Association Between Ambulance Station Case Volume and Clinical Outcomes in Moderate to Severe Trauma.

OBJECTIVES: The effect of the case volume of emergency medical services (EMS) on the clinical outcomes of trauma is uncertain. The purpose of this study was to evaluate the association between the case volume of an ambulance station and clinical outcomes in moderate to severe trauma patients. METHODS: Adult trauma patients with injury severity scores greater than 8 who were transported by the EMS between 2018 and 2019 were analyzed. The main exposure was the annual case volume of moderate to severe trauma at the ambulance station where the patient-transporting ambulance was based: low-volume (less than 60 cases), intermediate-volume (between 60 and 89 cases), and high-volume (equal or greater than 90 cases). The primary outcome was in-hospital mortality. Multilevel multivariable logistic regression analysis was conducted to calculate adjusted odds ratios (AORs) and 95% confidence intervals (CIs), with the high-volume group used as the reference. RESULTS: In total, 21,498 trauma patients were analyzed. The high-volume group exhibited lower in-hospital mortality, 447 (9.0%), compared to 867 (14.1%) in the intermediate-volume group and 1,458 (14.1%) in the low-volume group. There were a significantly higher odds of in-hospital mortality: the low-volume group (AOR 95% CI: 1.20 (0.95-1.51)) and intermediate-volume group (AOR 95% CI: 1.29 (1.02-1.64)) when compared to the high-volume group. CONCLUSIONS: The case volume at an ambulance station is associated with in-hospital mortality in patients with moderate to severe trauma. These results should be considered when constructing an EMS system and education program for prehospital trauma care.

Association between Case Volumes of Extracorporeal Life Support and Clinical Outcome in Out-of-Hospital Cardiac Arrest.

AIM: Extracorporeal life support (ECLS) for out-of-hospital cardiac arrest (OHCA) is increasing. There is little evidence identifying the association between hospital ECLS case volumes and outcomes in different populations receiving ECLS or conventional cardiopulmonary resuscitation (CPR). The goal of this investigation was to identify the association between ECLS case volumes and clinical outcomes of OHCA patients. METHODS: This cross-sectional observational study used the National OHCA Registry for adult OHCA cases in Seoul, Korea between January 2015 and December 2019. If the ECLS volume during the study period was >20, the institution was defined as a high-volume ECLS center. Others were defined as low-volume ECLS centers. Outcomes were good neurologic recovery (cerebral performance category 1 or 2) and survival to discharge. We performed multivariate logistic regression and interaction analyses to assess the association between case volume and clinical outcome. RESULTS: Of the 17,248 OHCA cases, 3,731 were transported to high-volume centers. Among the patients who underwent ECLS, those at high-volume centers had a higher neurologic recovery rate than those at low-volume centers (17.0% vs. 12.0%), and the adjusted OR for good neurologic recovery was 2.22 (95% confidence interval (CI): 1.15-4.28) in high-volume centers compared to low-volume centers. For patients who received conventional CPR, high-volume centers also showed higher survival-to-discharge rates (adjusted OR of 1.16, 95%CI: 1.01-1.34). CONCLUSIONS: High-volume ECLS centers showed better neurological recovery in patients who underwent ECLS. High-volume centers also had better survival-to-discharge rates than low-volume centers for patients not receiving ECLS.

Effects of Transport to Trauma Centers on Survival Outcomes Among Severe Trauma Patients in Korea: Nationwide Age-Stratified Analysis.

BACKGROUND: Previous studies showed that the prognosis for severe trauma patients is better after transport to trauma centers compared to non-trauma centers. However, the benefit from transport to trauma centers may differ according to age group. The aim of this study was to compare the effects of transport to trauma centers on survival outcomes in different age groups among severe trauma patients in Korea. METHODS: Cross-sectional study using Korean national emergency medical service (EMS) based severe trauma registry in 2018-2019 was conducted. EMS-treated trauma patients whose injury severity score was above or equal to 16, and who were not out-of-hospital cardiac arrest or death on arrival were included. Patients were classified into 3 groups: pediatrics (age < 19), working age (age 19-65), and elderly (age > 65). The primary outcome was in-hospital mortality. Multivariable logistic regression analysis was conducted to evaluate the effect of trauma center transport on outcome after adjusting of age, sex, comorbidity, mechanism of injury, Revised Trauma Score, and Injury Severity Score. All analysis was stratified according to the age group, and subgroup analysis for traumatic brain injury was also conducted. RESULTS: Overall, total of 10,511 patients were included in the study, and the number of patients in each age group were 488 in pediatrics, 6,812 in working age, and 3,211 in elderly, respectively. The adjusted odds ratio (95% confidence interval [CI]) of trauma center transport on in-hospital mortality from were 0.76 (95% CI, 0.43-1.32) in pediatrics, 0.78 (95% CI, 0.68-0.90) in working age, 0.71(95% CI, 0.60-0.85) in elderly, respectively. In subgroup analysis of traumatic brain injury, the benefit from trauma center transport was observed only in elderly group. CONCLUSION: We found out trauma centers showed better clinical outcomes for adult and elderly groups, excluding the pediatric group than non-trauma centers. Further research is warranted to evaluate and develop the response system for pediatric severe trauma patients in Korea.

Extracorporeal cardiopulmonary resuscitation for adult out-of-hospital cardiac arrest patients: time-dependent propensity score-sequential matching analysis from a nationwide population-based registry.

BACKGROUND: There is inconclusive evidence regarding the effectiveness of extracorporeal cardiopulmonary resuscitation (ECPR) for out-of-hospital cardiac arrest (OHCA) patients. We aimed to evaluate the association between ECPR and neurologic recovery in OHCA patients using time-dependent propensity score matching analysis. METHODS: Using a nationwide OHCA registry, adult medical OHCA patients who underwent CPR at the emergency department between 2013 and 2020 were included. The primary outcome was a good neurological recovery at discharge. Time-dependent propensity score matching was used to match patients who received ECPR to those at risk for ECPR within the same time interval. Risk ratios (RRs) and 95% confidence intervals (CIs) were estimated, and stratified analysis by the timing of ECPR was also performed. RESULTS: Among 118,391 eligible patients, 484 received ECPR. After 1:4 time-dependent propensity score matching, 458 patients in the ECPR group and 1832 patients in the no ECPR group were included in the matched cohort. In the matched cohort, ECPR was not associated with good neurological recovery (10.3% in ECPR and 6.9% in no ECPR; RR [95% CI] 1.28 [0.85-1.93]). In the stratified analyses according to the timing of matching, ECPR with a pump-on within 45 min after emergency department arrival was associated with favourable neurological outcomes (RR [95% CI] 2.51 [1.33-4.75] in 1-30 min, 1.81 [1.11-2.93] in 31-45 min, 1.07 (0.56-2.04) in 46-60 min, and 0.45 (0.11-1.91) in over 60 min). CONCLUSIONS: ECPR itself was not associated with good neurological recovery, but early ECPR was positively associated with good neurological recovery. Research on how to perform ECPR at an early stage and clinical trials to evaluate the effect of ECPR is warranted.

Effects of a Designated Ambulance Team Response on Prehospital Return of Spontaneous Circulation and Advanced Cardiac Life Support of Out-of-Hospital Cardiac Arrest: A Nationwide Natural Experimental Study.

OBJECTIVES: This study aimed to investigate the effects of adding advanced cardiac life support (ACLS) training to an existing basic life support program and the operation of a designated team response for patients with out-of-hospital cardiac arrest (OHCA) on prehospital return of spontaneous circulation (ROSC) and ACLS management. METHODS: A natural experimental study was conducted for emergency medical service (EMS)-treated adult patients with OHCA in 2020. In 2019, a quarter of the EMS clinicians were trained in a 3-day ACLS courses, and they were designated to be dispatched first in suspected OHCA. Some were dispatched only to major emergencies, such as OHCA and myocardial infarction (dedicated team), while others were dispatched to all emergencies with priority to major ones (non-dedicated team). The exposure was the ambulance response type: dedicated, non-dedicated, and basic teams (others). The primary outcome was prehospital ROSC. The secondary outcomes were prehospital ACLS (advanced airway management and intravenous access). A multivariable logistic regression analysis was conducted to investigate the effect of ambulance response type on study outcomes. RESULTS: Among 23,512 eligible patients with OHCA, 54.8% (12,874) were treated by the basic team, 36.5% (8,580) by the non-dedicated ACLS team, and 8.8% (2,058) were treated by the dedicated ACLS team. Prehospital ROSC was greater for the designated team than for the basic team (dedicated ACLS team 13.8%, non-dedicated ACLS team 11.3%, and basic team 6.7%) (p < 0.01). In the final logistic regression analysis, compared with the basic team, the designated ACLS team was associated with a higher probability of prehospital ROSC (AOR (95% CIs), 1.88 (1.68-2.09) compared to the non-dedicated ACLS team, and 2.46 (2.09-2.90) compared to the dedicated ACLS team), prehospital advanced airway management (1.72 (1.57-1.87) and 1.73 (1.48-2.03), respectively), and intravenous access (2.29 (2.16-2.43) and 2.76 (2.50-3.04), respectively). CONCLUSION: Additional ACLS training and operation of a designated OHCA team response were associated with higher rates of prehospital ROSC and prehospital ACLS provision. However, further research is needed to find the optimal operation for EMS to improve survival outcomes.

Sex Disparities in Prehospital Advanced Cardiac Life Support in Out-of-Hospital Cardiac Arrest in South Korea.

OBJECTIVE: Sex disparities have been reported in the prehospital and in-hospital care among patients with out-of-hospital cardiac arrest (OHCA). The aim of this study was to investigate the association between sex and prehospital advanced cardiac life support (ACLS) interventions provided by emergency medical services (EMS). METHODS: This was a cross-sectional observational study using a nationwide OHCA registry in South Korea. The study included adult OHCAs with presumed cardiac etiology from January 2016 to December 2019. The main exposure was the sex of the victim, and the primary outcomes were prehospital ACLS interventions, including advanced airway management (AAM), intravenous access (IV), and epinephrine (EPI) administration. Multivariable logistic regression analysis accounted for age group, health insurance, comorbidities, place of arrest, urbanization level, witness status, bystander CPR and initial rhythm was performed to calculate adjusted odds ratios (AORs) with 95% confidence intervals (95% CIs). RESULTS: Among 71,154 eligible patients, females with OHCA received less prehospital ACLS interventions than males: risk difference, (95% CIs) -2.76 (-3.41;-2.11) for AAM, -6.03 (-6.79;-5.27) for IV, and -3.81 (-4.37;-3.25) for EPI. In multivariable logistic regression analysis, female sex was significantly associated with a lower probability of prehospital ACLS provision: AOR, (95% CIs) 0.87 (0.84-0.91) for AAM, 0.85 (0.82-0.88) for IV, and 0.81 (0.77-0.84) for EPI. CONCLUSION: Compared to male patients, female patients were less likely to receive prehospital ACLS. This offers opportunities for EMS systems to reduce disparities and to improve compliance with OHCA resuscitation guidelines and outcomes through quality improvement and educational interventions.

Analysis of Trauma Characteristics Between the Older and Younger Adult Patient from the Pan Asian Trauma Outcome Study Registry (PATOS).

OBJECTIVE: Asia is experiencing a demographic shift toward an aging population at an unrivaled rate. This can influence the characteristics and outcomes of trauma. We aim to examine different characteristics of older adult trauma patients compared to younger adult trauma patients and describe factors that affect the outcomes in Asian countries. METHODS: This is a retrospective, international, multicenter study of trauma across participating centers in the Pan Asian Trauma Outcome Study (PATOS) registry, which included trauma cases aged ≥18 years, brought to the emergency department (ED) by emergency medical services (EMS) from October 2015 to November 2018. Data of older adults (≥65 years) and younger adults (<65 years) were analyzed and compared. The primary outcome measure was in-hospital mortality, and secondary outcomes were disability at discharge and hospital and intensive care unit (ICU) length of stays. RESULTS: Of 39,804 trauma patients, 10,770 (27.1%) were older adults. Trauma occurred more among older adult women (54.7% vs 33.2%, p < 0.001). Falls were more frequent in older adults (66.3% vs 24.9%, p < 0.001) who also had higher mean Injury Severity Score (ISS) compared to the younger adult trauma patient (5.4 ± 6.78 vs 4.76 ± 8.60, p < 0.001). Older adult trauma patients had a greater incidence of poor Glasgow Outcome Scale (GOS) (13.4% vs 4.1%, p < 0.001), higher hospital mortality (1.5% vs 0.9%, p < 0.001) and longer median hospital length of stay (12.8 vs 9.8, p < 0.001). Multiple logistic regression revealed age (adjusted odds ratio [AOR] 1.06, 95%CI 1.02-1.04, p < 0.001), male sex (AOR 1.60, 95%CI 1.04-2.46, p = 0.032), head and face injuries (AOR 3.25, 95%CI 2.06-5.11, p < 0.001), abdominal and pelvic injuries (AOR 2.78, 95%CI 1.48-5.23, p = 0.002), cardiovascular (AOR 2.71, 95%CI 1.40-5.22, p = 0.003), pulmonary (AOR 3.13, 95%CI 1.30-7.53, p = 0.011) and cancer (AOR 2.03, 95%CI 1.02-4.06, p = 0.045) comorbidities, severe ISS (AOR 2.06, 95%CI 1.23-3.45, p = 0.006), and Glasgow Coma Scale (GCS) ≤8 (AOR 12.50, 95%CI 6.95-22.48, p < 0.001) were significant predictors of hospital mortality. CONCLUSIONS: Older trauma patients in the Asian region have a higher mortality rate than their younger counterparts, with many significant predictors. These findings illustrate the different characteristics of older trauma patients and their potential to influence the outcome. Preventive measures for elderly trauma should be targeted based on these factors.

The impact of COVID-19 pandemic on out-of-hospital cardiac arrest system-of-care: Which survival chain factor contributed the most?

OBJECTIVES: In many communities, out-of-hospital cardiac arrest (OHCA) survival outcomes decreased after the coronavirus disease 2019 (COVID-19) pandemic. This study aimed to identify and compare the impacts of each survival chain factor on the change of survival outcomes after COVID-19. METHODS: Using a Korean out-of-hospital cardiac arrest registry, we analyzed OHCA patients whose arrest was not witnessed by emergency medical service (EMS) providers between 2017 and 2021. Because lack of hospital and survival information in 2021, the 2021 data were used only to identify the expected trend. We developed a prediction model for survival to discharge using patients from 2017 to 2019 (Pre-COVID-19 set) and validated it using patients from 2020 (post-COVID-19 set). Using Utstein elements, a stepwise logistic regression model was constructed, and discrimination and calibration were evaluated by c-statistics and scaled Brier score. Using the distribution change of predictors from one year before the pandemic (2019) to post-COVDI-19, we calculated the magnitude of survival difference according to each predictor's distribution change using the marginal standardization method. RESULTS: Among 83,273 patients (mean age 67.2 years and 64.3% males), 61,180 and 22,092 patients belonged to pre-COVOD-19 and post-COVID-19 sets. Survival to discharge was 5019 (8.2%) in pre-COVID-19 set and 1457 (6.6%) in post-COVID-19 set. The proportion of bystander cardiopulmonary resuscitation was 59.0% in the pre-COVID-19 set and 61.0% in the post-COVID-19 set. The median (interquartile range) response time was 7 (5-9) minutes in the pre-COVID-19 set and 8 (6-10) minutes in the post-COVID-19 set. The area under the receiver operating characteristic (AUROC) curve (95% confidence interval) was 0.907 (0.902-0.912) in the pre-COVID-19 set, and 0.924 (0.916-0.931) in the post-COVID-19 set, and scaled Brier score were 0.39 in pre-COVID-19 sets, and 0.40 in the post-COVID-19 set. Among various predictors, EMS factors showed the highest impact. Response time and on-scene management of EMS showed the highest impact on decreased survival. A similar trend was also expected in the 2021. CONCLUSION: The effort to create a rapid response system for OHCA patients could have priority for the recovery of survival outcomes in OHCA patients in the post-COVID-19 period. Further studies to recover survival outcomes of OHCA are warranted.

Association between prehospital airway type and oxygenation and ventilation in out-of-hospital cardiac arrest.

OBJECTIVES: This study aimed to evaluate the association between prehospital airway type and oxygenation and ventilation in out-of-hospital cardiac arrest (OHCA). METHODS: This retrospective observational study included OHCA patients who visited the emergency departments (EDs) between October 2015 and June 2021. The study groups were categorized according to the prehospital airway type: endotracheal intubation (ETI), supraglottic airway (SGA), or bag-valve-mask ventilation (BVM). The primary outcome was good oxygenation: partial pressure of oxygen (PaO2) ≥ 60 mmHg on the first arterial blood gas (ABG) test. The secondary outcome was good ventilation: partial pressure of carbon dioxide (PaCO2) ≤ 45 mmHg. Multivariate logistic regression was conducted to calculate the adjusted odds ratio (AOR) and 95% confidence interval (CI). RESULTS: A total of 7,372 patients were enrolled during the study period: 1,819 patients treated with BVM, 706 with ETI, and 4,847 who underwent SGA. In multivariable logistic regression analysis for good oxygenation outcomes, the ETI group showed a higher AOR than the BVM group (AOR [95% CIs]: 1.30 [1.06-1.59] in ETI and 1.05 [0.93-1.20] in SGA groups). Regarding good ventilation, the ETI group showed a higher AOR, and the SGA group showed a lower AOR compared to the BVM group (AOR [95% CIs] 1.33 [1.02-1.74] in the ETI and 0.83 (0.70-0.99) in the SGA groups). There was no significant difference in survival to discharge. CONCLUSIONS: ETI was significantly associated with good oxygenation and good ventilation compared to BVM in patients with OHCA, particularly during longer transports. This should be taken into consideration when deciding the prehospital advanced airway management in patients with OHCA.

Bystander cardiopulmonary resuscitation, automated external defibrillator use, and survival after out-of-hospital cardiac arrest.

INTRODUCTION: We aimed to investigate the association between bystander cardiopulmonary resuscitation (CPR) with and without automated external defibrillator (AED) use and neurological outcomes after out-of-hospital cardiac arrest (OHCA) in Korea. METHODS: This cross-sectional study used a nationwide Korean OHCA registry between 2015 and 2019. Patients were categorised into no bystander CPR and bystander CPR with and without AED use groups. The primary outcome was good neurological recovery at discharge. We also analysed the interaction effects of place of arrest, response time, and whether the OHCA was witnessed. RESULTS: In total, 93,623 patients were included. Among them, 35,486 (37.9%) were in the no bystander CPR group, 56,187 (60.0%) were in the bystander CPR without AED use group, and 1950 (2.1%) were in the bystander CPR with AED use group. Good neurological recovery was demonstrated in 1286 (3.6%), 3877 (6.9%), and 208 (10.7%) patients in the no CPR, bystander CPR without AED use, and bystander CPR with AED use groups, respectively. Compared to the no bystander CPR group, the adjusted odds ratio (95% confidence intervals) for good neurological recovery was 1.54 (1.45-1.65) and 1.37 (1.15-1.63) in the bystander CPR without and with AED use groups, respectively. The effect of bystander CPR with AED use was more apparent in OHCAs with witnessed arrest and prolonged response time (≥8 min). CONCLUSION: Bystander CPR was associated with better neurological recovery compared to no bystander CPR; however, the benefits of AED use were not significant. Efforts to disseminate bystander AED availability and ensure proper utilisation are warranted.

Extracorporeal cardiopulmonary resuscitation location, coronary angiography and survival in out-of-hospital cardiac arrest.

INTRODUCTION: The best location for safe and timely implementation of extracorporeal cardiopulmonary resuscitation (ECPR) is currently uncertain. We aimed to evaluate the association between the location of ECPR and survival outcomes in out-of-hospital cardiac arrest (OHCA) patients. We also evaluated whether the effects of ECPR location on survival differed between patients who underwent coronary angiography (CAG) and those who did not. METHODS: We used data collected between 2013 and 2020 from a nationwide OHCA database. Adult OHCA patients with presumed cardiac etiology who underwent ECPR were included in the study. The primary outcome was survival to discharge. The main exposure was the ECPR location (emergency department [ED] or cardiac catheterization laboratory [Cath lab]). We compared primary outcomes of ECPR between the ED and Cath lab using multivariable logistic regression. The interaction between ECPR location and CAG was also evaluated. RESULTS: Of 564 ECPR patients, 448 (79.4%) and 116 (20.6%) underwent ECPR in the ED and Cath lab, respectively. CAG was observed in 52.5% and 72.4% of the patients in the ED and Cath lab groups, respectively. There were no significant differences in survival to discharge between the ED and Cath lab groups (14.1% vs. 12.9%, p = 0.75, adjusted odds ratio [AOR] [95% confidence interval] 1.87 [0.85-4.11]). AOR of interaction analysis (95% CI) for survival to discharge of the ED group was 2.34 (1.02-5.40) in patients with CAG and 0.28 (0.04-1.84) in patients without CAG (p for interaction was 0.04). CONCLUSION: In adult OHCA patients who underwent ECPR and CAG, ECPR in the ED shortened time to ECMO pump-on time and increased survival to discharge compared to ECPR in the Cath lab.

Efficacy of distance training program for cardiopulmonary resuscitation utilizing smartphone application and home delivery system.

AIM OF THE STUDY: Community cardiopulmonary resuscitation (CPR) education is important for laypersons. However, during the COVID-19 pandemic, with social distancing, conventional face-to-face CPR training was unavailable. We developed a distance learning CPR training course (HEROS-Remote) using a smartphone application that monitors real-time chest compression quality and a home delivery collection system for mannikins. This study aimed to evaluate the efficacy of the HEROS-Remote course by comparing chest compression quality with that of conventional CPR training. METHODS: We applied layperson CPR education with HEROS-Remote and conventional education in Seoul during the COVID-19 pandemic. Both groups underwent a 2-min post-training chest compression test, and we tested non-inferiority. Chest compression depth, rate, complete recoil, and composite chest compression score was measured. Trainees completed a satisfaction survey on CPR education and delivery. The primary outcome was the mean chest compression depth. RESULTS: A total of 180 trainees were enrolled, with 90 assigned to each training group. Chest compression depth of HEROS-Remote training showed non-inferiority to that of conventional training (67.4 vs. 67.8, p = 0.78), as well as composite chest compression score (92.7 vs. 95.5, p = 0.16). The proportions of adequate chest compression depth, chest compression rate, and chest compressions with complete chest recoil were similar in both training sessions. In the HEROS-Remote training, 90% of the trainees were satisfied with CPR training, and 96% were satisfied with the delivery and found it convenient. CONCLUSION: HEROS-Remote training was non-inferior to conventional CPR training in terms of chest compression quality. Distance learning CPR training using a smartphone application and mannikin delivery had high user satisfaction and was logistically feasible.

Prehospital National Early Warning Score as a predictor of massive transfusion in adult trauma patients.

BACKGROUND: Previous studies have shown that an elevated prehospital National Early Warning Score (preNEWS) is associated with increased levels of adverse outcomes in patients with trauma. However, whether preNEWS is a predictor of massive transfusion (MT) in patients with trauma is currently unknown. This study investigated the accuracy of preNEWS in predicting MT and hospital mortality among trauma patients. METHODS: We analyzed adult trauma patients who were treated and transported by emergency medical services (EMS) between January 2018 and December 2019. The main exposure was the preNEWS calculated for the scene. The primary outcome was the predictive ability for MT, and the secondary outcome was 24 h mortality. We compared the prognostic performance of preNEWS with the shock index, modified shock index, and reverse shock index, and reverse shock index multiplied by Glasgow Coma Scale in the prehospital setting. RESULTS: In total, 41,852 patients were included, and 1456 (3.5%) received MT. preNEWS showed the highest area under the receiver operating characteristic (AUROC) curve for predicting MT (0.8504; 95% confidence interval [CI], 0.840-0.860) and 24 h mortality (AUROC 0.873; 95% CI, 0.863-0.883). The sensitivity of preNEWS for MT was 0.755, and the specificity of preNEWS for MT was 0.793. All indicies had a high negative predictive value and low positive predictive value. CONCLUSION: preNEWS is a useful, rapid predictor for MT and 24 h mortality. Calculation of preNEWS would be helpful for making the decision at the scene such as transfer straightforward to trauma center and advanced treatment.

Measurement of level of consciousness by AVPU scale assessment system based on automated video and speech recognition technology.

OBJECTIVE: To develop an alert/verbal/painful/unresponsive (AVPU) scale assessment system based on automated video and speech recognition technology (AVPU-AVSR) that can automatically assess a patient's level of consciousness and evaluate its performance through clinical simulation. METHODS: We developed an AVPU-AVSR system with a whole-body camera, face camera, and microphone. The AVPU-AVSR system automatically extracted essential audiovisual features to assess the AVPU score from the recorded video files. Arm movement, pain stimulus, and eyes-open state were extracted using a rule-based approach using landmarks estimated from pre-trained pose and face estimation models. Verbal stimuli were extracted using a pre-trained speech-recognition model. Simulations of a physician examining the consciousness of 12 simulated patients for 16 simulation scenarios (4 for each of "Alert", "Verbal", "Painful", and "Unresponsive") were conducted under the AVPU-AVSR system. The accuracy, sensitivity, and specificity of the AVPU-AVSR system were assessed. RESULTS: A total of 192 cases with 12 simulated patients were assessed using the AVPU-AVSR system with a multi-class accuracy of 0.95 (95% confidence interval [CI] (0.92-0.98). The sensitivity and specificity (95% CIs) for detecting impaired consciousness were 1.00 (0.97-1.00) and 0.88 (0.75-0.95), respectively. The sensitivity and specificity of each extracted feature ranged from 0.88 to 1.00 and 0.98 to 1.00. CONCLUSIONS: The AVPU-AVSR system showed good accuracy in assessing consciousness levels in a clinical simulation and has the potential to be implemented in clinical practice to automatically assess mental status.

Clinical factors associated with delayed emergency department visit in intracranial traumatic brain injury: from a multicenter injury surveillance registry.

INTRODUCTION: Early diagnosis and intervention by visiting the emergency department (ED) are important for traumatic brain injury (TBI). We evaluate the factors associated with delayed ED visits in patients with intracranial TBI. METHODS: A retrospective multicenter observational study using the ED-based injury in-depth surveillance database (EDIIS) was designed. Patients with intracranial TBI with an alert mentality at ED presentation from 2014 to 2019 were enrolled. Patients were categorized into four groups according to ED visit time after injury (<1 h, 1-3 h, 3-12 h, and >12 h). ED visits after 12 h were defined as delayed ED visits. The factors associated with delayed ED visits were identified using multivariable logistic regression analysis. RESULTS: Among 15,620 patients with TBI enrolled in the final analysis, 2,190 (14.0%) visited the ED 12 h after injury. Multivariable analysis identified the following factors as independent predictors for delayed ED visit such as unintentionally struck by or against an object or unintentional fall as a trauma mechanism, injury during ordinary activities, indoor injury, injury during nighttime, winter season, combined subdural hemorrhage and epidural hemorrhage. CONCLUSION: In patients with intracranial TBI with an alert mentality, multiple factors related to patient demographics and injury characteristics were associated with the time interval from injury to ED visit.

The Impact of the COVID-19 Outbreak on Emergency Medical Service: An Analysis of Patient Transportations and Time Intervals.

BACKGROUND: This study aimed to investigate the impact of the coronavirus disease 2019 (COVID-19) outbreak on the Emergency Medical Service (EMS) system in South Korea. The study focused on the differences in EMS time intervals following the COVID-19 outbreak, particularly for patients with fever. METHODS: A retrospective analysis of EMS patient transportation data from 2017 to 2022 was conducted using the national EMS database. RESULTS: Starting from the year 2020, coinciding with the COVID-19 outbreak, all EMS time intervals experienced an increase. For the years 2017 to 2022, the mean response time interval values were 8.6, 8.6, 8.6, 10.2, 12.8, and 11.4 minutes, and the mean scene time interval values were 7.1, 7.2, 7.4, 9.0, 9.8, and 10.9 minutes. The mean transport time interval (TTI) values were 12.1, 12.3, 12.4, 14.2, 16.9, and 16.2 minutes, and the mean turnaround time interval values were 27.6, 27.9, 28.7, 35.2, 42.0, and 43.1 minutes. Fever (≥ 37.5°C) patients experienced more pronounced prolongations in EMS time intervals compared to non-fever patients and had a higher probability of being non-transported. The mean differences in TTI between fever and non-fever patients were 0.8, 0.8, 0.8, 4.3, 4.8, and 3.2 minutes, respectively, from 2017 to 2022. Furthermore, the odds ratios for fever patients being transported to the emergency department were 2.7, 2.9, 2.8, 1.1, 0.8, and 0.7, respectively, from 2017 to 2022. CONCLUSION: The study findings highlight the significant impact of the COVID-19 outbreak on the EMS system and emphasize the importance of ongoing monitoring to evaluate the burden on the EMS system.

Use of Time-to-Event Analysis to Develop On-Scene Return of Spontaneous Circulation Prediction for Out-of-Hospital Cardiac Arrest Patients.

STUDY OBJECTIVE: We aimed to train and validate the time to on-scene return of spontaneous circulation prediction models using time-to-event analysis among out-of-hospital cardiac arrest patients. METHODS: Using a Korean population-based out-of-hospital cardiac arrest registry, we selected a total of 105,215 adults with presumed cardiac etiologies between 2013 and 2018. Patients from 2013 to 2017 and from 2018 were analyzed for training and test, respectively. We developed 4 time-to-event analyzing models (Cox proportional hazard [Cox], random survival forest, extreme gradient boosting survival, and DeepHit) and 4 classification models (logistic regression, random forest, extreme gradient boosting, and feedforward neural network). Patient characteristics and Utstein elements collected at the scene were used as predictors. Discrimination and calibration were evaluated by Harrell's C-index and integrated Brier score. RESULTS: Among the 105,215 patients (mean age 70 years and 64% men), 86,314 and 18,901 patients belonged to the training and test sets, respectively. On-scene return of spontaneous circulation was achieved in 5,240 (6.1%) patients in the former set and 1,709 (9.0%) patients in the latter. The proportion of emergency medical services (EMS) management was higher and scene time interval longer in the latter. Median time from EMS scene arrival to on-scene return of spontaneous circulation was 8 minutes for both datasets. Classification models showed similar discrimination and poor calibration power compared to survival models; Cox showed high discrimination with the best calibration (C-index [95% confidence interval]: 0.873 [0.865 to 0.882]; integrated Brier score at 30 minutes: 0.060). CONCLUSION: Incorporating time-to-event analysis could lead to improved performance in prediction models and contribute to personalized field EMS resuscitation decisions.

Machine Learning Analysis to Identify Data Entry Errors in Prehospital Patient Care Reports: A Case Study of a National Out-of-Hospital Cardiac Arrest Registry.

Background: The objective of this study was to develop and validate machine learning models for data entry error detection in a national out-of-hospital cardiac arrest (OHCA) prehospital patient care report database.Methods: Adult OHCAs of presumed cardiac etiology were included. Data entry errors were defined as discrepancies between the coded data and the free-text note documenting the intervention or event; for example, information that was recorded as "absent" in the coded data but "present" in the free-text note. Machine learning models using the extreme gradient boosting, logistic regression, extreme gradient boosting outlier detection, and K-nearest neighbor outlier detection algorithms for error detection within nine core variables were developed and then validated for each variable.Results: Among 12,100 OHCAs, the proportion of cases with at least one error type was 16.2%. The area under the receiver operating characteristic curve (AUC) of the best-performing model (model with the highest AUC for each outcome variable) was 0.71-0.95. Machine learning models detected errors most efficiently for outcome place and initial rhythm errors; 82.6% of place errors and 93.8% of initial rhythm errors could be detected while checking 11 and 35% of data, respectively, compared to the strategy of checking all data.Conclusion: Machine learning models can detect data entry errors in care reports of emergency medical services (EMS) clinicians with acceptable performance and likely can improve the efficiency of the process of data quality control. EMS organizations that provide more prehospital interventions for OHCA patients could have higher error rates and may benefit from the adoption of error-detection models.

Association between Scene Time Interval and Survival in EMS-Treated Major Trauma Admitted to the Intensive Care Unit: A Multinational, Multicenter Observational Study.

Objective: Major trauma is a major concern in public health and a leading cause of mortality worldwide. This study aimed to evaluate the association between the prehospital scene time interval (STI) and survival in emergency medical service (EMS)-assessed major trauma patients admitted to the intensive care unit (ICU). Methods: A retrospective observational study using the Pan-Asian Trauma Outcomes Study (PATOS) database was conducted. Adult trauma patients with injury severity scores (ISSs) greater than 15 who were admitted to the ICU were selected. EMS STIs were categorized into three groups: short (0-8 minutes), intermediate (9-16 minutes), and long (over 16 minutes). The primary outcome was survival to hospital discharge, and the secondary outcome was good neurological outcome at hospital discharge. Multivariable logistic regression analysis was conducted to calculate odds ratios and confidence intervals, adjusting for age, sex, mechanism of injury, prehospital alertness, prehospital shock index, response time interval, and EMS intervention (airway, oxygen supplementation, and intravenous fluid administration). Sensitivity analysis for patients who underwent surgery or nontraumatic brain injury cases and interaction analysis by EMS intervention were performed. Results: Data from a total of 1,874 eligible patients were analyzed. Intermediate and long STIs showed significant associations with outcomes, with adjusted ORs (95% CI) of 1.21 (1.07-1.38) in the intermediate STI group and 1.74 (1.55-1.96) in the long STI group for survival and 1.37 (1.32-1.40) in the intermediate STI group and 1.31 (1.22-1.41) in the long STI group for neurological outcome. In the sensitivity analysis, the highest ORs were found in the intermediate STI group, with adjusted ORs (95% CI) of 1.40 (1.37-1.42) for survival and 1.32 (1.26-1.38) for neurological outcome. In the interaction analysis, EMS intervention showed a positive interaction effect with an intermediate STI on survival. Conclusion: In EMS-assessed adult major trauma patients admitted to the ICU, we found significant associations between STIs longer than 8 minutes and outcomes. EMS intervention has a positive interaction effect with an intermediate STI on survival. More research is needed to understand the implications of practice for major trauma in the field.

Association between patient age and pediatric cardiac arrest recognition by emergency medical dispatchers.

BACKGROUND: Dispatcher-assisted cardiopulmonary resuscitation (DA-CPR) is an important prognostic factor in pediatric out-of-hospital cardiac arrest (OHCA). The recognition of cardiac arrest by dispatcher is a key factor for successful DA-CPR. In this study, we evaluated the association between pediatric age and dispatcher recognition. METHODS: A retrospective observational study was designed using a nationwide OHCA registry. Patients under 19 years of age were enrolled. Patients were categorized into four groups according to age (<1 year, 1-6 years, 7-13 years, and 14-18 years). The primary outcome was cardiac arrest recognition by dispatcher. A multivariable logistic regression analysis was performed. RESULTS: A total of 2754 pediatric OHCA patients were enrolled. A negative trend was observed between age and dispatcher performance (p < 0.01). The rate of cardiac arrest recognition was highest in patients under one year of age (61.5%) and lowest in patients ages 14-18 years old (47.1%). Patients in the 7-13 years and 14-18 years age groups were both associated with a decreased rate of recognition (adjusted odds ratio with 95% confidence interval: 0.55 (0.41-0.74) and 0.44 (0.34-0.57), respectively). In the interaction analysis, the association between age and outcomes was more prominent in patients with non-medical causes. CONCLUSION: Patients ages 7-18 years old were negatively associated with cardiac arrest recognition and DA-CPR instruction provision within optimal timeframes compared to those younger than one year old. Development of a tailored protocol could be considered according to age and cause of arrest for better dispatcher performance in pediatric OHCA patients.