The Effectivity of End-tidal CO2 and Oxygen Reserve Index (ORI) Monitoring to Detect Respiratory Events and Hypoxemia Before Pulse Oxymetry in Sedation

Endoscopic procedures are commonly performed using sedation. As drug-induced respiratory depression is a major cause of sedation-related morbidity, pulse oximetry has been established as standart practice . However SpO2 does not completely reflect ventilation. Capnography is an additional monitoring parameter which demonstrates respiration activity breath by breath. Unfortunately, in the state of moderate or deep sedation during diagnostic or therapeutic procedures (e.g.ERCP or colonoscopies), regular breathing is often disturbed by moving, squeezing, coughing or changes between nose and mouth ventilation causing leakage and therefore artifacts or misinterpretation of data acquired with ETCO2. These problems often restrict the use of side-stream capnography in clinical practice, although the American Society of Anesthesiologists have suggested in their guidelines that extended monitoring with capnography \'should be considered\'in deep sedation. The oxygen reserve index (ORI) is a new feature of multiple wavelength pulse oximetry that provides real-time visibility to oxygenation status in the moderate hyperoxic range (PaO2 of approximately 100-200 mm Hg). The ORI is an \"index\" with a unit-less scale between 0.00 and 1.00 that can be trended and has optional alarms to notify clinicians of changes in a patient\'s oxygen status. When utilized in conjunction with SpO2 monitoring the ORI may extend the visibility of a patient\'s oxygen status into ranges previously unmonitored in this fashion. The ORI may make pre-oxygenation visible, may provide early warning when oxygenation deteriorates, and may facilitate a more precise setting of the required FiO2 level. In this study we aimed to show effectivity of capnography and ORİ monitoring to avoid respiratory events and hypoxia in sedated endoscopic patients. In this study we targeted totally 300 sedated endoscopy patients. Patients will randomize to two groups. In Group I anaesthesiologis will be able to use all the monitoring, where as in Group II will be blinded for ORİ. We will apply pre-oxygenation to obtain long safe apnea time. Approximately 5 min pre-oxygenation (5L/min via nasal cannula) will be used to reach steady state in oxygen reserve. We defined hypoxemia ; SpO2\<95% and severe hypoxemia SpO2≤90%, hypoventilation; rise10 mmHg in ETCO2 compare to baseline, ETCO2≤30 mmHg and flat capnography.