Hypoxaemia is common, difficult to detect and deleterious. An experienced clinician can detect hypoxaemia on the basis of cyanosis only when blood oxygen saturation is 80% or less . Pulse oximetry is an easy-to-use and effective method for detecting hypoxaemia when the device recognizes a good pulse wave . Pulse oximetry should be used routinely for monitoring oxygen saturation; however, it tells nothing about ventilation .
