Polish Helicopter Emergency Medical Service (HEMS) Response to Out-of-Hospital Cardiac Arrest (OHCA): A Retrospective Study

Resuscitation of out-of-hospital cardiac arrest victims in Austria's largest helicopter emergency medical service: A retrospective cohort study

Background

Helicopter emergency medical services (HEMS) play a fundamental role in prehospital care. However, the impact of HEMS on survival of patients with out-of-hospital cardiac arrest (OHCA) is widely unknown. Therefore, the purpose of this study was to assess demographics, treatment, and outcome of patients with OHCA attended by physician-staffed helicopters.

Methods

Retrospective cohort study enrolling OHCA patients treated by HEMS during a ten-year period (2010-2019) in Austria. Patients were identified using electronic mission records of 13 HEMS bases run by the Austrian Automobile, Motorcycle and Touring Club (OEAMTC), and subsequently matched with the national register of deaths to determine 30-day and one-year survival rates. Results are reported according to the 2015 Utstein Style. Multivariable logistic regression analysis was used to identify factors associated with patient outcome.

Results

In total, 9344 presumed OHCA missions were identified. Cardiopulmonary resuscitation was attempted or continued by HEMS in 3889 cases. Approximately 32.2% of patients achieved return of spontaneous circulation (ROSC) and 22.5% sustained ROSC until arrival at the emergency department. Thirty-day and one-year survival rates were 14.0% and 12.4% respectively. HEMS response time, on-scene time, age, pathogenesis, arrest location, witness-status, first monitored rhythm, bystander automated external defibrillator (AED) use, airway type and administration of adrenaline were independent predictors of 30-day survival.

Conclusions

This study provides an extensive insight into the management of OHCA in an almost nationwide HEMS sample. Thirty-day and one-year survival rates are high, indicating high-quality care and systematic selection of patients with favorable prognosis.

Development and internal validation of an algorithm for estimating mortality in patients encountered by physician-staffed helicopter emergency medical services

BACKGROUND

Severity of illness scoring systems are used in intensive care units to enable the calculation of adjusted outcomes for audit and benchmarking purposes. Similar tools are lacking for pre-hospital emergency medicine. Therefore, using a national helicopter emergency medical services database, we developed and internally validated a mortality prediction algorithm.

METHODS

We conducted a multicentre retrospective observational register-based cohort study based on the patients treated by five physician-staffed Finnish helicopter emergency medical service units between 2012 and 2019. Only patients aged 16 and over treated by physician-staffed units were included. We analysed the relationship between 30-day mortality and physiological, patient-related and circumstantial variables. The data were imputed using multiple imputations employing chained equations. We used multivariate logistic regression to estimate the variable effects and performed derivation of multiple multivariable models with different combinations of variables. The models were combined into an algorithm to allow a risk estimation tool that accounts for missing variables. Internal validation was assessed by calculating the optimism of each performance estimate using the von Hippel method with four imputed sets.

RESULTS

After exclusions, 30 186 patients were included in the analysis. 8611 (29%) patients died within the first 30 days after the incident. Eleven predictor variables (systolic blood pressure, heart rate, oxygen saturation, Glasgow Coma Scale, sex, age, emergency medical services vehicle type [helicopter vs ground unit], whether the mission was located in a medical facility or nursing home, cardiac rhythm [asystole, pulseless electrical activity, ventricular fibrillation, ventricular tachycardia vs others], time from emergency call to physician arrival and patient category) were included. Adjusted for optimism after internal validation, the algorithm had an area under the receiver operating characteristic curve of 0.921 (95% CI 0.918 to 0.924), Brier score of 0.097, calibration intercept of 0.000 (95% CI -0.040 to 0.040) and slope of 1.000 (95% CI 0.977 to 1.023).

CONCLUSIONS

Based on 11 demographic, mission-specific, and physiologic variables, we developed and internally validated a novel severity of illness algorithm for use with patients encountered by physician-staffed helicopter emergency medical services, which may help in future quality improvement.

Mechanical Cardiopulmonary Resuscitation's Role in Helicopter Air Ambulances: A Narrative Review

Helicopter emergency medical services (HEMS) frequently respond to out-of-hospital cardiac arrest (OHCA) situations. Some have speculated mechanical cardiopulmonary resuscitation (mCPR) may be able to rectify the inadequacy of human performance of cardiopulmonary resuscitation (CPR) during transport. A number of studies have examined the performance of mCPR devices in the air medical setting specifically. Many aspects of the HEMS environment seem uniquely conducive to mCPR, and a growing body of research seems to suggest mCPR holds promise for the treatment of cardiac arrest by HEMS clinicians. Simulation studies show that mCPR leads to improved CPR performance compared with manual CPR in HEMS. Case reports and the experience of several HEMS programs suggest that mCPR can be effectively integrated into HEMS care. However, further research regarding the effectiveness of mCPR in the HEMS environment and in general cardiac arrest care is needed.

Visualized analysis of research on helicopter emergency medical service

BACKGROUND

Numerous studies have confirmed that helicopter emergency medical services (HEMS) play a positive role in prehospital care. However, few studies have used rigorous bibliometric tools to analyze the knowledge structure and distribution of HEMS research.

OBJECTIVES

The purpose of this study was to use bibliometric methods to conduct a quantitative and qualitative analysis of the HEMS-related literature and to determine the research status and hotspots of HEMS research.

METHODS

CiteSpace was used for bibliometric analysis of the HEMS-related literature retrieved from the Web of Science database from 1989 to 2021.

RESULTS

A total of 1378 HEMS-related literature were included. Collaboration among countries, authors, and institutions needs to be strengthened. The topics in HEMS research have mainly focused on the effectiveness of helicopter emergency medical services for trauma patients and the comparison of transport effectiveness between helicopters and ground emergency medical services on trauma patient transport. Research over the past 10 years has mainly focused on the application of HEMS in patients with trauma, myocardial infarction, cerebral apoplexy, application of tracheal intubation technology in HEMS, and advanced airway management. In recent years, HEMS research trends have mainly included out-of-hospital cardiac arrest, and transport.

CONCLUSIONS

CiteSpace was used to visualize and analyze the HEMS-related literature, which visually reflected the research status and hot spots, providing references for the topic selection and development direction of HEMS research.

Barriers and facilitators to cardiopulmonary resuscitation within pre-hospital emergency medical services: a qualitative study

Background

Out-of-hospital cardiopulmonary arrest is a common and fatal problem. Rescuing patients with this problem by pre-hospital emergency medical services is associated with various barriers and facilitators. Identifying these barriers as well as the facilitators in a qualitative and an information-rich way will help to improve the quality of performing the maneuver and to increase the patients’ survival. Therefore, the current study was qualitatively conducted with the aim of identifying the factors affecting the cardiopulmonary resuscitation within the pre-hospital emergency medical services.

Methods

This qualitative study was conducted using a content analysis approach in Iran in 2021. The participants were 16 Iranian emergency medical technicians who were selected through a purposive sampling method. For data collection, in-depth and semi-structured interviews were conducted. For data analysis, the Elo and Kyngäs method was applied.

Results

The mean participants’ age was 33.06 ± 7.85 years, and their mean work experience was 10.62 ± 6.63 years. The collected information was categorized into one main category called “complex context of the cardiopulmonary resuscitation” and 5 general categories with 17 subcategories. These categories and subcategories include patient condition (patient’s underlying diseases, age, high weight, number of children, and place of living), dominant atmosphere in companions at home (companions’ feeling of agitation, companions doing harm, and companions helping), policy (educational policy, human resource policy, up-to-date equipment and technology, and do-not-resuscitate policy), performance of the out-of-organizational system (disorganization in the patient handover process, and cooperation of the support organizations), and conditions related to the treatment team (conscience, cultural dominance, and shift burden).

Conclusions

The results showed that the conditions related to the patient and his/her companions, as well as the organizational factors such as the policies and the out-of-organizational factors act as the barriers and the facilitators to the cardiopulmonary resuscitation within pre-hospital emergency medical services. Therefore, the barriers can be modified and the facilitators can be enhanced by taking various measures such as educating, human resource policy-making, upgrading the equipment, and considering appropriate management policies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12873-021-00514-3.

Factors associated with return of spontaneous circulation after out-of-hospital cardiac arrest in Poland: a one-year retrospective study

Background

Out-of-hospital cardiac arrest (OHCA) is a common reason for calls for intervention by emergency medical teams (EMTs) in Poland. Regardless of the mechanism, OHCA is a state in which the chance of survival is dependent on rapid action from bystanders and responding health professionals in emergency medical services (EMS). We aimed to identify factors associated with return of spontaneous circulation (ROSC).

Methods

The medical records of 2137 EMS responses to OHCA in the city of Wroclaw, Poland between July 2017 and June 2018 were analyzed.

Results

The OHCA incidence rate for the year studied was 102 cases per 100,000 inhabitants. EMS were called to 2317 OHCA events of which 1167 (50.4%) did not have resuscitation attempted on EMS arrival. The difference between the number of successful and failed cardiopulmonary resuscitations (CPRs) was statistically significant (p < 0.001). Of 1150 patients in whom resuscitation was attempted, ROSC was achieved in 250 (27.8%). Rate of ROSC was significantly higher when CPR was initiated by bystanders (p < 0.001). Patients presenting with asystole or pulseless electrical activity (PEA) had a higher risk of CPR failure (86%) than those with ventricular fibrillation/ventricular tachycardia (VF/VT). Patients with VF/VT had a higher chance of ROSC (OR 2.68, 1.86–3.85) than those with asystole (p < 0.001). The chance of ROSC was 1.78 times higher when the event occurred in a public place (p < 0.001).

Conclusions

The factors associated with ROSC were occurrence in a public place, CPR initiation by witnesses, and presence of a shockable rhythm. Gender, age, and the type of EMT did not influence ROSC. Low bystander CPR rates reinforce the need for further efforts to train the public in CPR.

Adrenaline use as a poor predictor for the return of spontaneous circulation among victims of out-of-hospital cardiac arrest according to a national emergency medical services database

OBJECTIVE:

This study aimed to determine additional predictors of cardiopulmonary resuscitation success using a national emergency medical services (EMS) database.

METHODS:

This retrospective study was conducted by retrieving data from the Information Technology of Emergency Medical Service, a national EMS database. The inclusion criteria were adult patients (18 years old or over) who suffered from out-of-hospital cardiac arrest and received emergency life support. The outcome was a return of spontaneous circulation (ROSC). Predictors for ROSC were determined using multivariate logistic regression analysis.

RESULTS:

During the study period, 1070 patients met the study criteria, among whom 199 (18.60%) belonged to the ROSC group. Five factors were eligible for multivariate logistic regression analysis for predicting ROSC. Accordingly, only adrenaline administration was independently and negatively associated with ROSC with an adjusted odds ratio of 0.722 (95% confidence interval: 0.522, 0.997) and a Hosmer–Lemeshow Chi-square of 5.84 (P = 0.665).

CONCLUSIONS:

Adrenaline use may be a poor predictor for ROSC during out-of-hospital cardiac arrest.

Polish Helicopter Emergency Medical Service (HEMS) Response to Stroke: A Five-Year Retrospective Study

Background

A stroke is a serious life-threatening emergency that requires immediate intervention in an appropriate therapeutic center. The aim of this study was to analyze the time of medical procedures at the scene and changes in the state of stroke patients during transport by HEMS in Poland. The presented research is the first nationwide study covering such a large group of stroke patients, for whom aerial support was used in the therapeutic process.

Material/Methods

A retrospective cross-sectional study of 48553 missions performed by Polish Medical Air Rescue (PMAR) during the 5-year study period resulted in 3906 stroke patients who, after medical rescue operations by HEMS crew, were transported by helicopters to hospitals.

Results

Helicopters in 3475 (88.97%) cases were utilized as a support for Ground Emergency Medical Service (GEMS). The maximum duration of HEMS operation from activation to patient transfer to the hospital did not exceed 108 min and the median was 60 min. Over 87% of patients with HEMS reported stroke symptoms and arrived at the medical center with the possibility of implementing thrombolytic therapy. The factor that affected the deterioration of patients’ condition was the drawing out of the extent of time spent by the crew at the scene.

Conclusions

The use of HEMS in Poland in the case of patients with stroke symptoms ensures fast and professional assistance at the site of the medical emergency as well as safe transport to specialized centers, shortening the time of proper treatment implementation.