Defibrillation Procedures Research Articles

Augmented reality training in basic life support with the help of smart glasses. A pilot study

IntroductionLaypeople should be trained in basic life support and traditional and innovative methodologies may help to obtain this goal. However, there is a knowledge gap about the ideal basic life support training methods. Smart glasses could have a role facilitating laypeople learning of basic life support. AimTo analyze the potential impact on basic life support learning of a very brief training supported by smart glasses video communication. MethodsTwelve laypeople were basic life support tele-trained by means of smart glasses by an instructor in this pilot study. During training (assisted trough smart glasses) and after the training (unassisted) participants’ performance and quality of basic life support and automated external defibrillation procedure were assessed on a standardized simulated scenario. ResultsAfter the training all participants were able to deliver good quality basic life support, with results comparable to those obtained when real time remotely guided by the instructor through the smart glasses. Mean chest compression rate was significantly higher when not guided (113 /min vs. 103 /min, p = 0.001). When not assisted, the participants spent less time delivering the sequential basic life support steps than when assisted while training. ConclusionsA very brief remote training supported by instructor and smart glasses seems to be an effective educational method that could facilitate basic life support learning by laypeople. This technology could be considered in cases where instructors are not locally available or in general in remote areas, providing basic internet connection is available. Smart glasses could also be useful for laypeople rolling-refreshers.

An In-Silico model for evaluating the directional shock vectors in terminating and modulating rotors

Out-of-hospital cardiac arrest (OHCA) accounts for a majority of mortality worldwide. Survivability from an OHCA highly depends on timely and effective defibrillation. Most of the OHCA cases are due to ventricular fibrillation (VF), a lethal form of cardiac arrhythmia. During VF, previous studies have shown the presence of spatiotemporally organized electrical activities called rotors and that terminating these rotor-like activities could modulate or terminate VF in an in-hospital or research setting. However, such an approach is not feasible for OHCA scenarios. In the case of an OHCA, external defibrillation remains the main therapeutic option despite the low survival rates. In this study, we evaluated whether defibrillation effectiveness in an OHCA scenario could be improved if a shock vector directly targets rotor-like, spatiotemporal electrical activities on the myocardium. Specifically, we hypothesized that the position of defibrillator pads with respect to a rotor’s core axis and shock current density could influence the likelihood of rotor termination and thereby result in successful defibrillation. We created a bidomain cardiac model based on porcine heart data using Aliev–Panfilov bidomain equations. We simulated localized rotors, which we attempted to terminate using different defibrillation pad orientations relative to the rotor axis (i.e., perpendicular, parallel, and oblique). In addition, we gradually increased current densities for each defibrillation pad orientation from 4 to 12 A/m2. We repeated the above defibrillation procedure for rotors originating from four different locations on the ventricles. The shock parameters and the outcomes were analyzed using a Generalized Linear Mixed Model (GLMM) with Logistic Regression to link rotor termination with the defibrillation pad orientation and current density. Our results suggest the highest average likelihood of terminating rotors during VF is when defibrillator pads are placed perpendicular to the rotor axis (0.99 ± 0.03), with an average current density of 7.2 A/m2, compared to any other orientation (parallel: 0.76 ± 0.26 and oblique: 0.08 ± 0.12). Our simulations suggest that optimal defibrillator pad orientation, combined with sufficient current density magnitude, could improve the likelihood of rotor termination during VF and thereby improving defibrillation success in OHCA patients.

Pre-charging the defibrillator before rhythm analysis reduces hands-off time in patients with out-of-hospital cardiac arrest with shockable rhythm

AimTo evaluate the effect of pre-charging the defibrillator before rhythm analysis on hands-off time in patients suffering from out-of-hospital cardiac arrest with shockable rhythm. MethodsPre-charging was implemented in the Emergency Medical Service in the Central Denmark Region in June 2018. Training consisted of hands-on simulation scenarios, e-learning material, and written instructions. Data were extracted from the Danish Cardiac Arrest Registry for a 14-month period spanning the implementation of pre-charging. Patients having received at least one shock were included. Transthoracic impedance data were analysed. We recorded hands-off time and peri-shock pauses for all defibrillation procedures and the total hands-off fraction for all cardiac arrests. ResultsImpedance and outcome data were available for 178 patients. 523 defibrillation procedures were analysed. The pre-charge method was associated with shorter median hands-off time per defibrillation procedure (7.6 (IQR 5.8–9.9) vs. 12.6 (IQR 10–16.4) seconds, p < 0.001) but longer pre-shock pause (4 (IQR 2.7–6.1) vs 1.7 (IQR 1.2–3) seconds, p < 0.001) when compared to the current guideline-recommended defibrillation method. The total hands-off fraction per cardiac arrest was reduced after implementation of the pre-charge method (16.5% vs. 20.4%, p = 0.003). No increase in shocks to non-shockable rhythms or personnel was registered. Patients who received only pre-charge defibrillations had an increased odds ratio of return of spontaneous circulation (aOR 2.91; 95%CI 1.09–7.8, p = 0.03). ConclusionPre-charging the defibrillator reduced hands-off time during defibrillation procedures, reduces the total hands-off fraction and may be associated with increased return of spontaneous circulation in out-of-hospital cardiac arrest with shockable rhythm.

The level of knowledge of pediatricians on defibrillation

Objective: Defibrillation is part of the life-saving chain. Our aim in this study was to evaluate the level of knowledge of pediatricians on defibrillation procedures. Material and Methods: The questionnaire was administered to 308 pediatricians. The specialists were grouped according to their experience as under 5 years, 5-10 years and over 10 years while the research assistants were classified as 1st year, 2nd year, 3rd year and 4th year. Subjects with 0-2 correct answers were classified as less knowledgeable, 3-5 as moderately knowledgeable and 6-8 as knowledgeable. Results: A small percentage of the physicians had received training on the defibrillation procedure. The self-sufficiency rate for the use of the defibrillator device was around 50% in those who received training and around 20% among all physicians. The mean number of correct answers given to the 8 questions used to evaluate the level of knowledge was 4.36±1.77. Approximately half of the subjects (51%) had a moderate level of knowledge. The level of knowledge of the pediatricians who examined patients, had been trained on defibrillator use and used one themselves was significantly higher. The number of correct answers increased as the subject's self-assessment of his/her adequacy increased. There was a significant difference between the level of knowledge of specialists with less than and over 10 years of experience. Conclusion: We found that pediatricians participating in our study did not have adequate defibrillation knowledge. We believe that updating defibrillator device training and increasing the relevant self-confidence before the level of knowledge decreases is very important.

Forensic Aspects of Probable Life-Threatening Complications of Closed Chest Cardiopulmonary Resuscitation in Non-Traumatic Patients

Cardiopulmonary resuscitation (CPR)is a life-saving procedure that can also cause many life-threatening injuries to patients. The complications that can arise from the application of CPR are confronted by the existing legal system as a medical error and since forensic pathologists often encounter various types of CPR-related injuries during autopsies, they must be able to distinguish between CPR-related injuries and those caused by other factors. The aim of the present study was to analyze the findings of autopsy reports of patients who received CPR to determine the frequency of its related life-threatening injuries and to determine the possible factors that affect and increase the risk of these injuries. The study included 58 non-traumatic death cases that had undergone CPR and CPR-related injuries were determined based on X ray CT interpretation reports. The results concluded that the advanced life support was provided in the vast majority of cases (70.7%). The mean duration of CPR provided was (22.0 ± 12.35 & 21.5 ± 13.56 min.) in males and females respectively and defibrillation procedure took place in 79.3% of cases.The most common complications detected were the thoracic cage complications where the costal injuries were the most frequent complications in 48.4% of cases, mid-clavicular rib fracture was the most frequent one and 66.7% of sternal fractures were detected at the level of the third rib. Males were more susceptible to rib and sternal fractures than females. The factors of age, gender and CPR duration were found to have an effect on the increased risk of life-threatening injuries. The risk of injury increases especially when the compression depth exceeded 6 cm. and CPR duration exceeds 30 min. The present study concluded that CPR complications may decrease the patient’s chance of survival and can cause death by itself. The present study recommend detailed post-mortem studies on CPR related life-threatening injuries on a trial of their prevention.

Barriers in the implementation of the Resuscitation Guidelines: European survey of defibrillation techniques.

BackgroundThe European Resuscitation Council (ERC) Guidelines recommend providing chest compressions during defibrillator charging and using adhesive pads for defibrillation to increase the effectiveness of resuscitation. However, the most common defibrillation technique in each European country is unknown, as are the potential barriers in implementation of the guidelines. The aim of this study was to assess the techniques of defibrillation procedures performed by professional European healthcare providers and to estimate how frequently adhesive pads are used.MethodsWe sent an online questionnaire to the ERC National Representatives that contained 12 questions regarding the techniques of defibrillation and monitoring heart rhythm during cardiac arrest. We also evaluated the frequency and indications of manual paddles use.ResultsWe collected questionnaires from 27 out of 33 invited ERC member countries. The response rate was 82 %. Seventeen (17/27; 63 %) declared the use of adhesive pads. The leading cause for not using adhesive pads was economic reason (9/17; 53 %). Some respondents declared resistance to using adhesive pads by healthcare providers or tradition connected with manual paddles use. We found three leading techniques of defibrillation with manual paddles: Charging paddles keeping them on the defibrillator during chest compressions being delivered (9/21; 43 %), Charging paddles keeping them on the patient chest during chest compressions being delivered (6/21; 29 %), Charging paddles on the patient chest without chest compressions (5/21; 24 %). Respondents from 11 countries declared the use of gel or electrode pastes during defibrillation with manual paddles.DiscussionThis study collected preliminary data showing how defibrillation is performed in Europe. It revealed the recommeded techniques underuse and identyfied barriers in the Resuscitation Guidelines implementation. The survey should be open to a wider group of respondents. in each country in future.ConclusionsThere are limitations and barriers in the implementation of the defibrillation technique guidelines. There are still countries where the use of adhesive pads is low due to economic and traditional reasons. There is a need for further efforts focused on guidelines implementation.

NON-UNIFORMITY OF THE DISTRIBUTION OF ELECTRICAL TRANSMEMBRANE POTENTIALS IN CARDIAC DEFIBRILLATION

The need for emergency cessation of ventricular fibrillation is one of the problems of modern reanimatology. In spite of searches for novel methods, there is the only effective method — electrical cardiac defibrillation. Objective: to investigate the effect of different forms of pulses on cell membranes in a model experiment and to assess their use for effective cardiac defibrillation. Materials and methods. The Maxwell model was used for theoretical analysis of the spatial distribution of an electric field in the red blood cell membrane. The electric effect on a single cell was calculated using the experimental findings and the equivalent electrical circuit of the myocardial structure during a defibrillation procedure. The cardiomyocyte membrane potential upon exposure to defibrillator discharge was estimated. Exposure of the red blood cell membrane to single, two unipolar and two heteropolar pulses was examined. Results. There is non-additivity of speeds upon double exposure as compared to single one. Single pulse causes a lower effect of electroporation than two double pulses. Hyperpolarization and depolarization processes in the cardiomyocyte membranes occur successively during electrical cardiac defibrillation. Conclusion. Two heteropolar pulses cause an effect of biological membrane electroporation with a greater probability than two unipolar ones.

Assessment of the Quality of Basic and Expanded Resuscitative Measures in a Multifield Hospital (Simulation Course)

The survival of patients after the sudden circulatory arrest (SCA) depends not only on immediate onset of resuscitative measures, but also on their quality. The purpose of the study. The purpose is to assess the compliance of basic and expanded resuscitative measures carried out by healthcare providers in hospitals with modern national and international guidelines within the frames of a stimulation course. Materials and Methods. The research was perfomed in a multifield hospital in Moscow, in 2016. It consisted of two phases. During the first phase, within the frames of a simulation course, providers' skills in the cardiopul monary resuscitation (CPR) and chest compression (CC) technique mastership were evaluated. During the second stage, their skills in expanded CPR and ability to work as a part of resuscitation teams were assessed. During the simulation, all team activities were recorded (both audio and video); CC parameters were also registered using a CC pressure control sensor (hereinafter referred to as a sensor) and audiovisual tips. The European Resuscitation Council Guidelines for Resuscitation 2015 were used as reference criteria. The analysis was performed using the ZOLL RescueNet Code Review® software. A statistical analysis was performed using the Statistica 7.0 software (MannWhitney Utest). The data were presented as a mean, median ± 25—75 percentiles (25—75 IQR), minimum and maximum values. The difference was considered significant at P<0.05. Results. Test results of most healthcare providers were unsatisfactory when the CPR was performed without sensors and audiovisual tips: the percentage of target CCs was not more than 10% in 72% of providers (n=18). When the CPR was performed with sensors and audiovisual tips regulating the CC quality, the percentage of target CCs was 65.7%. i.e. it was significantly higher than that during the CPR without the sensor and the tips (P=0.0000). While only one provider was able to perform the target CC without the sensor and the tips (4%), 12 providers were able to do it with the sensor (48%) (P=0.0000). In all resuscitation teams, there was a lack in compliance with the ECR 2015 guidelines for expanded CPR, as well as ineffective team work was revealed. Chest compressions did not comply with recommended parameters; pauses before and after defibrillator discharge were too long. In most cases, there was hyperventilation during the artificial lung ventilation. The safety principle was not followed by one of resuscitation teams during the defibrillation procedure. Conclusion. The obtained data demonstrate that healthcare providers have poor skills in basic and expanded CPR. Therefore, it is important to train and retrain healthcare providers in basic and expanded CPR within the frames of simulation training courses on a regular basis (in accordance with European Resuscitation Council Guidelines for Resuscitation 2015 and National Resuscitation Council). During training, the use of technical means of monitoring of the chest compression quality control in CPR should be warranted. It is important to arrange regular retraining in order to keep the skills uptodate, as well as regular debriefings on the CPR quality after each case of resuscitation measures in a hospital.

Nurses' Resuscitation Performance: Study on the Effectiveness of Training and Support at a Teaching Hospital in KSA

Introduction: This paper discussed nurses' resuscitation trainings and their performance in a teaching hospital based on AHA guideline recommendations. The study explored the current standard practices and investigates the nurses' views on the effectiveness of the training, quality of equipment, familiarity and readiness of nurses in performing resuscitation. Methodology: A cross-sectional descriptive study conducted at teaching hospitals which mandate all nurses must be certified with the BLS and attends two code blue drill sessions per year. A self-administered questionnaire examined the support and guidance provided, the availability of resuscitation equipment and their quality/familiarity, the quality of training received in performing the resuscitation actions and finally explored the opinion in improving resuscitation. Results: The study revealed that the organization has established system to prepare the nurses adequately. Based on the 192 nurses, the total mean 2.63 supported that nurses are adequately trained with resuscitation knowledge and skills, 95% (n=171) of nurses were confident in announcing the code blue procedure, 93.3% (n=169) received appropriate training and 90% (n=162) found training instructors utilized standard method of simulation training which 90% (n=161) shared a real-life clinical scenarios are used in the training whilst 90.5% (n=162) stated SBAR is utilized as mode of communication and 66.6% (n=120) practiced post-procedure resuscitation debriefing. However, concerns were raised in three areas: availability of AEDs, cable and pad accessibility and permission to perform defibrillation procedures. In conclusion, study established nurses were well-prepared, trained and supported for resuscitation care.

Defibrillation safety: an examination of paramedic perceptions using eye-tracking technology

ObjectiveThe importance of access to early defibrillation for patients in cardiac arrest has been emphasised as a critical part of the chain of survival by resuscitation bodies internationally; as such...

Assessment of the teaching-learning process in students of the health area: cardiopulmonary resuscitation maneuvers

To evaluate the skills and knowledge of undergraduate students in the health area on cardiopulmonary resuscitation maneuvers with the use of an automatic external defibrillator. The evaluation was performed in three different stages of the teaching-learning process. A theoretical and practical course was taught and the theoretical classes included demonstration. The evaluation was performed in three different stages of the teaching-learning process. Two instruments were applied to evaluate the skills (30-items checklist) and knowledge (40-questions written test). The sample comprised 84 students. After the theoretical and practical course, an increase was observed in the number of correct answers in the 30-items checklist and 40-questions written test. After the theoretical class (including demonstration), only one of the 30-items checklist for skills achieved an index ≥ 90% of correct answers. On the other hand, an index of correct answers greater than 90% was achieved in 26 (86.7%) of the 30 items after a practical training simulation, evidencing the importance of this training in the defibrillation procedure.

Lung injury and pneumothorax after defibrillation as demonstrated with computed tomography

Many patients present for emergency services after electric injuries or require defibrillation during emergency services. Although the defibrillation process is safe, skin burns and myocardial injuries are reported after defibrillation procedures. There are limited data about the complications of defibrillation. In the case reported here, a lung injury and a small pneumothorax were observed after defibrillation. To the best of our knowledge, this is the first reported case in which computed tomography is used to demonstrate that a trace of electric current passed through the lung. Computed tomography may be an excellent diagnostic modality to demonstrate the severity and extent of electric injuries to the lung.

Fibrillar superstructure formation of hemoglobin A and its conductive, photodynamic and photovoltaic effects

The fabrication of biomaterials which serve as functional scaffolds exhibiting diversified effects has been valued. We report here a unique strategy to fibrillate hemoglobin A (HbA), which exhibits multiple photoelectrochemical properties, and a subsequent specific defibrillation procedure. A subtle structural rearrangement of the α/β-subunits within the quaternary structure of HbA is responsible for the HbA fibril formation in the presence of 0.5% CHCl₃. The narrow pH dependence of the suprastructure formation around pH 7.4 illustrates the highly sensitive nature of the structural alteration. The CHCl₃-induced fibrils become disintegrated by ascorbic acid, indicating that the oxidation-reduction process of the iron within the heme moiety could be involved in stabilization of the fibrillar structures. The electron-transferring property of the iron allows the fibrils to exhibit not only their conductive behavior but also a photodynamic effect generating hydroxyl radicals in the presence of H(2)O(2) with light illumination. A photovoltaic effect is also demonstrated with the HbA fibrils, which generate an electric current on the fibril-coated microelectrode upon irradiation at 405nm. Taken together, the multiple effects of HbA fibrils and the selective fibrillation/defibrillation procedures could qualify the fibrils to be employed for various future applications in biotechnology, including bio-machine interfaces.

Resolution of QRS Complexes in ECG Signals for Defibrillation and Cardioversion Procedures

Defibrillation and cardioversion are therapeutic pro cedures used for patients with cardiac rhythm disorders [1, 2]. During cardioversion, an electrical defibrillation pulse is synchronized with the ECG QRS complex [3 5]. There are many algorithms of identification of ECG QRS complexes. Most algorithms are based on ECG sig nal amplitude parameters [6]. Maximal amplitude of ECG signal in healthy subjects is inherent in R wave of the QRS complex [7]. Patients with various cardiac pathologies demonstrate variable ECG signals. The goal of this work was to suggest resolution of QRS complexes in ECG sig nals for defibrillation and cardioversion procedures. The QRS identification algorithm is based on additive thresh old amplitude values and ECG signal increase rate.

Defibrillation

Reading a learning zone article increased Lyn Kelly’s understanding of emergency defibrillation procedures

Use Of S(+)-Ketamine In A Patient With Chronic Chagasic Cardiopathy For Emergency Cardiac Defibrillation Procedure

Among the chronic clinical forms of Chagas disease, the anesthesiologists must pay attention to the chagasic cardiomyopathy, since the drugs used in anesthesia, in its majority, act like depressors of the cardiac function. A male 66 year-old patient presented with chronic chagasic cardiomyopathy (left ventricle ejection fraction of 34%). We admnistered continuous IV dobutamine and amiodarone. He presented with ventricular tachycardia associated to hypoxemia, pulmonary oedema and arterial hypotension, making necessary an emergency cardiac defibrillation procedure. Since this patient was found in cardiac and respiratory failure, S(+)-ketamine was administered and then 200J was applied for external defibrillation. Cardiac rhythm converted to sinus type. The patient did not recall the event. Etomidate and vecuronium are being used in patients with chagasic cardiopathy presenting satisfactory results. The use of S(+)-ketamine should be studied in this patients to determine its safety.

Do nurses and physiotherapists require training to use an automated external defibrillator?

Healthcare staff with the duty to perform CPR should also be capable of using an automated external defibrillator (AED). We investigate whether nurses and physiotherapists can use an AED without prior training. Subjects were tested on a manikin during a cardiac arrest scenario. All 15 untrained subjects could deliver a shock with an AED in 68.8±29.2 s (time±S.D., range, 40–169 s). Most failed to position the pads correctly (53%) or follow correct safety procedures (67%). After a standardised training session, the time to deliver a shock improved significantly to 48.5±5.5 s (range, 41–61 s, P<0.01) and all subjects placed the pads correctly and followed a safe defibrillation procedure. This study shows that nurses and physiotherapists, with no previous AED training, can deliver a shock with an AED. Training improves speed of shock delivery, correct pad placement and safety. This study suggests that it is feasible to train healthcare professionals to use an AED with relatively little training. This should allow rapid deployment of AEDs in those areas of the hospital where cardiac arrests are infrequent and staff do not have rhythm recognition skills.

External Defibrillation During Reoperative Heart Surgery

An inexpensive system for remote external defibrillation was evaluated in 25 patients undergoing repeat open-heart surgery. The system consists of a pair of self-adhesive pads connected with a remote bracket on which a standard pair of external shock electrodes are discharged. With this system 84% of the patients were successfully defibrillated: 12% converted spontaneously. The energy level at conversion was less than or equal to 200 Ws in 90% of the patients. There were no complications associated with the defibrillation procedure. By reducing the need for intrapericardial dissection this method shortens overall operating time and most probably decreases blood loss. The system can also be recommended for operations with a high risk of ventricular arrhythmia prior to pericardiotomy.

Improved defibrillator waveform safety factor with biphasic waveforms.

Excitation thresholds and arrhythmias were studied in "adult-type" cultured chick embryo myocardial cells after electric field stimulation with biphasic, truncated, and rectified underdamped RLC (resistance-inductance-capacitance) type waveforms, to test the hypothesis that the negative phase of biphasic waveforms ameliorates membrane dysfunction induced by the initial positive portion. Photocell mechanograms and intracellular microelectrodes monitored extrasystoles and depolarization-induced arrhythmias. Rectifying or truncating biphasic waveforms did not alter the excitation threshold. However, shock intensities producing specific postshock arrhythmias or a specific severity of postshock prolonged depolarization differed significantly when biphasic waveforms were truncated or rectified. The voltage gradient producing a specific dysfunction was 12-14% lower for the truncated version than for the biphasic; that for the rectified version was 17-27% lower than for the biphasic version (although both contained the same energy). Safety factor, the ratio between shock intensity producing specific dysfunction and that producing excitation, was determined for each waveform. Biphasic waveforms had larger safety factors than truncated or rectified waveforms. Since safety factor, as measured in cultured myocardial cells, closely corresponds with in situ defibrillating effectiveness (14), the significantly higher safety factors of biphasic waveforms suggest that carefully shaped biphasic waveforms might improve the efficacy and safety of cardiac defibrillation procedures.

Determination of safety factor for defibrillator waveforms in cultured heart cells.

We studied excitation thresholds and arrhythmias produced in cultured chick embryo myocardial cells subjected to electric shocks using rectangular, untruncated resistor-capacitor (RC), and critically damped resistor-inductor-capacitor (RLC) waveforms with variable intensities while photocell mechanograms were recorded. Strength-duration curves for excitation and production of a specific postshock arrhythmia (4-s arrest) were constructed. Excitation curves closely resembled those for in situ defibrillation threshold (or specific % success). The ratio between the shock intensity producing a 4-s arrest and that producing excitation at each duration (termed the "safety factor") was determined. Waveforms with a large safety factor in vitro defibrillated most effectively in situ with little postshock dysfunction. Waveforms with low safety factors had a low rate of success in situ and produced much postshock dysfunction. Safety factor of monophasic clinical waveforms were lower than that of the 5-ms rectangular wave. The close correspondence between in vitro safety factor and in situ defibrillating effectiveness, as reported in the literature, suggests that the cell culture system is an effective screening system for determining waveforms that will improve the efficacy and safety of defibrillation procedures.