A retrospective study on the impact of continuing low-flow anesthesia during the awakening period on recovery time and quality in general surgery cases

Low-flow anesthesia offers ecological and economic advantages. Its use, which provides numerous benefits for patients, is increasing globally. In this retrospective study, we investigated the effects of maintaining low-flow anesthesia during the awakening phase on recovery time and quality. We reviewed archival records for 80 patients who underwent surgery in the General Surgery Department between September 1 and November 31, 2023, and who met the study criteria. Patients were divided into two groups based on the flow rate used during awakening. Group 1 consisted of patients awakened with a flow rate of 1 L/min (n=42), while Group 2 consisted of patients awakened with a flow rate of 4 L/min (n=38). Demographic data, including sex, age, height, weight, body mass index (BMI), and ASA score, were recorded. The groups were found to be similar in terms of demographic variables. Systolic and diastolic blood pressures, heart rates, and SpO2 values were compared at six time points: pre-induction, post-induction, intraoperative maximum, intraoperative minimum, pre-extubation, and post-extubation. No significant differences were observed between the groups for any of these parameters (p>0.05). The durations from vaporizer shutdown to extubation and from the end of the surgical procedure to extubation were recorded. The time from vaporizer shutdown to extubation was significantly longer in Group 1 compared to Group 2 (p<0.05); however, since the vaporizer was turned off approximately 10 minutes before the end of the surgical procedure, this result was not clinically significant. Conversely, the time from the end of the surgical procedure to extubation was significantly longer in Group 2 compared to Group 1 (p<0.05). When comparing the groups, there were no significant differences in total Modified Aldrete Scores at 5 minutes post-extubation and at 20 minutes in the recovery unit (p>0.05). At 5 minutes post-extubation, significant differences were noted in consciousness and activity among the MAS parameters (p<0.05), while no significant differences were observed regarding circulation, respiration, and oxygen saturation (p>0.05). All patients scored a total of 10 on the Modified Aldrete Scores at 20 minutes in the recovery unit. The study concluded that the method of awakening with continued low flow anesthesia can be used as safely as the method of transitioning to high-flow anesthesia. Thus, the benefits of low-flow anesthesia can be maintained during the awakening period. Additionally, it was demonstrated that there was no time loss in transferring patients to the recovery unit, as the inhaled agent was discontinued approximately 10 minutes before the end of the surgical procedure. To better assess the recovery quality of patients, we suggest that the MAS be used in conjunction with different scoring systems. Keywords: Low-flow anesthesia, Recovery, Extubation time, Modified Aldrete Score.