The demand for prehospital advanced life support and the appropriateness of dispatch in Taipei

The variables predictive of ambulance non-conveyance of patients in the Western Cape, South Africa

Introduction

Emergency medical service (EMS) resources are limited and should be reserved for incidents of appropriate acuity. Over-triage in dispatching of EMS resources is a global problem. Analysing patients that are not transported to hospital is valuable in contributing to decision-making models/algorithms to better inform dispatching of resources. The aim is to determine variables associated with patients receiving an emergency response but result in non-conveyance to hospital.

Methods

A retrospective cross-sectional study was performed on data for the period October 2018 to September 2019. EMS records were reviewed for instances where a patient received an emergency response but the patient was not transported to hospital. Data were subjected to univariate and multivariate regression analysis to determine variables predictive of non-transport to hospital.

Results

A total of 245 954 responses were analysed, 240 730 (97.88 %) were patients that were transported to hospital and 5 224 (2.12 %) were not transported. Of all patients that received an emergency response, 203 450 (82.72 %) patients did not receive any medical interventions. Notable variables predictive of non-transport were green (OR 4.33 (95 % CI: 3.55-5.28; p<0.01)) and yellow on-scene (OR 1.95 (95 % CI: 1.60-2.37; p<0.01).Incident types most predictive of non-transport were electrocutions (OR 4.55 (95 % CI: 1.36-15.23; p=0.014)), diabetes (OR 2.978 (95 % CI: 2.10-3.68; p<0.01)), motor vehicle accidents (OR 1.92 (95 % CI: 1.51-2.43; p<0.01)), and unresponsive patients (OR 1.98 (95 % CI: 1.54-2.55; p<0.01)). The highest treatment predictors for non-transport of patients were nebulisation (OR 1.45 (95 % CI: 1.21-1.74; p<0.01)) and the administration of glucose (OR 4.47 (95 % CI: 3.11-6.41; p<0.01)).

Conclusion

This study provided factors that predict ambulance non-conveyance to hospital. The prediction of patients not transported to hospital may aid in the development of dispatch algorithms that reduce over-triage of patients, on-scene discharge protocols, and treat and refer guidelines in EMS.

Characteristics and Outcomes of Patients Injured in Road Traffic Crashes and Transported by Emergency Medical Services

To investigate the injury characteristics and mortality of patients transported by emergency medical services (EMS) and hospitalized for trauma following a road traffic crash, data obtained from the Trauma Registry System were retrospectively reviewed for trauma admissions between 1 January 2009 and 31 December 2013 in a Level I trauma center. Of 16,548 registered patients, 3978 and 1440 patients injured in road traffic crashes were transported to the emergency department by EMS and non-EMS, respectively. Patients transported by EMS had lower Glasgow coma scale (GCS) scores and worse hemodynamic measures. Compared to patients transported by non-EMS, more patients transported by EMS required procedures (intubation, chest tube insertion, and blood transfusion) at the emergency department. They also sustained a higher injury severity, as measured by the injury severity score (ISS) and the new injury severity score (NISS). Lastly, in-hospital mortality was higher among the EMS than the non-EMS group (1.8% vs. 0.3%, respectively; p < 0.001). However, we found no statistically significant difference in the adjusted odds ratio (AOR) for mortality among patients transported by EMS after adjustment for ISS (AOR 4.9, 95% CI 0.33-2.26), indicating that the higher incidence of mortality was likely attributed to the patients' higher injury severity. In addition, after propensity score matching, logistic regression of 58 well-matched pairs did not show a significant influence of transportation by EMS on mortality (OR: 0.578, 95% CI: 0.132-2.541 p = 0.468).

Prehospital triage accuracy in a criteria based dispatch centre

BACKGROUND

Priority dispatch accuracy is a key issue in optimizing the match between patients' medical needs and pre-hospital resources. This study measures the accuracy of a Criteria Based Dispatch (CBD) system, by evaluating discrepancies between dispatch priorities and ambulance crews' severity evaluations.

METHODS

This is a retrospective study conducted from January 2011 to December 2011. We ruled that a National Advisory Committee for Aeronautics (NACA) score > 3 (injuries/diseases which can possibly lead to deterioration of vital signs) to 7 (lethal injuries/ diseases) should require a priority dispatch with lights and siren (L&S), while NACA scores < 4 should require a priority dispatch without L&S. Over triage was defined as the proportion of L&S dispatches with a NACA score < 4, and under triage as the proportion of dispatches without L&S with a NACA score > 3.

RESULTS

There were 29,008 primary missions in 2011, 1122 were excluded. Of the 15,749 L&S missions, 12,333 patients had a NACA score < 4, leading to an over triage rate of 78 %; 561 missions out of 12,137 missions without L&S had a NACA score > 3, leading to an under triage rate of 4.6 %. Sensitivity was 86 % (95 % confidence interval: 85.6-86.4 %), specificity 48 % (47.4-48.6 %), positive predictive value 21.7 % (21.2-22.2 %), and negative predictive value 95.4 % (95.2-95.6 %).

CONCLUSION

The rates of over triage and under triage in our CBD are 78 and 4.6 % respectively. The lack of consistent or universal metrics is perhaps the most important limitation in dispatch accuracy research. This is mainly due to the large heterogeneity of dispatch systems and prehospital emergency system.

EMS in Taiwan: past, present, and future

Taiwan is a small island country located in East Asia. From around 1995 modern concepts of the EMS were imported and supported by legislation. Considerable progress has since been made towards the construction of an effective pre-hospital care system. This article introduces the current status of the EMS in Taiwan, including the systems, response configurations, funding, personnel, medical directorship, and outcome research. The features and problems of in-hospital emergency care are also discussed. Key areas for further development in the country vary depending on regional differences in available resource and population density. An analysis of the strength, weakness, opportunity, and threats of the evolving EMS in Taiwan could be an example for other countries where the EMS is undergoing a similar process of development and optimisation.

Video-recording and time-motion analyses of manual versus mechanical cardiopulmonary resuscitation during ambulance transport

INTRODUCTION

The quality of cardiopulmonary resuscitation (CPR) plays a crucial role in saving lives from out-of-hospital cardiac arrest (OHCA). Previous studies have identified sub-optimal CPR quality in the prehospital settings, but the causes leading to such deficiencies were not fully elucidated.

OBJECTIVE

This prospective study was conducted to identify operator- and ambulance-related factors affecting CPR quality during ambulance transport; and to assess the effectiveness of mechanical CPR device in such environment.

MATERIALS AND METHODS

A digital video-recording system was set up in two ambulances in Taipei City to study CPR practice for adult, non-traumatic OHCAs from January 2005 to March 2006. Enrolled patients received either manual CPR or CPR by a mechanical device (Thumper). Quality of CPR in terms of (1) adequacy of chest compressions, (2) instantaneous compression rates, and (3) unnecessary no-chest compression interval, was assessed by time-motion analysis of the videos.

RESULTS

A total of 20 ambulance resuscitations were included. Compared to the manual group (n=12), the Thumper group (n=8) had similar no-chest compression interval (33.40% versus 31.63%, P=0.16); significantly lower average chest compression rate (113.3+/-47.1 min(-1) versus 52.3+/-14.2 min(-1), P<0.05), average chest compression rate excluding no-chest compression interval (164.2+/-43.3 min(-1) versus 77.2+/-6.9 min(-1), P<0.05), average ventilation rate (16.1+/-4.9 min(-1) versus 11.7+/-3.5 min(-1), P<0.05); and longer no-chest compression interval before getting off the ambulance (5.7+/-9.9s versus 18.7+/-9.1s, P<0.05). The majority of the no-chest compression interval was considered operator-related; only 15.3% was caused by ambulance related factors.

CONCLUSIONS

Many unnecessary no-chest compression intervals were identified during ambulance CPR, and most of this was operator, rather than ambulance related. Though a mechanical device could minimise the no-chest compression intervals after activation, it took considerable time to deploy in a system with short transport time. Human factors remained the most important cause of poor CPR quality. Ways to improve the CPR quality in the ambulance warrant further study.

Outcomes from out-of-hospital cardiac arrest in Metropolitan Taipei: Does an advanced life support service make a difference?

BACKGROUND

Out-of-hospital cardiac arrest (OHCA) is of major medical and public health significance. It also serves as a good indicator in assessing the performance of local emergency medical services system (EMS). There have been arguments for and against the benefits of advanced life support (ALS) over basic life support with defibrillator (BLS-D) for treating OHCA.

AIMS OF THE STUDY

The study was conducted to characterise the outcomes of cardiac arrest victims in an Asian metropolitan city; to evaluate the impacts of ALS versus BLS-D services; and to explore the possible patient and arrest factors that may be associated with the observed differences in the outcomes between the two pre-hospital care models.

MATERIALS AND METHODS

Taipei is an Asian metropolitan city with an area of 272 km(2) and a population of 2.65 million. The fire-based BLS-D EMS system was in the process of phasing in ALS capability. While there were 40 BLS-D teams in the 12 city districts, two ALS teams were set up in the central part of the city. In this prospective study, all adult non-traumatic OHCA from September 2003 to August 2004 were included. Patient, arrest, care, and outcome variables for OHCA victims were collected from prehospital run sheets, automatic defibrillators, and emergency department and hospital records.

RESULTS

Among 1423 OHCA included in the analysis, 1037 (73%) received BLS-D service, and 386 (27%) received ALS services. The initial shockable rhythms and early bystander CPR were strongly associated with better survival for victims of cardiac arrests. Compared to BLS-D, ALS patients had similar age, sex, witness status, the rate of bystander CPR, and response timeliness but more patients in asystole (84% versus 72%, p=0.005). Patients treated by ALS were more likely to result in significantly higher rates of return of spontaneous circulation (29% versus 21%; OR=1.51 (95% CI 1.15-2.00); p=0.002) and survival to emergency department/intensive care unit admission (23% versus 15%; OR=1.66 (95% CI 1.22-2.24); p=0.001), but there was no difference in the rate of survival to hospital discharge (7% versus 5%; OR=1.39 (95% CI 0.84-2.23); p=0.17). The outcome difference from ALS services was more pronounced among patients in asystole and without bystander CPR.

CONCLUSIONS

In this metropolitan EMS in Asia, the implementation of ALS services improved the intermediate, but not the final outcomes. Communities with larger populations and lower incidence of initial shockable rhythms than the OPALS study should also prioritise their resources in setting up and optimising systems of basic life support and early defibrillations. Further studies are warranted to configure the optimal care model for combating cardiac arrest.