Different fresh gas flows in prone position under general anesthesia: comparison of costs and effects on airway and endotracheal cuff pressures

Abstract

Background/Aim: Many studies have been performed on different fresh gas flows for general anesthesia. In this study, we aimed to compare the costs, airway, and endotracheal cuff pressures of different fresh flows (low, medium, high) of patients receiving general anesthesia in the prone position. Methods: A total of 150 ASA I-II patients over the age of 18 years who underwent lumbar vertebral surgery in prone position were included in this retrospective cohort study. Patients were divided into three groups: Low-flow (n=50, fresh gas flow: 1 l/min), medium-flow (n=50, fresh gas flow: 2 l/min) and high-flow (n=50, fresh gas flow: 4 l/min). In addition to the preoperative heart rates, peripheral oxygen saturation, mean arterial pressures, endotracheal cuff pressures, airway peak and plateau pressures in the first 60 minutes (as 0th, 15th, 30th, 45th, 60th minutes) were noted, and the amount of inhaled gases (sevoflurane, oxygen, nitrogen protoxide) based on the data of the device were recorded to evaluate cost. Results: The two groups were similar in terms of hemodynamics, airway, and endotracheal cuff pressures. Regarding cost, there was a significant difference in the low-flow anesthesia group in terms of inhaled anesthetic agents, oxygen, and nitrogen protoxide. Conclusion: With modern anesthesia machines, it is unnecessary to avoid low-flow anesthesia applications. However, we recommend that the fresh gas flow be more than 2 l/min for anesthetists lacking experience or those who do not prefer low-flow anesthesia.