Adherence to guidelines when positioning the defibrillation electrodes

Barriers and facilitators for successful AED usage during in-situ simulated in-hospital cardiac arrest

Introduction

Methods

Results

Conclusion

Basic life support skills can be improved among certified basic life support instructors

Background

A correct visual skill demonstration is important when learning cardiopulmonary resuscitation (CPR) and the use of an automated external defibrillator (AED). Basic life support (BLS) instructors are expected to master and demonstrate CPR/AED skills correctly. The aim of this study was to evaluate certified BLS instructors’ competencies in demonstrating CPR and the use of an AED.

Methods

Certified BLS instructors demonstrated CPR and the use of an AED on a resuscitation manikin. Skills were evaluated using data collected from the manikin and video recordings and compared to resuscitation guidelines. Further, instructors completed questionnaires on resuscitation guidelines and rating of their own CPR/AED skills.

Results

Overall, we analyzed data from 125 instructors. Of all chest compressions, only 22% were within guideline recommendations regarding depth. Instructors performed chest compressions with excessive depth (mean depth 64 mm (7.3)) and a mean rate of 115 min⁻¹ (10.8). Only 25% of instructors placed the left AED electrode correctly (median distance 7.6 cm (5.0;10.5)), while the right AED electrode usually was placed correctly (median distance 2.9 cm (1.5;4.0), 85% placed correctly). Nearly half of the instructors failed to state correct answers regarding how to diagnose a cardiac arrest and where to place the AED electrodes. Despite their performance, instructors rated their BLS skills as good.

Conclusion

Certified BLS instructors’ have poor CPR/AED skills and several important knowledge gaps on CPR/AED guidelines in contrast to instructors’ self-reported skills. This highlights a need for improving BLS instructor education, including continuous faculty development to ensure optimal learning conditions for BLS course participants.

Electrocardiographic recording direction impacts ventricular fibrillation waveform measurements: A potential pitfall for VF-waveform guided defibrillation protocols

Aim

In cardiac arrest, ventricular fibrillation (VF) waveform analysis has identified the amplitude spectrum area (AMSA) as a key predictor of defibrillation success and favorable neurologic survival. New resuscitation protocols are under investigation, where prompt defibrillation is restricted to cases with a high AMSA. Appreciating the variability of in-field pad placement, we aimed to assess the impact of recording direction on AMSA-values, and the inherent defibrillation advice.

Methods

Prospective VF-waveform study on 12-lead surface electrocardiograms (ECGs) obtained during defibrillation testing in ICD-recipients (2010–2017). AMSA-values (mVHz) of simultaneous VF-recordings were calculated and compared between all limb leads, with lead II as reference (proxy for in-field pad position). AMSA-differences between leads I and II were quantified using Bland-Altman analysis. Moreover, we investigated differences between these adjacent leads regarding classification into high (≥15.5), intermediate (6.5–15.5) or low (≤6.5) AMSA-values.

Results

In this cohort (n = 243), AMSA-values in lead II (10.2 ± 4.8) differed significantly from the other limb leads (I: 8.0 ± 3.4; III: 12.9 ± 5.6, both p < 0.001). The AMSA-value in lead I was, on average, 2.24 ± 4.3 lower than in lead II. Of the subjects with high AMSA-values in lead II, only 15% were classified as high if based on assessments of lead I. For intermediate and low AMSA-values, concordances were 66% and 72% respectively.

Conclusions

ECG-recording direction markedly affects the result of VF-waveform analysis, with 20–30% lower AMSA-values in lead I than in lead II. Our data suggest that electrode positioning may significantly impact shock guidance by ‘smart defibrillators’, especially affecting the advice for prompt defibrillation.

Accuracy of instructional diagrams for automated external defibrillator pad positioning

INTRODUCTION

Correct defibrillation pad positioning optimises the chances of successful defibrillation. AEDs have pictoral representation to guide untrained bystanders in correct pad positioning. There is a wide variation in this pictoral guidance and evidence suggests that correct anatomical pad placement is poor. We reviewed all currently available diagrams and assessed the resultant pad placement achieved by untrained bystanders following these instructions.

METHODS

Twenty untrained bystanders were presented with a total of 27 different pad placement diagrams (including one designed by the researchers) in a random sequence and were asked to apply them to the chest of an adult manikin. The lateral/medial and cranial/caudal position in relation to the optimal position recommended by the European Resuscitation Council guidelines was then measured for each pair of pads.

RESULTS

Overall, the sternal pad was placed an average of 6.0 mm cranial to, and 3.2 mm medial to, the optimal position. The apical pad was placed an average of 78.2 mm caudal to, and 59.3 mm medial to, the optimal position. The pad position diagram we designed and assessed out performed existing diagrams.

CONCLUSION

All current defibrillation pad diagrams fail to achieve accurate defibrillation pad placement. A clearer, more effective diagram, such as the one we designed, is urgently needed to ensure bystander defibrillation is effective as possible.

Automated external defibrillation training on the left or the right side - a randomized simulation study

Background

Correct placement of the left automated external defibrillator (AED) electrode is rarely achieved. AED electrode placement is predominantly illustrated and trained with the rescuer sitting on the right side of the patient. Placement of the AED electrodes from the left side of the patient may result in a better overview of and access to the left lateral side of the thorax. This study aimed to investigate if training in automated external defibrillation on the left side compared to the right side of a manikin improves left AED electrode placement.

Methods

Laypeople attending basic life support training were randomized to learn automated external defibrillation from the left or right side of a manikin. After course completion, participants used an AED and placed AED electrodes in a simulated cardiac arrest scenario.

Results

In total, 40 laypersons were randomized to AED training on the left (n=19 [missing data =1], 63% female, mean age: 47.3 years) and right (n=20, 75% female, mean age: 48.7 years) sides of a manikin. There was no difference in left AED electrode placement when trained on the left or right side: the mean (SD) distances to the recommended left AED electrode position were 5.9 (2.1) cm vs 6.9 (2.2) cm (p=0.15) and to the recommended right AED electrode position were 2.6 (1.5) cm vs 1.8 (0.8) cm (p=0.06), respectively.

Conclusion

Training in automated external defibrillation on the left side of a manikin does not improve left AED electrode placement compared to training on the right side.

Hypertension guideline implementation: experiences of Finnish primary care nurses

RATIONALE, AIMS AND OBJECTIVES

Evidence-based guidelines on hypertension have been developed in many western countries. Yet, there is little evidence of their impact on the clinical practices of primary care nurses.

METHOD

We assessed the style of implementation and adoption of the national Hypertension Guideline (HT Guideline) in 32 Finnish health centres classified in a previous study as 'disseminators' (n = 13) or 'implementers' (n = 19). A postal questionnaire was sent to all nurses (n = 409) working in the outpatient services in these health centres. Additionally, senior nursing officers were telephoned to enquire if the implementation of the HT Guideline had led to a new division of labour between nurses and doctors.

RESULTS

Questionnaires were returned from 327 nurses (80.0%), while all senior nursing officers (n = 32) were contacted. The majority of nurses were of the opinion that the HT Guideline has been adopted into clinical practice. The recommendations in the HT Guideline were adopted in clinical practice with varying success, and slightly more often in implementer health centres than in disseminator health centres. Nurses in implementer health centres more often agreed that multiple channels had been used in the implementation (P < 0.001). According to senior nursing officers the implementation of the HT Guideline had led to a new division of labour between nurses and doctors in about a half of the health centres, clearly more often in implementer health centres (P < 0.001).

CONCLUSIONS

The HT Guideline was well adopted into clinical practice in Finland. The implementation of the HT Guideline had an impact on clinical practices, and on creating a new division of labour between nurses and doctors.

Effects of brief training on use of automated external defibrillators by people without medical expertise

OBJECTIVE

This study examined the effect of three types of brief training on the use of automatic external defibrillators (AEDs) by 43 lay users.

BACKGROUND

Because AEDs were recently approved for home use, brief training for nonprofessional users needs investigation.

METHOD

During training, the exposure training group read an article about AEDs that provided no information on how to operate them; the low-training group inspected the AED and read the operating instructions in the paper-based manual but was not allowed to use the device; and the high-training group watched a training video and performed a mock resuscitation using the AED but no manikin. All participants returned 2 weeks later and performed a surprise simulated AED resuscitation on a manikin.

RESULTS

Most participants in each training group met criteria of minimally acceptable performance during the simulated manikin resuscitation, as measured by time to first shock, pad placement accuracy, and safety check performance. All participants who committed errors were able to successfully recover from them to complete the resuscitation. Compared with exposure training, the low and high training had a beneficial effect on time to first shock and errors.

CONCLUSION

Untrained users were able to adequately use this AED, demonstrating walk-up-and-use usability, but additional brief training improved user performance.

APPLICATION

This study demonstrated the importance of providing high-quality but brief training for home AED users. In conjunction with other findings, the current study helps demonstrate the need for well-designed training for consumer medical devices.

Association of Pharmacist Presence on Compliance with Advanced Cardiac Life Support Guidelines During In-Hospital Cardiac Arrest

BACKGROUND:

The pharmacist has many potential roles as part of the resuscitation team during cardiopulmonary arrest. Limited published research has evaluated the practice of advanced cardiac life support (ACLS) during in-hospital arrest. Recent reviews indicate that an audit of in-hospital resuscitation practices should be performed to guide future resuscitation training programs for hospital personnel.

OBJECTIVE:

To assess compliance with ACLS guidelines during in-hospital cardiopulmonary arrest in a community teaching hospital and evaluate the association of compliance with the presence of a pharmacist on the resuscitation team.

METHODS:

A retrospective analysis of the records of 74 consecutive in-hospital arrests occurring between January 1, 2003, and June 30, 2004, was conducted to evaluate compliance with American Heart Association ACLS guidelines.

RESULTS:

A total of 74 arrests were evaluated. Noncompliance was noted in 58.1% of all documented arrests; of the 650 treatment interventions identified, 10.6% were noncompliant with ACLS guidelines. The reasons cited for noncompliance included an incorrect medication dosage (20.3%), prolonged period of time between sequential interventions (26.1%), omission of an indicated treatment (17.4%), deviation from recommended treatment guidelines (26.1%), and incorrect energy for defibrillation (10.1%). A pharmacist was present at 36.5% of documented arrests. Compliance with ACLS treatment guidelines was more likely during resuscitations in which a pharmacist was present (59.3% vs 31.9%; p = 0.03).

CONCLUSIONS:

Noncompliance with resuscitation guidelines was common during in-hospital resuscitation. The presence of a pharmacist on the resuscitation team was associated with improved compliance with treatment guidelines. Despite institutional requirements for pharmacist participation during resuscitation efforts, participation rates remain low. Further evaluation of the role of the pharmacist on the resuscitation team and the impact of the pharmacist on resuscitation practices should be considered.

Thoracic impedance changes measured via defibrillator pads can monitor ventilation in critically ill patients and during cardiopulmonary resuscitation

OBJECTIVE

Monitoring of ventilation performance during cardiopulmonary resuscitation would be desirable to improve the quality of cardiopulmonary resuscitation. To investigate the potential for measuring ventilation rate and inspiration time, we calculated the correlation in waveform between transthoracic impedance measured via defibrillator pads and tidal volume given by a ventilator.

DESIGN

Clinical study.

SETTING

Emergency department of a tertiary care university hospital.

PATIENTS

A convenience sample of mechanical ventilated patients (n = 32), cardiac arrest patients (n = 20), and patients after restoration of spontaneous circulation (n = 31) older than 18 were eligible.

INTERVENTIONS

The Heartstart 4000SP defibrillator (Laerdal Medical Cooperation, Stavanger, Norway) with additional capabilities of recording thoracic impedance changes was used.

MEASUREMENTS AND MAIN RESULTS

The relationship between impedance change and tidal volume (impedance coefficient) was calculated. The mean (sd) correlations between the impedance waveform and the tidal volume waveform in the patient groups studied were .971 (.027), .969 (.032), and .967 (.035), respectively. The mean (sd) impedance coefficient for all patients in the study was .00194 (.0078) Omega/mL, and the mean (sd) specific (weight-corrected) impedance coefficient was .152 (.048) Omega/kg/mL. The measured thorax impedance change for different tidal volumes (400-1000 mL) was approximately linear.

CONCLUSIONS

The impedance sensor of a defibrillator is accurate in identifying tidal volumes, when chest compressions are interrupted. This also allows quantifying ventilation rates and inspiration times. However this technology, at its present state, provides only limited practical means for exact tidal volume estimation.

Layperson positioning of defibrillation electrodes guided by pictorial instructions

BACKGROUND

Correct positioning of defibrillation electrodes is essential to achieve sufficient transmyocardial current to depolarize a critical mass of myocardium, and thus terminate ventricular fibrillation (VF).

AIM

To evaluate the pictures on the self-adhesive defibrillation electrodes in guiding laypersons to place the electrodes in the recommended position.

METHODS

Defibrillation electrodes from five manufactures (Access Cardio Systems, Schiller, Medtronic, Cardiac Science and Philips) were included in the study and compared with electrodes with a lateral view picture, designed for the study, showing the placement of the apical electrode. A total of 150 laypersons without any experience or training in use of a defibrillator participated in the study. The participants placed randomly selected electrodes on the chest of a resuscitation manikin without any guidance apart from the pictures on the electrodes. The distances of the electrodes from the recommended positions were measured.

RESULTS

The proportion of participants who placed both electrodes within 5 cm from recommended position varied from 8% to 36% with the different electrodes. Usually, the apical electrode was placed too anteriorly. Electrodes placed with help of the lateral instruction picture, (designed for the study), showing the placement of the apical electrode were placed significantly more often within 5 cm than any of the others (64%, 95% confidence interval 44-80, P < 0.05).

CONCLUSIONS

The current practice in designing pictures on the electrodes does not seem to be optimal in showing the recommended position of the apical electrode as recommended by Guidelines 2000. It is suggested that by showing a lateral view in the instructions, success in placing the apical electrodes correctly can be improved.