[Choice of respirators for anesthesia].

Criteria of quality of gases and vapours supply, ventilator, patient's circle circuit and monitoring devices are recalled to help the anesthetist to choose his anesthesia machine. Advantages of compact or modular apparatus are discussed. Four, now wellknown, anesthesia machines (modulus II+, Siemens 900 D+SAC985, Roche Kontron 4300 and Engstrom Elsa) were analysed in clinical controlled ventilation and in simulated spontaneous ventilation to study the imposed work of breathing. Results are discussed with regard to safety rules and to ergonomics, bearing in mind their respective prices. Comparison is made with an original "bisontin" prototype.