Measurement of the ventilatory response to hypoxia. A step hypoxia three-minute test

A step hypoxia method for testing response of patients has been described. It involves a well-trained operator who must observe the patient while monitoring and adjusting alveolar oxygen and CO2 tensions. The advantages of the step test are that the time effects can be examined and that quantitative information in a steady-state can be obtained in a relatively short period of time. It can be done at several different levels of CO2.