title: Very-nearly-closed-circuit anaesthesia. A computer analysis.
abstract: A simple analogue study of inspired oxygen concentrations in a circle absorber system was made. Good agreement with clinical observations and figures reported by others was obtained. The suggested low-flow regime was nitrous oxide 1 litre/min and oxygen 0.6 litre/min, which provides inspired oxygen concentrations between 35-25%, over a range of oxygen consumption from 150-300 ml/min. The use of such low flows is economical and reduces atmospheric pollution in the operating theatre.
mesh_terms: D000397:Air Pollution / Q000517:prevention & control; D000758:Anesthesia / Q000379:methods*; D000776:Anesthesiology / Q000295:instrumentation; D003202:Computers, Analog; D008962:Models, Theoretical; D009609:Nitrous Oxide; D010100:Oxygen
chemical_list: D009609:Nitrous Oxide; D010100:Oxygen