Transthoracic impedance variability to assess quality of chest compression in out-of-hospital cardiac arrest

BACKGROUND

Chest compression is a lifesaving intervention in out-of-hospital cardiac arrest (OHCA), but the optimal metrics to assess its quality have yet to be identified. The objective of this study was to investigate whether a new parameter, that is, the variability of the chest compression-generated transthoracic impedance (TTI), namely ImpCC , which measures the consistency of the chest compression maneuver, relates to resuscitation outcome.

METHODS

This multicenter observational, retrospective study included OHCAs with shockable rhythm. ImpCC variability was evaluated with the power spectral density analysis of the TTI. Multivariate regression model was used to examine the impact of ImpCC variability on defibrillation success. Secondary outcome measures were return of spontaneous circulation and survival.

RESULTS

Among 835 treated OHCAs, 680 met inclusion criteria and 565 matched long-term outcomes. ImpCC was significantly higher in patients with unsuccessful defibrillation compared to those with successful defibrillation (p = .0002). Lower ImpCC variability was associated with successful defibrillation with an odds ratio (OR) of 0.993 (95% confidence interval [95% CI], 0.989-0.998, p = .003), while the standard chest compression fraction (CCF) was not associated (OR 1.008 [95 % CI, 0.992-1.026, p = .33]). Neither ImpCC nor CCF was associated with long-term outcomes.

CONCLUSIONS

In this population, consistency of chest compression maneuver, measured by variability in TTI, was an independent predictor of defibrillation outcome. ImpCC may be a useful novel metrics for improving quality of care in OHCA.

Impact of Two Resuscitation Sequences on Alveolar Ventilation during the First Minute of Simulated Pediatric Cardiac Arrest: Randomized Cross-Over Trial

The International Liaison Committee on Resuscitation regularly publishes a Consensus on Science with Treatment Recommendations, but guidelines can nevertheless differ when knowledge gaps persist. In case of pediatric cardiac arrest, the American Heart Association recommends following the adult resuscitation sequence, i.e., starting with chest compressions. Conversely, the European Resuscitation Council advocates the delivery of five initial rescue breaths before starting chest compressions. This was a superiority, randomized cross-over trial designed to determine the impact of these two resuscitation sequences on alveolar ventilation in a pediatric model of cardiac arrest. The primary outcome was alveolar ventilation during the first minute of resuscitation maneuvers according to the guidelines used. A total of 56 resuscitation sequences were recorded (four sequences per team of two participants). The ERC approach enabled higher alveolar ventilation volumes (370 mL [203−472] versus 276 mL [140−360], p < 0.001) at the cost of lower chest compression fractions (57% [54;64] vs. 66% [59;68], p < 0.001). Although statistically significant, the differences found in this simulation study may not be clinically relevant. Therefore, and because of the importance of overcoming barriers to resuscitation, advocating a pediatric-specific resuscitation algorithm may not be an appropriate strategy.

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.

The factor influencing the rate of ROSC for nontraumatic OHCA in New Taipei city

ABSTRACT

Return of spontaneous circulation (ROSC) from out-of-hospital cardiac arrest (OHCA) is critical for the Emergency Medical Services System. When compared to other developed countries, Taiwan has lower rate of ROSC in OHCA patients.We conducted a retrospective study of cardiac arrest using The Emergency Medical Service Dispatching Center in Northern Taiwan and The Prehospital Care System of New Taipei City Paramedic Service. Patients suffering from nontraumatic OHCA between August of 2019 to February of 2020 were included. We analyzed the cardiopulmonary resuscitation (CPR) quality parameters such as chest compression interruptions, bystander CPR, shockable rhythm, CPR interruption, chest compression fraction (CCF) average, patient transportation in buildings, and adrenaline injection during CPR. Multivariable logistic regression analysis was performed to assess the relationship between potential independent variables and ROSC.In our study, we involved 1265 subjects suffering from nontraumatic OHCA, among which 587 patients met inclusion criteria. We identified that CCF> 0.8, chest compression interruption greater than 3 times, and patient transportation in the building were the most critical factors influencing ROSC. However, patient transportation in a building was identified as a dependent predictor variable (P = .4752).We concluded that CCF > 0.8 and chest compression interruption greater than 3 times were essential factors affecting the CPR ROSC rate. The most significant reason for suboptimal CCF and CPR interruption is patient transportation in a building. Improving the latter point could facilitate high-quality CPR.

Quality of Cardiopulmonary Resuscitation and 5-Year Survival Following in-Hospital Cardiac Arrest

Purpose

To improve cardiac arrest survival, international resuscitation guidelines emphasize measuring the quality of cardiopulmonary resuscitation (CPR). We aimed to investigate CPR quality during in-hospital cardiac arrest (IHCA) and study long-term survival outcomes.

Patients and Methods

This was a cohort study of IHCA from December 2011 until November 2014. Data were collected from the hospital switch board, patient records, and from defibrillators. Impedance data from defibrillators were analyzed manually at the level of single compressions. Long-term survival at 1-, 3-, and 5 years is reported.

Results

The study included 189 IHCAs; median (interquartile range (IQR)) time to first rhythm analysis was 116 (70-201) seconds and median (IQR) time to first defibrillation was 133 (82-264) seconds. Median (IQR) chest compression rate was 126 (119-131) per minute and chest compression fraction (CCF) was 78% (69-86). Thirty-day survival was 25%, while 1-year-, 3-year-, and 5-year survival were 21%, 14%, and 13%, respectively. There was no significant association between any survival outcomes and CCF, whereas chest compression rate was associated with survival to 30 days and 3 years. Overall, 5-year survival was associated with younger age (median 68 vs 74 years, p=0.003), less comorbidity (Charlson comorbidity index median 3 vs 5, p<0.001), and witnessed cardiac arrest (96% vs 77%, p=0.03).

Conclusion

We established a systematic collection of IHCA CPR quality data to measure and improve CPR quality and long-term survival outcomes. Median time to first rhythm check/defibrillation was <3 minutes, but median chest compression rate was too fast and median CCF slightly below 80%. More than half of 30-day survivors were still alive at 5 years.

Effect on Chest Compression Fraction of Continuous Manual Compressions with Asynchronous Ventilations Using an i-gel® versus 30:2 Approach during Simulated Out-of-Hospital Cardiac Arrest: Protocol for a Manikin Multicenter Randomized Controlled Trial

The optimal airway management strategy during cardiopulmonary resuscitation is uncertain. In the case of out-of-hospital cardiac arrest, a high chest compression fraction is paramount to obtain the return of spontaneous circulation and improve survival and neurological outcomes. To improve this fraction, providing continuous chest compressions should be more effective than using the conventional 30:2 ratio. Airway management should, however, be adapted, since face-mask ventilation can hardly be carried out while continuous compressions are administered. The early insertion of a supraglottic device could therefore improve the chest compression fraction by allowing ventilation while maintaining compressions. This is a protocol for a multicenter, parallel, randomized simulation study. Depending on randomization, each team made up of paramedics and emergency medical technicians will manage the 10-min scenario according either to the standard approach (30 compressions with two face-mask ventilations) or to the experimental approach (continuous manual compressions with early insertion of an i-gel® supraglottic device to deliver asynchronous ventilations). The primary outcome will be the chest compression fraction during the first two minutes of cardiopulmonary resuscitation. Secondary outcomes will be chest compression fraction (per cycle and overall), compressions and ventilations quality, time to first shock and to first ventilation, user satisfaction, and providers' self-assessed cognitive load.

The feasibility of emergency medical technicians performing intermittent high-quality cardiopulmonary resuscitation

Background: Whether intermittent chest compressions have an effect on the quality of CPR is worthy of discussion. The purpose of this study was to investigate differences in the chest compression quality of emergency medical technicians (EMTs) performing cardiopulmonary resuscitation (CPR) with different rest intervals. Methods: Seventy male firefighters with EMT licenses participated in this study. Participants completed body composition measurements and three CPR quality tests, as follows: (1) CPR-uninterrupted for 10 minutes; (2) after 2 days of rest, CPR 10s-intermittent (CPR-10s), for 2 minutes each time and 5 cycles; (3) after another 2 days of rest, CPR 20s-intermittent (CPR-20s), for 2 minutes each time and 5 cycles. Results: Body composition results showed that body mass (BM), body mass index (BMI), upper limb muscle mass (ULMM), core muscle mass (CMM), and upper limb-core muscle mass (UL+CMM) were positively correlated with chest compression depth (CCD) (p < 0.05). Analysis of the three different modes of CPR quality analysis indicated significant differences in the chest compression fraction (CCF, F = 6.801, p = 0.001), chest compression rebound rate (CCRR, F = 3.919, p = 0.021), and ratings of perceived exertion (RPE, F = 23.815, p < 0.001). Among the different performance cycles of CPR-10s, significant differences were found in CCF, CCD, CCR (chest compression rate), and RPE (p < 0.05). On the other hand, among the different performance cycles of CPR-20s, significant differences were found in CCD, CCR, and RPE (p < 0.05). Moreover, the CCF, CCD, and RPE scores of the two tests reached significant differences in specific phases (p < 0.05). Conclusions: This study confirmed that the upper limb muscle mass or the weight of the upper body of EMTs is positively correlated with the quality of CPR. In addition, intermittent chest compressions with safe interruption intervals can reduce fatigue caused by long-term chest compressions and maintain better chest compression quality.

Advanced Airway Type and Its Association with Chest Compression Interruptions During Out-of-Hospital Cardiac Arrest Resuscitation Attempts

OBJECTIVE

To assess interruptions in chest compressions associated with advanced airway placement during cardiopulmonary resuscitation (CPR) of out-of-hospital cardiac arrest (OHCA) victims.

METHODS

The method used was observational analysis of prospectively collected clinical and defibrillator data from 339 adult OHCA victims, excluding victims with <5 minutes of CPR. Interruptions in CPR, summarized by chest compression fraction (CCF), longest pause, and the number of pauses greater than 10 seconds, were compared between patients receiving bag valve mask (BVM), supraglottic airway (SGA), endotracheal intubation (ETI) via direct laryngoscopy (DL), and ETI via video laryngoscopy (VL). Secondary outcomes included first pass success and the effect of multiple airway attempts on CPR interruptions.

RESULTS

During the study period, paramedics managed 23 cases with BVM, 43 cases with SGA, 148 with DL, and 125 with VL. There were no statistically significant differences between the airway groups with regard to longest compression pause (BVM 18 sec [IQR 11-33], SGA 29 sec [IQR 15-65], DL 26 sec [IQR 12-59], VL 22 sec [IQR 14-41]), median number of pauses greater than 10 seconds (BVM 2 [IQR 1-3], SGA 2 [IQR 1-3], DL 2 [IQR 1-4], VL 2 [IQR 1-3]), or CCF (0.92 for all groups). However, each additional attempt following failed initial DL was associated with an increase in the risk of additional chest compression pauses (relative risk 1.29, 95% confidence interval 1.02-1.64). Such an association was not observed with additional attempts using VL or SGA. First pass success was highest with SGA (77%), followed by between DL (68%) and VL (67%); these differences were not statistically significant.

CONCLUSIONS

While summary measures of chest compression delivery did not differ significantly between airway classes in this observational study, repeated attempts following failed initial DL during cardiopulmonary resuscitation were associated with an increase in the number of pauses in chest compression delivery observed.