The Effect of High-flow Nasal Oxygenation to the Saturation During Analgo-sedation in Different ASA Risk Class Patients

Plain-language summary

Analgo-sedation is standard procedure in anesthesiology practice and is often given for colonoscopy in the setting of daily hospital. Ideally, patients should be sedated with preserved spontaneous breathing and adequate blood O2 saturation. To maintain adequate oxygenation, low-flow O2 (2-6 L/min) is usually delivered through standard nasal catheter which can provide inspired fraction (FiO2) of 40% (low-flow nasal oxygenation - LFNO). Coldness and dryness of LFNO applied may be uncomfortable to patient. Standardly applied intravenous anesthetics can lead to transient ceasing of breathing and O2 desaturation despite LFNO. Respiratory instability can also potentiate circulatory instability - undesirable changes in heart rate (HR) and blood pressure (BP). Unlike LFNO, high-flow heated and humidified nasal oxygenation (HFNO) is characterized by the oxygen-air mixture flow of 20 to 70 L/min up to 100% FiO2. Warm and humidified O2, delivered via soft, specially designed nasal cannula, is pleasant to patient. HFNO develops continuous positive pressure of 3 to 7 cmH2O in upper airway which enables noninvasive support to patient's spontaneous breathing thus prolonging time of adequate O2 saturation. Aim of this study is to compare effect of HFNO and LFNO on oxygenation maintenance before, during and after standardized procedure of intravenous analgo-sedation in normal weight patients of ASA risk I, II and III. Investigators hypothesize that application of HFNO compared to LFNO, in patients with preserved spontaneous breathing during procedural analgo-sedation, will contribute to maintaining of adequate oxygenation, consequentially adding to greater circulatory and respiratory patients' stability. Investigators expect that patients who receive HFNO will better maintain adequate oxygenation regarding improved spontaneous breathing. Also patients will have shorter intervals of blood oxygen desaturation, less pronounced rise in blood CO2 level and lesser fall of blood O2 level, less change in HR and BP. Investigators will have to exactly estimate partial and global respiratory insufficiency (blood CO2 and O2 levels) associated with LFNO and HFNO, which will be done by blood-gas analysis of 3 arterial blood samples collected before, during and after analgo - sedation via previously, in local anesthesia, placed arterial cannula. Possible complications will be explained in written uniformed consent and by anesthesiologist.

Who can participate

What they're measuring

Trial details