Effect of cardiopulmonary resuscitation training for layperson bystanders on outcomes of out-of-hospital cardiac arrest: A prospective multicenter observational study.

BACKGROUND: Effective bystander cardiopulmonary resuscitation (CPR) improves outcomes in out-of-hospital cardiac arrest (OHCA) patients. However, the effect of CPR training on the rate of return of spontaneous circulation (ROSC) among laypersons has yet to be thoroughly evaluated. METHODS: This prospective, multicenter observational study was conducted across 42 centers in Japan. We assessed OHCA patients who received bystander CPR from a layperson, excluding those performed by healthcare staff. The primary outcome was the ROSC rate. Secondary outcomes included pre-hospital ROSC, ROSC after hospital arrival, favorable neurological outcomes, and 30-day survival. Propensity score with inverse probability treatment weighting (IPTW) was used to adjust for confounders, including age, sex, presence or absence of witnesses, and past medical history. RESULTS: A total of 969 OHCA patients were included, divided into CPR-trained (n = 322) and control (n = 647). Before adjustment, the ROSC rate was higher in the trained group than the control (40.1% vs. 30.1%, P < 0.01). After IPTW adjustment, the trained group showed a significantly higher ROSC rate (36.7% vs. 30.6%; P = 0.02). All secondary outcomes in the trained group were significantly improved before adjustment. After IPTW adjustment, the trained group showed improved rates of pre-hospital ROSC and ROSC after hospital arrival (30.7% vs. 24.0%; P < 0.01, 23.9% vs. 20.7%; P = 0.04). There were no differences in neurological outcomes and 30-day survival. CONCLUSION: This study demonstrated that CPR training for laypersons was associated with increased ROSC rates in OHCA patients, indicating potential advantages of CPR training for non-healthcare professionals.

Effectiveness of the Abdominal Thrust Maneuver for Airway Obstruction Removal: Analysis of Data from the National Emergency Medical Services Information System.

BACKGROUND: Foreign body airway obstruction (FBAO) is a life-threatening emergency. Abdominal thrusts are recommended as first aid, but the success rate for this technique is unclear. Using information from a large database of emergency medical services (EMS) data in the United States, we evaluated the success rate of abdominal thrusts and identified patient characteristics that were associated with the success of the technique. METHODS: A retrospective observational study was conducted using data from the National Emergency Medical Services Information System (NEMSIS) to ascertain the success of abdominal thrusts in patients with FBAO from nearly 14,000 EMS agencies. Success was defined by positive evaluations on subjective and objective EMS criteria. RESULTS: Analysis of 1,947 cases yielded a 46.6% success rate for abdominal thrusts in removing obstructions. The age distribution was bimodal, with peaks during infancy and old age. June had the highest incidence of FBAO. Incidents were most frequent during lunch and dinner times, and most cases occurred in private residences. The first-time success rate was 41.5%, and a lower level of impaired consciousness was associated with lower success rates. A lower incidence of cardiac arrest was noted in successful cases. The success rate was high (60.2%) for children (age ≤15 years), with differences in demographic characteristics and a lower rate of impaired consciousness and cardiac arrests, as compared with unsuccessful interventions in the same age group. CONCLUSIONS: Our study showed a 46.6% success rate for abdominal thrusts in patients with FBAO. The success group had a lower proportion of impaired consciousness and cardiopulmonary arrest than the failure group. Future studies should attempt to identify the most effective maneuvers for clearing airway obstruction.

Agonal breathing upon hospital arrival as a prognostic factor in patients experiencing out-of-hospital cardiac arrest.

Background: Agonal breathing is a relatively common symptom that follows cardiac arrest when the brainstem function is preserved. Agonal breathing is associated with favorable survival in patients experiencing out-of-hospital cardiac arrest (OHCA). While previous studies focused on agonal breathing observed in the pre-hospital setting for all study subjects, we focused on agonal breathing observed upon hospital arrival. In this multicenter prospective study, we aimed to assess the prognosis of patients exhibiting agonal breathing upon hospital arrival were compared. We hypothesized that agonal breathing at hospital arrival would be associated with favorable neurological outcomes among patients with OHCA. Methods: The data on incidence of agonal breathing were prospectively collected for all evaluable participants in a multicenter, observational study in Japan (SOS-KANTO [Survey of Survivors after Out-of-Hospital Cardiac Arrest in Kanto Area] 2017 Study). Groups with and without agonal breathing were compared upon hospital arrival. Propensity-score with inverse probability of treatment weighting (IPTW) analysis was performed to adjust for confounding factors. The primary outcome was a favorable neurological outcome (Cerebral Performance Category 1-2) at 1 month. Results: A total of 6,457 participants out of the 9,909 registered in SOS-KANTO 2017 (in which 42 facilities participated) were selected for the current study. There were 128 patients (2.0%) in the with-agonal breathing group and 6,329 (98.0%) in the withoutagonal breathing group. The primary outcome was 1.1% in the with-agonal breathing group and 0.6% in the without-agonal breathing group (risk difference, 0.55; 95% confidence interval, 0.23-0.87) after IPTW analysis. Conclusion: In this multicenter prospective study, agonal breathing at hospital arrival was significantly associated with better neurological outcomes and increased survival at 1 month. Thus, agonal breathing at hospital arrival may be a useful prognostic predictor for patients experiencing OHCA.

Usefulness of Self-Selected Scenarios for Simple Triage and Rapid Treatment Method Using Virtual Reality.

BACKGROUND: Repeated triage training is necessary to maintain and improve the accuracy of simple triage and rapid treatment (START), a popular triage method. Virtual reality (VR) may be more effective than conventional training methods. This study aimed to verify the educational usefulness of START using VR originally developed for students. METHODS: A VR was initially developed with a function that allowed students to select the triage procedure and its evaluation. Triage was performed using a simple modified START method, and eight scenarios were developed. The participants included 70 paramedic students classified into VR and live lecture groups. They took a 20-question written test that evaluated their academic ability before the course. After the course, a practical test and a 20-question written test were conducted. The total score of the practical test was 43 points. Triage procedure (1 point), observation and evaluation (1-5 points), and triage categories (1 point) were evaluated in this test. RESULTS: The VR and live lecture groups consisted of 33 and 29 participants, respectively. No significant differences were observed pre- and post-test. In the practical test, the median (interquartile range) score was 29 (26-32) and 25 (23-29) for the VR and live lecture groups, respectively, with the VR group scoring significantly higher (P=0.03). CONCLUSION: Our results confirmed the educational usefulness of selective VR for active learning of START. Therefore, VR combined with live lectures and simulations would be an optimal educational technique.

Development of a Machine Learning Model to Predict Cardiac Arrest during Transport of Trauma Patients.

BACKGROUND: Trauma is a serious medical and economic burden worldwide, and patients with traumatic injuries have a poor survival rate after cardiac arrest. The authors developed a prediction model specific to prehospital trauma care and used machine learning techniques to increase its accuracy. METHODS: This retrospective observational study analyzed data from patients with blunt trauma injuries due to traffic accidents and falls from January 1, 2018, to December 31, 2019. The data were collected from the National Emergency Medical Services Information System, which stores emergency medical service activity records nationwide in the United States. A random forest algorithm was used to develop a machine learning model. RESULTS: The prediction model had an area under the curve of 0.95 and a negative predictive value of 0.99. The feature importance of the predictive model was highest for the AVPU (Alert, Verbal, Pain, Unresponsive) scale, followed by oxygen saturation (SpO2). Among patients who were progressing to cardiac arrest, the cutoff value was 89% for SpO2 in nonalert patients. CONCLUSIONS: The machine learning model was highly accurate in identifying patients who did not develop cardiac arrest.

A Study on Points of Respiratory Assist Devices Using in Pre-Hospital Care Respiratory Assist Devices in Pre-Hospital Care.

BACKGROUND: In Japan, increasing the number of ambulance requests, the case with the use of respiratory assistance devices in prehospital care by paramedics is also increasing1. When patient experiences respiratory failure, the first responders frequently select a respiratory assist device (RAD) such as Bag Valve Mask (BVM), Jackson Rees (JR), or BVM with Gas Supply Valve® (BVM+GSV). This is based on both evaluation and experience as there is no study indicating which RAD is the best choice at the pre-hospital emergency site. This study clarified the precautions when using BVM, JR, and BVM+GSV in pre-hospital emergency medical care with healthy volunteers. METHODS: Twenty healthy adults were fitted with a RAD while breathing spontaneously, and changes in vital signs and ETCO2 were observed. RESULTS: The level of ETCO2 became elevated after each RAD was attached. The value was significantly higher in the JR group than in the others. CONCLUSIONS: The study showed that even in the presence of spontaneous breathing, ETCO2 increased markedly with the application of respiratory assist devices that are used in pre-hospital care for conditions such as hypoxemia and ventilatory disturbance. The increase in ETCO2 was particularly significant in the JR group, suggesting the need for caution when selecting JRs for pre-hospital care. As the number of subjects was only 20 for each RAD, studies with a larger sample size are needed.

Evaluation of outcomes after EMS-witnessed traumatic out-of-hospital cardiac arrest caused by traffic collisions.

AIM: The survival rate of patients with traumatic cardiac arrest is 3% or lower. Cardiac arrest witnessed by emergency medical services (EMS) accounts for approximately 16% of prehospital traumatic cardiac arrests, but the prognosis is unknown. We aimed to compare the 1-month survival rate of cardiac arrest witnessed by EMS with that of cardiac arrest witnessed by bystanders and unwitnessed cardiac arrest in traffic trauma victims; further, the time from injury to cardiac arrest was assessed. METHODS: This analysis used the Utstein Registry in Japan and included data of 3883 patients with traumatic cardiac arrest caused by traffic collisions registered between 2014 and 2019 in Japan. RESULTS: The 1-month survival rate was 10.9% in the EMS-witnessed cardiac arrest group; this was significantly higher than that in the bystander-witnessed (7.2%) and unwitnessed (5.6%) cardiac arrest groups (P < 0.01). The median time from injury to cardiac arrest was 18 min (25% quartile: 12, 75% quartile: 26). CONCLUSION: The 1-month survival rate was significantly higher in the EMS-witnessed cardiac arrest group than in the bystander-witnessed and unwitnessed cardiac arrest groups. It is important to prevent progression to cardiac arrest in trauma patients with intact respiratory function and pulse rate at the time of contact with EMS. A system for early recognition of severe trauma is needed, and a doctor's car or helicopter can be requested as needed. We believe that early recognition and prompt intervention will improve the prognosis of prehospital traumatic cardiac arrest.