Catch and release: evaluating the safety of non-fatal heroin overdose management in the out-of-hospital environment

The onset and severity of acute opioid toxicity in heroin overdose cases: a retrospective cohort study at a supervised injecting facility in Melbourne, Australia

AIM

To differentiate the severity of acute opioid toxicity and describe both the clinical and physiological features associated with heroin overdose in a cohort of witnessed overdose cases.

METHODS

Witnessed heroin overdose cases over a 12-month period (30 June 2018 - 30 June 2019) at the Medically Supervised Injecting Room (MSIR) in Melbourne, Australia were examined. The severity of acute opioid toxicity was classified according to the level of clinical intervention required to manage the overdose cases where an escalating level of care was provided. Heroin overdose cases were classified into one of three graded severity categories and a fourth complicated heroin overdose category.

RESULTS

A total of 1218 heroin overdose cases were identified from 60,693 supervised injecting visits over the study period. On the spectrum of toxicity, 78% (n = 955) of overdose cases were classified as Grade 1 severity, 7% (n = 83) as Grade 2 severity, and 13% (n = 161) as Grade 3 acute opioid toxicity severity cases, as well as 2% (n = 19) classified as complicated heroin overdose cases. The median onset time for heroin overdose cases was 17 min (IQR 11-28 min) from the time the individual was ready to prepare and inject heroin until clinical intervention was initiated.

CONCLUSION

We demonstrated that heroin overdose is a dynamic illness and cases differ in the severity of acute opioid toxicity. The risk of airway occlusion including positional asphyxia was an early and consistent feature across all levels of toxicity, while exaggerated respiratory depression together with exaggerated depression of consciousness was increasingly observed with greater levels of toxicity. We also demonstrated the importance of early intervention in overdose cases, where in a large cohort of heroin overdose cases there were no fatal outcomes, a very low hospitalisation rate and most cases were able to be managed to clinical resolution on-site.

Unspecified opioids among opioid overdoses in Oslo, Norway

OBJECTIVE

Since 2017, an increasing number of opioid overdoses in Oslo, Norway, has been categorized as involving unspecified opioids, as noted in the patient records by the doctor treating the patient. In this study we compare the characteristics of overdoses involving unspecified opioids, long-acting opioids, and heroin. Data on patients presenting with opioid overdose was retrospectively collected from 1 October 2013 to 31 December 2019 at the Oslo Accident and Emergency Outpatient Clinic.

RESULTS

Among 2381 included cases, 459 (19.3%) involved unspecified opioids, 134 (5.6%) long-acting opioids, and 1788 (75.1%) heroin. Overdoses involving unspecified opioids needed longer observation, median 5 h 29 min vs. 4 h 54 min (long-acting opioids) and 4 h 49 min (heroin) (p < 0.001), and had a lower Glasgow coma scale score, median 10 vs. 13 in both the other groups (p < 0.001). Naloxone was given in 23.3% of cases involving unspecified opioids, vs. 12.7% involving long-acting opioids and 30.2% involving heroin (p < 0.001). A larger proportion of patients were transferred to hospital care when unspecified or long-acting opioids were involved compared to heroin, 16.3% and 18.7% respectively vs. 10.1% (p < 0.001). Our results indicate that the category "unspecified opioids" encompasses a substantial proportion of opioids acting longer than heroin.

Non-transport after Prehospital Naloxone Administration Is Associated with Higher Risk of Subsequent Non-fatal Overdose

Objective: U.S. opioid overdoses increased nearly sixfold from 1999 to 2018, and greater than 1% of all emergency medical services (EMS) encounters now involve naloxone administration. While "treat and release" protocols may have low short-term mortality, the risk of subsequent non-fatal overdoses is not known. This study compares the risk of repeat overdose encounters between patients transported to an emergency department (ED) and those who refused transport after prehospital naloxone administration. Methods: All EMS charts within a large single-tier fire-based urban EMS system between January 1 and August 31, 2018 were reviewed if either naloxone administration or a clinical impression related to opioid overdose was documented. Charts were excluded if there was no documented evidence of an opioid toxidrome (respiratory depression or altered mental status), if there was another clear explanation for the symptoms (e.g., hypoglycemia), or if naloxone was not administered. Ten percent of charts were reviewed by a second author to assess reliability. Cox regression (survival analysis) was used to estimate the risk of a subsequent EMS encounter with naloxone administration following an index encounter with naloxone administration. Results: Of the 2143 charts reviewed, 1311 unique patients with 1600 overdose encounters involving naloxone administration were identified. Inter-rater reliability for chart inclusion was strong [κ = 0.83 (95% CI: 0.72-0.90)]. Police/bystanders administered naloxone in 208/1600 (13.0%) encounters. A substantial proportion of encounters resulted in transport refusal (674/1600, 42.1%). The final Cox model included only refusal vs. acceptance of transport to an ED during the index EMS encounter. Patient age, gender, and naloxone administration prior to EMS arrival were not statistically significant in univariate or multivariable analyses, nor were they significant confounders. Refusal of transport was associated with a hazard ratio of 1.66 (95% CI: 1.23-2.23) for subsequent EMS encounters with naloxone administration. Conclusions: Non-transport after prehospital naloxone administration is associated with an increased risk of subsequent non-fatal overdose requiring EMS intervention. Limitations include the use of a single EMS agency as patients may have had uncaptured overdose encounters in neighboring municipalities.

Endogenous Opiates and Behavior: 2018

This paper is the forty-first consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2018 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (2), the roles of these opioid peptides and receptors in pain and analgesia in animals (3) and humans (4), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (5), opioid peptide and receptor involvement in tolerance and dependence (6), stress and social status (7), learning and memory (8), eating and drinking (9), drug abuse and alcohol (10), sexual activity and hormones, pregnancy, development and endocrinology (11), mental illness and mood (12), seizures and neurologic disorders (13), electrical-related activity and neurophysiology (14), general activity and locomotion (15), gastrointestinal, renal and hepatic functions (16), cardiovascular responses (17), respiration and thermoregulation (18), and immunological responses (19).

Prehospital naloxone administration - what influences choice of dose and route of administration?

Background

Amidst the ongoing opioid crisis there are debates regarding the optimal route of administration and dosages of naloxone. This applies both for lay people administration and emergency medical services, and in the development of new naloxone products.

We examined the characteristics of naloxone administration, including predictors of dosages and multiple doses during patient treatment by emergency medical service staff in order to enlighten this debate.

Methods

This was a prospective observational study of patients administered naloxone by the Oslo City Center emergency medical service, Norway (2014–2018). Cases were linked to The National Cause of Death Registry. We investigated the route of administration and dosage of naloxone, clinical and demographic variables relating to initial naloxone dose and use of multiple naloxone doses and one-week mortality.

Results

Overall, 2215 cases were included, and the majority (91.9%) were administered intramuscular naloxone. Initial doses were 0.4 or 0.8 mg, and 15% of patients received multiple dosages. Unconscious patients or those in respiratory arrest were more likely to be treated with 0.8 mg naloxone and to receive multiple doses. The one-week mortality from drug-related deaths was 4.1 per 1000 episodes, with no deaths due to rebound opioid toxicity.

Conclusions

Intramuscular naloxone doses of 0.4 and 0.8 mg were effective and safe in the treatment of opioid overdose in the prehospital setting. Emergency medical staff appear to titrate naloxone based on clinical presentation.