Although low-flow anaesthesia (LFA) has been described for many years and its benefits are known, its clinical use has been limited. Concerns about the risk of hypoxia contributed to this situation. Although the risk of hypoxia is almost prevented with advanced anaesthesia machines, the use of LFA has not reached the desired levels. However, in recent years, as adverse developments related to climate change have started to affect us all, LFA has started to be on the agenda of anaesthetists again. In this study, our aim is to examine the feasibility of its clinical use in order to popularise the use of LFA.

ASA 1-2 patients who will undergo elective surgery under general anaesthesia in 38 operating rooms of Inonu University Faculty of Medicine will be prospectively recruited for 3 months (May-June-July). Emergency cases, patients under the age of 18 and over 65, laparoscopic surgeries, heart-lung surgeries that may impair oxygenation will not be included in the study.

Inhaler anaesthesia will be administered after anaesthesia induction and tracheal intubation. Fresh gas flow (FGF) will be determined as 1 l/min, MAC=1, FiO2=40% with target controlled automatic gas control mode (AGC). FGF will be decreased to 0.5 l/min 10 minutes after surgical incision, if successful, it will be decreased to 0.3 l/min 10 minutes later and it will be checked whether it is successful. The study will be terminated and FGF will be increased to 1 l/min again.

Demographic data of the patients and FGF levels that can provide FiO2=40% will be recorded.

Inclusion Criteria:

• Patients undergoing surgery under general anaesthesia

Exclusion Criteria:

• Emergency operations
• Previously diagnosed heart, lung, liver and kidney disease
• Surgeries that may impair oxygenation (laparoscopic, Heart, Lung surgeries)

ASA 1-2 patients who will undergo elective surgery under general anaesthesia in 38 operating rooms of Inonu University Faculty of Medicine will be prospectively recruited for 3 months (May-June-July). Emergency cases, patients under the age of 18 and over 65, laparoscopic surgeries, heart-lung surgeries that may impair oxygenation will not be included in the study.