What intraoperative monitoring makes sense?

The routine practice of monitoring oxygenation, ventilation, circulation, a nd temperature during surgery is now the standard of care. However, with th e possible exception of pulse oximetry and capnography, extensive physiolog ic monitoring has not been shown to reduce the incidence of adverse anesthe stic-related events. Monitors are useful adjuncts, but they alone cannot re place careful observation by a vigilant anesthesiologist.