Using machine learning to assess the extent of busy ambulances and its impact on ambulance response times: A retrospective observational study.

BACKGROUND: Ambulance response times are considered important. Busy ambulances are common, but little is known about their effect on response times. OBJECTIVE: To assess the extent of busy ambulances in Central Norway and their impact on ambulance response times. DESIGN: This was a retrospective observational study. We used machine learning on data from nearby incidents to assess the probability of up to five different ambulances being candidates to respond to a medical emergency incident. For each incident, the probability of a busy ambulance was estimated by summing the probabilities of candidate ambulances being busy at the time of the incident. The difference in response time that may be attributable to busy ambulances was estimated by comparing groups of nearby incidents with different estimated busy probabilities. SETTING: Medical emergency incidents with ambulance response in Central Norway from 2013 to 2022. MAIN OUTCOME MEASURES: Prevalence of busy ambulances and differences in response times associated with busy ambulances. RESULTS: The estimated probability of busy ambulances for all 216,787 acute incidents with ambulance response was 26.7% (95% confidence interval (CI) 26.6 to 26.9). Comparing nearby incidents, each 10-percentage point increase in the probability of a busy ambulance was associated with a delay of 0.60 minutes (95% CI 0.58 to 0.62). For incidents in rural and urban areas, the probability of a busy ambulance was 21.6% (95% CI 21.5 to 21.8) and 35.0% (95% CI 34.8 to 35.2), respectively. The delay associated with a 10-percentage point increase in busy probability was 0.81 minutes (95% CI 0.78 to 0.84) and 0.30 minutes (95% CI 0.28 to 0.32), respectively. CONCLUSION: Ambulances were often busy, which was associated with delayed ambulance response times. In rural areas, the probability of busy ambulances was lower, although the potentially longer delays when ambulances were busy made these areas more vulnerable.

Feasibility of quality indicators on prehospital advanced airway management in a physician-staffed emergency medical service: survey-based assessment of the provider point of view.

OBJECTIVE: We aimed to determine the feasibility of quality indicators (QIs) for prehospital advanced airway management (PAAM) from a provider point of view. DESIGN: The study is a survey based feasibility assessment following field testing of QIs for PAAM. SETTING: The study was performed in two physician staffed emergency medical services in Switzerland. PARTICIPANTS: 42 of the 44 emergency physicians who completed at least one case report form (CRF) dedicated to the collection of the QIs on PAAM between 1 January 2019 and 31 December 2021 participated in the study. INTERVENTION: The data required to calculate the 17 QIs was systematically collected through a dedicated electronic CRF. PRIMARY AND SECONDARY OUTCOME MEASURES: Primary outcomes were provider-related feasibility criteria: relevance and acceptance of the QIs, as well as reliability of the data collection. Secondary outcomes were effort to collect specific data and to complete the CRF. RESULTS: Over the study period, 470 CRFs were completed, with a median of 11 per physician (IQR 4-17; range 1-48). The median time to complete the CRF was 7 min (IQR 3-16) and was considered reasonable by 95% of the physicians. Overall, 75% of the physicians assessed the set of QIs to be relevant, and 74% accepted that the set of QIs assessed the quality of PAAM. The reliability of data collection was rated as good or excellent for each of the 17 QIs, with the lowest rated for the following 3 QIs: duration of preoxygenation, duration of laryngoscopy and occurrence of desaturation during laryngoscopy. CONCLUSIONS: Collection of QIs on PAAM appears feasible. Electronic medical records and technological solutions facilitating automatic collection of vital parameters and timing during the procedure could improve the reliability of data collection for some QIs. Studies in other services are needed to determine the external validity of our results.

Extracorporeal membrane oxygenation in the therapy of cardiogenic shock: 1-year outcomes of the multicentre, randomized ECMO-CS trial.

AIMS: Among patients with cardiogenic shock, immediate initiation of extracorporeal membrane oxygenation (ECMO) did not demonstrate any benefit at 30 days. The present study evaluated 1-year clinical outcomes of the Extracorporeal Membrane Oxygenation in the therapy of Cardiogenic Shock (ECMO-CS) trial. METHODS AND RESULTS: The ECMO-CS trial randomized 117 patients with severe or rapidly progressing cardiogenic shock to immediate initiation of ECMO or early conservative strategy. The primary endpoint for this analysis was 1-year all-cause mortality. Secondary endpoints included a composite of death, resuscitated cardiac arrest or implantation of another mechanical circulatory support device, duration of mechanical ventilation, and the length of intensive care unit (ICU) and hospital stays. In addition, an unplanned post-hoc subgroup analysis was performed. At 1 year, all-cause death occurred in 40 of 58 (69.0%) patients in the ECMO arm and in 40 of 59 (67.8%) in the early conservative arm (hazard ratio [HR] 1.02, 95% confidence interval [CI] 0.66-1.58; p = 0.93). The composite endpoint occurred in 43 (74.1%) patients in the ECMO group and in 47 (79.7%) patients in the early conservative group (HR 0.83, 95% CI 0.55-1.25; p = 0.29). The durations of mechanical ventilation, ICU stay and hospital stay were comparable between groups. Significant interaction with treatment strategy and 1-year mortality was observed in subgroups according to baseline mean arterial pressure (MAP) indicating lower mortality in the subgroup with low baseline MAP (<63 mmHg: HR 0.58, 95% CI 0.29-1.16; pinteraction = 0.017). CONCLUSIONS: Among patients with severe or rapidly progressing cardiogenic shock, immediate initiation of ECMO did not improve clinical outcomes at 1 year compared to the early conservative strategy. However, immediate ECMO initiation might be beneficial in patients with advanced haemodynamic compromise.