Emergency Medical Service Providers' Experiences with Traffic Congestion

Temporal trends of ambulance time intervals for suspected stroke/transient ischaemic attack (TIA) before and during the COVID-19 pandemic in Ireland: a quasi-experimental study

OBJECTIVES

Time is a fundamental component of acute stroke and transient ischaemic attack (TIA) care, thus minimising prehospital delays is a crucial part of the stroke chain of survival. COVID-19 restrictions were introduced in Ireland in response to the pandemic, which resulted in major societal changes. However, current research on the effects of the COVID-19 pandemic on prehospital care for stroke/TIA is limited to early COVID-19 waves. Thus, we aimed to investigate the effect of the COVID-19 pandemic on ambulance time intervals and suspected stroke/TIA call volume for adults with suspected stroke and TIA in Ireland, from 2018 to 2021.

DESIGN

We conducted a secondary data analysis with a quasi-experimental design.

SETTING

We used data from the National Ambulance Service in Ireland. We defined the COVID-19 period as '1 March 2020-31 December 2021' and the pre-COVID-19 period '1 January 2018-29 February 2020'.

PRIMARY AND SECONDARY OUTCOME MEASURES

We compared five ambulance time intervals: 'allocation performance', 'mobilisation performance', 'response time', 'on scene time' and 'conveyance time' between the two periods using descriptive and regression analyses. We also compared call volume for suspected stroke/TIA between the pre-COVID-19 and COVID-19 periods using interrupted time series analysis.

PARTICIPANTS

We included all suspected stroke/TIA cases ≥18 years who called the National Ambulance Service from 2018 to 2021.

RESULTS

40 004 cases were included: 19 826 in the pre-COVID-19 period and 19 731 in the COVID-19 period. All ambulance time intervals increased during the pandemic period compared with pre-COVID-19 (p<0.001). Call volume increased during the COVID-19-period compared with the pre-COVID-19 period (p<0.001).

CONCLUSIONS

A 'shock' like a pandemic has a negative impact on the prehospital phase of care for time-sensitive conditions like stroke/TIA. System evaluation and public awareness campaigns are required to ensure maintenance of prehospital stroke pathways amidst future healthcare crises. Thus, this research is relevant to routine and extraordinary prehospital service planning.

First Description of a Helicopter-Borne ECPR Team for Remote Refractory Out-of-Hospital Cardiac Arrest

Introduction: Access time to extracorporeal cardiopulmonary resuscitation (ECPR) refractory out of hospital cardiac arrest (OHCA) is a crucial factor. In our region, some patients are not eligible to this treatment due to the impossibility to reach the hospital with reasonable delay (ideally 60 min). In order to increase accessibility for patients far from ECPR centers, we developed a helicopter-borne ECPR-team which is sent out to the patient for ECPR implementation on the scene of the OHCA.Methods: We conducted a retrospective monocentric study to evaluate this strategy. The team is triggered by the local emergency medical service and heliborne on the site of the OHCA. All consecutive patients implemented with ECPR by our heliborne ECPR team from January 2014 to December 2017 were included. We analyzed usual CA characteristics, different times (no-flow, low-flow, time between OHCA and dispatch…), and patient outcome.Results: During this 4-year study period, 33 patients were included. Mean age was 43.9 years. Mean distance from the ECPR-team base to OHCA location was 41 km. Mean low-flow time was 110 minutes. Five patients survived with good neurological outcome; 6 patients developed brain death and became organ donors.Conclusion: These results show the possibility to make ECPR accessible for patients far from ECPR centers. Survival rate is non negligible, especially in the absence of therapeutic alternative. An earlier trigger of the ECPR-team could reduce the low-flow time and probably increase survival. This strategy improves equity of access to ECPR and needs to be confirmed by further studies.

Logistics of air medical transport: When and where does helicopter transport reduce prehospital time for trauma?

BACKGROUND

Trauma is a time sensitive disease. Helicopter emergency medical services (HEMS) have shown benefit over ground emergency medical services (GEMS), which may be related to reduced prehospital time. The distance at which this time benefit emerges depends on many factors that can vary across regions. Our objective was to determine the threshold distance at which HEMS has shorter prehospital time than GEMS under different conditions.

METHODS

Patients in the Pennsylvania trauma registry 2000 to 2013 were included. Distance between zip centroid and trauma center was calculated using straight-line distance for HEMS and driving distance from geographic information systems network analysis for GEMS. Contrast margins from linear regression identified the threshold distance at which HEMS had a significantly lower prehospital time than GEMS, indicated by nonoverlapping 95% confidence intervals. The effect of peak traffic times and adverse weather on the threshold distance was evaluated. Geographic effects across EMS regions were also evaluated.

RESULTS

A total of 144,741 patients were included with 19% transported by HEMS. Overall, HEMS became faster than GEMS at 7.7 miles from the trauma center (p = 0.043). Helicopter emergency medical services became faster at 6.5 miles during peak traffic (p = 0.025) compared with 7.9 miles during off-peak traffic (p = 0.048). Adverse weather increased the distance at which HEMS was faster to 17.1 miles (p = 0.046) from 7.3 miles in clear weather (p = 0.036). Significant variation occurred across EMS regions, with threshold distances ranging from 5.4 to 35.3 miles. There was an inverse but non-significant relationship between urban population and threshold distance across EMS regions (ρ, -0.351, p = 0.28).

CONCLUSION

This is the first study to demonstrate that traffic, weather, and geographic region significantly impact the threshold distance at which HEMS are faster than GEMS. Helicopter emergency medical services was faster at shorter distances during peak traffic while adverse weather increased this distance. The threshold distance varied widely across geographic region. These factors must be considered to guide appropriate HEMS triage protocols.

LEVEL OF EVIDENCE

Therapeutic, level IV.

Response time in the emergency services. Systematic review

The growth of the urban population raises concern about municipal public managers in the sense of providing emergency medical services (EMS) that are aligned with the needs of prehospital emergency medical care demanded by the population. The literature review aims at presenting the response time of emergency medical services in several parts of the world and discussing some factors that interfere in the result of this indicator such as GDP (Gross Domestic Product) percentage spent on health and life expectancy of countries. The study will also show that in some of the consulted articles, authors suggest to EMS recommendations for decreasing the response time using simulations, heuristics and metaheuristics. Response time is a basic indicator of emergency medical services, in such a way that researchers use the descriptive statistics to evaluate this parameter. Europe and the USA outstand in the publication of studies that present this information. Some articles use stochastic and mathematical methods to suggest models that simulate scenarios of response time reduction and suggest such proposals to the local EMS. Countries in which the response time was identified have a high index of human development and life expectancy between 74.7 and 83.7 years.

Characterizing the influence of transportation infrastructure on Emergency Medical Services (EMS) in urban area-A case study of Seoul, South Korea

In highly urbanized area where traffic condition fluctuates constantly, transportation infrastructure is one of the major contributing factors to Emergency Medical Service (EMS) availability and patient outcome. In this paper, we assess the impact of traffic fluctuation to the EMS first response availability in urban area, by evaluating the k-minute coverage under 21 traffic scenarios. The set of traffic scenarios represents the time-of-day and day-of-week effects, and is generated by combining road link speed information from multiple historical speed databases. In addition to the k-minute area coverage calculation, the k-minute population coverage is also evaluated for every 100m by 100m grid that partitions the case study area of Seoul, South Korea. In the baseline case of traveling at the speed limit, both the area and population coverage reached nearly 100% when compared to the five-minute travel time national target. Employing the proposed LoST (Loss of Serviceability due to Traffic) index, which measures coverage reduction in percentage compared to the baseline case, we find that the citywide average LoST for area and population coverage are similar at 34.2% and 33.8%. However, district-wise analysis reveals that such reduction varies significantly by district, and the magnitude of area and population coverage reduction is not always proportional. We conclude that the effect of traffic variation is significant to successful urban EMS first response performance, and regional variation is evident among local districts. Complexity in the urban environment requires a more adaptive approach in public health resource management and EMS performance target determination.