Opioid-induced respiratory depression (OIRD) is common on hospital general-care floors (med-surg), yet there is no reliable tool currently available to predict which patients are most likely to experience OIRD. In their effort to change that, researchers from 16 medical centers and seven countries are conducting a study called the PRODIGY (PRediction of Opioid-induced respiratory Depression In patients monitored by capnoGraphY). The objective is to find out if continuous cardiorespiratory monitoring may be a solution to inform early intervention, mitigating further deterioration. Additionally, the PRODIGY trial aims to help clinicians with a validated respiratory depression-risk prediction scoring tool — the first of its kind — for adult hospital patients receiving opioids.
The Journal of Critical Care recently published the first manuscript, “Respiratory Depression in Low Acuity Hospital Settings — Seeking Answers from the PRODIGY Trial” with more to come over the next six months. Healthcare Purchasing News asked lead author Ashish K. Khanna, MD, FCCP, FCCM, an intensivist and anesthesiologist and Vice-Chief for Research for the Center for Critical Care at the Cleveland Clinic a couple of questions about the current state of OIRD prevention practices and what healthcare providers might expect in the future.
HPN: If no reliable tool exists to predict OIRD in a hospital setting, what then are clinicians doing to prevent it, and why do you consider current methods unreliable?
Dr. Khanna: The problem is twofold — first and foremost is the lack of predictability and secondly is current patient monitoring protocols in our hospitals.
The lack of predictability stems from the fact that no two patients are alike. Pre-existing medical problems, pulmonary status, age, body weight, nature and duration of surgery or medical insult and inherent pharmacokinetic response to pain medication, along with dosing schemes utilized and combination with sedatives/sleep supporting medication are just some of the many factors that are thought to play a part in the occurrence of a possible respiratory depression event on the floor.
We have seen in previous investigative work done by our group at the Cleveland Clinic that the nature of pain medication used ( i.e., long vs. short acting medication) and the presence of obstructive sleep apnea based on a validated screening tool (the STOP-BANG score), did not alter the amount or duration of hypoxemia (a component of respiratory depression) in patients recovering from non-cardiac surgery. This was counter intuitive to popular belief; however this work along with previous work that had shown that hypoxemia was common and more prevalent than we thought in patients on the hospital floor, truly highlighted the nature, scope and complexity of the issue of respiratory depression in our patients in
these ‘safe’ environments. The alarming truth is that these events are truly difficult to predict, and hence there is a large “at risk” population.
The other issue is monitoring. Clinicians are currently relying on ‘spot checks’ every four to six hours in general-care ward patients. This means that there are large stretches of time where patients may have respiratory depression that largely goes undetected, essentially because we do not know that it is occurring. Here is where there is a window of opportunity. Most patients will show a pattern of change in their breathing and hemodynamic patterns, sometimes many hours before they finally have a catastrophic event.
Better portable continuous monitoring solutions in the general-care ward patient will provide an opportunity to our bedside nurses and doctors to identify these patterns and intervene proactively, on time, and possibly save a life.
Considering how critical an issue OIRD is, why hasn’t this problem been addressed until now?
Not till very recently have we really identified that this is a major safety issue for our patients. Not that we have not done anything about it — most large hospital systems have multi-disciplinary rapid response teams (RRTs) in place. These teams composed of physicians trained in anesthesia, critical care and emergency medicine, along with nurses and respiratory therapists are deployed around the clock to respond to the catastrophes that happen. And there is data to believe that the advent of these RRTs has made a difference. However, these actions are mostly not proactive, and occur after the occurrence of an event. What we need are proactive actions to identify a patient at risk, identify the danger signals based on continuous monitoring that can tell the clinician that this patient is going to face a life- threatening deterioration and allow these RRT teams to act before it is too late.
The other part of this piece is until we truly deploy continuous and better monitoring we will not have a real-time dynamic early-warning-sign system to base our critical interventions. Because these systems are in an infancy of their development and have not been operational or validated in major clinical trial, we know little in this area and are not currently in place to develop sound solutions.
The PRODIGY trial is unique in that this is truly the first international prospective observational trial of continuous multi-parameter cardiorespiratory monitoring in both medical and surgical patients on the floor. To allow us to better ascertain the true nature of the problem and the predictive signals, we blinded physicians and caregivers to monitor alarms and numbers. This meant that the data uncovered is in turn a goldmine of information across thousands of patients, which will allow us to apply predictive analytics and come up with a sound solution to this problem. Our hope is to develop a novel PRODIGY score that will tell us who to monitor, how to monitor, how long to monitor and when to intervene.