Monitoring--the anaesthetist's view

There is large variability in the pharmacokinetics and pharmacodynamics of sedative drugs in patients thus, a standard dose of sedative may produce undersedation in certain patients and substantial oversedation, resulting in anaesthesia, in others. Those who administer sedatives should, therefore, have the knowledge, skill, and equipment (including monitoring devices) to enable them to deal with an oversedated patient. Certain patients are at an increased risk of complications owing to sedative administration. Preoperative assessment of patients will enable the endoscopist to determine when and how to monitor the patient. If continuous monitoring is used, early detection of any potentially dangerous pathophysiology is more likely, and thus, the risk of cardiorespiratory arrest is minimized. Clinical observation is essential but can be supplemented by some extremely reliable and effective devices. Of these, the most important and relevant for monitoring during endoscopy is finger pulse oximetry. This technique is easy to use, does not interfere with the endoscopy procedure, enables continuous monitoring, and is extremely versatile. Pulse oximetry can also alert staff to cardiorespiratory problems.