Breath monitoring improves patient safety during endoscopy unit procedures in pilot project

By Mae Burke and Cheryl Ha

A pilot project in the Therapeutic Endoscopy Unit at St Michael’s Hospital in Toronto shows encouraging results for reducing respiratory complications in sedated patients by monitoring their breathing with capnography equipment during routine endoscopy procedures.

The pilot, carried out within the Endoscopy Unit in partnership with Medtronic Canada, determined the incidence of respiratory adverse events in the hospital’s endoscopy unit was higher than had previously been recognized and that capnography helped reduce these events by approximately 40%.

“The ultimate goal for our project was to assess our current level of patient safety during procedural sedation, particularly patient safety events related to respiratory causes,” says Mae Burke, Clinical Leader Manager of the Therapeutic Endoscopy Unit. “We also wanted to see whether capnography monitoring could improve outcomes in a real-life clinical setting.”

While the Canadian Society of Gastroenterology Nurses & Associates procedural sedation position statement has recommended capnography as the “gold standard” since 2015, most hospitals currently rely on pulse oximetry and visual assessment to monitor oxygen saturation in patients who undergo procedures requiring sedation in its endoscopy unit, such as colonoscopies or endoscopies.

Capnography measures the amount of carbon dioxide (CO2) in breath each time a patient exhales. A filter line is fitted under the patient’s nose which is connected to a monitor and also to an oxygen supply, if needed. Some medications can slow down breathing and heart rate. If that happens, an alarm will let the doctor or nurse know. Respiratory compromise is the main cause of adverse events during procedural sedation, such as apnea (temporary cessation of breathing), hypoxemia (oxygen deficiency), bradycardia (a slower-than-normal heart rate), cardiovascular shock and cardiac arrest.

Research has shown that capnography can alert clinicians to respiratory depression a full minute sooner on average than pulse oximetry and that capnography is 17 times more likely to detect respiratory depression.

St. Michael’s Endoscopy Unit, which conducts approximately 13,000 procedures using sedation annually, wanted to determine if capnography could help improve patient safety.

The pilot project, carried out between December 2017 and June 2018, evaluated data collected on a total of 1,742 endoscopy procedures. Roughly half of these procedures – 906 – were carried out without breath monitoring. The remainder – 836 – were completed using Medtronic’s Microstream capnography equipment, following a training period.

Clinical staff used a software data collection tool based on adverse event definitions developed by the World SIVA International Task Force. The tools enabled the nursing team to enter the risk profile of the patient, type of procedure, type of clinician, sedation regime, occurrence of any adverse events and interventions.

The drop in adverse events in patients whose breathing was monitored through capnography was even greater than the hospital’s endoscopy staff had expected. Prior to beginning the pilot, the hospital hypothesized that the rate of adverse events with capnography may be reduced by as much as 20%. The pilot showed the decrease was nearly twice as high at 39.6%.

Medtronic provided intensive training to the nursing staff in the hospital’s endoscopy unit on how to use the capnography equipment at the beginning of the project. To reinforce the nursing group’s confidence around the technology, a second round of training was provided part-way through. After a review of the outcomes data, the impact of the continuous training was clear. In the group where patients did not receive capnography, there was an average of 8.72 adverse events per 100 procedures. In the group of patients whose breathing was monitored with capnography, there was an average of 5.26 adverse events per 100 procedures. This number dropped even lower – to 3.07 adverse events per 100 procedures – after the period of retraining for the team.

In another key finding, relative risk of four major adverse events all decreased with capnography, including oxygen desaturation (a drop of 32%), severe oxygen desaturation (a drop of 69%), bradycardia (a drop of 35%) and cardiovascular shock/collapse (a drop of 46%).

“In keeping with St Michael’s endoscopy unit’s strong emphasis on patient safety, quality and patient outcomes in our site, our goal is to use the results of the pilot project to support the conclusion that capnography does make economic sense as well as offer superior, timely care for patients,” says Burke.


Mae Burke is the Clinical Leader Manager of the Therapeutic Endoscopy Unit at St. Michael’s Hospital, Toronto and Cheryl Ha, Senior Marketing Manager, Medtronic Canada.