Clinical trials of monitoring in anaesthesia, critical care and acute ward care: a review.

During anaesthesia monitoring is used as part of a complex feedback-control system to keep the patient in a safe physiological 'envelope' and so is central to the conduct of a modern anaesthetic. The utility of basic monitoring is universally acknowledged and will never be assessed using randomized controlled trials. However, each time a new monitoring device is introduced, it can be assessed to see if it adds to the safety and effectiveness of anaesthetics. This review highlights some of the studies that have assessed new monitors in anaesthesia, critical care, and other areas of acute care.