety and Depression Inventory. A series of univariate analyses of covariance (ANCOVA) for repeated measures will be used to test the three-way (i.e. "group × condition × time") and two-way ("group × condition" and "group × time") interactions. Analyses will be adjusted for possible confounding, by adding age, sex, smoking, prior AMS, and medication status in the models as covariates. Ethics and dissemination: Ethical approval has been obtained from the ethics committee of the Medical University of Innsbruck (1250/2021).

Pediatric Obstructive Sleep Apnea Syndrome (OSAS) is common, often due to enlarged tonsils/adenoids. Tonsillectomy/adenoidectomy frequently performed under GA with tracheal intubation due to the age of children. Risk of hypoxemia and respiratory complications during the peri-extubation period is high.

This study investigates whether respiratory muscle training (RMT) and dietary nitrate supplementation can improve exercise tolerance under simulated moderate altitude conditions. Exposure to reduced oxygen availability at altitude places additional strain on the cardiovascular and respiratory systems, which may limit endurance performance. By combining RMT-designed to strengthen the muscles involved in breathing-with nitrate therapy, which enhances nitric oxide availability and vascular function, this study aims to determine whether these interventions independently or synergistically improve oxygen delivery, reduce physiological strain, and enhance exercise performance. The findings will help identify non-pharmacological strategies to improve physical performance and tolerance to hypoxia in both clinical and operational environments.

Hypoxia represents the prevailing adverse occurrence during the sedation of patients undergoing gastrointestinal endoscopy with propofol. This is particularly true for obese patients, who have a higher incidence of hypoxia. A recent innovation in this domain is the COMBO Endoscopy Oropharyngeal Airway-a multifaceted device that encompasses capnography monitoring, bite block , oxygenation support, and oropharyngeal airway management. This device has been purposefully designed to cater to the unique requirements of endoscopic procedures. The principal objective of this study is to assess the efficacy and safety of the COMBO Endoscopy Oropharyngeal Airway in reducing the incidence of hypoxia in obese patients undergoing gastrointestinal endoscopy under sedation.

The purpose of this study is to examine hypoxic vasodilation and the role of beta-adrenergic receptors in younger premenopausal, perimenopausal, and older postmenopausal women.

Guidelines for noninvasive ventilation (NIV) recommend continuous positive airway pressure in patients with thoracic trauma who remain hypoxic . However, no any suggestion was applied for high flow nasal cannula (HFNC). Therefore, Our aim was to determine whether HFNC reduces intubation in severe trauma-related hypoxemia.

The aim of this project is to test the accuracy of pulse oximeters during mild, moderate and severe hypoxia. This is done by comparing the reading of the pulse oximeter during brief, steady state hypoxia with a gold-standard measurement of blood oxygen. This study will be done on healthy male or females between the age group of 18-50.

Gastroscopy is a commonly used, direct, and reliable method for screening and diagnosing digestive tract diseases. However, as an invasive examination, it can cause adverse reactions such as pain, nausea, vomiting, and choking cough in patients. Compared with ordinary gastroscopy, painless gastroscopy offers higher comfort and satisfaction for patients and greater convenience for endoscopists during operation. The most common complication of painless gastroscopy diagnosis and treatment is hypoxia. High-flow nasal cannulala (HFNC) provides a higher oxygen concentration and flow rate than an ordinary nasal catheter. It has the functions of heating and humidifying, which can relieve the pressure on the nasal mucosa cilia, keep the airway unobstructed and moist, and reduce the risk of epistaxis. Due to changes in airway anatomical structures such as fat accumulation in the head and neck and hyperplasia of oropharyngeal soft tissues, obese patients are more prone to hypoxia during gastroscopy under sedation. Therefore, HFNC is often used to reduce the occurrence of hypoxia. The nasopharyngeal airway (NPA) is used to maintain the patency of the upper respiratory tract and is suitable for patients with spontaneous breathing but partial obstruction of the upper respiratory tract. It is worth exploring how effective the combination of HFNC and NPA is in improving hypoxemia in obese patients during sedation.