Pulse oximetry is a relatively simple technology that measures arterial oxygen saturation in real time. The oximeters that are routinely used in clinical care are display- only instruments; they do not produce a continuous historical record of oxygen saturation. When saturation falls below a certain threshold, an alarm is sounded, unambiguously signaling that the patient needs more oxygen or that the instrument has become detached or dysfunctional. In either case, definitive action can be taken at once. These factors make oximetry an ideal safety technology. It helps prevent injuries while not otherwise affecting record- keeping or staffing practices. This is not entirely due to special virtues of oximetry.

It is rare that the patient is left completely alone in the operating room. The genius of oximetry is that it is an easily understandable monitor. When the alarm goes off, the surgeon can call for help if the anesthesiologist has drifted away. It can be assumed that oximetry used as a remote-sensing, continuous- recording technology will pose the same documentation and staffing problems as fetal heart monitors. These may be outweighed by the clear intervention signal provided by oximetry. If, however, hospitals use recording-remote oximeters in situations where this clear signal is ignored, they will suddenly find oximetry to be a fertile source of litigation.