Low flow, minimal flow and closed circuit system inhalational anesthesia in modern clinical practice

Low, minimal flow and closed circuit anesthesia has been pursued since the beginning of the history of anesthesia. For many decades this form of anesthesia has been restricted to devoted enthusiasts and those very fond of gas kinetics. For most clinicians, selecting a fresh flow gas higher than 3-5 L/min was widely accepted as a routine anesthesia technique. The introduction onto the market of new volatile agents as well as advanced anesthesia machines accompanied by highly reliable monitoring systems, made minimal flow or closed system anesthesia feasible on a daily basis. Clinical, cultural, environmental, pharmacological, technological and economic reasons, force the modern anesthesiologist to reconsider the role of minimal flow and closed circuit volatile anesthesia, in clinical practice. This paper analyses the main advantages offered by these anesthesia techniques.