Probability Of Return Of Spontaneous Circulation Research Articles

Does the type of mechanical chest compressor affect resuscitation outcome of out of hospital cardiac arrest patients? A propensity-score based comparison of three devices

Abstract Background Mechanical cardiopulmonary resuscitation (CPR) devices are currently recommended when high-quality CPR could not be provided and only if used by trained rescuers. Guidelines are against their routinely use since clinical trials results are controversial, and solid evidence of improved survival are missing. Moreover, many studies compared these devices to very high-quality manual CPR, hardly replicable in a pre-hospital emergency setting. Nowadays, different machines are available but literature is poor in direct comparison studies. Purpose To assess whether the type of mechanical chest compressor could affect the probability of return of spontaneous circulation (ROSC) and of 30-days mortality after an out-of-hospital cardiac arrest (OHCA) as compared to manual standard CPR. Methods Data were prospectively collected from our Utstein-based cardiac arrest registry. We considered all OHCAs from January 1, 2015 to December 31, 2022 from 7 provinces covered by the same regional emergency system (population covered 4.2mln. inhabitants) but equipped with three different types of mechanical compressor: Autopulse®; LUCAS® and Easy Pulse®. Patients treated with mechanical CPR and manual CPR were randomly matched via a multivariable logistic regression propensity score considering age, gender, witnessed OHCA, presence of bystander CPR, first rhythm recorded, EMS arrival time and lay defibrillation before EMS arrival. Logistic regression and COX regression models were performed and adjusted for resuscitation duration to investigate the association between the type of CPR and the probability of ROSC and of 30-day mortality. Results Among 13,203 OHCAs with attempted CPR, 10,497 (79.5%) received manual CPR and in 2,405 (18.2%) mechanical CPR [Easy Pulse® in 1,102(45.8%), Autopulse® in 776 (32.3%) and LUCAS® in 521 (21.7%)]. ROSC before hospital admission was obtained in 1,712 patients (13.0%) and 762 (5.8%) were alive after 30 days. After propensity score matching two homogeneous groups of 1,946 patients each (manual and mechanical CRP) were identified. The rate of ROSC and of 30-day survival were lower in the mechanical CPR group (ROSC: 14.7% vs 24.1%; p<0.001; 30-day survival 6% vs 14%; p<0.001). The three devices showed an independent association with the probability of ROSC as compared to manual CPR [Autopulse®: OR 1.76, 95% CI (1.36-2.28) p<0.001; LUCAS®:OR 1.55, 95% CI (1.13-2.13), p=0.006 and Easy Pulse®:OR 0.49; 95% CI (0.37-0.65), p<0.001] (Figure 1A). Only Autopulse® was independently associated with 30-day mortality [AutoPulse HR 0.87, 95%CI (0.79-0.97), p=0.01; LUCAS®: HR 1.00, 95%CI (0.88-1.14), p=0.97) and Easy Pulse®: HR: 1.06, 95%CI (0.97-1.16), p=0.19] (Figure 1B). Conclusions This is the first study comparing the performance of three devices for mechanical chest compressions revealing that they differently affect the probability of ROSC and of 30-day survival.

Abstract 186: Regional Cerebral Oxygen Saturation to Predict Neurologic Outcome During Out-of-Hospital-Cardiac -Arrest: An Ancillary Analysis of a Prospective Interventional Study

Background: Very few prognosis markers are available to help emergency medical services decide whether to continue or terminate cardiopulmonary resuscitation (CPR). ETCO 2 has been described to predict return of spontaneous circulation (ROSC) but its ability to predict neurologic outcome is poor. Cerebral tissue oxygen saturation (RSO 2 ) during CPR, as measured by near-infrared spectroscopy (NIRS) represents hemoglobin oxygenation within the cerebral tissue. The measure is feasible during CPR. It has been associated with the probability of ROSC. The aim of this study was to assess the predictive value of RSO2 regarding 30 days favorable neurologic outcome after out-of-hospital cardiac arrest (OHCA). Method: Data were collected during a prospective single center before-after interventional study comparing conventional CPR (C-CPR) with Automated head and thorax elevation CPR (AHUP). C-CPR was performed manually and AHUP-CPR was delivered using a LUCAS Active Decompression (Stryker Medical, USA), an EleGARD Patient Positioning System (AdvancedCPR Solutions, USA), and an impedance threshold device (ResQPOD-16, Zoll, USA). The study was carried out in four fire stations and one physician staffed advanced life support emergency medical services in France. ETCO2 (using an EMMA, Massimo or Lifepack 15, Stryker, USA) and RSO2 (H500, Nonin, USA) were collected as soon as possible during CPR. Favorable neurologic outcome was defined as MRS score of 0 to 3 at 30 days. Results are presented as mean ± standard deviation. Results: ETCO 2 was collected in 118 patients (11 with good neurologic outcome) and RSO 2 in 69 patients (6 with good neurologic outcome). Maximum ETCO 2 during CPR was 43±19mmHg in favorable neurologic outcome patients vs. 35±16mmHg (p=0.13). ETCO 2 alone had an AUC of 0,63 (IC95% 0.46-0.79). Maximum RSO2 during CPR was 68±13% for favorable neurologic outcome patients vs. 49±13% (p<0.001). For survival with favorable neurologic outcome, rSO 2 alone had an AUC of 0.85 (IC95% 0.71-0.99). With a maximum RSO 2 value below 51% there was no patient with favorable neurologic outcome. Conclusion: In this prospective interventional study, unlike EtCO 2 , RSO 2 values were significantly associated with favorable neurological survival at 30 days.

Faster time to automated elevation of the head and thorax during cardiopulmonary resuscitation increases the probability of return of spontaneous circulation

ObjectivesResuscitation in the Head Up position improves outcomes in animals treated with active compression decompression cardiopulmonary resuscitation and an impedance threshold device (ACD + ITD CPR).We assessed impact of time to deployment of an automated Head Up position (AHUP) based bundle of care after out-of-hospital cardiac arrest on return of spontaneous circulation (ROSC). MethodsObservational data were analyzed from a patient registry. Patients received treatment with 1) ACD + and/or automated CPR 2) an ITD and 3) an AHUP device. Probability of ROSC (ROSCprob) from the 9-1-1 call to AHUP device placement was assessed with a restricted cubic spline model and linear regression. ResultsOf 11 sites, 6 recorded the interval from 9-1-1 to AHUP device (n = 227). ROSCprobfor all rhythms was 34%(77/227). Median age (range) was 66 years (19-101) and 68% men. TheROSCprobfor shockable rhythms was 47%(18/38). Minutes from 9-1-1 to AHUP device (median, range) varied between sites: 1) 6.4(4,15), 2) 8.0(5,19), 3) 9.9(4, 12), 4) 14.1(6, 36), 5) 15.9(6, 34), 6) 19.0(8, 38),(p = 0.0001).ROSCprobalso varied; 1) 55.1%(16/29), 2) 60%(3/5), 3) 50%(3/6), 4) 22.7%(17/75), 5) 26.4%(9/34), and 6) 37.1%(29/78), (p = 0.019). For all rhythms between 4 and 12 min (n = 85),ROSCprobdeclined 5.6% for every minute elapsed (p = 0.024). For shockable rhythms, between 6 and 15 min (n = 23),ROSCprobdeclined 9.0% for every minute elapsed (p = 0.006). ConclusionsFaster time to deployment of an AHUP based bundle of care is associated with higher incidence of ROSC. This must be considered when evaluating and implementing this bundle.

Validation of the return of spontaneous circulation after cardiac arrest (RACA) score in two different national territories

BackgroundThe likelihood of return of spontaneous circulation (ROSC) after out-of-hospital cardiac arrest (OHCA) is influenced by unmodifiable (gender, aetiology, location, the presence of witnesses and initial rhythm) and modifiable factors (bystander CPR and the time to EMS arrival). All of these have been included in the ROSC After Cardiac Arrest (RACA) score. PurposeTo test the ability of the RACA score to predict the probability of ROSC in two different regions with different local resuscitation networks: the Swiss Canton Ticino and the Italian Province of Pavia. Methods and ResultsAll OHCAs occurred between January 1st 2015 and December 31st 2017 were included. The original regression coefficients for all RACA score variables were applied. The probability to obtain the ROSC as measured with the RACA score was divided in tertiles. Overall, 2041 OHCAs were included in the analysis. The RACA score showed good discrimination for ROSC (AUC 0.76) and calibration, without interaction (p 0.28) between the region and the probability of ROSC. The probability of ROSC was 15% for RACA scores <0.28, 20% for RACA scores between 0.28 and 0.42, increasing to 55% for RACA scores >0.42. ConclusionsThe application of the RACA score reliably assess the probability to obtain the ROSC, with equal effectiveness in the two regions, despite different organization of the resuscitation network. Patients with a RACA score >0.42 had more than 50% probability to obtain ROSC.

Abstract 12833: Can We Predict the Probability of ROSC by the Change in Cerebral rSO 2 Value?

Introduction: There is no consensus on how long we should continue cardiopulmonary resuscitation (CPR). When determining this, it is important to assess the probability of return of spontaneous circulation (ROSC). We have been evaluating the usefulness of regional cerebral oxygen saturation (rSO 2 ) during resuscitation since 2007. At the 2014 AHA congress, we reported that the probability of ROSC would be low if the rSO 2 was less than 55%. In the present study, we focused on the relation between the rate of rSO 2 increase and the occurrence of ROSC from the time of hospital arrival. Methods: This was a retrospective study of out-of-hospital cardiac arrest (OHCA) patients with successful measurement of rSO 2 from December 2012 to December 2015. During CPR, rSO 2 was recorded continuously from the forehead of the patients by a TOS-OR (TOSTEC, Japan). CPR for patients with OHCA was performed according to the 2010 JRC guidelines. Results: Ninety patients with OHCA (59 men, 31 women; mean age 74.8 years) were included in this study, of whom 35 had ROSC. The baseline value of rSO 2 was determined as the mean value of the initial 1 minute of rSO 2 . The rate of change in rSO 2 was calculated as the ratio of the maximum rSO 2 value at 4, 8, 12, 16, and 20 minutes to the baseline value. Receiver operating characteristic curve analysis showed that the area under the curve was 0.72 with the cut-off value set at 14.5%. The specificity and sensitivity of ROSC were 68.6% and 68.6%, respectively. Although this cut-off value is not a criterion for stopping CPR, the probability of ROSC would be low if the rate of change in rSO 2 is less than 14.5%. Conclusions: The rate of change in the rSO 2 value during CPR might be a new index for the prediction of ROSC.

Return of Spontaneous Circulation (ROSC) in Out-of Hospital Cardiac Arrest (OHCA) and type of bystanders (lay/health personnel): The 2015 analysis of the provincial “Out-of-Hospital Cardiac Arrest Registry” of the emergency medical system “Trentino Emergenza” in the Autonomous Province of Trento (Italy)

Purpose of the study: The study aimed to prove that the probability of ROSC is higher in cases where CPR maneuvers are provided by a bystander-type healthcare professional than a layman.

ROSC after cardiac arrest—the RACA score to predict outcome after out-of-hospital cardiac arrest

Return of spontaneous circulation (ROSC) following cardiopulmonary resuscitation from cardiac arrest (CA) depends on numerous variables. The aim of this study was to develop a score to predict the initial resuscitation outcome-the RACA (ROSC after cardiac arrest) score. Based on 5471 prospectively registered out-of-hospital CAs patients between 1998 and 2008 within the German Resuscitation Registry, calculation of the RACA score was performed by multivariate logistic regression analysis with ROSC as the outcome variable. The probability of ROSC was defined as 1/(1 + e(-X)), where X is the weighted sum of independent factors. Additional 2218 patients documented between 2009 and 2010 were used for validation of the RACA score. The following independent variables were found to have a significant positive (+) or negative (-) impact on the probability of ROSC: male gender (-0.2); age ≥80 years (-0.2); witnessing by lay people (+0.6) and by professionals (+0.5); asystole (-1.1); location at doctor's office (+1.2), medical institution (+0.5), public place (+0.3) and nursing home (-0.3); presumable aetiology of hypoxia (+0.7), intoxication (+0.5) and trauma (-0.6); and time until professionals arrival (-0.04 per minute). In a validation cohort, observed ROSC (43.8%) did not differ from predicted ROSC (43.7%). The RACA score represents a simple tool and enables comparison between observed and predicted ROSC rates based on readily available variables after CA. Thereby, the RACA score may contribute to preclinical quality assessment and may help analysing the effects of different (post)-resuscitation strategies.

Part 6: Defibrillation

Part 6: Defibrillation

Using within-patient correlation to improve the accuracy of shock outcome prediction for cardiac arrest

Analysis of the electrocardiogram (ECG) can to a certain extent predict if a cardiac arrest patient in ventricular fibrillation will get return of spontaneous circulation (ROSC) if defibrillated. The accuracy of such methods determines how useful it is clinically and for retrospective analysis. We have tested the accuracy of a new shock outcome prediction algorithm that is the first to use an updating algorithm capable of learning from previous shocks within a resuscitation effort. The algorithm relies on known predictive features from the pre-shock ECG, but for each delivered shock it re-estimates the patient-dependent relationship between predictive feature value and probability of ROSC by incorporating the information from the already performed shocks. The predictive features mean-slope, median-slope, cardioversion-outcome-predictor and amplitude-spectrum-analysis originally had areas under the receiver operating characteristics curve of 0.843, 0.846, 0.837 and 0.819, respectively. The improvements in areas after applying the algorithm were (bootstrap estimate of mean improvement, 95% confidence interval in parentheses): mean-slope, 0.019 (0.00036, 0.042); median-slope, 0.024 (0.0013, 0.048); cardioversion-outcome-predictor, 0.021 (0.0010, 0.051); amplitude-spectrum-analysis, 0.026 (0.0016, 0.051). The predictions for the first shock to each patient were not included when calculating the areas, as for the first shocks the new algorithm has no previous shocks to learn from and give predictions identical to those of the original features. It is possible to improve current shock prediction methods by using an updating algorithm capable of learning from previous shocks within a resuscitation effort.

Using ECG-analysis to quantify the effect of increasing pre-shock pauses in chest compressions on the probability of ROSC

Introduction: Pauses in chest compressions are currently required for rhythm analysis and to ensure CPR provider safety during defibrillation. Probability of return of spontaneous circulation (PROSC) after defibrillation attempts is believed to decrease with increasing pause duration. Our aim was to quantify this effect using ECG-analysis during chest compression pauses. A previous study with a similar approach failed to properly handle random short variations in the PROSC estimates. In this work we have overcome this problem.

Association of delay to first intervention with return of spontaneous circulation in a swine model of cardiac arrest

No single drug improves survival after cardiac arrest, despite success in animal studies. We sought to determine the duration of circulatory arrest after which maximal drug treatment and a rescue shock would fail to achieve return of spontaneous circulation (ROSC). Retrospective analysis of 271 swine (20-30 kg) resuscitation attempts during ventricular fibrillation. Protocols were divided into five categories: immediate countershock, cardiopulmonary resuscitation (CPR) with standard-dose drugs, CPR alone, CPR and high-dose epinephrine (CPR+HDE) (0.1 mg/kg), and CPR with a drug cocktail (CPR+DC) of propanolol (1 mg), epinephrine (adrenaline) (0.1 mg/kg) and vasopressin (40IU). Time to first CPR, time to first drug administration, time to first shock, and protocol were examined as predictors of ROSC using logistic regression with Hosmer-Lemeshow test of fit. Probability of ROSC was calculated from logistic curves. ROSC occurred in 119 of the 271 swine (44%). Time to first drug and the CPR+DC group were predictors of ROSC. Time to first CPR, the CPR+DC group, and the CPR+HDE group were also predictors of ROSC. Time to first rescue shock, the CPR+DC group, and the CPR+HDE groups were predictors of ROSC. In the CPR+DC group, 50% ROSC occurred at a first CPR time of 13.4 min, first drug time of 14.1 min and first rescue shock time of 17.5 min. Pre-shock delivery of CPR+DC increases the likelihood of ROSC, and reaches 50% with a time of drug delivery of 14.1 min. ROSC rates of 50% may be achievable using an optimized resuscitation in experimental CPR.

Effects of interrupting precordial compressions on the calculated probability of defibrillation success during out-of-hospital cardiac arrest.

Cardiopulmonary resuscitation (CPR) creates artifacts on the ECG and, with automated defibrillators, a pause in CPR is mandatory during rhythm analysis. The rate of return of spontaneous circulation (ROSC) is reduced with increased duration of this hands-off interval in rats. We analyzed whether similar hands-off intervals in humans with ventricular fibrillation causes changes in the ECG predicting a lower probability of ROSC. The probability of ROSC after a shock was continually determined from ECG signal characteristics for up to 20 seconds of 634 such hands-off intervals in patients with ventricular fibrillation. In hands-off intervals with an initially high (40% to 100%) or median (25% to 40%) probability for ROSC, the probability was gradually reduced with time to a median of 8% to 11% after 20 seconds (P<0.001). In episodes with a low initial probability (0% to 25%; median, 5%), there was no further reduction with time. The interval between discontinuation of chest compressions and delivery of a shock should be kept as short as possible.

Colorimetric end-tidal CO2 detector for verification of endotracheal tube placement in out-of-hospital cardiac arrest.

To evaluate the ability of a disposable, colorimetric end-tidal CO2 detector to verify proper endotracheal (ET) tube placement in out-of-hospital cardiac arrest, and to correlate semiquantitative CO2 measurements with the rate of return of spontaneous circulation (ROSC). Prospective, observational study using a convenience sample of intubated out-of-hospital cardiac arrest patients. A disposable, colorimetric end-tidal CO2 detector was attached to the ET tube after intubation. In the absence of a colorimetric change, the paramedics reassessed the tube placement and could reintubate the patient. Tube placement was verified at the hospital. Paramedics were instructed to contact the base station and report the colorimetric change upon hospital arrival. ROSC was defined as restoration of a self-sustaining pulse until hospital arrival. Between December 1990 and May 1993, ET tubes were placed in 566 victims of out-of-hospital cardiac arrest. 541 of the 566 intubations (95.6%) were associated with a color change. In one case with a color change and out-of-hospital clinical evidence of proper tube placement, the tube was determined to be in the esophagus at the hospital. Correct placement of the remaining 565 of 566 (99.8%) tubes was verified. Of the 566 patients who had a colorimetric change, 91 (16%) had ROSC vs one of 25 (4%) patients who did not have a color change. In one subgroup (n = 179), the degree of color change was highly associated with ROSC (p = 0.004). A disposable, colorimetric end-tidal CO2 detector appears reliable in verifying proper ET tube placement in victims of out-of-hospital cardiac arrest. The degree of color change correlates with the probability of ROSC.