Hypoglycemic Events Focusing on Situational Factors, Bystander Identification, and Prehospital Management

Background: Severe hypoglycemia is a major reason for emergency medical service (EMS) activation among patients with diabetes. However, real-world epidemiology, including onset location, timing, caller identity, and prehospital management, remains insufficiently described. This study aimed to characterize these cases and assess prehospital interventions and patient outcomes. Methods: We conducted a retrospective, descriptive study using EMS transport records and emergency department (ED) data from two core hospitals and their regional EMS systems in Japan between January 2018 and December 2023. Included patients were those transported by EMS for hypoglycemia with a corresponding ED diagnosis. Extracted data included patient characteristics, episode location and time, EMS caller identity, prehospital interventions, and clinical outcomes. Results: Among 237 episodes, the median age was 74 years and 59.9% were male. Most events occurred at home (78.1%) and during evening or nighttime hours (51.9%). Family members were the most frequent EMS callers (67.5%), yet 12.5% of patients received bystander medical intervention. EMS teams performed most prehospital interventions (68.8%), primarily intravenous glucose administration (65.2%). At EMS arrival, 16.0% were fully conscious and 21.1% were comatose. Hospitalization occurred in 44.3%. The hospitalization rate was 34.2% among patients who received prehospital intervention and 53.2% among those who did not. Conclusions: Most hypoglycemia episodes were discovered by family members, but bystander intervention was uncommon. Differences in hospitalization rates were observed according to the presence and timing of prehospital intervention.