Management of Opioid Overdose by Ambulance Services 2018-2024 in Tallinn, Estonia

Introduction: Tallinn Emergency Medical Service is the public ambulance service for the densely populated region of 500,000. Treatment protocols for ambulance guide the use of naloxone in opioid overdose with appropriate monitoring. However, the exact number of used doses, time at dispatch, and disposition after treatment is not proven. Methods: The electronic database of Tallinn Emergency Medical Service was analyzed for two periods. 2018-2019 (1 st period) and in 2023-2024 (2 nd period). In 2028-2019, the main overdose substance was fentanyl. In 2023 -2024, in addition to common street drugs, nitazene was introduced. All ambulance dispatches for “possible overdose” and dispatches for diagnosed opioid overdoses were analyzed. All cases for opioid overdose were analyzed for several naloxone doses, time on dispatch, time onsite, and disposition after treatment. Results: In general, during the 1 st period, all street drug overdose-related visits comprised 0.22-0.43% of all ambulance visits, and opioids constituted 23-28% (51-91 dispatches annually) of all street drug-related visits. During the 2 nd period, the corresponding numbers were 0.67-0.75 and 41-44% (221-295 annually). The frequency of hospitalization was 14.7-19.6% during both periods. The mean time onsite was similar during the two periods for patients treated onsite, 21.5-26.2 minutes. The mean on-scene time for patients who needed hospitalization was 52,7-67,2 minutes. The analysis of 2023 data showed that after 40 minutes on-scene, 65.4% of patients were hospitalized, and after 60 minutes, 95%. Hospitalization rate after naloxone doses was similar during both periods. Hospitalization rates were 4.9% after one dose of naloxone, 18.3% after the second dose, 32.5% after the third dose, and 30% after the fourth dose. Conclusion: The number of ambulance dispatches due to drug overdose has increased significantly during the second period. The use and efficacy of naloxone have not changed during the two periods. Time at the scene for more than 40 minutes translates into a need for hospitalization.