At least 130 people die every day in the United States from an opioid overdose, according to the Centers for Disease Control and Prevention. In 2017, a record year, two-thirds of the 72,000 drug overdose deaths were from opioids, and preliminary estimates signal the numbers will be even higher for 2018.
Measures, such as cutting back on opioid prescriptions, expanding access to addiction treatment and broader distribution of the opioid overdose antidote naloxone — also known as Narcan — recently have been implemented to combat the issue but have had little effect thus far.
Failing to have a solution is costing the U.S. plenty. The CDC estimates that the total economic burden of prescription opioid misuse in the United States is $78.5 billion a year, including the costs of health care, lost productivity, addiction treatment and criminal justice involvement.
A group of researchers at the University of Washington believe technology could be the answer — in the form of a smartphone app.
At high doses opioids, particularly fentanyl, causes rapid cessation of breathing, respiratory failure and death, the physiologic sequence by which people commonly succumb from an unintentional opioid overdose. Yet most times death can be prevented through early detection and timely intervention if naloxone is administered in time, because it quickly restores normal respiration to a person whose breathing has slowed or stopped as a result of an opioid overdose.
Unfortunately, those who overdose are powerless to call for help in an emergency and therefore fail to ever receive the lifesaving opioid antidote naloxone.
"We're experiencing an unprecedented epidemic of deaths from opioid use, and it's unfortunate because these overdoses are a completely reversible phenomena if they're detected in time," said Dr. Jacob Sunshine, an assistant professor of anesthesiology and pain medicine at the UW School of Medicine.
So Sunshine, along with UW researchers Rajalakshmi Nandakumar and Shyamnath Gollakota from the Paul G. Allen School of Computer Science and Engineering, developed a smartphone app called Second Chance, which they claim has the potential to save thousands of lives.
Funded by the UW Alcohol and Drug Abuse Institute and the National Science Foundation, the app is a contactless system that converts a smartphone into a short-range active sonar, using frequency shifts to identify respiratory depression, apnea and gross motor movements associated with acute opioid toxicity.
The team is currently applyiing for FDA approval, and they estimate the app will be on the market in about eight months, or sooner if they get fast track priority approval by the FDA, said Gollakota. The researchers have plans to commercialize this technology through a UW spinout called Sound Life Sciences and are currently working with naloxone companies, insurance companies and the local communities that are heavily addressing the opioid crisis to make this happen. So far, they say they have received a very positive response from many potential stakeholders.
While this app could be used for all forms of opioid use, the team cautions that right now they have only tested it on illegal injectable opioid use because deaths from those overdoses are the most common.
During an overdose, a person breathes slower or stops breathing altogether. Second Chance monitors a person's breathing pattern by sending inaudible sound waves from the phone to a person's chest and then monitoring the way the sound waves return to the phone. If the app detects decreased or absent breathing, it sends an alarm asking the person to interact with it. If the person fails to interact with the app, Second Chance will immediately contact emergency services or a trusted friend or family member who has access to and can administer naloxone.
"We're looking for two main precursors to opioid overdose: when a person stops breathing, or when a person's breathing rate is seven breaths per minute or lower," said Sunshine. "Less than eight breaths per minute is a common cutoff point in a hospital that would trigger people to go to the bedside and make sure a patient is OK," he said.
Gollakota said the user can either decide they want to be connected to 911 or input a phone number of a friend or family member who has access to naxolone. If a suspected overdose occurs, they will receive a text alert and be able to apply the naxolone in a timely manner.
"This is a tragic occurrence that happens, when people have a loved one who dies when they are in the same house. People who are there and could have potentially helped," said Sunshine. "And it also happens with people who may be on chronic opioids and fall asleep and basically never wake up and have a partner in the bed. These are extremely tragic events that do happen, and this could potentially mitigate the risk of that happening."
He added: "There's two known things: What overdose looks like — the respiratory physiology of it — it's all known. The treatment for it; it's all known. It's just connecting those two in a timely fashion that is needed, and that's the missing link that this tech is trying to solve," said Sunshine.
In addition to monitoring breathing patterns, Second Chance also monitors how people move.
"People aren't always perfectly still while they're injecting drugs, so we want to still be able to track their breathing as they're moving around," said Nandakumar, the lead author of the study and a doctoral student in the Allen School. "We can also look for characteristic motions during opioid overdose, like if someone's head slumps or nods off."
The UW researchers claim the app's algorithm accurately detects overdose-related symptoms about 90 percent of the time and can track someone's breathing from up to 3 feet away.
To gain access to real-world data to design and test the algorithm, the UW researchers partnered with the Insite supervised injection facility in Vancouver, Canada. Insite is the first legal supervised consumption site in North America. As part of the study, participants at Insite wore monitors on their chests that track breathing rates.
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"We asked participants to prepare their drugs like they normally would, but then we monitored them for a minute pre-injection so the algorithm could get a baseline value for their breathing rate," said Nandakumar. "After we got a baseline, we continued monitoring during the injection and then for five minutes afterward, because that's the window when overdose symptoms occur."
Of the 94 participants who tested the algorithm, 47 had a breathing rate of seven breaths per minute or slower, 49 stopped breathing for a significant period, and two people experienced an overdose event that required oxygen, ventilation and/or naloxone treatment. On average the algorithm correctly identified breathing problems that foreshadow overdose 90 percent of the time.
The researchers also wanted to make sure the algorithm could detect actual overdose events, because these occur infrequently at Insite. The researchers worked with anesthesiology teams in the operating room at UW Medical Center to "simulate" overdoses, allowing the app to monitor people and detect when they stop breathing.
"When patients undergo anesthesia, they experience much of the same physiology that people experience when they're having an overdose," said Sunshine. "Nothing happens when people experience this event in the operating room, because they're receiving oxygen and they are under the care of an anesthesiology team. But this is a unique environment to capture difficult-to-reproduce data to help further refine the algorithms for what it looks like when someone has an acute overdose."
For the simulation, the team recruited healthy participants undergoing previously scheduled elective surgeries. After providing informed consent, the patients then received standard anesthetic medications that led to 30 seconds of slower or absent breathing, and these events were captured by the device. The algorithm correctly predicted 19 out of the 20 simulated overdoses. For the one case it was wrong, the patient's breathing rate was just above the algorithm's threshold.
"The goal of this project is to try to connect people who are often experiencing overdoses alone to known therapies that can save their lives," Gollakota said. "We hope that by keeping people safer, they can eventually access long-term treatment."