Amiodarone for sustained stable ventricular tachycardia in the prehospital setting

OBJECTIVE

Amiodarone is commonly used in the treatment of stable ventricular tachycardia (VT), but its efficacy has not been empirically examined in the prehospital setting. The objective of this study was to examine the safety and efficacy of amiodarone administered by paramedics to patients with stable VT.

METHODS

Patient records from Victoria, Australia between 1 May 2007 and 30 June 2017 were examined retrospectively. Patients attended by Ambulance Victoria with stable sustained VT who were administered amiodarone by paramedics as the initial treatment were included. Data were used to determine the prevalence of treatment with amiodarone, the incidence of VT termination prior to transfer of care, and the incidence of progression to electrical cardioversion.

RESULTS

Sixty-one patients were identified who met the inclusion criteria. The mean age was 72 years (standard deviation = 14) with 77% (n = 47) being male. Of the patients treated with amiodarone, 52% (n = 32) reverted successfully during paramedic care while 48% (n = 29) did not. Two patients required cardioversion for haemodynamic instability after amiodarone administration. One patient experienced cardiac arrest after receiving amiodarone and was successfully resuscitated by paramedics.

CONCLUSIONS

Approximately half of the patients treated with amiodarone reverted from VT while under paramedic care. Patient deterioration was rare, with cardiac arrest or requirement for cardioversion occurring very infrequently. Amiodarone was relatively safe and moderately effective for the treatment of sustained stable VT. However, given recent evidence of increased efficacy of procainamide for stable VT, further studies are required in the prehospital setting to compare these two drugs.

Efficacy of pre-hospital rapid sequence intubation in paediatric traumatic brain injury: A 9-year observational study

INTRODUCTION

Prehospital airway management of the paediatric patient with traumatic brain injury (TBI) is controversial. Endotracheal intubation of children in the field requires specific skills and has potential benefits but also carries potentially serious complications. We aimed to compare mortality and functional outcomes after six months between children with TBI who either underwent prehospital rapid sequence intubation (RSI) by trained Intensive Care paramedics (ICP) or received no intubation.

METHODS

We conducted a retrospective study of patients aged ≤14 years with suspected TBI in Victoria, Australia. Patients were either transported via helicopter and received RSI by an ICP (2005-2013) or via road ambulance and received no intubation (2006-2013). Prehospital data was linked to hospital and 6-month follow-up data to assess mortality and functional outcome.

RESULTS

A total of 106 patients were included in the study of which 87 received RSI by paramedics and 19 did not receive intubation. Overall, the intubation success rate was 99% (86/87), with a first-pass success rate of 93% (81/87). In total, 67% of patients (n = 41) receiving RSI had a favourable functional outcome, compared with 54% of non-intubated patients (n = 7) (p = 0.36). In the 75 children with major trauma, prehospital RSI was associated with a significant decrease in length of hospital stay (523 h vs. 1939 h, p = 0.03). In the 53 children in this subgroup with available six months data the difference in favourable functional outcome increased to 66% (n = 31)vs. 17% (n = 1) (p = 0.06).

DISCUSSION

Prehospital RSI in paediatric patients with TBI can safely be performed by highly trained paramedics. Overall, we observed more favourable long-term outcomes in patients who received prehospital intubation than those who did not, however our study is not powered to detect a significant difference. Intubation prior to transport might be beneficial for major trauma patients.

Manual Versus Semiautomatic Rhythm Analysis and Defibrillation for Out-of-Hospital Cardiac Arrest

BACKGROUND

Although manual and semiautomatic external defibrillation (SAED) are commonly used in the management of out-of-hospital cardiac arrest, the optimal strategy is not known. We hypothesized that SAED would reduce the time to first shock and lead to higher rates of cardioversion and survival compared with a manual strategy.

METHODS AND RESULTS

Between July 2005 and June 2015, we included adult out-of-hospital cardiac arrest of presumed cardiac pathogenesis. On October 2012, a treatment protocol using SAED was introduced after years of manual defibrillation. The effect of the SAED implementation on the time to first shock, successful cardioversion, and patient outcomes was assessed using interrupted time series regression adjusting for arrest factors and temporal trend. Of the 14 776 cases, 10 224 (69.2%) and 4552 (30.8%) occurred during the manual and SAED protocols, respectively. Although the proportion of patients shocked within 2 minutes of arrival increased during the SAED protocol for initial shockable rhythms (from 58.9% to 69.2%; P<0.001), there was no difference in unadjusted rate of successful cardioversion after first shock (from 12.3% to 13.8%; P=0.13). After adjustment, the odds of delivering the first shock within 2 minutes of arrival increased under the SAED protocol (adjusted odds ratio [AOR], 1.72; 95% confidence interval [CI], 1.32-2.26; P<0.001). Despite this, the SAED protocol was associated with a reduction in survival to hospital discharge (AOR, 0.71; 95% CI, 0.55-0.92; P=0.009), event survival (AOR, 0.74; 95% CI, 0.62-0.88; P=0.001), and prehospital return of spontaneous circulation (AOR, 0.81; 95% CI, 0.68-0.96; P=0.01) when compared with the manual protocol. There was also no improvement in the rate of successful cardioversion after first shock (AOR, 0.73; 95% CI, 0.51-1.06; P=0.10).

CONCLUSIONS

Although SAED improved the time to first shock, this did not translate into higher rates of successful cardioversion or survival after out-of-hospital cardiac arrest. Advanced life support providers should be trained to use a manual defibrillation protocol.

Impact of a public awareness campaign on out-of-hospital cardiac arrest incidence and mortality rates

Aims

Increased public awareness of the warning signs of a heart attack and the importance of early medical intervention may help to prevent premature deaths from out-of-hospital cardiac arrest (OHCA). We sought to investigate the impact of the Heart Foundation's public awareness campaigns on the monthly incidence of, and deaths from, OHCA in Melbourne, Australia.

Methods and results

Between July 2005 and June 2015, we included registry data for 25 060 OHCA of presumed cardiac aetiology. Time series models with distributed lags were used to explore the effect of campaign activity on OHCA outcomes. A sensitivity analysis involving segmented regression of the pre-intervention, intervention, and post-intervention time segments was also performed. The mean monthly incidence of, and deaths from, OHCA was 207 and 189 events respectively. After adjustment for temporal trends, campaign activity was associated with a 6.0% [95% confidence interval (CI): 2.8-9.0%; P < 0.001] reduction in the monthly incidence of OHCA, or 11.7% (95% CI: 7.7-15.5%, P < 0.001) with the addition of residual effects in two additional lag months. Similarly, the rate of deaths from OHCA reduced by 6.4% (95% CI: 2.8-10.0%; P = 0.001) during months with campaign activity. Campaign activity had a greater effect in males and patients aged ≥65 years, and reduced the incidence of OHCA in unwitnessed and initial non-shockable arrests. In the segmented regression analysis, the intervention period was associated with a 15.2% (95% CI: 9.2-20.9%; P < 0.001) reduction in the mean monthly incidence and a 16.6% (95% CI: 9.9-22.7%; P < 0.001) reduction in deaths from OHCA.

Conclusion

A comprehensive mass media campaign targeting the community's awareness of heart attack symptoms was associated with a substantial reduction in the incidence of OHCA and associated deaths.

Long-term functional recovery and health-related quality of life of elderly out-of-hospital cardiac arrest survivors

INTRODUCTION

Understanding the prognosis of elderly out-of-hospital cardiac arrest (OHCA) patients is vital to informing resuscitation and advanced care planning decisions. However, short-term outcomes such as survival to hospital discharge do not account for post-arrest quality of life. We describe the 12-month functional recovery and health-related quality of life (HR-QOL) of elderly OHCA survivors, including those arresting in aged care facilities.

METHODS

We conducted a retrospective analysis of Victorian Ambulance Cardiac Arrest Registry data for all OHCA survivors to hospital discharge aged ≥65 years between 1 January 2010 and 30 June 2016. The influence of age on functional recovery and independent living was assessed using multivariable logistic regression.

RESULTS

During the study period, 20,103 elderly OHCAs were attended, 9016 (44.9%) of whom received a resuscitation attempt. In total, 876 (9.7%) patients survived to hospital discharge and 777 were alive 12 months post-arrest. Of these, 651 participated in 12-month follow-up (response rate 83.8%). Most (60.6%) resided at home without additional care and 66.6% reported a good functional recovery, however both measures decreased with increasing age (p < 0.001). Mental HR-QOL increased with increasing age and was significantly better than the age- and sex-matched Australian population. Each 10-year increase in age was associated with a 40.8% (95%CI 25.6-53.0%) reduction in the odds of good functional recovery, and a 65.8% (95%CI 55.8-73.5%) reduction in the odds of living independently. Of the 2575 OHCAs in an aged care facility, 2.2% survived to hospital discharge, however no patient reported a good 12-month functional recovery.

CONCLUSIONS

Most elderly OHCA survivors resided independently with good functionality 12 months post-arrest. However, increasing age was associated with less favourable outcomes. New strategies are needed with regard to resuscitation in aged care facilities.

Prehospital Rapid Sequence Intubation by Intensive Care Flight Paramedics

OBJECTIVE

Rapid sequence intubation (RSI) is an advanced airway procedure for critically ill or injured patients. Paramedic-performed RSI in the prehospital setting remains controversial, as unsuccessful or poorly conducted RSI is known to result in significant complications. In Victoria, intensive care flight paramedics (ICFPs) have a broad scope of practice including RSI in both the adult and pediatric population. We sought to describe the success rates and characteristics of patients undergoing RSI by ICFPs in Victoria, Australia.

METHODS

A retrospective data review was conducted of adult (≥ 16 years) patients who underwent RSI by an ICFP between January 1, 2011, and December 31, 2016. Data were sourced from the Ambulance Victoria data warehouse.

RESULTS

A total of 795 cases were included in analyses, with a mean age of 45 (standard deviation = 19.6) years. The majority of cases involved trauma (71.7%), and most patients were male (70.1%). Neurological pathologies were the most common clinical indication for RSI (68.3%). The first pass success rate of intubation was 89.4%, and the overall success rate was 99.4%. Of the 5 failed intubations (0.6%), all patients were safely returned to spontaneous respiration. Two patients were returned via bag/valve/mask (BVM) support alone, two with BVM and oropharyngeal airway, and one via supraglottic airway. No surgical airways were required. Overall, we observed transient cases of hypotension (5.2%), hypoxemia (1.3%), or both (0.1%) in 6.6% of cases during the RSI procedure.

CONCLUSION

A very high RSI procedural success rate was observed across the study period. This supports the growing recognition that appropriately trained paramedics can perform RSI safely in the prehospital environment.

Delayed Sequence Intubation by Intensive Care Flight Paramedics in Victoria, Australia

OBJECTIVE

Delayed sequence intubation (DSI) involves the administration of ketamine to facilitate adequate preoxygenation in the agitated patient. DSI was introduced into the Clinical Practice Guideline for Intensive Care Flight Paramedics in Victoria in late 2013. We aimed to describe the clinical characteristics of patients receiving DSI.

METHODS

A retrospective analysis was undertaken of patients who received DSI between January 1, 2014, and December 31, 2016, during both primary response and retrieval missions. Patients' clinical characteristics, DSI success rates, and complications were determined from electronic patient care records.

RESULTS

Forty patients received DSI during the study period. Of these, 32 were intubated to manage traumatic injury and the remaining 8 were intubated for medical reasons. On arrival of the first road ambulance, median oxygen saturation was 96.5%, and immediately prior to DSI the median was 98.0%. One patient had a period of self-limiting apnea (< 15 seconds) following ketamine administration. Oxygen saturation was either maintained or increased prior to laryngoscopy in all patients. Post-intubation, one patient experienced bradycardia (heart rate < 60 beats per minute), two patients had a systolic blood pressure drop of > 20 mm Hg, one patient experienced an increase in heart rate of > 20 beats per minute, and two patients had transient oxygen desaturation (< 85%). No patients experienced cardiac arrest or required surgical airway intervention. All patients were successfully intubated. After DSI, the median oxygen saturation was 100%.

CONCLUSIONS

DSI provides a reasonably safe and effective approach for intensive care flight paramedics in the preoxygenation of agitated, hypoxic patients in order to decrease the risk of peri-intubation desaturation and related hypoxic injury.

Stormy weather: a retrospective analysis of demand for emergency medical services during epidemic thunderstorm asthma

OBJECTIVES

To describe the demand for emergency medical assistance during the largest outbreak of thunderstorm asthma reported globally, which occurred on 21 November 2016.

DESIGN

A time series analysis was conducted of emergency medical service caseload between 1 January 2015 and 31 December 2016. Demand during the thunderstorm asthma event was compared to historical trends for the overall population and across specific subgroups.

SETTING

Victoria, Australia.

MAIN OUTCOME MEASURES

Number of overall cases attended by emergency medical services, and within patient subgroups.

RESULTS

On 21 November 2016, the emergency medical service received calls for 2954 cases, which was 1014 more cases than the average over the historical period. Between 6 pm and midnight, calls for 1326 cases were received, which was 2.5 times higher than expected. A total of 332 patients were assessed by paramedics as having acute respiratory distress on 21 November, compared with a daily average of 52 during the historical period. After adjustment for temporal trends, thunderstorm asthma was associated with a 42% (95% confidence interval 40% to 44%) increase in overall caseload for the emergency medical service and a 432% increase in emergency medical attendances for acute respiratory distress symptoms. Emergency transports to hospital increased by 17% (16% to 19%) and time critical referrals from general practitioners increased by 47% (21% to 80%). Large increases in demand were seen among patients with a history of asthma and bronchodilator use. The incidence of out-of-hospital cardiac arrest increased by 82% (67% to 99%) and pre-hospital deaths by 41% (29% to 55%).

CONCLUSIONS

An unprecedented outbreak of thunderstorm asthma was associated with substantial increase in demand for emergency medical services and pre-hospital cardiac arrest. The health impact of future events may be minimised through use of preventive measures by patients and predictive early warning systems.

Predicting outcomes in traumatic out-of-hospital cardiac arrest: the relevance of Utstein factors

BACKGROUND

Given low survival rates in cases of traumatic out-of-hospital cardiac arrest (OHCA), there is a need to identify factors associated with outcomes. We aimed to investigate Utstein factors associated with achieving return of spontaneous circulation (ROSC) and survival to hospital in traumatic OHCA.

METHODS

The Victorian Ambulance Cardiac Arrest Registry (VACAR) was used to identify cases of traumatic OHCA that received attempted resuscitation and occurred between July 2008 and June 2014. We excluded cases aged <16 years or with a mechanism of hanging or drowning.

RESULTS

Of the 660 traumatic OHCA patients who received attempted resuscitation, ROSC was achieved in 159 patients (24%) and 95 patients (14%) survived to hospital (ROSC on hospital handover). Factors that were positively associated with achieving ROSC in multivariable logistic regression models were age ≥65 years (adjusted OR (AOR)=1.56, 95% CI: 1.01 to 2.43) and arresting rhythm (shockable (AOR=3.65, 95% CI: 1.64 to 8.11) and pulseless electrical activity (AOR=2.15, 95% CI: 1.36 to 3.39) relative to asystole). Similarly, factors positively associated with survival to hospital were arresting rhythm (shockable (AOR=3.92, 95% CI: 1.64 to 9.41) relative to asystole), and the mechanism of injury (falls (AOR=2.16, 95% CI: 1.03 to 4.54) relative to motor vehicle collisions), while trauma type (penetrating (AOR=0.27, 95% CI: 0.08 to 0.91) relative to blunt trauma) and event region (rural (AOR=0.39, 95% CI: 0.19 to 0.80) relative to urban) were negatively associated with survival to hospital.

CONCLUSIONS

Few patient and arrest characteristics were associated with outcomes in traumatic OHCA. These findings suggest there is a need to incorporate additional information into cardiac arrest registries to assist prognostication and the development of novel interventions in these trauma patients.

Deconstruction of Interhospital Transfer Workflow in Large Vessel Occlusion

Background and Purpose—

Interhospital transfer is a critical component in the treatment of acute anterior circulation large vessel occlusive stroke transferred for mechanical thrombectomy. Real-world data for benchmarking and theoretical modeling are limited. We sought to characterize transfer workflow from primary stroke center (PSC) to comprehensive stroke center after the publication of positive thrombectomy trials.

Methods—

Consecutive patients transferred from 3 high-volume PSCs to a single comprehensive stroke center between January 2015 and August 2016 were included in a retrospective study. Factors associated with key time metrics were analyzed with emphasis on PSC intrahospital workflow.

Results—

Sixty-seven patients were identified. Median age was 74 years (interquartile range [IQR], 63.5–78) and National Institutes of Health Stroke Scale 17 (IQR, 12–21). Median transfer time measured by PSC-door-to-comprehensive stroke center-door was 128 minutes (IQR, 107–164), of which 82.8% was spent at PSCs (door-in-door-out [DIDO]; 106 minutes; IQR, 86–143). The lengthiest component of DIDO was computed-tomography-to-retrieval-request (median 59.5 minutes; IQR, 44–83). The 37.3% had DIDO exceeding 120 minutes. DIDO times differed significantly between PSCs ( P =0.01). In multivariate analyses, rerecruiting the initial ambulance crew for transfer ( P <0.01) and presentation during working hours ( P =0.04) were associated with shorter DIDO times.

Conclusions—

In a metropolitan hub-and-spoke network, PSC-door-to-comprehensive stroke center-door and DIDO times are long even in high-volume PSCs. Improving PSC workflow represents a major opportunity to expedite mechanical thrombectomy and improve patient outcomes.

Characteristics of Fixed Wing Air Ambulance Transports in Victoria, Australia

OBJECTIVE

Air medical transport is important for the transfer of patients in the prehospital and interhospital environment. Few studies have described the services provided by fixed wing ambulances or the broader clinical profiles of patients they transport. Such information may be useful for the planning and allocation of resources, assistance with training, and refining clinical protocols. We sought to describe the characteristics of patients transported by fixed wing aircraft at Air Ambulance Victoria (AAV) and the service AAV provides in Victoria, Australia.

METHODS

A retrospective data review of patients transported by AAV fixed wing aircraft between January 1, 2011, and June 30, 2015, was performed. Data were sourced from the Ambulance Victoria data warehouse. Retrievals involving physicians were excluded.

RESULTS

A total of 16,579 patients were transported during the study period, with a median age of 66 years. Most patients were male (58.7%), and cardiovascular/hematologic conditions (27.2%) were most common. Overall, 51.7% of cases were prebooked routine transfers, 47.4% were interhospital routine transfers, and 0.9% were primary responses. Caseloads were largest in the regions furthest from the capital city.

CONCLUSION

The AAV fixed wing service in Victoria enables regional and remote patients to be transported to definitive care without major disruption to ground ambulances.

Resuscitation attempts and duration in traumatic out-of-hospital cardiac arrest

BACKGROUND

This study aimed to understand factors associated with paramedics' decision to attempt resuscitation in traumatic out-of-hospital cardiac arrest (OHCA) and to characterise resuscitation attempts ≤10min in patients who die at the scene.

METHODS

The Victorian Ambulance Cardiac Arrest Registry (VACAR) was used to identify all cases of traumatic OHCA between July 2008 and June 2014. We excluded cases <16 years of age or with a mechanism of hanging or drowning.

RESULTS

Of the 2334 cases of traumatic OHCA, resuscitation was attempted in 28% of cases and this rate remained steady over time (p=0.10). Multivariable logistic regression revealed that the arresting rhythm [shockable (adjusted odds ratio (AOR)=18.52, 95% confidence interval (CI):6.68-51.36) or pulseless electrical activity (AOR=12.58, 95%CI:9.06-17.45) relative to asystole] and mechanism of injury [motorcycle collision (AOR=2.49, 95%CI:1.60-3.86), fall (AOR=1.91, 95%CI:1.17-3.11) and shooting/stabbing (AOR=2.25, 95%CI:1.17-4.31) relative to a motor vehicle collision] were positively associated with attempted resuscitation. Arrests occurring in rural regions had a significantly lower odds of attempted resuscitation relative to those in urban regions (AOR=0.64, 95%CI:0.46-0.90). Resuscitation attempts ≤10min represented 34% of cases in which resuscitation was attempted but the patient died at the scene. When these resuscitation attempts were selectively excluded from the overall EMS treated population, survival to hospital discharge non-significantly increased from 3.8% to 5.0% (p=0.314).

CONCLUSION

Survival in our study was consistent with existing literature, however the large proportion of cases with resuscitation attempts ≤10min may under-represent survival in those patients that receive full resuscitation attempts.

Incidence of Roentgen Contrast Medium Reactions after Intravenous Injection in Pre-Registration Trials and Post-Marketing Surveillances

The relative risk of adverse drug reactions of ionic versus non-ionic contrast media injected i.v. were compared for different types of trials using odds-ratio. The absolute and relative risk found in large post-marketing trials were compared with that found in the iohexol pre-registration trials. The absolute risks were 2 to 10 times higher in the pre-registration trials compared to the post-marketing surveillances. The relative risk for all adverse drug reactions was 3 to 6 times higher for ionic vs. non-ionic media and independent of pre- or post-registration studies. The odds-ratio seems to be a feasible method of comparing the relative risk of adverse reactions in various trials.

Adverse Reactions following Two Separate Intravascular Injections of Contrast Media in the Same Patient

Adverse reactions following contrast medium injections in 26 non-comparative and parallel trials were extracted from the iohexol vascular clinical trial program in Northern Europe. Six hundred and forty-one patients (13–88 years old) in whom information was available about a vascular contrast medium examination before the iohexol clinical trials were included, enabling a retrospective within patient comparison of adverse reactions. Iohexol gave a lower recurrence frequency (approximately 3.5 times) of reactions than ionic monomers in patients who previously experienced adverse reactions to vascular contrast media. In order to overcome some of the drawbacks with the present retrospective design, prospective comparative studies are recommended.

Renal Effects of the Non-Ionic Contrast Medium Iopentol after Intravenous Injection in Healthy Volunteers

Renal effects of the new non-ionic contrast medium iopentol in increasing doses were assessed and compared with the effects of physiologic saline. Twenty-four healthy male volunteers, allocated to three dose groups, were given iopentol intravenously in doses of 0.3, 0.6, and 1.2 g I/kg body weight, respectively. The highest dose group was also given physiologic saline separately as a control. The diuresis increased in all groups, most in the highest dose group, and with a concomitant fall of urine osmolality and increase in osmolar clearance. A slight decrease of serum osmolality, creatinine and urea occurred at 3 hours due to hemodilution. The glomerular filtration rate was unaffected by iopentol. The urinary excretion of albumin and β2-microglobulin was unchanged. However, urinary N-acetyl-β-glucosaminidase and alkaline phosphatase increased significantly, most in the highest dose group. All changes were reversible.

Excretion of Iohexol and Metrizoate in Human Breast Milk

Six lactating women undergoing contrast media examination had milk and blood taken to determine the rate and extent of excretion of iohexol (Omnipaque) (four mothers) and metrizoate (Isopaque) (two mothers). Blood samples were taken up to 45 minutes and milk samples up to 48 hours after the contrast medium injection. The excretion was low, reaching a maximum at 3 to 6 hours and showing a slow decay curve (t 1/2 = 15 to 108 hours). One mother, who was weaning her baby, showed a different excretion pattern. The amount excreted during 24 hours was about 0.5 per cent of the weight adjusted maternal dose for both iohexol and metrizoate. It is not likely, that such a low dose of poorly absorbed drug would cause any adverse effects in the infant, unless it is hypersensitive to the drug already. The authors consider breast feeding to be acceptable for mothers receiving iohexol or metrizoate.

Comparison of health-related quality of life and functional recovery measurement tools in out-of-hospital cardiac arrest survivors

INTRODUCTION

Although a number of validated health-related quality of life (HR-QOL) instruments exist for critical care populations, a standardised approach to assessing the HR-QOL of out-of-hospital cardiac arrest (OHCA) survivors has not been developed. We sought to compare the responses of 12-month OHCA survivors to three HR-QOL and functional recovery instruments, and assess instrument validity.

METHODS

The Victorian Ambulance Cardiac Arrest Registry invited 12-month OHCA survivors to participate in telephone follow-up between January 2011 and December 2015. Responders provided answers to the 12 Item Short Form Health Survey (SF-12), Three-Level EuroQol-5D (EQ-5D-3L) and the Glasgow Outcome Scale-Extended (GOSE). The SF-12 was also used to derive the SF-6D. Responses were used to assess the interpretability and construct validity of the instruments.

RESULTS

A total of 1188 patients and proxies responded. Large ceiling effects were observed for the EQ-5D-3L (patients=46%, proxies=23%). Substantial variability was also observed in SF-6D responses for patients who reported full health according to the EQ-5D-3L. For patient responders, the strongest correlations were observed between the EQ-5D-3L index score and SF-6D (ρ=0.65, p<0.001), and between the SF-6D and SF-12 physical component (ρ=0.69, p<0.001). The distribution of the SF-6D and EQ-5D-3L differed significantly for patients reporting a lower or upper moderate GOSE outcome and lower or upper good recovery (p<0.001 for all comparisons).

CONCLUSIONS

The EQ-5D-3L demonstrated limited interpretability due to the presence of ceiling effects. However, the measurement properties of the SF-12, SF-6D and GOSE suggest that these may be useful measures of HR-QOL and functional recovery in OHCA survivors.

Factors Influencing the Timeliness of Emergency Medical Service Response to Time Critical Emergencies

OBJECTIVE

While emergency medical service (EMS) response times (ERT) remain a leading measure of system performance in many developed countries, relatively few studies have explored the factors associated with meeting benchmark performance for potentially time critical incidents. The purpose of this study was to identify system-level and patient-level factors associated with ERT, which are readily available at the time of ambulance dispatch.

METHODS

Between July 2009 and June 2014, we included data from 1,000,458 EMS responses to time critical "lights and sirens" incidents in Melbourne, Australia. The primary outcome measure was ERT, defined as the time from emergency call to the arrival of the first EMS team on scene. Quantile regression models were used to identify system-level and patient-level factors associated with 10-percentile intervals of ERT.

RESULTS

The median ERT was 10.6 minutes (IQR: 8.1-14.0), increasing from 9.6 minutes (IQR: 7.6-12.5) in 2009/10 to 11.0 minutes (IQR: 8.4-14.7) in 2013/14 (p < 0.001). System-level factors independently associated with the 90th percentile ERT were distance to scene, activation time, turnout time, case upgrade, hour of day, day of week, workload in the previous hour, ambulance skill set, priority zero case (e.g., suspected cardiac or respiratory arrest), and average hospital delay time in the previous hour. Patient-level factors such as age, gender, chief medical complaint, and severity of complaint were also significantly associated with ERT.

CONCLUSIONS

System-level and patient-level factors available at the time of ambulance dispatch are useful predictors of ERT performance, which could be used to improve the timeliness of EMS response.