Active clinical trials for "Hypoxia"

This observational study will investigate whether differences in birth events and oxygen levels during the newborn period affects the brain activity of children during the middle childhood years.

Myocardial injury after non-cardiac surgery (MINS) is common in patients undergoing major surgery. Many of the events are undetected and associated with a high 30-day mortality risk. Knowledge of which perioperative factors that predicts MINS is lacking. Decrease in tissue oxygenation (StO2) is common in patients undergoing major spine surgery and is associated with postoperative complications in these patients. However, an association between decrease in tissue oxygenation and MINS has not been examined. This group of patients may have other potential predictors of postoperative complications that the study group would like to investigate. In this observational cohort study, we will include 70 patients undergoing major spine surgery at University of California San Francisco. The primary hypothesis is that decrease in intraoperative tissue oxygenation is associated with postoperative myocardial injury.

This study involves the administration of a hypoxia marker, pimonidazole hydrochloride, taken orally approximately 24 hours before surgical resection of a pancreatic tumor in order to identify areas of lower oxygen content on tumor samples.

The primary objective of the study is to validate the proposed claims for the OxiCable device, for pulse rate and saturation accuracy in a diverse subject population over a specified saturation range.

Validate Non-Motion SpO2 Accuracy from 70%-100% of various pulse oximeter/ sensor combinations and various OEM pulse oximeter modules and sensor combinations during induced hypoxia (desaturation).

Aim of the study is to investigate the function of the systemic vascular endothelium in individuals susceptible to high-altitude pulmonary oedema during normoxia and normobaric hypoxia.

The objective of the present protocol is to study whether a low level of oxygen in the blood will affect the immune response to as well as cerebral blood flow and metabolism during an infection and, conversely, whether the acute systemic and cerebral physiologic response to hypoxia is modified by an ongoing inflammatory response.

The non-invasive measurement of dysfunctional hemoglobins allows physicians to monitor levels in affected individuals without requiring blood samples or laboratory testing. Nonin Medical Inc, has recently developed a multi-wavelength device that measures carboxyhemoglobin and methemoglobin non-invasively. The primary objective of this study is to validate %MetHb and SpO2 accuracy performance of the study device. Evaluations will be for the range of 0 to 15% MetHb with 95-100% SaO2 as assessed by CO-oximetry, and 0-15% MetHb accuracy under conditions of elevated HHb (SaO2 80-100%) as assessed by CO-oximetry, and SpO2 with 80-100% SaO2 during elevated MetHb as assessed by CO-oximetry.

During One-lung ventilation, the use of lower tidal volumes (VT) is helpful to avoid over-distension, provide sufficient oxygenation, but can result in increased atelectasis. Nevertheless, it is not known if, during one-lung ventilation with constant low VT, moderate levels of PEEP combined with lung recruitment maneuvers are superior to variable PEEP for intraoperative oxygenation and protection against PPCs. Aim of the study is to compare a strategy using constant tidal volume with recruitment maneuvers versus variable PEEP with recruitment maneuvers during thoracic surgery in adults. The investigators hypothesize that in adult, non-obese patients undergoing thoracic surgery under standardized OLV with variable PEEP and recruitment maneuvers as compared to constant PEEP without recruitment maneuvers prevent PPCs. Patients will be randomly assigned to one of two groups: FIX TIDAL VOLUME GROUP (Groupfix): mechanical ventilation with constant (6 ml/kgIBW) tidal volume and PEEP of 5 cmH2O with recruitment maneuvers VARIABLE TIDAL VOLUME GROUP (Groupvar): mechanical ventilation with constant (6 ml/kgIBW) tidal volume with variable PEEP with recruitment maneuvers.

Patients with chronic lung diseases travelling by plane often suffer with symptoms related to lower oxygen levels they are exposed to while flying. Therefore, patients with respiratory conditions are routinely assessed to establish if they need supplemental oxygen in flight. A hypoxic altitude simulation test (HAST) is often part of this assessment and consists in having patients breathe a oxygen/nitrogen blend with a lower oxygen concentration compared to normal room air, simulating in-flight conditions. Oxygen levels are measured before and after the test through a blood sample (from the earlobe or an artery in the wrist) and with a finger probe. In-flight oxygen is required if the oxygen level in the blood is lower than 6.6 kPa. HASTs are time consuming, costly, and require a dedicated hospital appointment. Using historical data, the Investigators developed scores based on capillary blood gas (blood sample from the earlobe), diagnosis and sex to predict the outcome of the HASTs. The Investigators validated the proposed scores in a separate historic cohort of patients and showed it had good concordance with the HASTs results. In this study, the Investigators want to confirm prospectively if the score, based on blood results (venous and/or earlobe), can predict the outcome of the HASTs and therefore reduce the number of tests performed, travel time for patients, and costs for the NHS. All patients, aged 18 or older, who are having a HAST for clinical purposes at the cardio-respiratory lab at Leeds Teaching Hospital NHS Trust will be invited to take part in the study. The Investigators will record diagnosis, results of HAST and previous spirometry from the medical notes, perform a spirometry if not done in the previous 12 months and collect a blood sample (one tube, 4 mls). With these data, the Investigators will calculate the score and assess its agreement with the outcome of the HAST. Each participant's involvement in the study will last for approximately 90-120 minutes, which is the normal duration of a HAST. The Investigators aim to include up to 280 subjects in the study.