Monitoring and alarms—philosophy and practice

Summary The 1986 acceptance of monitoring standards adopted by the American Society of Anesthesiologists has led to widespread use of capnometers, pulse oximeters and gaseous oxygen analysers in the United States. Each of these types of instruments are now the subject of national and international voluntary consensus standards, but problems remain with their clinical performance. Another area of shortcoming is that alarm hierarchies and systems are not yet optimal in many operating rooms, and the sounds generated are too stressful for the operating team and distracting for the surgeon. Adoption four years ago by the Harvard University Medical School hospitals of slightly more stringent monitoring standards than those passed by the House of Delegates of the American Society of Anesthesiologists has been associated with an approximately threefold decrease in serious anaesthetic accidents to American Society of Anesthesiologists Preoperative Class I and Class II patients.