An Evaluation of the Utility of the ExSpiron Respiratory Variation Monitor During Upper GI Endoscopy

Purpose: To assess the utility of a new medical device that monitors a patient's breathing during medical procedures in which a patient is sedated, but not mechanically ventilated. In minor procedures, such as endoscopy (where the doctor examines a patient's digestive tract by a TV camera inserted through the mouth), patients do not require general anesthesia, in which a machine would take over their breathing while they are unconscious for surgery. However, during endoscopic procedures it is sometimes difficult for the anesthesiologist to monitor the patient's breathing-specifically, to monitor changes in breathing patterns and the adequacy of breathing. In endoscopy procedures, the room is darkened, and the patient's mouth is generally occupied by the endoscope. While the anesthesiologist can listen to the patient's breathing sounds with a stethoscope, this type of monitoring can only be done periodically, and there is limited ability to gauge the adequacy of ventilation. This study will use the ExSpiron Respiratory Volume Monitor (RVM), which measures non-invasive minute ventilation (MV), tidal volume (TV) and respiratory rate (RR), in patients undergoing an endoscopic procedure to provide additional information regarding the effects of clinical interventions such as drug administrations or airway maneuvers on the patient's respiratory status. For patients who give informed consent, study participation means that they will have a PadSet consisting of 3 electrodes applied to the chest. Another component, a nasal cannula (a thin clear plastic tube that goes under the nose) will give patients supplemental oxygen, and is standard of care for endoscopy at UVM Medical Center. Patients will then be asked to breathe in and out of a portable spirometer (breath meter) for 30 seconds up to five times. This data will be compared to data recorded by the monitor to confirm that the monitor is recording accurately. The procedure will then go forward in the normal fashion. Patients will be randomly placed into one of two groups. In the first group during the procedure, the anesthesiologist will not be able to see the numbers (MV, TV, and RR) displayed screen of the monitor, so the data will not be used to guide the patient's clinical care. In the second group, the anesthesiologist will be able to see the RVM measurements of MV, TV, and RR to evaluate the effect of the interventions. Monitoring for both groups will continue in the recovery room, until discharge.