Journal Article•
Abstract 83: High Incidence of Chest Compression Oscillations Associated With Capnography During Out-of-Hospital Cardiopulmonary Resuscitation
TL;DR: To assess the proportion of capnograms with chest compression oscillations recorded during OOH CPR, electronic recordings made with the Philips HeartSmart MRx monitor-defibrillator during Ooh CPR in 210 patients with sudden cardiac arrest from 2008 to 2010 are collected.
Abstract: Background: Capnography is commonly used to guide ventilation in out-of-hospital (OOH) cardiopulmonary resuscitation (CPR). Advantages of continuous capnography include verification of airway placement, prevention of hyper- or hypoventilation, and identification of airway dislodgement. Chest compressions sometimes produce high frequency waveforms that are superimposed on the much lower frequency respiratory capnogram waveform, but this has not been studied systematically. Chest compression oscillations may be caused by gas moving in and out of the airway during compression/decompression phases of CPR. A few studies reported that chest compressions produce tidal volumes that are less than physiological dead space. Objective: To assess the proportion of capnograms with chest compression oscillations recorded during OOH CPR. Methods: We collected electronic recordings made with the Philips HeartSmart MRx monitor-defibrillator during OOH CPR in 210 patients with sudden cardiac arrest (CA) from 2008 to 2010 in...
Citations
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TL;DR: The thoracic impedance (TI) signal can be reliably used to measure all the CPR quality metrics proposed in this study, except for the instantaneous ventilation rate.
40 citations
TL;DR: An automatic algorithm based on the capnogram to detect ventilations and provide feedback on ventilation rate during CPR was evaluated, and its accuracy was proven even in intervals where canpography signal was severely corrupted by CCs.
32 citations
TL;DR: Capnogram-based ventilation detection during CPR using the designed algorithm was compromised by the presence of chest compression artefact, which strongly degraded ventilation detection, and caused a high number of false hyperventilation alarms.
32 citations
01 Jun 2020
TL;DR: The goals of this narrative review are to evaluate the available evidence regarding the role of ventilation in out‐of‐hospital cardiac arrest resuscitation and to provide recommendations for future directions.
Abstract: Out-of-hospital cardiac arrest continues to be a devastating condition despite advances in resuscitation care. Ensuring effective gas exchange must be weighed against the negative impact hyperventilation can have on cardiac physiology and survival. The goals of this narrative review are to evaluate the available evidence regarding the role of ventilation in out-of-hospital cardiac arrest resuscitation and to provide recommendations for future directions. Ensuring successful airway patency is fundamental for effective ventilation. The airway management approach should be based on professional skill level and the situation faced by rescuers. Evidence has explored the influence of different ventilation rates, tidal volumes, and strategies during out-of-hospital cardiac arrest; however, other modifiable factors affecting out-of-hospital cardiac arrest ventilation have limited supporting data. Researchers have begun to explore the impact of ventilation in adult out-of-hospital cardiac arrest outcomes, further stressing its importance in cardiac arrest resuscitation management. Capnography and thoracic impedance signals are used to measure ventilation rate, although these strategies have limitations. Existing technology fails to reliably measure real-time clinical ventilation data, thereby limiting the ability to investigate optimal ventilation management. An essential step in advancing cardiac arrest care will be to develop techniques to accurately and reliably measure ventilation parameters. These devices should allow for immediate feedback for out-of-hospital practitioners, in a similar way to chest compression feedback. Once developed, new strategies can be established to guide out-of-hospital personnel on optimal ventilation practices.
16 citations
TL;DR: Capnogram-based ventilation detection during CPR was enhanced after suppressing the artifact caused by chest compressions, so the simplicity of fixed-coefficient filters would take advantage for a practical implementation.
Abstract: Background
During cardiopulmonary resuscitation (CPR), there is a high incidence of capnograms distorted by chest compression artifact. This phenomenon adversely affects the reliability of automated ventilation detection based on the analysis of the capnography waveform. This study explored the feasibility of several filtering techniques for suppressing the artifact to improve the accuracy of ventilation detection.
Materials and methods
We gathered a database of 232 out-of-hospital cardiac arrest defibrillator recordings containing concurrent capnograms, compression depth and transthoracic impedance signals. Capnograms were classified as non-distorted or distorted by chest compression artifact. All chest compression and ventilation instances were also annotated. Three filtering techniques were explored: a fixed-coefficient (FC) filter, an open-loop (OL) adaptive filter, and a closed-loop (CL) adaptive filter. The improvement in ventilation detection was assessed by comparing the performance of a capnogram-based ventilation detection algorithm with original and filtered capnograms.
Results
Sensitivity and positive predictive value of the ventilation algorithm improved from 91.9%/89.5% to 97.7%/96.5% (FC filter), 97.6%/96.7% (OL), and 97.0%/97.1% (CL) for the distorted capnograms (42% of the whole set). The highest improvement was obtained for the artifact named type III, for which performance improved from 77.8%/74.5% to values above 95.5%/94.5%. In addition, errors in the measurement of ventilation rate decreased and accuracy in the detection of over-ventilation increased with filtered capnograms.
Conclusions
Capnogram-based ventilation detection during CPR was enhanced after suppressing the artifact caused by chest compressions. All filtering approaches performed similarly, so the simplicity of fixed-coefficient filters would take advantage for a practical implementation.
12 citations