Part 5: Adult Basic Life Support

Incorporation of Drone Technology Into the Chain of Survival for OHCA: Estimation of Time Needed for Bystander Treatment of OHCA and CPR Performance

BACKGROUND

Drone-delivered automated external defibrillators (AEDs) hold promises in the treatment of out-of-hospital cardiac arrest. Our objective was to estimate the time needed to perform resuscitation with a drone-delivered AED and to measure cardiopulmonary resuscitation (CPR) quality.

METHODS

Mock out-of-hospital cardiac arrest simulations that included a 9-1-1 call, CPR, and drone-delivered AED were conducted. Each simulation was timed and video-recorded. CPR performance metrics were recorded by a Laerdal Resusci Anne Quality Feedback System. Multivariable regression modeling examined factors associated with time from 9-1-1 call to AED shock and CPR quality metrics (compression rate, depth, recoil, and chest compression fraction). Comparisons were made among those with recent CPR training (≤2 years) versus no recent (>2 years) or prior CPR training.

RESULTS

We recruited 51 research participants between September 2019 and March 2020. The median age was 34 (Q1-Q3, 23-54) years, 56.9% were female, and 41.2% had recent CPR training. The median time from 9-1-1 call to initiation of CPR was 1:19 (Q1-Q3, 1:06-1:26) minutes. A median time of 1:59 (Q1-Q3, 01:50-02:20) minutes was needed to retrieve a drone-delivered AED and deliver a shock. The median CPR compression rate was 115 (Q1-Q3, 109-124) beats per minute, the correct compression depth percentage was 92% (Q1-Q3, 25-98), and the chest compression fraction was 46.7% (Q1-Q3, 39.9%-50.6%). Recent CPR training was not associated with CPR quality or time from 9-1-1 call to AED shock. Younger age (per 10-year increase; β, 9.97 [95% CI, 4.63-15.31] s; P<0.001) and prior experience with AED (β, -30.0 [95% CI, -50.1 to -10.0] s; P=0.004) were associated with more rapid time from 9-1-1 call to AED shock. Prior AED use (β, 6.71 [95% CI, 1.62-11.79]; P=0.011) was associated with improved chest compression fraction percentage.

CONCLUSION

Research participants were able to rapidly retrieve an AED from a drone while largely maintaining CPR quality according to American Heart Association guidelines. Chest compression fraction was lower than expected.

Foreign body aspiration in children: our pediatric tertiary care experience

PURPOSE

Inhalation of a foreign body is a real emergency in pediatric age and requires prompt diagnosis and treatment to reduce mortality. The objective of this study is to analyze clinical and radiological details, types, and localization of foreign bodies in patients conducted or to our hospital with suspected inhalation.

METHODS

We conducted a retrospective analysis of all cases of foreign body inhalation admitted to our Pediatric Emergency Room between January 2009 and June 2022.

RESULTS

171 patients were included in the study. In 83 patients, the FB was detected. The mean age of presentation was 2.3 years (SD: ± 2). Cough (73%) and unilateral reduced breath sound (51%) were the most common clinical symptom and clinical sign. The most frequent localization was the right main bronchus (43%). The foreign bodies retrieved were vegetable (83%), of which peanut was the most common. Chest radiographs were normal in 25%. The mean duration of hospitalization was 5 days (± 2.9). Complications such as pneumothorax were seen in two cases.

CONCLUSIONS

Foreign body inhalation represents a true pediatric emergency and still a challenge in clinical practice. The best way to manage it is an early diagnosis and removal by fully trained staff.

Comparison of Three Airway Maneuvers of Jaw Thrust, Two-Handed E-C Technique With Head in Neutral Position, and Two-Handed E-C Technique With Head Fully Extended: A Prospective, Randomized, Double-Blind Crossover Study

Background Bag-mask ventilation is an essential life-saving skill. The E-C technique of mask holding is the most popular. In patients with suspected cervical injury, the jaw thrust maneuver is recommended instead of the E-C technique with head tilt-chin lift. Should jaw thrust fail to produce adequate chest rise, the operator is advised to switch to the E-C technique with the head tilt-chin lift maneuver with head extension as it is vital to move oxygen into the lungs. We hypothesized that the E-C clamp with the head in the neutral position without head tilt might permit adequate ventilation without producing excessive movement of the cervical spine, which in turn might translate as less strain to the cervical spine. Methods In this prospective, randomized, double-blind, crossover study, we evaluated the relative efficacy of three airway maneuvers in opening the airway in anesthetized and paralyzed adults: jaw thrust, two-handed E-C technique with head in the neutral position, and two-handed E-C technique with head fully extended. The tidal volume generated during mechanical ventilation using these three techniques was considered as the primary outcome. Seventy-two subjects were recruited for this trial and all three techniques of mask holding were performed in each of these subjects in a sequence as dictated by a randomization table. Results The jaw thrust technique provided a mean tidal volume significantly higher than the two-handed E-C technique, with the head in the neutral position (p<0.001). Similarly, the two-handed E-C technique with the head fully extended provided a mean tidal volume significantly higher than the two-handed E-C technique with the head in neutral position (p<0.011). The mean tidal volume obtained with jaw thrust and two-handed E-C technique with head fully extended were comparable (p=0.78). Conclusion The two-handed E-C technique with the head fully extended, and the jaw thrust technique both produce good and comparable tidal volumes. The two-handed E-C technique with the head in a neutral position provides adequate though lower tidal volumes as compared to the other two techniques.

Bag-Valve-Mask Ventilation and Survival From Out-of-Hospital Cardiac Arrest: A Multicenter Study

BACKGROUND

Few studies have measured ventilation during early cardiopulmonary resuscitation (CPR) before advanced airway placement. Resuscitation guidelines recommend pauses after every 30 chest compressions to deliver ventilations. The effectiveness of bag-valve-mask ventilation delivered during the pause in chest compressions is unknown. We sought to determine: (1) the incidence of lung inflation with bag-valve-mask ventilation during 30:2 CPR; and (2) the association of ventilation with outcomes after out-of-hospital cardiac arrest.

METHODS

We studied patients with out-of-hospital cardiac arrest from 6 sites of the Resuscitation Outcomes Consortium CCC study (Trial of Continuous Compressions versus Standard CPR in Patients with Out-of-Hospital Cardiac Arrest). We analyzed patients assigned to the 30:2 CPR arm with ≥2 minutes of thoracic bioimpedance signal recorded with a cardiac defibrillator/monitor. Detectable ventilation waveforms were defined as having a bioimpedance amplitude ≥0.5 Ω (corresponding to ≥250 mL VT) and a duration ≥1 s. We defined a chest compression pause as a 3- to 15-s break in chest compressions. We compared the incidence of ventilation and outcomes in 2 groups: patients with ventilation waveforms in <50% of pauses (group 1) versus those with waveforms in ≥50% of pauses (group 2).

RESULTS

Among 1976 patients, the mean age was 65 years; 66% were male. From the start of chest compressions until advanced airway placement, mean±SD duration of 30:2 CPR was 9.8±4.9 minutes. During this period, we identified 26 861 pauses in chest compressions; 60% of patients had ventilation waveforms in <50% of pauses (group 1, n=1177), and 40% had waveforms in ≥50% of pauses (group 2, n=799). Group 1 had a median of 12 pauses and 2 ventilations per patient versus group 2, which had 12 pauses and 12 ventilations per patient. Group 2 had higher rates of prehospital return of spontaneous circulation (40.7% versus 25.2%; P<0.0001), survival to hospital discharge (13.5% versus 4.1%; P<0.0001), and survival with favorable neurological outcome (10.6% versus 2.4%; P<0.0001). These associations persisted after adjustment for confounders.

CONCLUSIONS

In this study, lung inflation occurred infrequently with bag-valve-mask ventilation during 30:2 CPR. Lung inflation in ≥50% of pauses was associated with improved return of spontaneous circulation, survival, and survival with favorable neurological outcome.

Monitoring cardiopulmonary resuscitation quality in emergency departments: a national survey in China on current knowledge, attitudes, and practices

BACKGROUND

To investigate current knowledge, attitudes, and practices for CPR quality control among emergency physicians in Chinese tertiary hospitals.

METHODS

Anonymous questionnaires were distributed to physicians in 75 tertiary hospitals in China between January and July 2018.

RESULTS

A total of 1405 respondents answered the survey without obvious logical errors. Only 54.4% respondents knew all criteria of high-quality CPR. A total of 91.0% of respondents considered CPR quality monitoring should be used, 72.4% knew the objective method for monitoring, and 63.2% always/often monitored CPR quality during actual resuscitation. The main problems during CPR were related to chest compression: low quality due to fatigue (67.3%), inappropriate depth (57.3%) and rate (54.1%). The use of recommended monitoring methods was reported as follows, ETCO2 was 42.7%, audio-visual feedback devices was 10.1%, coronary perfusion pressure was 17.9%, and invasive arterial pressure was 31.1%. A total of 96.3% of respondents considered it necessary to participate in regular CPR retraining, but 21.4% did not receive any retraining. The ideal retraining interval was considered to be 3 to 6 months, but the actual interval was 6 to 12 months. Only 49.7% of respondents reported that feedback devices were always/often used in CPR training.

CONCLUSION

Chinese emergency physicians were very concerned about CPR quality, but they did not fully understand the high-quality criteria and their impact on prognosis. CPR quality monitoring was not a routine procedure during actual resuscitation. The methods recommended in guidelines were rarely used in practice. Many physicians had not received retraining or received retraining at long intervals. Feedback devices were not commonly used in CPR training.

Iatrogenic rib fractures and the associated risks of mortality

PURPOSE

Rib fractures, though typically associated with blunt trauma, can also result from complications of medical or surgical care, including cardiopulmonary resuscitation. The purpose of this study is to describe the demographics and outcomes of iatrogenic rib fractures.

METHODS

Patients with rib fractures were identified in the 2016 National Inpatient Sample. Mechanism of injury was defined as blunt traumatic rib fracture (BTRF) or iatrogenic rib fracture (IRF). IRF was identified as fractures from the following mechanisms: complications of care, drowning, suffocation, and poisoning. Differences between BTRF and IRF were compared using rank-sum test, Chi-square test, and multivariable regression.

RESULTS

34,644 patients were identified: 33,464 BTRF and 1180 IRF. IRF patients were older and had higher rates of many comorbid medical disorders. IRF patients were more likely to have flail chest (6.1% versus 3.1%, p < 0.001). IRF patients were more likely to have in-hospital death (20.7% versus 4.2%, p < 0.001) and longer length of hospitalization (11.8 versus 6.9 days, p < 0.001). IRF patients had higher rates of tracheostomy (30.2% versus 9.1%, p < 0.001). In a multivariable logistic regression of all rib fractures, IRF was independently associated with death (OR 3.13, p < 0.001). A propensity matched analysis of IRF and BTRF groups corroborated these findings.

CONCLUSION

IRF injuries are sustained in a subset of extremely ill patients. Relative to BTRF, IRF is associated with greater mortality and other adverse outcomes. This population is understudied. The etiology of worse outcomes in IRF compared to BTRF is unclear. Further study of this population could address this disparity.

The PHOENIX: Design and Development of a Three-Dimensional-Printed Drone Prototype and Corresponding Simulation Scenario Based on the Management of Cardiac Arrest

Sudden cardiac arrest (SCA) remains one of the most prevalent cardiovascular emergencies in the world. The development of international protocols and the use of accessible devices such as automated external defibrillators (AEDs) allowed for the standardization and organization of medical care related to SCA. When defibrillation is performed within five minutes of starting ventricular fibrillation (VF) and pulseless ventricular tachycardia (VT), the victim survival rate has increased considerably. Therefore, training healthcare professionals to use AEDs correctly is essential to improve patient outcomes and response time in the intervention. In this technical report, we advocate simulation-based education as a teaching methodology and an essential component of drone adaptation, novel technology, that can deliver AEDs to the site, as well as a training scenario to teach healthcare professionals how to operate the real-time communication components of drones and AEDs efficiently. Studies have suggested that simulation can be an effective way to train healthcare professionals. Through teaching methodology using simulation, training these audiences has the potential to reduce the response time to intervention, consequently, increasing the patient's chance of surviving.

Chest Compression Fraction and Factors influencing it

Introduction:

Chest compression fraction (CCF) is the cumulative time spent providing chest compressions divided by the total time taken for the entire resuscitation. Targeting a CCF of at least 60% is intended to limit interruptions in compressions and maximize coronary perfusion during resuscitation. We aimed to identify the mean CCF and its relationship with various factors affecting it.

Methods:

Patients presenting to the emergency department in cardiac arrest at a single center were prospectively included in this study. Resuscitation was provided by trained health-care providers. The feedback device Cprmeter2™ was placed on the patient's sternum at the beginning of resuscitation. The total time taken for the entire resuscitation was noted by the device and CCF calculated.

Results:

The mean CCF was analyzed using descriptive statistics and was found to be 71.60% ± 7.52%. The total duration of resuscitation (R = −0.55, P = < 0.001, min-max, 2.02–34.31, mean 12.25 ± 6.54), number of people giving chest compressions (R = −0.48, P = < 0.001, min-max, 1–6, mean 4.04 ± 1.12), and total number of team members in resuscitation (R = −0.50, P = < 0.001, min-max, 4–10, mean 6.65 ± 1.32) had negative correlation with CCF. Diurnal variation (day, n = 35; mean 69.20% ± 7% and night, n = 20; mean 75.80% ± 5.6%, P = 0.001) and patients receiving defibrillation (receiving n = 10 mean 67.00% ± 4.11% and not receiving n = 45 mean 72.62 ± 7.42%, P = 0.005) were found to significantly affect CCF.

Conclusion:

The mean CCF for cardiac arrest patients was well within the targets of guideline recommendation. CCF decreased when resuscitation lasted longer, during daytime when the defibrillator was used, the total team members increased, and also when the number of people giving chest compressions increased. CCF during resuscitation may improve if there is a focus on improving these factors and requires validation in multicentric settings.

Lifesaving Medications Use By Athletic Trainers

The athletic trainer's (AT) emergency management skill set requires competency in the delivery of basic lifesaving medications. Some lifesaving medications have been a part of athletic training practice for decades, but that list has grown as ATs' practice setting has expanded - increasing the types of em ergent conditions that the AT may have to treat. The 2020 CAATE curricular standards require athletic training students be trained to administer the following: supplemental oxygen, nitroglycerine, low dose aspirin, bronchodilators, epinephrine using automated injection device, glucagon, and naloxone. Clinically, the conditions treated by these medications can be categorized as follows: cardiac, respiratory, hypoglycemia, or anaphylaxis. All ATs should know the indications, contraindications, administration methods, and the details of patient monitoring for each medication. Generally, these medications are safe, have clear indications for use, and few contraindications. While ATs are trained to administer these medications, they must consider state laws and local policies.

The effect of personal protective equipment on cardiac compression quality

Introduction

Cardiac compression is a cumbersome procedure. The American Heart Association suggests switching of cardiopulmonary resuscitation (CPR) provider every 2 min to prevent any decrease in resuscitation quality. High quality CPR is associated with improved outcomes. Previous studies have highlighted the difficulties in providing high quality CPR particularly while wearing personal protective equipment (PPE). This study aimed to evaluate the impact of personal protective equipment (PPE) use on CPR quality in prehospital cardiac arrest situations.

Methods

In this prospective simulation study, we compared the cardiac compression qualities and fatigue rates among prehospital health care professionals (HCPs) who were or were not using PPE.

Results

A total of 76 prehospital HCPs comprising 38 compression teams participated in this study. The mean compression rate was 117.71 ± 8.27/min without PPE and 115.58 ± 9.02/min with PPE (p = 0.191). Overall compression score was 86.95 ± 4.39 without PPE and 61.89 ± 14.43 with PPE (p < 0.001). Post-cardiac compression fatigue score was 4.42 ± 0.5 among HCPs who used their standard uniform and 7.74 ± 0.92 among those who used PPE (p < 0.001). The overall compression score difference between the two conditions was 25.05 ± 11.74 and the fatigue score difference was 3.31 ± 0.98.

Discussion

PPE use is associated with decreased cardiac compression quality and significantly higher fatigue rates than those associated with the use of standard uniforms. Routine use of mechanical compression devices should be considered when PPE is required for out-of-cardiac arrests.

Survival after traumatic out-of-hospital cardiac arrest in Vietnam: a multicenter prospective cohort study

BACKGROUND

Pre-hospital services are not well developed in Vietnam, especially the lack of a trauma system of care. Thus, the prognosis of traumatic out-of-hospital cardiac arrest (OHCA) might differ from that of other countries. Although the outcome in cardiac arrest following trauma is dismal, pre-hospital resuscitation efforts are not futile and seem worthwhile. Understanding the country-specific causes, risk, and prognosis of traumatic OHCA is important to reduce mortality in Vietnam. Therefore, this study aimed to investigate the survival rate from traumatic OHCA and to measure the critical components of the chain of survival following a traumatic OHCA in the country.

METHODS

We performed a multicenter prospective observational study of patients (> 16 years) presenting with traumatic OHCA to three central hospitals throughout Vietnam from February 2014 to December 2018. We collected data on characteristics, management, and outcomes of patients, and compared these data between patients who died before hospital discharge and patients who survived to discharge from the hospital.

RESULTS

Of 111 eligible patients with traumatic OHCA, 92 (82.9%) were male and the mean age was 39.27 years (standard deviation: 16.38). Only 5.4% (6/111) survived to discharge from the hospital. Most cardiac arrests (62.2%; 69/111) occurred on the street or highway, 31.2% (29/93) were witnessed by bystanders, and 33.7% (32/95) were given cardiopulmonary resuscitation (CPR) by a bystander. Only 29 of 111 patients (26.1%) were taken by the emergency medical services (EMS), 27 of 30 patients (90%) received pre-hospital advanced airway management, and 29 of 53 patients (54.7%) were given resuscitation attempts by EMS or private ambulance. No significant difference between patients who died before hospital discharge and patients who survived to discharge from the hospital was found for bystander CPR (33.7%, 30/89 and 33.3%, 2/6, P > 0.999; respectively) and resuscitation attempts (56.3%, 27/48, and 40.0%, 2/5, P = 0.649; respectively).

CONCLUSION

In this study, patients with traumatic OHCA presented to the ED with a low rate of EMS utilization and low survival rates. The poor outcomes emphasize the need for increasing bystander first-aid, developing an organized trauma system of care, and developing a standard emergency first-aid program for both healthcare personnel and the community.

Effects of Cardiac Massage and β-Blocker Pretreatment on the Success Rate of Cardiopulmonary Resuscitation Assessed by the Canine Ischemia/Reperfusion-Induced Ventricular Fibrillation Model

BACKGROUND

Effects of rapid electrical defibrillation and β-blockade on coronary ischemia/reperfusion-induced ventricular fibrillation (VF) during cardiopulmonary resuscitation (CPR) remain unknown.

METHODS AND RESULTS

After induction of VF by 30 min of ischemia followed by reperfusion, animals were treated with defibrillation alone (Group A, n=13), 2 min of open-chest cardiac massage followed by defibrillation (Group B, n=11), or the same therapy to Group B with propranolol (1 mg/kg, i.v.) treatment before ischemia/reperfusion (Group C, n=11). If return of spontaneous circulation (ROSC) was not attained, each therapy was repeated ≤3 times (Set-1). When ROSC was not obtained within Set-1, cardiac massage was applied to all animals followed by defibrillation, which was repeated ≤3 times (Set-2). ROSC after Set-1 was 8% in Group A, 82% in Group B and 82% in Group C, whereas that after Set-2 was 62% in Group A, 100% in Group B and 82% in Group C. Each animal with ROSC in Groups A (n=8) and B (n=11) showed sinus rhythm, whereas those in Group C (n=9) had sinus rhythm (n=5), atrial fibrillation (n=1), accelerated idioventricular rhythm (n=2) and atrioventricular block (n=1). Post ROSC heart rate and mean arterial pressure were significantly lower in Group C.

CONCLUSIONS

Cardiac massage increased the likelihood of ROSC vs. rapid defibrillation, but β-blocker pretreatment may worsen hemodynamics and electrical stability after ROSC.

Worldviews on Evidence-Based Cardiopulmonary Resuscitation Using a Novel Method

The evaluation of scientific content by researchers, as well as the knowledge networks and working groups of cardiopulmonary resuscitation, can help to improve and expand new scientific evidence in this field. The aim of this study was to identify the global scientific publications on cardiopulmonary resuscitation research using a novel method. The method used was based on obtaining bibliographic data automatically from scientific publications through the use of the Scopus Database API Interface. A total of 17,917 results were obtained, with a total of 60,226 reports and 53,634 authors. Six categories were detected with 38.56% corresponding to cardiac arrest, 21.8% to cardiopulmonary resuscitation, 17.16% to life-support training and education, 12.45% to ethics and decision-making in cardiac arrest, 4.77% to therapeutic treatment, and 3.72% to life-support techniques. Analyzing and identifying the main scientific contributions to this field of study can make it possible to establish collaboration networks and propose new lines of research, as well as to unify criteria for action. Future research should delve into the analyses of the other elements involved in this area.

Commencing one-handed chest compressions while activating emergency medical system using a handheld mobile device in lone-rescuer basic life support: a randomised cross-over simulation study

INTRODUCTION

In conventional basic life support (c-BLS), a lone rescuer is recommended to start chest compressions (CCs) after activating the emergency medical system. To initiate earlier CCs in lone-rescuer BLS, we designed a modified BLS (m-BLS) sequence in which the lone rescuer commences one-handed CCs while calling for help using a handheld cellular phone with the other free hand. This study aimed to compare the quality of BLS between c-BLS and m-BLS.

METHODS

This was a simulation study performed with a randomised cross-over controlled trial design. A total of 108 university students were finally enrolled. After training for both c-BLS and m-BLS, participants performed a 3-minute c-BLS or m-BLS on a manikin with a SkillReporter at random cross-over order. The paired mean difference with SE between c-BLS and m-BLS was assessed using paired t-test.

RESULTS

The m-BLS had reduced lag time before the initiation of CCs (with a mean estimated paired difference (SE) of -35.0 (90.4) s) (p<0.001). For CC, a significant increase in compression fraction and a higher number of CCs with correct depth were observed in m-BLS (with a mean estimated paired difference (SE) of 16.2% (0.6) and 26.9% (3.3), respectively) (all p<0.001). However, no significant paired difference was observed in the hand position, compression rate and interruption time. For ventilation, the mean tidal volumes did not differ. However, the number of breaths with correct tidal volume was higher in m-BLS than in c-BLS.

CONCLUSION

In simulated lone-rescuer BLS, the m-BLS could deliver significantly earlier CCs than the c-BLS while maintaining high-quality cardiopulmonary resuscitation.

Impact of the Opioid Epidemic

In recent years the prescription opioid overdose epidemic has decreased, but has been more than offset by increases in overdose caused by fentanyl and fentanyl analogues. Opioid overdose patients should receive naloxone if they have significant respiratory depression and/or loss of protective airway reflexes. Patients who receive naloxone should be observed for recurrent opioid effects. Patients with opioid overdose may be admitted to the intensive care unit for naloxone infusions, treatment of noncardiogenic pulmonary edema, autonomic instability, or sequelae of hypoxia-ischemia or cardiac arrest. Primary and secondary prevention are important to reduce the number of people with life-threatening opioid overdose.

Immediate Bystander Cardiopulmonary Resuscitation to Sudden Cardiac Arrest During Sports is Associated with Improved Survival-a Video Analysis

Background

Sudden cardiac arrest (SCA) during sports can be the first symptom of yet undetected cardiovascular conditions. Immediate chest compressions and early defibrillation offer SCA victims the best chance of survival, which requires prompt bystander cardiopulmonary resuscitation (CPR).

Aims

To determine the effect of rapid bystander CPR to SCA during sports by searching for and analyzing videos of these SCA/SCD events from the internet.

Methods

We searched images.google.com, video.google.com, and YouTube.com, and included any camera-witnessed non-traumatic SCA during sports. The rapidity of starting bystander chest compressions and defibrillation was classified as < 3, 3–5, or > 5 min.

Results

We identified and included 29 victims of average age 27.6 ± 8.5 years. Twenty-eight were males, 23 performed at an elite level, and 18 participated in soccer. Bystander CPR < 3 min (7/29) or 3–5 min (1/29) and defibrillation < 3 min was associated with 100% survival. Not performing chest compressions and defibrillation was associated with death (14/29), and > 5 min delay of intervention with worse outcome (death 4/29, severe neurologic dysfunction 1/29).

Conclusions

Analysis of internet videos showed that immediate bystander CPR to non-traumatic SCA during sports was associated with improved survival. This suggests that immediate chest compressions and early defibrillation are crucially important in SCA during sport, as they are in other settings. Optimal use of both will most likely result in survival. Most videos showing recent events did not show an improvement in the proportion of athletes who received early resuscitation, suggesting that the problem of cardiac arrest during sports activity is poorly recognized.

Effectiveness of Mechanical Chest Compression Devices over Manual Cardiopulmonary Resuscitation: A Systematic Review with Meta-analysis and Trial Sequential Analysis

Introduction

Our goal was to systematically review contemporary literature comparing the relative effectiveness of two mechanical compression devices (LUCAS and AutoPulse) to manual compression for achieving return of spontaneous circulation (ROSC) in patients undergoing cardiopulmonary resuscitation (CPR) after an out-of-hospital cardiac arrest (OHCA).

Methods

We searched medical databases systematically for randomized controlled trials (RCT) and observational studies published between January 1, 2000–October 1, 2020 that compared mechanical chest compression (using any device) with manual chest compression following OHCA. We only included studies in the English language that reported ROSC outcomes in adult patients in non-trauma settings to conduct random-effects metanalysis and trial sequence analysis (TSA). Multivariate meta-regression was performed using preselected covariates to account for heterogeneity. We assessed for risk of biases in randomization, allocation sequence concealment, blinding, incomplete outcome data, and selective outcome reporting.

Results

A total of 15 studies (n = 18474), including six RCTs, two cluster RCTs, five retrospective case-control, and two phased prospective cohort studies, were pooled for analysis. The pooled estimates’ summary effect did not indicate a significant difference (Mantel-Haenszel odds ratio = 1.16, 95% confidence interval, 0.97 to 1.39, P = 0.11, I2 = 0.83) between mechanical and manual compressions during CPR for ROSC. The TSA showed firm evidence supporting the lack of improvement in ROSC using mechanical compression devices. The Z-curves successfully crossed the TSA futility boundary for ROSC, indicating sufficient evidence to draw firm conclusions regarding these outcomes. Multivariate meta-regression demonstrated that 100% of the between-study variation could be explained by differences in average age, the proportion of females, cardiac arrests with shockable rhythms, witnessed cardiac arrest, bystander CPR, and the average time for emergency medical services (EMS) arrival in the study samples, with the latter three attaining statistical significance.

Conclusion

Mechanical compression devices for resuscitation in cardiac arrests are not associated with improved rates of ROSC. Their use may be more beneficial in non-ideal situations such as lack of bystander CPR, unwitnessed arrest, and delayed EMS response times. Studies done to date have enough power to render further studies on this comparison futile.

Shoulder strap fixation of LUCAS-2 to facilitate continuous CPR during non-supine (stair) stretcher transport of OHCAs patients

Early recognition and rapid initiation of high-quality cardiopulmonary resuscitation (CPR) are key to maximising chances of achieving successful return of spontaneous circulation in patients with out-of-hospital cardiac arrests (OHCAs), as well as improving patient outcomes both inside and outside hospital. Mechanical chest compression devices such as the LUCAS-2 have been developed to assist rescuers in providing consistent, high-quality compressions, even during transportation. However, providing uninterrupted and effective compressions with LUCAS-2 during transportation down stairwells and in tight spaces in a non-supine position is relatively impossible. In this study, we proposed adaptations to the LUCAS-2 to allow its use during transportation down stairwells and examined its effectiveness in providing high-quality CPR to simulated OHCA patients. 20 volunteer emergency medical technicians were randomised into 10 pairs, each undergoing 2 simulation runs per experimental arm (LUCAS-2 versus control) with a loaded Resusci Anne First Aid full body manikin weighing 60 kg. Quality of CPR compressions performed was measured using the CPRmeter placed on the sternum of the manikin. The respective times taken for each phase of the simulation protocol were recorded. Fisher’s exact tests were used to analyse categorical variables and median test to analyse continuous variables. The LUCAS-2 group required a longer time (~ 35 s) to prepare the patient prior to transport (p < 0.0001) and arrive at the ambulance (p < 0.0001) compared to the control group. The CPR quality in terms of depth and rate for the overall resuscitation period did not differ significantly between the LUCAS-2 group and control group, though there was a reduction in both parameters when evaluating the device’s automated compressions during transport. Nevertheless, the application of the LUCAS-2 device yielded a significantly higher chest compression fraction of 0.76 (p < 0.0001). Our novel adaptations to the LUCAS-2 device allow for uninterrupted compressions in patients being transported down stairwells, thus yielding better chest compression fractions for the overall resuscitation period. Whether potentially improved post-OHCA survival rates may be achieved requires confirmation in a real-world scenario study.

Demonstrating equivalence and non-inferiority of medical education concepts

CONTEXT

In medical education, there are often several didactic methods for teaching and learning a specific medical skill. For educators, there are often pragmatic reasons to decide for one or another of them, such as costs, infrastructural requirements, time expenditure or qualification of the teacher. However, a central aspect to consider is the learning outcome: Does a new method achieve a similar learning success as an established standard method? To answer this question, we need an appropriate method to assess comparability of learning outcomes.

METHODS

In this paper, we present two essential statistical concepts that can address the issue of comparability of learning outcomes: Equivalence and non-inferiority testing. We explain the ideas behind these concepts and illustrate them with an example data set. To clarify several concepts, we use theoretical examples from one selected field: the teaching and assessment of Basic Life Support (BLS).

CONCLUSIONS

Equivalence and non-inferiority tests can be powerful tools for comparing teaching and assessment methods. However, their correct application requires adequate knowledge about their strengths, pitfalls and application fields. The aim of this paper is to deliver this knowledge and to provide clinician researchers with a practical guidance to a successful application of these methods.

Comparison of clinical outcomes between patients with pulseless-ventricular tachycardia and ventricular fibrillation in out-of-hospital cardiac arrest

Aim

While previous studies have shown that the initial documented rhythm is associated with clinical outcomes in out-of-hospital cardiac arrest (OHCA), little is known about the difference in clinical outcomes between pulseless ventricular tachycardia (p-VT) and ventricular fibrillation (VF).

Methods

From a nationwide, prospective population-based database of OHCA from 2011 to 2015, we selected bystander-witnessed adult patients who were not treated with a public automated external defibrillator. The outcomes examined were favorable 30-day neurological survival rates, 30-day survival rates, and prehospital return of spontaneous circulation (ROSC) rates. To determine the association of the initial documented rhythm with outcome, we used a logistic regression model while adjusting for patient factors and prehospital care-related factors.

Results

A total of 19,594 bystander-witnessed OHCA patients who had a shockable rhythm were included: 454 (2.3%) were p-VT and 19,140 (97.7%) were VF. Compared to VF patients, p-VT patients were older, less likely to have a cardiogenic cause, and had shorter resuscitation-related time intervals (collapse to bystander cardiopulmonary resuscitation, collapse to emergency medical services contact, collapse to first ROSC, and first defibrillation to first ROSC). After adjustment for covariates, p-VT was associated with high favorable 30-day neurological survival rates (adjusted odds ratio [OR], 1.85; 95% confidence interval [CI], 1.30-2.64, p = 0.001), 30-day survival rates (adjusted OR, 1.41; 95% CI, 1.03-1.95, p = 0.037), and prehospital ROSC rates (adjusted OR, 1.90; 95% CI, 1.42-2.55, p < 0.001).

Conclusion

In this study, patients with p-VT as the initial documented rhythm had significantly better outcomes than those with VF.

Caregiver Characteristics Associated With Quality of Cardiac Compressions on an Adult Mannequin With Real-Time Visual Feedback: A Simulation-Based Multicenter Study

INTRODUCTION

Chest compression (CC) quality directly impacts cardiac arrest outcomes. Provider body type can influence the quality of cardiopulmonary resuscitation (CPR); however, the magnitude of this impact while using visual feedback is not well described. The aim of the study was to determine the association between provider anthropometric variables on fatigue and CC adherence to 2015 American Heart Association CPR while receiving visual feedback.

METHODS

This was a planned secondary analysis of healthcare professionals from multiple hospitals performing continuous CC for 2 minutes on an adult CPR mannequin with dynamic visual feedback. Main outcome measures include compression data (depth, rate, and lean) evaluated in 30-second epochs to explore performance fatigue. Multivariable models examined the relationship of provider anthropometrics to CC quality. Binomial mixed effects models were used to characterize fatigue by examining performance for 4 epochs.

RESULTS

Three hundred seventy-seven 2-minute CC episodes were analyzed. Extreme (low and high) BMI and weight are associated with poorer CC. Larger size (height, weight, and BMI) is associated with better depth but worse lean compliance. Performance fatigued for all providers for 2 minutes, but shorter, lighter weight, female participants had the greatest decline. On multivariable analysis, rate compliance did not deteriorate regardless of provider anthropometrics.

CONCLUSIONS

Anthropometrics impact provider CC quality. Despite visual feedback, variable effects are seen on compression depth, rate, recoil, and fatigue depending on the provider sex, weight, and BMI. The 2-minute interval for changing chest compressors should be reconsidered based on individual provider characteristics and risk of fatigue's impact on high-quality CPR.

Emergency Department Vacuum Extraction of an Obstructing Tracheal Foreign Body Using a Meconium Aspirator and Modified Endotracheal Tube

BACKGROUND

A meconium aspirator is a simple plastic adapter that allows for rapid suctioning of the trachea when attached to an endotracheal tube and a source of continuous negative pressure, as was historically done for suspected neonatal meconium aspiration. Adaptation of this technique for the emergent vacuum extraction of an obstructing tracheal foreign body in an adult has not been previously described.

CASE REPORT

We report the case of a 33-year-old woman with cardiorespiratory arrest after choking on food. Complete tracheal obstruction precluding oxygenation and ventilation due to aspirated chicken was diagnosed by emergency physicians and managed immediately with vacuum extraction using the technique described in this report. No additional airway interventions were necessary and the patient made a full neurologic recovery. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Vacuum extraction using a meconium aspirator and modified endotracheal tube is a novel and potentially life-saving approach to the emergency management of airway obstruction after choking, especially if the foreign material is below the vocal cords and not amenable to manual extraction with a Magill forceps.

Variation in pre-hospital outcomes after out-of-hospital cardiac arrest in Michigan

AIM

Care by emergency medical service (EMS) agencies is critical for optimizing prehospital outcomes following out-of-hospital cardiac arrest (OHCA). We explored whether substantial differences exist in prehospital outcomes across EMS agencies in Michigan-specifically focusing on rates of sustained return of spontaneous circulation (ROSC) upon emergency department (ED) arrival.

METHODS

Using data from Michigan Cardiac Arrest Registry to Enhance Survival (MI-CARES) for years 2014-2017, we calculated rates of sustained ROSC upon ED arrival across EMS agencies in Michigan. We used hierarchical logistic regression models that accounted for patient, arrest-, community-, and response-level characteristics to determine adjusted rates of sustained ROSC among EMS agencies.

RESULTS

A total of 103 EMS agencies and 20,897 OHCA cases were included. Average age of the cohort was 62.5 years (SD = 19.6), 39.7% were female, and 17.9% had an initial shockable rhythm due to ventricular fibrillation or pulseless ventricular tachycardia. The adjusted rate of sustained ROSC upon ED arrival across all EMS agencies was 23.8% with notable variation across EMS agencies (interquartile range [IQR], 20.5-29.2%). The top five EMS agencies had mean adjusted rates of sustained ROSC upon ED arrival of 42.7% (95% CI: 34.6-51.1%) while the bottom five had mean adjusted rates of 9.8% (95% CI: 7.6-12.7%).

CONCLUSIONS

Substantial variation in sustained ROSC upon ED arrival exists across EMS agencies in Michigan after adjusting for patient-, arrest, community-, and response-level features. Such differences suggest opportunities to identify and improve best practices in EMS agencies to advance OHCA care.

Assessment of changes in cardiopulmonary resuscitation practices and outcomes on 1005 victims of out-of-hospital cardiac arrest during the COVID-19 outbreak: registry-based study

Background

The COVID-19 outbreak requires a permanent adaptation of practices. Cardiopulmonary resuscitation (CPR) is also involved and we evaluated these changes in the management of out-of-hospital cardiac arrest (OHCA).

Methods

OHCA of medical origins identified from the French National Cardiac Arrest Registry between March 1st and April 31st 2020 (COVID-19 period), were analysed. Different resuscitation characteristics were compared with the same period from the previous year (non-COVID-19 period).

Results

Overall, 1005 OHCA during the COVID-19 period and 1620 during the non-COVID-19 period were compared. During the COVID-19 period, bystanders and first aid providers initiated CPR less frequently (49.8% versus 54.9%; difference, − 5.1 percentage points [95% CI, − 9.1 to − 1.2]; and 84.3% vs. 88.7%; difference, − 4.4 percentage points [95% CI, − 7.1 to − 1.6]; respectively) as did mobile medical teams (67.3% vs. 75.0%; difference, − 7.7 percentage points [95% CI, − 11.3 to − 4.1]). First aid providers used defibrillators less often (66.0% vs. 74.1%; difference, − 8.2 percentage points [95% CI, − 11.8 to − 4.6]). Return of spontaneous circulation (ROSC) and D30 survival were lower during the COVID-19 period (19.5% vs. 25.3%; difference, − 5.8 percentage points [95% CI, − 9.0 to − 2.5]; and 2.8% vs. 6.4%; difference, − 3.6 percentage points [95% CI, − 5.2 to − 1.9]; respectively).

Conclusions

During the COVID-19 period, we observed a decrease in CPR initiation regardless of whether patients were suspected of SARS-CoV-2 infection or not. In the current atmosphere, it is important to communicate good resuscitation practices to avoid drastic and lasting reductions in survival rates after an OHCA.

Transesophageal echocardiography in patients with cardiac arrest: from high-quality chest compression to effective resuscitation

BACKGROUND

Survival after cardiac arrest depends on prompt and effective cardiopulmonary resuscitation (CPR). Transesophageal echocardiography (TEE) can be applied to evaluate the effectiveness of chest compression-decompression maneuvers in the setting of cardiac arrest undergoing CPR. The efficacy of chest compression can be continuously assessed by TEE that can improve the effectiveness of CPR guiding the rescuer to optimize or correct chest compression and decompression by directly examining the movements of the cardiac walls and valve leaflets.

PURPOSE

The review describes how to perform TEE in the emergency setting of cardiopulmonary arrest, its advantages, and limitations, and ultimately propose an echo-guided approach to CPR.

Enhancing Prehospital Outcomes for Cardiac Arrest (EPOC) study: sequential mixed-methods study protocol in Michigan, USA

INTRODUCTION

Out-of-hospital cardiac arrest (OHCA) is a common, life-threatening event encountered routinely by first responders, including police, fire and emergency medical services (EMS). Current literature suggests that there is significant regional variation in outcomes, some of which may be related to modifiable factors. Yet, there is a persistent knowledge gap regarding strategies to guide quality improvement efforts in OHCA care and, by extension, survival. The Enhancing Prehospital Outcomes for Cardiac Arrest (EPOC) study aims to fill these gaps and to improve outcomes.

METHODS AND ANALYSIS

This mixed-methods study includes three aims. In aim I, we will define variation in OHCA survival to the emergency department (ED) among EMS agencies that participate in the Michigan Cardiac Arrest Registry to Enhance Survival (CARES) in order to sample EMS agencies with high-survival and low-survival outcomes. In aim II, we will conduct site visits to emergency medical systems-including 911/dispatch, police, non-transport fire, and EMS agencies-in approximately eight high-survival and low-survival communities identified in aim I. At each site, key informant interviews and a multidisciplinary focus group will identify themes associated with high OHCA survival. Transcripts will be coded using a structured codebook and analysed through thematic analysis. Results from aims I and II will inform the development of a survey instrument in aim III that will be administered to all EMS agencies in Michigan. This survey will test the generalisability of factors associated with increased OHCA survival in the qualitative work to ultimately build an EPOC Toolkit which will be distributed to a broad range of stakeholders as a practical 'how-to' guide to improve outcomes.

ETHICS AND DISSEMINATION

The EPOC study was deemed exempt by the University of Michigan Institutional Review Board. Findings will be compiled in an 'EPOC Toolkit' and disseminated in the USA through partnerships including, but not limited to, policymakers, EMS leadership and health departments.

Impact de la Covid-19 sur les arrêts cardiaques extrahospitaliers en phase de suractivité épidémique : données du registre RéAC

Introduction : Notre objectif était d’analyser la survie des patients victimes d’un arrêt cardiaque extrahospitalier (ACEH) durant la pandémie Covid-19 et de comparer les données en fonction du centre de traitement de l’appel choisi, le 15 ou le 18.

Méthode : Nous avons extrait les données exhaustives du Registre des arrêts cardiaques (RéAC), entre le 1er mars et le 30 avril 2020. Nous avons effectué trois comparaisons de la survie à 30 jours (J30) de cohortes de patients : 1) Covid vs non-Covid ; 2) appels arrivés au service d’aide médicale urgente (Samu) (15) vs aux sapeurs-pompiers (SP) (18) et 3) appels arrivés au 15 vs 18 pour les patients Covid.

Résultats : Sur un total de 870 ACEH, 184 étaient atteints de la Covid. Nous avons observé 487 (56 %) appels arrivés au 15 et 383 (44 %) au 18. La survie à J30 était de 3 %. Les ACEH Covid avaient une survie à J30 plus faible que les non-Covid (0 vs 4 %, p < 0,001). Le délai d’arrivée de SP était plus long lors d’un appel au 15. En revanche, aucune différence de survie n’est observée entre les appels arrivés au 15 ou au 18.

Conclusion : La survie consécutive à un ACEH durant la pandémie est extrêmement faible. Cependant, quel que soit le numéro composé (15 ou 18), la survie n’est pas différente, même si le délai d’arrivée des prompts secours est plus court lors d’un appel au 18.

Survival after out-of-hospital cardiac arrest, Viet Nam: multicentre prospective cohort study

Objective

To investigate factors associated with survival after out-of-hospital cardiac arrest in Viet Nam.

Methods

We did a multicentre prospective observational study of people (> 18 years) presenting with out-of-hospital cardiac arrest (not caused by trauma) to three tertiary hospitals in Viet Nam from February 2014 to December 2018. We collected data on characteristics, management and outcomes of patients with out-of-hospital cardiac arrest and compared these data by type of transportation to hospital and survival to hospital admission. We assessed factors associated with survival to admission to and discharge from hospital using logistic regression analysis.

Findings

Of 590 eligible people with out-of-hospital cardiac arrest, 440 (74.6%) were male and the mean age was 56.1 years (standard deviation: 17.2). Only 24.2% (143/590) of these people survived to hospital admission and 14.1% (83/590) survived to hospital discharge. Most cardiac arrests (67.8%; 400/590) occurred at home, 79.4% (444/559) were witnessed by bystanders and 22.3% (124/555) were given cardiopulmonary resuscitation by a bystander. Only 8.6% (51/590) of the people were taken to hospital by the emergency medical services and 32.2% (49/152) received pre-hospital defibrillation. Pre-hospital defibrillation (odds ratio, OR: 3.90; 95% confidence interval, CI: 1.54-9.90) and return of spontaneous circulation in the emergency department (OR: 2.89; 95% CI: 1.03-8.12) were associated with survival to hospital admission. Hypothermia therapy during post-resuscitation care was associated with survival to discharge (OR: 5.44; 95% CI: 2.33-12.74).

Conclusion

Improvements are needed in the emergency medical services in Viet Nam such as increasing bystander cardiopulmonary resuscitation and public access defibrillation, and improving ambulance and post-resuscitation care.

Retention of Basic-Life-Support Knowledge and Skills in Second-Year Medical Students

Purpose

Basic life support (BLS) training is crucial in improvement of cardiopulmonary resuscitation (CPR) outcomes. Many studies have demonstrated improvement of skills after BLS training but the skills significantly decrease over time. Our study aimed to evaluate the retention of knowledge and skills after training following 2010 BLS guidelines in second year medical students at Faculty of Medicine, Thammasat University.

Materials and Methods

One hundred and forty-nine second-year medical students were enrolled in the prospective cohort study. Participants were tested for knowledge and skills of BLS prior to training (pre-test), immediately after training (post-test) and six months after training (retention test).

Results

The mean scores of pre-test, immediate post-test and retention-test were 8.52 (SD 1.88), 12.12 (SD 1.52) and 10.83 (SD 1.95), respectively. Improvement in knowledge score post-test and retention test were 3.60 (95% CI 3.22,3.99 P<0.001) and 2.31 (95% CI 1.92,2.70 P<0.001) respectively, compared with pre-test score. In post-test, detection skill, activation skill and compression skill were improved 1.67 (95% CI 1.28,2.19 P<0.001), 5.15 (95% CI 3.41,7.77 P<0.001) and 3.88 times (95% CI 2.24,6.71 P<0.001) compared with pre-test evaluation. Comparison between retention test and pre-test was improved detection skill 1.72 (95% CI 1.31,2.26 P<0.001), activation skill 4.4 (95% CI 2.93,6.75 P<0.001) and compression skill 2.56 (95% CI 1.44,4.57 P=0.001). Knowledge decreased 1.29 times in retention test compared with post-test (95% CI −1.67,0.92 P<0.001). In retention test, detection skill increased 1.03 times (95% CI 0.81,1.29 P = 0.810), activation skill decreased 0.86 times (95% CI 0.98,1.10 P =0.24) and compression skill decreased 0.66 times (95% CI 0.45,0.98 P=0.04) compared with post-test.

Conclusion

Knowledge and skills of BLS significantly improved after training in second year medical students. However, the knowledge decreased at 6 months after training although the BLS skills still remained.

Comparison of cardiopulmonary resuscitation that applied synchronous 30 compressions–2 ventilations with that applied asynchronous 110/min compression–10/min ventilation: A mannequin study

Background:

CPR model of a resuscitation to be ventilated with a bag valve mask constitutes a discussion when evaluated with the current guidance.

Objective:

This study aims to compare the synchronous (30–2) ventilation–compression method with asynchronous 110/min compression–10/min ventilation in cardiac arrests where an advanced airway management is not applied and where ventilation is provided by a bag valve mask on a mannequin.

Methods:

This simulation trial was performed using two clinical cardiopulmonary resuscitation scenarios: an asynchronous scenario with 10 ventilations per minute asynchronously when compression is applied as 110 compression per minute and a synchronous scenario in which 30 compressions:2 ventilations were performed synchronously. A total of 100 people in 50 groups applied these two scenarios on mannequin. Ventilation and compression data of both scenarios were recorded.

Results:

Evaluating the compression criteria in both the scenarios performed by 50 groups in total, in terms of all criteria except compression fraction, there was no statistically difference between the two scenarios (p > 0.05). Compression fraction values in the asynchronous scenario were found to be statistically significantly higher than the synchronous scenario (96.02 ± 2.35, 81.34 ± 4.42, p < 0.001). Evaluating the ventilation criteria in both the scenarios performed by 50 groups in total; there was a statistically significant difference in all criteria. Mean ventilation rate of the asynchronous scenario was statistically higher than the synchronous scenario (7.22 ± 2.42, 5.08 ± 0.75, p < 0.001). Mean ventilation volume of the synchronous scenario was statistically higher than the asynchronous scenario (353.24 ± 45.46, 527.40 ± 96.60, p < 0.001). Ventilation ratio in sufficient volume of the synchronous scenario was statistically higher than the asynchronous scenario (36.84 ± 14.47, 75.00 ± 21.24, p < 0.001). Ventilation ratio below the minimum volume limit of the asynchronous scenario was statistically higher than the synchronous scenario (62.48 ± 14.72, 17.86 ± 19.50, p < 0.001).

Conclusion:

In our study, we concluded that the cardiopulmonary resuscitation applied by the synchronous method reached better ventilation volumes. Evaluating together with any interruption in compression, comprehensive studies are needed to reveal which patients would benefit from this result.

Removal of foreign body airway obstruction: A systematic review of interventions

OBJECTIVE

To summarise in a systematic review the effectiveness of interventions to treat foreign body airway obstructions (FBAO).

METHODS

We searched MEDLINE, EMBASE, and the Cochrane library from inception on 30th September 2019 for studies that described the effectiveness of interventions to treat FBAO in adults and children. We included randomised controlled trials, observational studies and case series (≥5 cases) that described evidence of benefit. For evidence of harm/complications, we included case reports. Two reviewers independently assessed study eligibility, extracted study data, and assessed risk of bias. Data are summarised in a narrative synthesis. The GRADE system is used to assess evidence certainty.

RESULTS

We included 69 publications, comprising three cross-sectional studies (557 patients); eight case series (755 patients), and 59 were case reports (64 patients). One paper was included as a case series and cross-sectional study. For all interventions and associated outcomes, evidence certainty was very low. Early removal of FBAO by bystanders was associated with improved neurological survival (odds ratio 6.0, 95% confidence interval 1.5 to 23.4). Identified evidence showed that key interventions (back blows, abdominal thrusts, chest thrusts/compressions, Magill forceps, manual removal of obstructions from the mouth, suction-based airway clearance devices) are effective in relieving FBAO. We identified reports of harm in relation to back blows, abdominal thrusts, chest thrusts/compressions, and blind finger sweeps.

CONCLUSIONS

Key interventions successfully relieve FBAO, but may be associated with important harms. Guidelines for FBAO management should balance the benefits and harms of interventions.

Association of Intra-arrest Transport vs Continued On-Scene Resuscitation With Survival to Hospital Discharge Among Patients With Out-of-Hospital Cardiac Arrest

Importance

There is wide variability among emergency medical systems (EMS) with respect to transport to hospital during out-of-hospital cardiac arrest (OHCA) resuscitative efforts. The benefit of intra-arrest transport during resuscitation compared with continued on-scene resuscitation is unclear.

Objective

To determine whether intra-arrest transport compared with continued on-scene resuscitation is associated with survival to hospital discharge among patients experiencing OHCA.

Design, Setting, and Participants

Cohort study of prospectively collected consecutive nontraumatic adult EMS-treated OHCA data from the Resuscitation Outcomes Consortium (ROC) Cardiac Epidemiologic Registry (enrollment, April 2011-June 2015 from 10 North American sites; follow-up until the date of hospital discharge or death [regardless of when either event occurred]). Patients treated with intra-arrest transport (exposed) were matched with patients in refractory arrest (at risk of intra-arrest transport) at that same time (unexposed), using a time-dependent propensity score. Subgroups categorized by initial cardiac rhythm and EMS-witnessed cardiac arrests were analyzed.

Exposures

Intra-arrest transport (transport initiated prior to return of spontaneous circulation), compared with continued on-scene resuscitation.

Main Outcomes and Measures

The primary outcome was survival to hospital discharge, and the secondary outcome was survival with favorable neurological outcome (modified Rankin scale <3) at hospital discharge.

Results

The full cohort included 43 969 patients with a median age of 67 years (interquartile range, 55-80), 37% were women, 86% of cardiac arrests occurred in a private location, 49% were bystander- or EMS-witnessed, 22% had initial shockable rhythms, 97% were treated by out-of-hospital advanced life support, and 26% underwent intra-arrest transport. Survival to hospital discharge was 3.8% for patients who underwent intra-arrest transport and 12.6% for those who received on-scene resuscitation. In the propensity-matched cohort, which included 27 705 patients, survival to hospital discharge occurred in 4.0% of patients who underwent intra-arrest transport vs 8.5% who received on-scene resuscitation (risk difference, 4.6% [95% CI, 4.0%- 5.1%]). Favorable neurological outcome occurred in 2.9% of patients who underwent intra-arrest transport vs 7.1% who received on-scene resuscitation (risk difference, 4.2% [95% CI, 3.5%-4.9%]). Subgroups of initial shockable and nonshockable rhythms as well as EMS-witnessed and unwitnessed cardiac arrests all had a significant association between intra-arrest transport and lower probability of survival to hospital discharge.

Conclusions and Relevance

Among patients experiencing out-of-hospital cardiac arrest, intra-arrest transport to hospital compared with continued on-scene resuscitation was associated with lower probability of survival to hospital discharge. Study findings are limited by potential confounding due to observational design.

Validating peer-led assessments of CPR performance

BACKGROUND

A patient's survival from cardiac arrest is improved if they receive good quality chest compressions as soon as possible. During cardiopulmonary resuscitation (CPR) training subjective assessments of chest compression quality is still common. Recently manikins allowing objective assessment have demonstrated a degree of variance with Instructor assessment. The aim of this study was to compare peer-led subjective assessment of chest compressions in three groups of participants with objective data from a manikin.

METHOD

This was a quantitative multi-center study using data from simulated CPR scenarios. Seventy-eight Instructors were recruited, from different backgrounds; lay persons, hospital staff and emergency services personnel. Each group consisted of 13 pairs and all performed 2 ​min of chest compressions contemporaneously by peers and manikin (Brayden PRO®). The primary hypothesis was subjective and objective assessment methods would produce different test outcomes.

RESULTS

13,227 chest compressions were assessed. The overall median score given by the manikin was 88.5% (interquartile range 71.75-95), versus 92% (interquartile range 86.75-98) by observers. There was poor correlation in scores between assessment methods (Kappa -0.051 - +0.07). Individual assessment of components within the manikin scores demonstrated good internal consistency (alpha ​= ​0.789) compared to observer scores (alpha ​= ​0.011).

CONCLUSION

Observers from all backgrounds were consistently more generous in their assessment when compared to the manikin. Chest compressions quality influences outcome following cardiac arrest, the findings of this study support increased use of objective assessment at the earliest opportunity, irrespective of background.

Characterization of troponin I levels post synchronized direct current cardioversion of atrial arrhythmias in patients with and without cardiomyopathy

BACKGROUND

Cardiac-specific markers of myocardial injury, such as troponin I (TnI), are often elevated following procedures that stimulate the myocardium. This study aimed to determine the effect of synchronized direct current (DC) cardioversion of atrial arrhythmias on myocardial injury 6-h post-procedure, as measured by cardiac TnI in patients with and without cardiomyopathy.

METHODS

Seventy-three individuals (59 M:14 F) participated in this study. Inclusion criteria were subjects 18 and older undergoing DC cardioversion for an atrial arrhythmia, including elective and non-elective admissions. Exclusion criteria included MI or CABG within the past month, cardioversion for a ventricular arrhythmia, or recent shock by implantable internal cardioverter defibrillator. Patients underwent standard DC cardioversion procedure with blood work (TnI and CRP) prior to and 6-h post-cardioversion. Primary outcome was change in TnI. Secondary outcomes included changes in CRP, correlation of TnI with cumulative energy and LVM, and a sub-group analysis in patients with cardiomyopathy.

RESULTS

There was no significant change in TnI following cardioversion (20.4 ± 7.9 vs. 17.5 ± 6.5 ng/L, F(1,72) = 2.651, p = 0.108). When stratified by cardiomyopathy status, there was a statistically significant reduction in TnI following cardioversion in the non-cardiomyopathy group (6.7 ± 3.7 ng/L vs. 6.2 ± 3.2 ng/L, F(1,58) = 6.481, p = 0.014) and a clinically significant reduction in the cardiomyopathy group (74.4 ± 136.7 ng/L vs. 54.6 ± 104.3 ng/L, F(1,13) = 3.676, p = 0.07). There was no significant relationship between change in TnI and cumulative energy or LVM (r = 0.137, p = 0.306 and r = 0.125, p = 0.412 respectively).

CONCLUSIONS

Synchronized DC cardioversion of an atrial arrhythmia did not cause myocardial injury 6-h post-cardioversion. Sub-group analysis suggests that cardioversion of patients with cardiomyopathy may result in normalization of TnI levels.

Cerebral oxygenation monitoring during resuscitation by emergency medical technicians: a prospective multicenter observational study

Aim

To assess the feasibility and predictive ability of regional cerebral oxygen saturation monitoring during cardiopulmonary resuscitation by emergency medical technicians.

Methods

This prospective observational study included 33 cardiac arrest patients who received cardiopulmonary resuscitation in a prehospital setting. Patients were connected to a near‐infrared spectrometer through two disposable probes immediately after entering the ambulance. The monitor, which showed regional cerebral oxygen saturation readings, was obscured by covering it with a sheet of paper. Regional cerebral oxygen saturation was measured continuously until hospital arrival. Outcome variables included the prehospital return of spontaneous circulation, survival to hospital admission, and survival at 90 days.

Results

For patients who survived >90 days after hospital admission (n = 2), the mean regional cerebral oxygen saturation values upon ambulance and hospital arrival were 24% and 60%, respectively; for patients who did not survive (n = 31), the mean regional cerebral oxygen saturation values were 15% and 17%, respectively. Regional cerebral oxygen saturation values increased to a greater extent between ambulance arrival and hospital arrival in patients who survived >90 days (median, 36%; interquartile range, 32–40%) than in those who did not survive (0; 0–6%; P = 0.07). Additionally, regional cerebral oxygen saturation values were not related to the prehospital return of spontaneous circulation or survival to hospital admission.

Conclusion

Regional cerebral oxygen saturation could be monitored during resuscitation by emergency medical technicians, and it can be used during physiological monitor‐guided cardiopulmonary resuscitation.

Cardiac Emergencies in Patients with Left Ventricular Assist Devices

Continuous-flow left ventricular assist devices are frequently used for management of patients with advanced heart failure with reduced ejection fraction. Although technologic advancements have contributed to improved outcomes, several complications arise over time. These complications result from several factors, including medication effects, physiologic responses to chronic exposure to circulatory support that is minimally/entirely nonpulsatile, and dysfunction of the device itself. Clinical presentation can range from chronic and indolent to acute, life-threatening emergencies. Several areas of uncertainty exist regarding best practices for managing complications; however, growing awareness has led to development of new guidelines to reduce risk and improve outcomes.

Simplified instructional phrasing in dispatcher-assisted cardiopulmonary resuscitation - when 'less is more'

INTRODUCTION

In our national emergency dispatch centre, the standard protocol for dispatcher-assisted cardiopulmonary resuscitation (DACPR) in out-of-hospital cardiac arrests (OHCAs) involves the instruction "push 100 times a minute 5 cm deep". As part of quality improvement, the instruction was simplified to "push hard and fast".

METHODS

We analysed all dispatcher-diagnosed OHCAs over four months in 2018: January to February ("push 100 times a minute 5 cm deep") and August to September ("push hard and fast"). We also performed secondary per-protocol analysis based on the protocol used: (a) standard (n = 48); (b) simplified (n = 227); and (c) own words (n = 231).

RESULTS

506 cases were included, 282 in the 'before' group and 224 in the 'after' group. Adherence to the protocol was 15.2% in the 'before' phase and 72.8% in the 'after' phase (p < 0.001). The mean time between instruction and first compression for the 'before' and 'after' groups was 34.36 seconds and 26.83 seconds, respectively (p < 0.001). Time to first compression was 238.62 seconds and 218.83 seconds in the 'before' and 'after' groups, respectively (p = 0.016). In the per-protocol analysis, the interval between instruction and compression was 37.19 seconds, 28.31 seconds and 32.40 seconds in the standard protocol, simplified protocol and 'own words' groups, respectively (p = 0.005). The need for paraphrasing was 60.4% in the standard protocol group and 81.5% in the simplified group (p < 0.001).

CONCLUSION

Simplified instructions were associated with a shorter interval between instruction and first compression. Efforts should be directed at simplifying DACPR instructions.

Medical Student Skill Retention After Cardiopulmonary Resuscitation Training: A Cross-Sectional Simulation Study

INTRODUCTION

The retention of cardiopulmonary resuscitation skills and the ideal frequency of retraining remain unanswered. This study investigated the retention of cardiopulmonary resuscitation skills by medical students for up to 42 months after training.

METHODS

In a cross-sectional study, 205 medical students received 10 hours of training in basic life support in 3 practical classes, during their first semester at school. Then, they were divided into 4 groups, according to the time elapsed since the training: 73 after 1 month, 55 after 18 months, 41 after 30 months, and 36 after 42 months. Nineteen cardiopulmonary resuscitation skills and 8 potential technical errors were evaluated by mannequin-based simulation and reviewed using filming.

RESULTS

The mean retention of the skills was 90% after 1 month, 74% after 18 months, 62% after 30 months, and 61% after 42 months (P < 0.001). The depth of chest compressions had the greatest retention over time (87.8%), with no significant differences among groups. Compressions performed greater than 120 per minute were less likely to be done with adequate depth. Ventilation showed a progressive decrease in retention from 93% (n = 68) after 1 month to 19% (n = 7) after 42 months (P < 0.001). All 205 students were able to turn the automated external defibrillator on and deliver the shock.

CONCLUSIONS

The depth of chest compressions and the use of an automated external defibrillator were the skills with the highest retention over time. Based on a skills retention prediction curve, we suggest that 18 to 24 months as the minimum retraining interval to maintain at least 70% of skills.

Comparing Surf Lifeguards and Nurse Anesthetists' Use of the i-gel Supraglottic Airway Device - An Observational Simulation Study

Purpose

Using a supraglottic airway (SGA) may provide more effective ventilations compared with a mouth-to-pocket-mask for drowning victims. SGAs are widely used by nurse anesthetists but it is unknown whether surf lifeguards can use SGAs effectively. We aimed to compare the use of SGA by surf lifeguards and experienced nurse anesthetists.

Materials and Methods

Surf lifeguards inserted a SGA (i-gel O₂, size 4) in a resuscitation manikin during cardiopulmonary resuscitation (CPR) and nurse anesthetists inserted a SGA in a resuscitation manikin placed on a bed, and performed ventilations. Outcome measures: time to first ventilation, tidal volume, proportion of ventilations with visible manikin chest rise, and ventilations within the recommended tidal volume (0.5–0.6 L).

Results

Overall, 30 surf lifeguards and 30 nurse anesthetists participated. Median (Q1–Q3) time to first ventilation was 20 s (15–22) for surf lifeguards and 17 s (15–21) for nurse anesthetists (p=0.31). Mean (SD) tidal volume was 0.55 L (0.21) for surf lifeguards and 0.31 L (0.10) for nurse anesthetists (p<0.0001). Surf lifeguards and nurse anesthetists delivered 100% and 95% ventilations with visible manikin chest rise (p=0.004) and 19% and 5% ventilations within the recommended tidal volume, respectively (p<0.0001).

Conclusion

In a simulated setting, there was no significant difference between surf lifeguards and experienced nurse anesthetists in time to first ventilation when using a SGA. Surf lifeguards delivered a higher tidal volume, and a higher proportion of ventilations within guideline recommendations, but generally ventilations caused visible manikin chest rise for both groups.

Concordance between the 2010 and 2015 Resuscitation Guidelines of International Liaison Committee of Resuscitation Councils (ILCOR) members and the ILCOR Consensus of Science and Treatment Recommendations (CoSTRs)

BACKGROUND

Cardiac arrests are associated with poor outcomes. The International Liaison Committee on Resuscitation (ILCOR) evaluates resuscitation science and produced, until 2015, five-yearly consensus on science and treatment recommendations (CoSTRs), informing global resuscitation guidelines. We aimed to identify similarities/differences in resuscitation guidelines from ILCOR members, noting concurrence over time, and CoSTRs influence on these guidelines.

METHODS

We considered the component elements of paediatric and adult, basic and advanced resuscitation guidelines, published in 2010 and 2015, along with matching ILCOR CoSTRs to examine their influence. We contacted the responsible councils when guidelines were unavailable online.

RESULTS

Complete resuscitation guidelines were found for six of the seven ILCOR council members. The Resuscitation Council of Asia only had adult basic life support (BLS) guidelines in English. Three members used the AHA guidelines. Therefore, five rather than seven sets of resuscitation guidelines were compared to the CoSTRs. Concurrence between CoSTRs recommendations and ILCOR council member's resuscitation guidelines has improved over time. Minor variations were identified in both basic and advanced life support, with most variance in paediatric guidelines, but these narrowed over time.

CONCLUSION

The improved concurrence across the resuscitation guidelines with the CoSTRs suggests that ILCOR members accept and hence incorporate CoSTRs recommendations to inform their own resuscitation guidelines. This is one step towards the development of international universal guidelines for adult and paediatric resuscitation.

Differences in the performance of resuscitation according to the resuscitation guideline terminology during infant cardiopulmonary resuscitation: "Approximately 4 cm" versus "at least one-third the anterior-posterior diameter of the chest"

Aim

This study was conducted to investigate the effect of resuscitation guideline terminology on the performance of infant cardiopulmonary resuscitation (CPR).

Methods

A total of 40 intern or resident physicians conducted 2-min CPR with the two-finger technique (TFT) and two-thumb technique (TT) on a simulated infant cardiac arrest model with a 1-day interval. They were randomly assigned to Group A or B. The participants of Group A conducted CPR with the chest compression depth (CCD) target of “approximately 4 cm” and those of Group B conducted CPR with the CCD target of “at least one-third the anterior-posterior diameter of the chest”. Single rescuer CPR was performed with a 15:2 compression to ventilation ratio on the floor.

Results

In both chest compression techniques, the average CCD of Group B was significantly deeper than that of Group A (TFT: 41.0 [range, 39.3–42.0] mm vs. 36.5 [34.0–37.9] mm, P = 0.002; TT: 42.0 [42.0–43.0] mm vs. 37.0 [35.3–38.0] mm, P < 0.001). Adequacy of CCD also showed similar results (Group B vs. A; TFT: 99% [82–100%] vs. 29% [12–58%], P = 0.001; TT: 100% [100–100%] vs. 28% [8–53%], P < 0.001).

Conclusions

Using the CCD target of “at least one-third the anterior-posterior diameter of the chest” resulted in deep and adequate chest compressions during simulated infant CPR in contrast to the CCD target of “approximately 4 cm”. Therefore, changes in the terminology used in the guidelines should be considered to improve the quality of CPR.

Trial registration

Clinical Research Information Service; cris.nih.go.kr/cris/en (Registration number: KCT0003486).

A systematic review on the effectiveness of anti-choking suction devices and identification of research gaps

AIM

Despite an obstructed airway (choking) being a relatively preventable injury, it has a considerable mortality burden globally, with increasing incidence. Given new technologies in choking management, this systematic review aimed to assess current literature on the effectiveness of anti-choking suction devices at relieving obstructions.

METHODS

Ovid MEDLINE, Embase, PubMed, The Cochrane Library, SCOPUS, Web of Science, CINAHL Plus and the English websites of the devices were searched on September 23, 2019. Studies were included if they reported the anti-choking devices' dislodgment success rate (primary outcome) or associated adverse events (secondary outcome). Articles, conference abstracts or technical reports were included if peer reviewed. Certainty of evidence was assessed in accordance with GRADE.

RESULTS

Five studies satisfied the inclusion criteria for this review. Two studies (40%) reported findings of a single centre mannequin trial, one (20%) of a single centre cadaveric trial, and two (40%) were case series. Cohen's Kappa for the first and second round of screening was 0.904 and 0.674 respectively. Although several devices have been manufactured worldwide, the LifeVac© has been most extensively studied, with a combined dislodgement success rate of 94.3% on first attempt. However, certainty of evidence for the primary outcome was evaluated as very low.

CONCLUSIONS

There are many weaknesses in the available data and few unbiased trials that test the effectiveness of anti-choking suction devices resulting in insufficient evidence to support or discourage their use. Practitioners should continue to adhere to guidelines authored by local resuscitation authorities which align with ILCOR recommendations.

Comparing student nurse knowledge and performance of basic life support algorithm actions: An observational post-retention test design study

This study aims to identify which basic life support skills of student nurses deteriorate in a period of four months. Secondly, it investigates the link between a specific cognitive skill and its corresponding motor skill in BLS. The population for this study consisted of 169 general nursing students within the first year cohort of a three-year undergraduate nursing education program. Following a BLS course, a multiple-choice questionnaire and a BLS performance test on a manikin was administered two weeks (post) and four months (retention) after the course. Seven BLS subcomponents were compared. In both the post and retention test, knowledge was better than the corresponding motor skill for five of the seven subcomponents. Two weeks after training, more than 50% of the students failed to perform 'time to check respiration', 'ventilation volume', 'compression depth' and 'compression frequency' correctly. Four months after training, significantly more students reached a correct 'ventilation volume' but performed it incorrectly. Nurse educators are recommended to spend more time on hands-on skills practice than on theory. Special attention should be given to the performance of a correct ventilation technique, a sufficiently deep chest compression and a correct compression frequency.

Reduction of Arterial Oxygen Saturation Among Rescuers During Cardiopulmonary Resuscitation in a Hypobaric Hypoxic Environment

We experienced a case involving prolonged cardiopulmonary resuscitation (CPR) during cardiac arrest on Mt. Fuji (3776 m), demanding lengthy exertion by the rescuers performing CPR. Considering the effects of exertion on the rescuers, we examined their percutaneous arterial oxygen saturation during simulated CPR and compared the effects of compression-only and conventional CPR at 3700 m above sea level. The effects of CPR on the physical condition of rescuers were examined at the summit of Mt. Fuji: three rescue staff equipped with pulse-oximeters performed CPR with or without breaths using a CPR mannequin. At 3700 m, the rescuers' heart rate increased during CPR regardless of the presence or absence of rescue breathing. Percutaneous arterial oxygen saturation measured in such an environment was reduced only when CPR without rescue breathing was performed. Scores on the Borg scale, a subjective score of fatigue, after CPR in a 3700 m environment were 13 to 15 of 20 (somewhat hard to hard). Performing CPR at high altitude exerts a significant physical effect upon the condition of rescuers. Compression-only CPR at high altitude may cause a deterioration in rescuer oxygenation, whereas CPR with rescue breathing might ameliorate such deterioration.