Rescue under ongoing CPR from an upper floor: evaluation of three different evacuation routes and mechanical and manual chest compressions: a manikin trial

Mathematical Model of Blood Circulation with Compression of the Prototype's Mechanical CPR Waveform

The waveform of chest compressions directly affects the blood circulation of patients with cardiac arrest. Currently, few pieces of research have focused on the influence of the cardiopulmonary resuscitation (CPR) device's mechanical waveform on blood circulation. This study investigates the effect of the mechanical waveform from a novel CPR prototype on blood circulation and explores the optimal compression parameters of the mechanical waveform to optimize blood circulation. A novel CPR prototype was designed and built to establish a kinetic model during compressions. The prototype's mechanical waveforms at various operating conditions were obtained for comparison with manual waveforms and the investigation of the optimal compression parameters. The novel CPR prototype can complete chest compressions quickly and stably. The cardiac output (CO), coronary perfusion pressure (CPP), and cerebral flow (CF) obtained by mechanical waveform compressions (1.22367 ± 0.00942 L/min, 30.95083 ± 0.24039 mmHg, 0.31992 ± 0.00343 L/min, respectively) were significantly better than those obtained by manual waveform compressions (1.10783 ± 0.03601 L/min, 21.39210 ± 1.42771 mmHg, 0.29598 ± 0.01344 L/min, respectively). With the compression of the prototype, the blood circulation can be optimized at the compression depth of 50 mm, approximately 0.6 duty cycle, and approximately 110 press/min, which is of guiding significance for the practical use of CPR devices to rescue patients with cardiac arrest.

Quality of chest compressions during prehospital resuscitation phase from scene arrival to ambulance transport in out-of-hospital cardiac arrest

AIM

Prehospital cardiopulmonary resuscitation is performed from scene arrival to hospital arrival. The diverse prehospital resuscitation phases can affect the quality of chest compressions. This study aimed to evaluate the dynamic changes in chest compression quality during prehospital resuscitation.

METHODS

Adult out-of-hospital cardiac arrest patients treated without prehospital return of spontaneous circulation were included in Seoul between July 2020 and September 2021. The chest compressions quality was assessed using a real-time chest compression feedback device. The prehospital phase was divided by key events during the prehospital resuscitation timeline (phase 1: first 2 min after initiation of chest compression, phase 2: from the end of phase 1 to 1 min prior to ambulance departure; phase 3: from 1 min before to 1 min after ambulance departure; phase 4: from the end of phase 3 to hospital arrival). The main outcome was no-flow fraction. The no-flow fraction between prehospital phases was compared using repeated-measure analysis of variance.

RESULTS

In total, 788 patients were included. Mean no-flow fraction was the highest in phase 3 (phase 1: 11.3% ± 13.8, phase 2: 19.3% ± 12.3, phase 3: 33.0% ± 34.9, phase 4: 18.7% ± 23.7, p < 0.001). The mean number of total no-flow events per minute was also the highest in phase 3. The minute-by-minute analysis showed that the no-flow fraction rapidly increased before ambulance departure and decreased during ambulance transport.

CONCLUSION

Dynamic changes in chest compression quality were observed during prehospital resuscitation phase. The no-flow fraction was the highest from 1 min before to 1 min after ambulance departure.

Cardiac Arrest Occurring in High-Rise Buildings: A Scoping Review

Out-of-hospital cardiac arrests (OHCAs) occurring in high-rise buildings are a challenge to Emergency Medical Services (EMS). Contemporary EMS guidelines lack specific recommendations for systems and practitioners regarding the approach to these patients. This scoping review aimed to map the body of literature pertaining to OHCAs in high-rise settings in order to clarify concepts and understanding and to identify knowledge gaps. Databases were searched from inception through to 6 May 2021 including OVID Medline, PubMed, Embase, CINAHL, and Scopus. Twenty-three articles were reviewed, comprising 8 manikin trials, 14 observational studies, and 1 mathematical modelling study. High-rise settings commonly have lower availability of bystanders and automatic external defibrillators (AEDs), while height constraints often lead to delays in EMS interventions and suboptimal cardiopulmonary resuscitation (CPR), scene access, and extrication. Four studies found return of spontaneous circulation (ROSC) rates to be significantly poorer, while seven studies found rates of survival-to-hospital discharge (n = 3) and neurologically favourable survival (n = 4) to be significantly lower in multistorey settings. Mechanical chest compression devices, transfer sheets, and strategic defibrillator placement were suggested as approaches to high-rise OHCA management. A shift to maximising on-scene treatment time, along with bundling novel prehospital interventions, could ameliorate some of these difficulties and improve clinical outcomes for patients.

Cardiopulmonary resuscitation is more effective for in-hospital cardiac arrest when performed on a stretcher. A manikin study

Objectives:

To compare the efficacies of various chest compression procedures performed on a stretcher during dynamic transport of patients with in-hospital cardiac arrest.

Methods:

This prospective and randomized cross-over study used manikins. Practitioners were asked to perform chest compressions on a manikin placed on a moving stretcher for 2 minutes. Cardiopulmonary resuscitation (CPR) procedures were included the following 3 types: i) CPR-walking (CPR-W) ii) CPR-straddling (CPR-S), and iii) CPR-mechanical chest compression device (CPR-MCCD). Demographic data of the participants, CPR quality indicators, the time between the start command and first compression, level of difficulty, and the distance covered by the stretcher for the duration of each application were recorded.

Results:

Thirty-two physicians (9 female, 23 male), participated in this study. The CPR-MCCD procedure was the most effective for all parameters, except the time between the start command and first compression. On the other hand, the compression rate at optimal depth, CPR success score, distance covered, and level of difficulty parameters were significantly favored in the CPR-S group, when compared to the CPR-W group (p<0.001, all comparisons).

Conclusions:

It is possible to perform high-quality chest compressions during patient transport using the CPR-MCCD method. The CPR-S method allowed practitioners to perform higher-quality chest compressions compared to CPR-W.

Transportation during and after cardiac arrest: who, when, how and where?

PURPOSE OF REVIEW

Out-of-hospital cardiac arrest (OHCA) is the most devastating and time-critical medical emergency. Survival after OHCA requires an integrated system of care, of which transport by emergency medical services is an integral component. The transport system serves to commence and ensure uninterrupted high-quality resuscitation in suitable patients who would benefit, terminate resuscitation in those that do not, provide critical interventions, as well as convey patients to the next appropriate venue of care. We review recent evidence surrounding contemporary issues in the transport of OHCA, relating to who, where, when and how to transport these patients.

RECENT FINDINGS

We examine the clinical and systems-related evidence behind issues including: contemporary approaches to field termination of resuscitation in patients in whom continued resuscitation and transport to hospital would be medically futile, OHCA patients and organ donation, on-scene versus intra-transport resuscitation, significance of response time, intra-transport interventions (mechanical chest compression, targeted temperature management, ECMO-facilitated cardiopulmonary resuscitation), OHCA in high-rise locations and cardiac arrest centers. We highlight gaps in current knowledge and areas of active research.

SUMMARY

There remains limited evidence to guide some decisions in transporting the OHCA patient. Evidence is urgently needed to elucidate the roles of cardiac arrest centers and ECPR in OHCA.

Testing mechanical chest compression devices of different design for their suitability for prehospital patient transport - a simulator-based study

Background

Mechanical chest compression (mCPR) offers advantages during transport under cardiopulmonary resuscitation. Little is known how devices of different design perform en-route. Aim of the study was to measure performance of mCPR devices of different construction-design during ground-based pre-hospital transport.

Methods

We tested animax mono (AM), autopulse (AP), corpuls cpr (CC) and LUCAS2 (L2). The route had 6 stages (transport on soft stretcher or gurney involving a stairwell, trips with turntable ladder, rescue basket and ambulance including loading/unloading). Stationary mCPR with the respective device served as control. A four-person team carried an intubated and bag-ventilated mannequin under mCPR to assess device-stability (displacement, pressure point correctness), compliance with 2015 ERC guideline criteria for high-quality chest compressions (frequency, proportion of recommended pressure depth and compression-ventilation ratio) and user satisfaction (by standardized questionnaire).

Results

All devices performed comparable to stationary use. Displacement rates ranged from 83% (AM) to 11% (L2). Two incorrect pressure points occurred over 15,962 compressions (0.013%). Guideline-compliant pressure depth was > 90% in all devices. Electrically powered devices showed constant frequencies while muscle-powered AM showed more variability (median 100/min, interquartile range 9). Although physical effort of AM use was comparable (median 4.0 vs. 4.5 on visual scale up to 10), participants preferred electrical devices.

Conclusion

All devices showed good to very good performance although device-stability, guideline compliance and user satisfaction varied by design. Our results underline the importance to check stability and connection to patient under transport.