Quality of chest compressions by healthcare professionals using real-time audiovisual feedback during in-hospital cardiopulmonary resuscitation.

INTRODUCTION: A high quality of chest compressions, e.g. sufficient depth (5-6 cm) and rate (100-120 per min), has been associated with survival. The patient's underlay affects chest compression depth. Depth and rate can be assessed by feedback systems to guide rescuers during cardiopulmonary resuscitation. AIM: The purpose of this study was to describe the quality of chest compressions by healthcare professionals using real-time audiovisual feedback during in-hospital cardiopulmonary resuscitation. METHOD: An observational descriptive study was performed including 63 cardiac arrest events with a resuscitation attempt. Data files were recorded by Zoll AED Pro, and reviewed by RescueNet Code Review software. The events were analysed according to depth, rate, quality of chest compressions and underlay. RESULTS: Across events, 12.7% (median) of the compressions had a depth of 5-6 cm. Compression depth of >6 cm was measured in 70.1% (median). The underlay could be identified from the electronic patient records in 54 events. The median compression depth was 4.5 cm (floor) and 6.7 cm (mattress). Across events, 57.5% (median) of the compressions were performed with a median frequency of 100-120 compressions/min and the most common problem was a compression rate of <100 (median=22.3%). CONCLUSIONS: Chest compression quality was poor according to the feedback system. However, the distribution of compression depth with regard to underlay points towards overestimation of depth when treating patients on a mattress. Audiovisual feedback devices ought to be further developed. Healthcare professionals need to be aware of the strengths and weaknesses of their devices.

Sensitivity and specificity of two different automated external defibrillators.

AIM: The aim was to investigate the clinical performance of two different types of automated external defibrillators (AEDs). METHODS: Three investigators reviewed 2938 rhythm analyses performed by AEDs in 240 consecutive patients (median age 72, q1-q3=62-83) who had suffered cardiac arrest between January 2011 and March 2015. Two different AEDs were used (AED A n=105, AED B n=135) in-hospital (n=91) and out-of-hospital (n=149). RESULTS: Among 194 shockable rhythms, 17 (8.8%) were not recognized by AED A, while AED B recognized 100% (n=135) of shockable episodes (sensitivity 91.2 vs 100%, p<0.01). In AED A, 8 (47.1%) of these episodes were judged to be algorithm errors while 9 (52.9%) were caused by external artifacts. Among 1039 non-shockable rhythms, AED A recommended shock in 11 (1.0%), while AED B recommended shock in 63 (4.1%) of 1523 episodes (specificity 98.9 vs 95.9, p<0.001). In AED A, 2 (18.2%) of these episodes were judged to be algorithm errors (AED B, n=40, 63.5%), while 9 (81.8%) were caused by external artifacts (AED B, n=23, 36.5%). CONCLUSIONS: There were significant differences in sensitivity and specificity between the two different AEDs. A higher sensitivity of AED B was associated with a lower specificity while a higher specificity of AED A was associated with a lower sensitivity. AED manufacturers should work to improve the algorithms. In addition, AED use should always be reviewed with a routine for giving feedback, and medical personnel should be aware of the specific strengths and shortcomings of the device they are using.

[Semi-automatic defibrillators does not always interpret heart rhythms correctly. Five patients were defibrillated despite non-shockable rhythms]. / Halvautoma-tiska hjärtstartare tolkar inte alltid rätt - Fem patienter defibrillerades trots icke-defibrillerbar rytm.

Automated external defibrillators (AED) have become an important part of the ¼the chain of survival« in case of sudden cardiac arrest (SCA), where early defibrillation is lifesaving. The American Heart Association demands that AEDs have a specificity of >99 % to recognize normal sinus rhythm and >95 % for the other non-shockable rhythms. Reports on their performance in the field are scarce. We present five cases in which AED recommended shock for apparently non-shockable rhythms. This indicates the necessity to systematically reevaluate AED performance.