Initial end-tidal carbon dioxide as a prognostic indicator for inpatient PEA arrest

AimInvestigate the relationship of initial PetCO2 values of patients during inpatient pulseless electrical activity (PEA) cardiopulmonary arrest with return of spontaneous circulation (ROSC) and survival to discharge.MethodsThis study was performed in two urban, academic inpatient hospitals. Patients were enrolled from July 2009 to July 2013. A comprehensive database of all inpatient resuscitative events is maintained at these institutions, including demographic, clinical, and outcomes data. Arrests are stratified by primary etiology of arrest using a priori criteria. Inpatients with PEA arrest for whom recorded PetCO2 was available were included in the analysis. Capnography data obtained after ROSC and/or more than 10 min after initiation of CPR were excluded. Multivariable logistic regression was used to explore the association between initial PetCO2 >20 mmHg and both ROSC and survival-to-discharge.ResultsA total of 50 patients with PEA arrest and pre-ROSC capnography were analyzed. CPR continued an average of 11.8 min after initial PetCO2 was recorded confirming absence of ROSC at time of measurement. Initial PetCO2 was higher in patients with versus without eventual ROSC (25.3 ± 14.4 mmHg versus 13.4 ± 6.9 mmHg, P = 0.003). After adjusting for age, gender, and arrest location (ICU versus non-ICU), initial PetCO2 >20 mmHg was associated with increased likelihood of ROSC (adjusted OR 4.8, 95% CI 1.2–19.2, P = 0.028). Initial PetCO2 was not significantly associated with survival-to-discharge (P = 0.251).ConclusionsInitial PetCO2 >20 mmHg during CPR was associated with ROSC but not survival-to-discharge among inpatient PEA arrest victims. This analysis is limited by relatively small sample size.     

P RECIPITOUS B REECH D ELIVERY OF T WINS

Abstract

Introduction. The amount of myocardial perfusion required for successful defibrillation after prolonged cardiac arrest is not known. Coronary perfusion pressure (CPP) is a surrogate for myocardial perfusion. One limited clinical study reported that a threshold of 15 mmHg was necessary for return of spontaneous circulation (ROSC), and that CPP was predictive of ROSC. A distinction between threshold and dose of CPP has not been reported. Objective. To test the hypothesis that swine achieving ROSC will have higher preshock mean CPP and higher preshock area under the CPP curve (AUC) than swine not attaining ROSC. Methods. Data from four similar swine cardiac arrest studies were retrospectively pooled. Animals had undergone 8–11 minutes of untreated ventricular fibrillation, 2 minutes of mechanical cardiopulmonary resuscitation (CPR), administration of drugs, and 3 more minutes of CPR prior to the first shock. Mean CPP ± standard error of the mean (SEM) was derived from the last 20 compressions of each 30-second epoch of CPR and compared between ROSC/no-ROSC groups by repeated-measures analysis of variance (RM-ANOVA). AUC for all compressions delivered over the 5 minutes was calculated by direct summation and compared by Kruskal-Wallis test. Prediction of ROSC was assessed by logistic regression. Results. Throughout the first 5 minutes of CPR (n = 80), mean CPP ± SEM was consistently higher in animals with ROSC (n = 63) (maximum CPP 41.2 ± 0.6 mmHg) than animals with no ROSC (maximum CPP 20.1 ± 0.3 mmHg) (p = 0.0001). Animals with ROSC received more total reperfusion (43.9 ± 17.6 mmHg × 10²) than animals without ROSC (21.4 ± 13.7 mmHg × 10²) (p < 0.001). Two regression models identified CPP (odds ratio [OR] 1.11; 95% confidence interval [CI] 1.05, 1.18) and AUC (OR 1.10; 95% CI 1.05, 1.16) as predictors of ROSC. Experimental study also predicted ROSC in each model (OR 1.70; 95% CI 1.15, 2.50; and OR 1.59; 95% CI 1.12, 2.25, respectively). Conclusion. Higher CPP threshold and dose are associated with and predictive of ROSC.     

Effect of the Abdominal Aortic and Junctional Tourniquet on chest compressions in a swine model of ventricular fibrillation

IntroductionMortality for out-of-hospital cardiac arrest is high when traditional chest compressions are used without adjuncts. The abdominal aortic and junctional tourniquet (AAJT) is a device with a wedge-shaped air bladder that occludes the aortic bifurcation, augmenting blood flow to the heart and brain. Previously, the addition of AAJT during chest compression led to an increase in rate of survival in a model of traumatic cardiac arrest.HypothesisThis study was designed to determine if application of the AAJT would lead to more effective chest compressions as measured by improved hemodynamic parameters and an increased rate of return of spontaneous circulation (ROSC).MethodsYorkshire swine (n = 6 per group) underwent general anesthesia and instrumentation. Ventricular fibrillation (Vfib) was electrically induced and animals were allocated into groups with or without the AAJT. The AAJT was inflated if selected after four minutes of compressions. Following a total of ten minutes of compressions, the animals entered into a ten-minute advanced cardiac life support phase. Hemodynamics and blood gas measurements were compared between groups.ResultsROSC or cardioversion from Vfib was not achieved in either group. The AAJT group had improved hemodynamic parameters with significantly higher carotid diastolic pressure and higher blood flow in the carotid artery (p = 0.016 and 0.028 respectively). However, no significant differences were observed with coronary perfusion pressure or end tidal CO₂.ConclusionThe AAJT did not confer a survival advantage during chest compressions, but hemodynamic improvements were observed while the AAJT was in place.     

Female sex is not associated with improved rates of ROSC or short term survival following prolonged porcine ventricular fibrillation

ObjectivesThere may be a survival benefit in female patients experiencing cardiac arrest, which could affect the interpretation of in vivo animal studies. We hypothesized that sex predicts return of spontaneous circulation (ROSC) and short-term survival (SURV) in porcine studies of prolonged ventricular fibrillation (VF).MethodsRetrospective analysis of eight comparable experiments performed in our lab using mixed-breed domestic swine of either sex. All experiments included prolonged untreated VF, CPR, defibrillation, and drugs. We defined ROSC as systolic blood pressure ≥80 mmHg for ≥1 min. Short-term survival was defined 20 or 60 min, depending on protocol. Categorical variables were compared with chi-square test and Fisher's exact test. Continuous variables were compared with two-sample t-test and one-way ANOVA. Multiple logistic regression determined predictors of ROSC and SURV, utilizing cluster analysis by experimental protocol. Candidate variables were sex, weight, anesthesia duration, VF duration, and CPR ratio.ResultsOf 263 swine analyzed (53.2% male), 58.6% of males and 68.3% of females had ROSC (p = 0.10), whereas 50.0% of males and 61.0% of females experienced SURV (p = 0.07).ResultsOf 263 swine analyzed (53.2% male), 58.6% of males and 68.3% of females had ROSC (p = 0.10), whereas 50.0% of males and 61.0% of females experienced SURV (p = 0.07). Neither sex nor any identified candidate variable predicted ROSC or SURV. Both models had acceptable fit with Hosmer–Lemeshow values of 0.35 and 0.31, respectively.ConclusionsSex predicts neither ROSC nor SURV in a swine model of prolonged VF.     

Pharmacokinetic effects of endotracheal,intraosseous, and intravenous epinephrine in a swine model of traumatic cardiac arrest

IntroductionLimited prospective data exist regarding epinephrine's controversial role in managing traumatic cardiac arrest (TCA). This study compared the maximum concentration (Cmax), time to maximum concentration (Tmax), plasma concentration over time, return of spontaneous circulation (ROSC), time to ROSC, and odds of ROSC of epinephrine administered by the endotracheal (ETT), intraosseous (IO), and intravenous (IV) routes in a swine TCA model.MethodsForty-nine Yorkshire-cross swine were assigned to seven groups: ETT, tibial IO (TIO), sternal IO (SIO), humeral IO (HIO), IV, CPR with defibrillation (CPRD), and CPR only. Swine were exsanguinated 31% of their blood volume and cardiac arrest induced. Chest compressions began 2 min post-arrest. At 4 min post-arrest, 1 mg epinephrine was administered, and blood specimens collected over 4 min. Resuscitation continued until ROSC or 30 min elapsed.ResultsThe Cmax of IV epinephrine was significantly higher than the TIO group (P = 0.049). No other differences in Cmax, Tmax, ROSC, and time to ROSC existed between the epinephrine groups (P > 0.05). Epinephrine levels were detectable in two of seven ETT swine. No significant difference in ROSC existed between the epinephrine groups and CPRD group (P > 0.05). Significant differences in ROSC existed between all groups and the CPR only group (P < 0.05). No significant differences in odds of ROSC were noted.ConclusionsThe pharmacokinetics of IV, HIO, and SIO epinephrine were comparable. Endotracheal epinephrine absorption was highly variable and unreliable compared to IV and IO epinephrine. Epinephrine appeared to have a lesser role than volume replacement in resuscitating TCA.     

Changes of end-tidal carbon dioxide during cardiopulmonary resuscitation from ventricular fibrillation versus asphyxial cardiac arrest

BACKGROUND:

Partial pressure of end-tidal carbon dioxide (P_ETCO₂) has been used to monitor the effectiveness of precordial compression (PC) and regarded as a prognostic value of outcomes in cardiopulmonary resuscitation (CPR). This study was to investigate changes of P_ETCO₂ during CPR in rats with ventricular fibrillation (VF) versus asphyxial cardiac arrest.

METHODS:

Sixty-two male Sprague-Dawley (SD) rats were randomly divided into an asphyxial group (n=32) and a VF group (n=30). P_ETCO₂ was measured during CPR from a 6-minute period of VF or asphyxial cardiac arrest.

RESULTS:

The initial values of P_ETCO₂ immediately after PC in the VF group were significantly lower than those in the asphyxial group (12.8±4.87 mmHg vs. 49.2±8.13 mmHg, P=0.000). In the VF group, the values of P_ETCO₂ after 6 minutes of PC were significantly higher in rats with return of spontaneous circulation (ROSC), compared with those in rats without ROSC (16.5±3.07 mmHg vs. 13.2±2.62 mmHg, P=0.004). In the asphyxial group, the values of P_ETCO₂ after 2 minutes of PC in rats with ROSC were significantly higher than those in rats without ROSC (20.8±3.24 mmHg vs. 13.9±1.50 mmHg, P=0.000). Receiver operator characteristic (ROC) curves of P_ETCO₂ showed significant sensitivity and specificity for predicting ROSC in VF versus asphyxial cardiac arrest.

CONCLUSIONS:

The initial values of P_ETCO₂ immediately after CPR may be helpful in differentiating the causes of cardiac arrest. Changes of P_ETCO₂ during CPR can predict outcomes of CPR.KEY WORDS: Partial pressure of end-tidal carbon dioxide, Cardiac arrest, Cardiopulmonary resuscitation, Return of spontaneous circulation, Rats     

Impact of dispatcher assisted CPR on ROSC rates: A National Cohort Study

IntroductionOut of hospital cardiac arrest (OHCA) is a leading cause of mortality. Bystander CPR is associated with increased OHCA survival rates. Dispatcher assisted CPR (DA-CPR) increases rates of bystander CPR, shockable rhythm prevalence, and improves ROSC rates. The aim of this article was to quantify and qualify DA-CPR (acceptance/rejection), ROSC, shockable rhythms, and associations between factors as seen in MDA, Israel, during 2018.MethodsAll 2018 OHCA incidents in Israel's national EMS database were studied retrospectively. We identified rates and reasons for DA-CPR acceptance or rejection. Reasons DA-CPR was rejected/non-feasible by caller were categorized into 5 groups. ROSC was the primary outcome. We created two study groups: 1) No DA-CPR (n = 542). 2) DA-CPR & team CPR (n = 1768).ResultsDA-CPR was accepted by caller 76.5% of incidents. In group 1, ROSC rates were significantly lower compared to patients in group 2 (12.4% vs. 21.3% p < .001). Group 1 had 12.4% shockable rhythms vs. 17.1% in group 2 (DA-CPR and team CPR). Of the total 369 shockable cases, 42.3% (156) achieved ROSC, in the non-shockable rhythms only 14.8% achieved ROSC.ConclusionsOHCA victims receiving dispatcher assisted bystander CPR have higher rates of ROSC and more prevalence of shockable rhythms. MDA dispatchers offer DA-CPR and it is accepted 76.5% of the time. MDA patients receiving DA-CPR had higher ROSC rates and more shockable rhythms. MDA's age demographic is high, possibly affecting ROSC and shockable rhythm rates.     

The effects of sodium bicarbonate during prolonged cardiopulmonary resuscitation

BackgroundThis study was performed to determine the effects of sodium bicarbonate injection during prolonged cardiopulmonary resuscitation (for > 15 minutes).MethodsThe retrospective cohort study consisted of adult patients who presented to the emergency department (ED) with the diagnosis of cardiac arrest in 2009. Data were retrieved from the institutional database.ResultsA total of 92 patients were enrolled in the study. Patients were divided into 2 groups based on whether they were treated (group1, n = 30) or not treated (group 2, n = 62) with sodium bicarbonate. There were no significant differences in demographic characteristics between groups. The median time interval between the administration of CPR and sodium bicarbonate injection was 36.0 minutes (IQR: 30.5-41.8 minutes). The median amount of bicarbonate injection was 100.2 mEq (IQR: 66.8-104.4). Patients who received a sodium bicarbonate injection during prolonged CPR had a higher percentage of return of spontaneous circulation, but not statistical significant (ROSC, 40.0% vs. 32.3%; P = .465). Sustained ROSC was achieved by 2 (6.7%) patients in the sodium bicarbonate treatment group, with no survival to discharge. No significant differences in vital signs after ROSC were detected between the 2 groups (heart rate, P = .124; systolic blood pressure, P = .094). Sodium bicarbonate injection during prolonged CPR was not associated with ROSC after adjust for variables by regression analysis (Table 3; P = .615; odds ratio, 1.270; 95% confidence interval: 0.501-3.219)ConclusionsThe administration of sodium bicarbonate during prolonged CPR did not significantly improve the rate of ROSC in out-of-hospital cardiac arrest.     

The prognostic value of early lactate clearance for survival after out-of-hospital cardiac arrest

BackgroundPrognostication of survival after out-of-hospital cardiac arrest (OHCA) remains challenging with current guidelines recommending the prognostication no earlier than 72 h after return of spontaneous circulation (ROSC). Prognostic factors that could be used earlier after ROSC, like lactate clearance, are still being studied.ObjectivesThis paper aims to investigate the prognostic strength of early lactate clearance for survival after OHCA.MethodsThis retrospective observational single-center study focuses on patients for whom ROSC was achieved after OHCA. Patients ≥18 years admitted between September 2012 and January 2019, for which arterial serum lactate measurements were available immediately at and 3 h after hospital admission (T0 and T3), were included.Results192 patients were included. Lactate clearance at T3 (p < 0.001) was identified as an independent predictor for 24 h, 48 h and 72 h survival. Witnessed arrest, bystander CPR and initial shockable rhythm were independent significant predictors for long term survival after ROSC (1 month, 3 months and 1 year; p < 0.05), but not for 24 h survival. Age (above or below 65 years) was not significant for predicting survival. Upon combination of witnessed arrest, bystander CPR and initial shockable rhythm in a multivariate logistic regression model for long term survival, the initial rhythm was the dominant factor in the combined model, making witnessed arrest and bystander CPR redundant.ConclusionLactate clearance at T3 after ROSC is associated with 24 h, 48 h and 72 h survival. Further research is needed to determine how to incorporate lactate clearance as part of a clinically useful tool to predict long term survival.     

Effects of an Impedance Threshold Device on Hemodynamics andRestoration of Spontaneous Circulation in Prolonged Porcine Ventricular Fibrillation

Background. An impedance threshold device (ITD) has been designed to enhance circulation during CPR by creating a negative intrathoracic pressure during the relaxation phase of chest compression. Hypothesis. We sought to determine the effects of the ITD on coronary perfusion pressure (CPP), return of spontaneous circulation (ROSC), andshort-term survival (20 minutes after ROSC). We hypothesized that the ITD would improve all 3 variables when compared to standard CPR. Methods. Using a case-control design nested within a randomized primary study, we compared CPR with the ITD (ITD-CPR) to standard CPR without the device (S-CPR). We systematically assigned 36 domestic swine, weighing 23–29 kg, (18 per group) to resuscitation with either ITD-CPR or S-CPR after 8 minutes of untreated ventricular fibrillation (VF). At minute 8, mechanical chest compression andventilation began, anddrugs (0.1 mg/kg epinephrine, 40U vasopressin, 1.0 mg propranolol, 1 mEq/kg sodium bicarbonate) were given. The first rescue shock (150J biphasic) was delivered at minute 11 of VF. We recorded CPP, ROSC (systolic pressure > 80 mmHg sustained for 60 s continuously), andsurvival. Data were analyzed with Fisher's exact test andgeneralized estimating equations (GEE), with alpha = 0.05. Results. We analyzed 3,150 compressions. CPP for the ITD-CPR group (28.1 mmHg [95% CI 27–29.3 mmHg]), did not differ from the S-CPR group (32.3 mmHg [95% CI 31.2–33.4 mmHg]). ROSC occurred in 6/18 (33%) animals in the ITD-CPR, and14/18 (78%) in the S-CPR group (p = 0.02). Survival occurred in 3/18 (17%) ITD-CPR and13/18 (72%) S-CPR group (p = 0.003). Conclusions. ITD-CPR did not improve CPP compared to S-CPR. ROSC andsurvival were significantly lower with ITD-CPR.     

An outcome study of adult in-hospital cardiac arrests in non-monitored areas with resuscitation attempted using AED

ObjectivesTo investigate the outcomes of patients with in-hospital cardiac arrest (IHCA) who underwent cardiopulmonary resuscitation (CPR) using an automated external defibrillator (AED) in non-monitored areas. Additionally, to detect correlated factors associated with rate of return of spontaneous circulation (ROSC) and survival rate, among collected data.MethodsThis study included 109 patients. After investigating patient characteristics and resuscitation-related factors, the correlated factors associated with ROSC rates and survival rate were analyzed using univariate and multivariate analyses.ResultsThe rate of survival to hospital discharge was 21.1%. CPR with AED performed since 2013 was associated with a higher ROSC rate (adjusted odds ratio [AOR] 3.24, 95% confidence interval [CI]: 1.21 to 9.52, p < 0.05), but not with the survival rate after ROSC. Tracheal intubation was significantly associated with a higher ROSC rate (AOR 3.62, 95% CI: 1.27 to 11.7, p < 0.05) and a lower survival rate after ROSC (hazard ratio 6.6, 95% CI: 1.2 to 43.3, p < 0.05). Dysrhythmia as the cause of cardiac arrest and intensive care unit (ICU) admission after ROSC were associated with higher survival rates (hazard ratio 0.056, 95% CI: 0.004 to 0.759, p < 0.05, and hazard ratio 0.072, 95% CI: 0.017 to 0.264, p < 0.0001, respectively).ConclusionsThe factors associated with ROSC rate and those associated with the survival rate after ROSC were different. Although initial shockable rhythms on AED were not associated with the survival rate, dysrhythmia as the etiology of cardiac arrest, and ICU admission were significantly associated with higher survival rates after ROSC.     

Periodic acceleration (pGz) CPR in a swine model of asphyxia induced cardiac arrest. Short-term hemodynamic comparisons

BACKGROUND: Asphyxia is one of the most common causes of pediatric cardiac arrest, and becoming a more frequently recognized cause in adults. Periodic acceleration (pGz) is a novel method of cardiopulmonary resuscitation (CPR). pGz is achieved by rapid motion of the supine body headward-footward that generates adequate perfusion and ventilation during cardiac arrest. In a swine ventricular fibrillation cardiac arrest model, pGz produced a higher return of spontaneous circulation (ROSC), superior neurological outcome, less echocardiography evidence of post resuscitation myocardial stunning, and decreased indices of tissue injury. In contrast to standard chest compression CPR, pGz does not produce rib fractures. We investigated the feasibility of pGz in severe asphyxia cardiac arrest and assessed whether beneficial effects seen in the VF model of cardiac arrest could be realized. METHODS AND RESULTS: Sixteen swine weight 4+/-1 kg were anesthetized, tracheally intubated, and instrumented to measure, hemodynamics and echocardiography. Asphyxia was induced by occlusion of the tracheal tube. After loss of aortic pulsations (median time 10 min) animals were observed for three additional minutes following which all were in cardiac arrest. The animals were then randomized to receive 10 min of pGz or standard chest compression ventilation performed with a commercial device (Thumper). A single dose of epinephrine (adrenaline) and sodium bicarbonate were given and defibrillation attempted if appropriate for a maximum of 10 min. Both groups received fractional inspired O2 concentration of 100% during CPR and after resuscitation. Four animals in each group (50%) had an initial ROSC, however only two of the four initial survivors remained alive 3h after ROSC. There were no significant differences in blood pressure, coronary perfusion pressure during CPR and after early ROSC between groups. pGz treated animals had significantly lower pulmonary artery pressure; 20+/-4 mmHg compared to Thumper 46+/-5 mmHg, 30 min after ROSC (p<0.01). Surviving animals in both groups had severe myocardial dysfunction at 30 min after ROSC. At necropsy, 25% of the Thumper treated animals had rib fractures, while none occurred in the pGz group. CONCLUSIONS: In a lethal model of asphyxia cardiac arrest, pGz is equivalent to standard CPR, with respect to acute outcomes and resuscitation survival rates but is associated with significantly lower pulmonary artery pressures and does not produce traumatic rib fractures.     

Outcome of out-of-hospital cardiac arrest over a period of 15 years in comparison to the RACA score in a physician staffed urban emergency medical service in Germany

BackgroundPatient outcome after out of hospital cardiac arrest (OHCA) depends on the cardiopulmonary resuscitation (CPR) performance and might also be influenced by organisation of the emergency medical service (EMS) and implementation of guidelines.AimTo assess the rate of return of spontaneous circulation (ROSC) after cardiac arrest to the predicted rate by the ROSC after cardiac arrest (RACA) score over a 15-year period reflecting three different implemented ALS-guidelines in a physician-staffed EMS.MethodsAll adult patients with non-traumatic OHCA in the EMS of Bonn from 1996 to 2011 were included. Utstein data from three 5-years time periods (1996–2001, 2001–2006, 2006–2011) representing different ALS-guideline implementations were collected. Group comparisons were made in terms of incidence, epidemiology and short-term outcome of CPR with emphasis on changes over time and factors of importance. In each group observed ROSC rate were compared to the predicted ROSC rates (the RACA score).ResultsCPR by the ALS unit was attempted in a total of 1989 patients (735, 666, and 588 patients in the first, second and third period, respectively). Average crude incidence of CPR per 100,000 person-years decreased over time (61.3; 55.5; 49.0/100,000/years) while patients treated were significantly older (65.5 ± 16.5; 67.9 ± 15; 68.9 ± 15.7 (p < 0.001)). Observed ROSC rates were higher than predicted by the RACA score in all time periods, however, admittance to ICU decreased significantly from 50% in the first five-year period to 38% last five-year period (p < 0.001). From first to third period the proportion of arrests with first observed rhythm of VT/VF arrests did not change (29% vs. 27%, p = 0.323) nor there were changes in bystander CPR rates (17% vs. 17%, p = 0.520).ConclusionsIn a 15-years period and in the setting of a physician-staffed EMS the ROSC rates remain higher than predicted by the RACA score but the admittance to the ICU after OHCA declined significantly. This finding was accompanied by a decrease in CPR incidence and an increase in age of patients.     

Socioeconomic disparities in prehospital cardiac arrest outcomes: An analysis of the NEMSIS database

BackgroundSocioeconomic disparities are engrained in the US healthcare system and may extend to the prehospital cardiac arrest setting where mortality is high.MethodsUsing the National Emergency Medical Services Information System (NEMSIS) database, 150,003 cases were analyzed comparing socioeconomic status and cardiac arrest outcomes. Cardiac arrest outcomes were measured by the percent of cases that achieved return of spontaneous circulation (ROSC) and the percent of cases in which ROSC occurred in the Emergency Department (ED) as opposed to a prehospital setting which was a proxy for the length of time spent in cardiac arrest. Chi-square tests checked for statistical significance and effect size was measured using Pearson's r values and linear regression coefficients.ResultsComparing neighborhood poverty level and the percent of cardiac arrest cases that achieved ROSC resulted in a Pearson's r value of 0.9424 (R² = 0.8881, p < 0.005) and a linear regression coefficient of 2.088 (p < 0.05, R² = 0.8881, 95% CI [1.059, 3.117]) meaning for every interval increase in poverty, the chance of an individual in cardiac arrest achieving ROSC decreases 2.09%. Comparing neighborhood poverty level and the percent of ROSC cases that occurred in the ED yielded a Pearson's r value of 0.9005 (R² = 0.8109, p < 0.05) and a linear regression coefficient of 0.7701 (p < 0.05, R² = 0.8109, 95% CI [0.254, 1.286]) meaning for every interval increase in poverty, the chance that ROSC is delayed increases 0.77%.ConclusionsLow income individuals in cardiac arrest have a statistically significant lower probability of achieving ROSC and a higher chance of delayed ROSC.     

Ethyl pyruvate enhances intra-resuscitation hemodynamics in prolonged ventricular fibrillation arrest

Aims

As the duration of untreated cardiac arrest increases, the effectiveness of standard therapies declines, and may be more harmful than helpful. We investigated the hemodynamic, metabolic and anti-inflammatory effects of Ringer's ethyl pyruvate solution (REPS) versus Ringer's solution (RS) in the acute model of prolonged porcine arrest.

Methods

Seventeen mixed-breed swine were induced into ventricular fibrillation (VF) and left untreated for 8 min. CPR was begun using a mechanical chest compression device at a rate of 100 per minute. At the onset of CPR, animals were randomly assigned to treatment with either 25 mL/kg of RS or 25 mL/kg of REPS containing 40 mg/kg of ethyl pyruvate, infused over 5 min in blinded fashion. CPR continued with administration of a drug cocktail at 2 min and the first rescue shock was delivered at minute 13 of VF. Animals having ROSC were supported with standardized care for 2 h.

Results

Both groups had 100% ROSC and 100% 2-h survival. The REPS group exhibited higher median CPP (27.3 mmHg) than the control group (16.5 mmHg) by 3 min of CPR, which continued throughout the duration of CPR (p = 0.02). The median time to hypotension following ROSC was 9.64 min in the REPS group and 7.25 min in controls (p = 0.04) and there was a non-significant trend of decreased use of vasopressors for the duration of resuscitation. There was no difference in systemic or cerebral metabolism between groups. There were non-significant trends of decreased IL-6, increased Il-10 and decreased mesenteric bacterial colony growth in those treated with REPS when compared to RS.

Conclusions

The administration of REPS with CPR significantly improved intra- and post-resuscitation hemodynamics in this swine model of prolonged cardiac arrest, but did not definitely change the metabolic or inflammatory profile during the acute resuscitation period.     

Comparison of manual and mechanical chest compression techniques using cerebral oximetry in witnessed cardiac arrests at the emergency department: A prospective,randomized clinical study

AimWe aimed to compare regional cerebral oxygen saturation (rSO₂) levels during cardiopulmonary resuscitation (CPR), performed either manually or using a mechanical chest compression device (MCCD), in witnessed cardiac arrest cases in the emergency department (ED), and to evaluate the effects of both the CPR methods and perfusion levels on patient survival and neurological outcomes.MethodsThis single-center, randomized study recruited patients aged ≥18 years who had witnessed a cardiopulmonary arrest in the ED. According to the relevant guidelines, CPR was performed either manually or using an MCCD. Simultaneously, rSO₂ levels were continually measured with near-infrared spectroscopy.ResultsSeventy-five cases were randomly distributed between the MCCD (n = 40) and manual CPR (n = 35) groups. No significant difference in mean rSO₂ levels was found between the MCCD and manual CPR groups (46.35 ± 14.04 and 46.60 ± 12.09, respectively; p = 0.541). However, a significant difference in rSO₂ levels was found between patients without return of spontaneous circulation (ROSC) and those with ROSC (40.35 ± 10.05 and 50.50 ± 13.44, respectively; p < 0.001). In predicting ROSC, rSO₂ levels ≥24% provided 100% sensitivity (95% confidence interval [CI] 92–100), and rSO₂ levels ≥64% provided 100% specificity (95% CI 88–100). The area under the curve for ROSC prediction using rSO₂ levels during CPR was 0.74 (95% CI 0.62–0.83).ConclusionA relationship between ROSC and high rSO₂ levels in witnessed cardiac arrests exists. Monitoring rSO₂ levels during CPR would be useful in CPR management and ROSC prediction. During CPR, MCCD or manual chest compression has no distinct effect on oxygen delivery to the brain.Trial registration: clinicaltrials.gov identifier: NCT03238287.     

Automated pupillometry helps monitor the efficacy of cardiopulmonary resuscitation and predict return of spontaneous circulation

BackgroundWe investigated the effectiveness of automated pupillometry on monitoring cardiopulmonary resuscitation (CPR) and predicting return of spontaneous circulation (ROSC) in a swine model of cardiac arrest (CA).MethodsSixteen male domestic pigs were included. Traditional indices including coronary perfusion pressure (CPP), end-tidal carbon dioxide (ETCO₂), regional cerebral tissue oxygen saturation (rSO₂) and carotid blood flow (CBF) were continuously monitored throughout the experiment. In addition, the pupillary parameters including the initial pupil size before constriction (Init, maximum diameter), the end pupil size at peak constriction (End, minimum diameter), and percentage of change (%PLR) were measured by an automated quantitative pupillometer at baseline, at 1, 4, 7 min during CA, and at 1, 4, 7 min during CPR.ResultsROSC was achieved in 11/16 animals. The levels of CPP, ETCO₂, rSO₂ and CBF were significantly greater during CPR in resuscitated animals than those non-resuscitated ones. Init and End were decreased and %PLR was increased during CPR in resuscitated animals when compared with those non-resuscitated ones. There were moderate to good significant correlations between traditional indices and Init, End, and %PLR (|r| = 0.46–0.78, all P < 0.001). Furthermore, comparable performance was also achieved by automated pupillometry (AUCs of Init, End and %PLR were 0.821, 0.873 and 0.821, respectively, all P < 0.05) compared with the traditional indices (AUCs = 0.809–0.946).ConclusionThe automated pupillometry may serve as an effective surrogate method to monitor cardiopulmonary resuscitation efficacy and predict ROSC in a swine model of cardiac arrest.     

QRS duration predicts outcomes in cardiac arrest survivors undergoing therapeutic hypothermia

BackgroundWhether the electrocardiography (ECG) serial changes predict outcomes in cardiac arrest survivors undergoing therapeutic hypothermia remains unclear.Methods and resultsThis retrospective observational study enrolled 366 adult nontraumatic cardiac arrest survivors who underwent therapeutic hypothermia in a tertiary transfer center during 2006–2018. The ECG at return of spontaneous circulation (ROSC), during hypothermia and after rewarming were analyzed. 295 cardiac arrest survivors were included. Compared with the survivors, the non-survivors had longer QRS durations at the ROSC (118.33 ± 32.47 ms vs 106.88 ± 29.78 ms, p < 0.001) and after rewarming (99.26 ± 25.07 ms vs 93.03 ± 19.09 ms, p = 0.008). The enrolled patients were classified into 4 groups based on QRS duration at the ROSC and after rewarming, namely (1) narrow–narrow (narrow QRS at ROSC and narrow QRS after rewarming, n = 156), (2) narrow–wide (n = 29), (3) wide–narrow (n = 87), and (4) wide–wide (n = 23) group. The wide–wide group had the worst survival rates [odds ratio (OR) = 0.141, p = 0.001], followed by the narrow–wide group (OR 0.223, p = 0.003) and the wide–narrow group (OR 0.389, p = 0.003).ConclusionsIn cardiac arrest survivors given therapeutic hypothermia, QRS durations at the ROSC, after rewarming and their changes may predict survival to hospital discharge.     

Intra-arrest hypothermia: Both cold liquid ventilation with perfluorocarbons and cold intravenous saline rapidly achieve hypothermia,but only cold liquid ventilation improves resumption of spontaneous circulation

BackgroundRapid intra-arrest induction of hypothermia using total liquid ventilation (TLV) with cold perfluorocarbons improves resuscitation outcome from ventricular fibrillation (VF). Cold saline intravenous infusion during cardiopulmonary resuscitation (CPR) is a simpler method of inducing hypothermia. We compared these 2 methods of rapid hypothermia induction for cardiac resuscitation.MethodsThree groups of swine were studied: cold preoxygenated TLV (TLV, n = 8), cold intravenous saline infusion (S, n = 8), and control (C, n = 8). VF was electrically induced. Beginning at 8 min of VF, TLV and S animals received 3 min of cold TLV or rapid cold saline infusion. After 11 min of VF, all groups received standard air ventilation and closed chest massage. Defibrillation was attempted after 3 min of CPR (14 min of VF). The end point was resumption of spontaneous circulation (ROSC).ResultsPulmonary arterial (PA) temperature decreased after 1 min of CPR from 37.2 °C to 32.2 °C in S and from 37.1 °C to 34.8 °C in TLV (S or TLV vs. C p < 0.0001). Coronary perfusion pressure (CPP) was higher in TLV than S animals during the initial 3 min of CPR. Arterial pO₂ was higher in the preoxygenated TLV animals. ROSC was achieved in 7 of 8 TLV, 2 of 8 S, and 1 of 8 C (TLV vs. C, p = 0.03).ConclusionsModerate hypothermia was achieved rapidly during VF and CPR using both cold saline infusion and cold TLV, but ROSC was higher than control only in cold TLV animals, probably due to better CPP and pO₂. The method by which hypothermia is achieved influences ROSC.     

Perfluorocarbon induced intra-arrest hypothermia does not improve survival in a swine model of asphyxial cardiac arrest

Background

Pulseless electrical activity is an important cause of cardiac arrest. Our purpose was to determine if induction of hypothermia with a cold perfluorocarbon-based total liquid ventilation (TLV) system would improve resuscitation success in a swine model of asphyxial cardiac arrest/PEA.

Methods

Twenty swine were randomly assigned to control (C, no ventilation, n = 11) or TLV with pre-cooled PFC (n = 9) groups. Asphyxia was induced by insertion of a stopper into the endotracheal tube, and continued in both groups until loss of aortic pulsations (LOAP) was reached, defined as a pulse pressure less than 2 mmHg. The TLV animals underwent asphyxial arrest for an additional 2 min after LOAP, followed by 3 min of hypothermia, prior to starting CPR. The C animals underwent 5 min of asphyxia beyond LOAP. Both groups then underwent CPR for at least 10 min. The endpoint was the resumption of spontaneous circulation maintained for 10 min.

Results

Seven of 9 animals achieved resumption of spontaneous circulation (ROSC) in the TLV group vs. 5 of 11 in the C group (p = 0.2). The mean pulmonary arterial temperature was lower in total liquid ventilation animals starting 4 min after induction of hypothermia (TLV 36.3 ± 0.2 °C vs. C 38.1 ± 0.2 °C, p < 0.0001). Arterial pO₂ was higher in total liquid ventilation animals at 2.5 min of CPR (TLV 76 ± 12 mmHg vs. C 44 ± 2 mmHg; p = 0.03).

Conclusion

Induction of moderate hypothermia using perfluorocarbon-based total liquid ventilation did not improve ROSC success in this model of asphyxial cardiac arrest.