Incidence of Adverse Airway Events in High Risk Patients Undergoing Upper GI Endoscopy Under Anesthesia

We propose to collect the data of vital signs and anesthesia medications administered in a
subcategory of patients coming for anesthesia for upper GI endoscopy. This data will be
analyzed to see any relation between the preoperative risk factors, procedure, type of
anesthesia and the airway intervention. The adverse events that will be automatically
recorded and later analyzed will be number of apnea episodes (described as no respiration for
at least 30 seconds) duration of each apnea, number and duration of each desaturation event
(oxygen saturation as measured by the pulse oximeter). A pulse oximeter saturation of less
than 93 percent and lasting 30 seconds will be considered as a desaturation event. The airway
interventions that will be recorded will be anything other than considered being routine.
This includes LMA insertion, endotracheal intubation and the need to withdraw gastroscope to
facilitate face mask ventilation. We also propose to monitor their awareness/depth of
sedation/depth of anesthesia levels. This will be done using a monitor that analyses brain
waves and gives an idea of sleep (anesthesia) depth. We can then see any correlation between
any unwanted events and the sleep depth.