麻豆传媒

SAN DIEGO -- Chest wall rigidity, loss of control, extreme potency, and rapid onset were among observed and reported characteristics of fentanyl-related use and overdoses, a study from Canada found.

The findings indicate that improved rescue breathing and higher naloxone doses are needed in those suspected of overdosing from fentanyl, reported Samara Mayer, MPH, of the BC Centre on Substance Use in Vancouver, Canada, and colleagues.

The study was presented at the .

From December 2016 to April 2017, Mayer's group conducted ethnographic field work in Vancouver and performed qualitative interviews at overdose prevention sites and supervised consumption sites.

"In addition to helping to reduce overdose-related mortality and overdose-related harms," she explained, these sites are "really effective tools for community-level surveillance of adulteration of the local drug supply."

The researchers interviewed 72 participants -- 44 of whom had overdosed in the past year -- on their experience with fentanyl use.

Among the 44 individuals, 10 (23%) reported two overdoses in that span and 19 (43%) reported three or more overdoses. Fifteen participants reported having overdosed in the 30 days prior to the interview. Roughly a quarter reported suspected fentanyl exposure during their previous overdose.

The approach used in this study "is a very valuable step that we need to take in understanding drug use practices and what the experience on the ground is like," said Benjamin Bearnot, MD, of Massachusetts General Hospital and Harvard Medical School in Boston, who was not involved with the study. "Doctors and nurses are not there when the drug overdoses are happening, so learning about it through the stories of individuals is really important."

Speed of Onset and Potency

"It hits you like a Mack truck," reported one study participant, describing the sudden onset of fentanyl. "You're sitting there waiting for something, and the next thing you know there is an ambulance attendant there."

Another interview subject described the rapid onset of the drug's effects. "Fentanyl goes bam, stays with you for a little, but maybe an hour -- maybe a tiny bit more -- and then you're full on sick as a dog, like you haven't used at all."

Bearnot told 麻豆传媒, "normally we think about heroin overdoses happening in minutes to hours, but what's happening with fentanyl is that it's happening in seconds -- people are having instantaneous overdoses."

Many subjects were long-time heroin users, but were unprepared for the potency of fentanyl.

"One of the major findings is that really high doses of naloxone were required," said Mayer, with up to 4 or 5 times the typical amounts of naloxone needed to reverse overdoses.

In addition to the higher doses, Bearnot added that the speed with which naloxone is delivered is critical. "Time is brain cells in this instance, so we need to deliver the medication quickly," he said.

Chest Wall Rigidity

At some of the overdose prevention sites, body and chest wall rigidity -- colloquially called "wooden chest syndrome" -- were observed in patients who overdosed. This can pose complications for frontline response, Mayer told 麻豆传媒. "Some best practices have been emerging around the need to provide rescue breathing and to monitor oxygen levels."

Slumping over would be a more typical presentation of a heroin overdose, but those who overdose on fentanyl often remain upright. This can delay the identification of an overdose and the rigidity itself creates difficulty for emergency services.

"These people are unable to breath, it's difficult to ventilate them with traditional mouth to mouth or bag-valve ventilation," said Bearnot. "We still have a lot to learn about what that syndrome is and why it's so hard to treat those people with these rigid states with fentanyl overdose."

Testing for Adulterated Heroin

JoAn Laes, MD, of Hennepin County Medical Center in Minneapolis, told 麻豆传媒 that one strategy to reduce overdose risk is urging users to perform "drug testing on the substance that they're using to see if there's actually fentanyl in it." Another poster presented at the meeting touched on this, reporting a high willingness to use rapid fentanyl-detecting test strips among heroin users.

But there are also challenges in testing fentanyl and its many analogs.

"They're changing the drugs by just simply adding on a side chain," Laes said, referring to the manufacturers of illicit fentanyl. "It shows up differently on drug tests when you alter the structure like that."

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