As a follow-up to our latest podcast interview with Thomas W. Frederickson, MD, FACP, SFHM, MBA – lead author of the Society of Hospital Medicine RADEO guide (“Reducing Adverse Drug Events Related to Opioids”) – we focused on the advantages and limitations of pulse oximetry in monitoring patients for opioid-induced respiratory depression.
Most importantly, Dr. Frederickson highlighted that the alerts provided by pulse oximetry can be a lagging indicator of patient ventilation, particularly when supplemental oxygen is administered. One solution to improving the care provided to patients is to understand that pulse oximetry is one part of a comprehensive monitoring strategy.
Another key strategy to improving the safety of patients receiving opioids is to monitor with capnography. When used correctly, capnography can provide an earlier measure of respiratory compromise than pulse oximetry alone. Here are 3 strategies to successfully implementing capnography.
#1. Implement Capnography With High Risk Patients
In part one of our interview, Dr. Frederickson identifies obstructive sleep apnea (OSA) as a key risk condition for respiratory distress. The Joint Commission Sentinel Event Alert #49 “Safe use of opioids in hospitals” says patients with OSA are at risk for opioid-induced respiratory depression, along with those who are morbidly obese, very young, elderly, very ill, and/or are concurrently receiving other drugs that are central nervous system and respiratory depressants.
For these patients in particular, early recognition of the signs of respiratory distress is paramount. In another interview with Peggy Lange, RT (Director of the Respiratory Care Department, St. Cloud Hospital), Ms. Lange found that monitoring trends in CO2 provided an earlier indication of respiratory compromise. A key study by Melissa Langhan (Melissa Langhan, MD (Assistant Professor of Pediatrics, Emergency Medicine, Yale School of Medicine), quantified this as an average of 3.7 minutes quicker than pulse oximetry monitoring.
Use of capnographic monitoring is made more important by the common use of supplemental oxygen for patients receiving opioids, which can delay pulse oximetry alerts tied to oxygen saturation.
#2. Educate Staff on Recording and Understanding Trends
While capnography can more accurately detect the signs of respiratory depression, determining alarm thresholds requires a greater understanding of the data output. Says Dr. Frederickson:
“Trends and end tidal CO2 tend to be much more important than absolute numbers, and that’s harder to monitor a trend than it is an absolute number.”
Because capnography provides a breath-to-breath waveform, the ability to record and understand trending over time can be invaluable, particularly when changing caregivers. Ms. Lange recommends using the trended number to capture the full picture of a patient’s respiratory condition.
For an article on the benefits of capnography, please see Bob Sullivan’s review “5 things to know about capnography”.
#3. Address Patient Comfort with Education
In our interview, Dr. Frederickson cautions that capnography monitors can be “somewhat uncomfortable” for patients. Compliance by patients and family can affect successful implementation of any monitoring system.
One simple solution comes from an interview PPAHS conducted with Harold Oglesby, RRT, Manager, The Center for Pulmonary Health, Candler Hospital, St. Joseph’s/Candler Health System (SJ/C). Mr. Ogelsby found that educating patients on why they were wearing the device significantly increased compliance.
“Once patients and their families understood what the nasal cannula was there for, our compliance shot through the roof and we had no issues with compliance in wearing the device.
Sometimes the patients and family members have even educated some of our staff and remind them why the patient was on the end tidal CO2 monitor and not to get too concerned about alarms.”
Successfully implementing monitoring with capnography, and encouraging patients to wear the monitors, is a driving factor in St. Joseph’s/Candler celebrating 10 event free years as of 2015.
Haven’t caught up with the latest interview with Dr. Frederickson?