Preliminary results from a new Medtronic (NYSE:MDT) study pinpoint a greater-than-previously measured rate of respiratory depression in patients receiving IV opioids for pain.
The prospective, observational Prodigy study, which analyzed 1,335 patients across 16 sites in the U.S., Europe and Asia, found that respiratory depression, as defined by changes in pulse oximetry and capnography monitoring parameters, occurred in 46% of medical and surgical patients evaluated who were receiving IV opioids for pain.
This incidence rate is significantly higher than previously reported in clinical literature, according to the company. The complete study results are published online in Anesthesia and Analgesia, the journal of the International Anesthesia Research Society.
Opioid-induced respiratory depression is a potentially life-threatening form of respiratory compromise that may impede breathing. Conclusions from the study data enabled the development of the Prodigy risk score, a risk prediction tool to identify patients at high risk of respiratory depression who would benefit from continuous monitoring with capnography and pulse oximetry.
The Prodigy risk score uses risk factors including: age > 60 years, male gender, opioid naïvety, sleep disorders and chronic heart disease for predicting the risk of respiratory depression. In the study, the risk prediction tool showed significant separation between patients with and without respiratory depression (P < .001) and an odds ratio of 6.07 (95% confidence interval) between the high- and low-risk groups. Compared to patients without respiratory depression episodes, mean hospital length of stay was 3 days longer in patients with ≥1 respiratory depression episode identified using continuous oximetry and capnography monitoring, investigators found.
Capnography and pulse oximetry data were collected by Medtronic Microstream capnography and Nellcor pulse oximetry technology. Bedside providers were blinded to continuous monitoring systems and alarms were silenced. All patients experiencing respiratory depression were reviewed and confirmed by an independent clinical event committee of physicians with expertise in perioperative respiratory medicine, according to a news release.
“Prodigy data confirms that respiratory depression in patients receiving parenteral opioids occur frequently and are potentially unknown to hospital healthcare providers,” said primary study investigator Dr. Ashish K. Khanna, and an associate professor of Anesthesiology, section head for Research and intensivist at Wake Forest School of Medicine. “Together with risk assessment using the Prodigy risk score, the use of capnography and oximetry for continuous monitoring of patients identified as high risk for respiratory depression may increase safety when parenteral opioid analgesia cannot be avoided.”
There are no universally accepted guidelines to direct effective and safe assessment and monitoring practices for patients receiving in-hospital opioid analgesia, according to a 2018 study by Khanna and associates.
“The Prodigy risk score has acceptable accuracy for risk stratification using several robust methods of internal validation, addressing significant gaps in preventing this common and potentially deadly condition,” said Frank Chan, VP and GM of the patient monitoring business within the Minimally Invasive Therapies Group at Medtronic. “Patients with respiratory depression were more likely to experience an adverse event that prolonged hospitalization and more likely to require rescue action, including rapid response team activation.”
