Survival and Rearrest in out-of-Hospital Cardiac Arrest Patients with Prehospital Return of Spontaneous Circulation: A Prospective Multi-Regional Observational Study

Post-ROSC Atrial fibrillation is not associated with rearrest but is associated with stroke and mortality following out of hospital cardiac arrest

BACKGROUND

Atrial fibrillation (AF) in patients resuscitated from cardiac arrest (CA) is associated with increased short-term mortality. However, whether this is because AF adversely affects early resuscitation success, causes post-resuscitation morbidity, or because it is a marker for patient co-morbidities, remains unclear. We aimed to determine the prevalence of AF in patients with ROSC to test the hypothesis that AF is associated with increased risk of rearrest and to determine its impact on mortality and stroke risk.

METHODS

We performed a retrospective study of emergency medical services patients with OHCA and ROSC. To examine long-term morbidity and mortality due to AF, an additional observational cohort analysis was performed using a large electronic health record (EHR) database.

RESULTS

One hundred nineteen patients with ROSC prior to ED arrival were identified. AF was observed in 39 (33%) of patients. Rearrest was not different between AF and no AF groups (44% vs. 41%, p = 0.94). In the EHR analysis, mortality at one year in patients who developed AF was 59% vs. 39% in no AF patients. Odds of stroke was 5x greater in AF patients (p < 0.001), with the majority not anticoagulated (93%, p < 0.001) and comorbidities were greater p < 0.001).

CONCLUSIONS

AF was common following ROSC and not associated with rearrest. AF after CA was associated with increased mortality and stroke risk. These data suggest rhythm control for AF in the immediate post-ROSC period is not warranted; however, vigilance is required for patients who develop persistent AF, particularly with regards to stroke risk and prevention.

A retrospective, multi-agency 'target trial emulation' for the comparison of post-resuscitation epinephrine to norepinephrine

INTRODUCTION

Epinephrine and norepinephrine are the two most commonly used prehospital vasopressors in the United States. Prior studies have suggested that use of a post-ROSC epinephrine infusion may be associated with increased rearrest and mortality in comparison to use of norepinephrine. We used target trial emulation methodology to compare the rates of rearrest and mortality between the groups of OHCA patients receiving these vasopressors in the prehospital setting.

METHODS

Adult (18-80 years of age) non-traumatic OHCA patients in the 2018-2022 ESO Data Collaborative datasets with a documented post-ROSC norepinephrine or epinephrine infusion were included in this study. Logistic regression modeling was used to evaluate the association between vasopressor agent and outcome using two sets of covariables. The first set of covariables included standard Utstein factors, the dispatch to ROSC interval, the ROSC to vasopressor interval, and the follow-up interval. The second set added prehospital systolic blood pressure and SpO2 values. Kaplan-Meier time-to-event analysis was also conducted and the vasopressor groups were compared using a multivariable Cox regression model.

RESULTS

Overall, 1,893 patients treated by 309 EMS agencies were eligible for analysis. 1,010 (53.4%) received an epinephrine infusion and 883 (46.7%) received a norepinephrine infusion as their initial vasopressor. Adjusted analyses did not discover an association between vasopressor agent and rearrest (aOR: 0.93 [0.72, 1.21]) or mortality (aOR: 1.00 [0.59, 1.69]).

CONCLUSIONS

In this multi-agency target trial emulation, the use of a post-resuscitation epinephrine infusion was not associated with increased odds of rearrest in comparison to the use of a norepinephrine infusion.

The association of clinical, treatment, and demographic characteristics with rearrest in a national dataset

INTRODUCTION

Following initial resuscitation from out-of-hospital cardiac arrest, rearrest frequently occurs and has been associated with adverse outcomes. We aimed to identify clinical, treatment, and demographic characteristics associated with prehospital rearrest at the encounter and agency levels.

METHODS

Adult non-traumatic cardiac arrest patients who achieved ROSC following EMS resuscitation in the 2018-2021 ESO annual datasets were included in this study. Patients were excluded if they had a documented DNR/POLST or achieved ROSC after bystander CPR only. Rearrest was defined as post-ROSC CPR initiation, administration of ≥ 1 milligram of adrenaline, defibrillation, or a documented non-perfusing rhythm on arrival at the receiving hospital. Multivariable logistic regression modeling was used to evaluate the association between rearrest and case characteristics. Linear regression modeling was used to evaluate the association between agency-level factors (ROSC rate, scene time, and scene termination rate), and rearrest rate.

RESULTS

Among the 53,027 cases included, 16,116 (30.4%) experienced rearrest. Factors including longer response intervals, longer 'low-flow' intervals, unwitnessed OHCA, and a lack of bystander CPR were associated with rearrest. Among agencies that treated ≥ 30 patients with outcome data, the agency-level rate of rearrest was inversely associated with agency-level rate of survival to discharge to home (R2 = -0.393, p < 0.001).

CONCLUSIONS

This multiagency retrospective study found that factors associated with increased ischaemic burden following OHCA were associated with rearrest. Agency-level rearrest frequency was inversely associated with agency-level survival to home. Interventions that decrease the burden of ischemia sustained by OHCA patients may decrease the rate of rearrest and increase survival.

A novel predictor of unsustained return of spontaneous circulation in cardiac arrest patients through a combination of capnography and pulse oximetry: a multicenter observational study

BACKGROUND

Unsustained return of spontaneous circulation (ROSC) is a critical barrier to survival in cardiac arrest patients. This study examined whether end-tidal carbon dioxide (ETCO2) and pulse oximetry photoplethysmogram (POP) parameters can be used to identify unsustained ROSC.

METHODS

We conducted a multicenter observational prospective cohort study of consecutive patients with cardiac arrest from 2013 to 2014. Patients' general information, ETCO2, and POP parameters were collected and statistically analyzed.

RESULTS

The included 105 ROSC episodes (from 80 cardiac arrest patients) comprised 51 sustained ROSC episodes and 54 unsustained ROSC episodes. The 24-hour survival rate was significantly higher in the sustained ROSC group than in the unsustained ROSC group (29.2% vs. 9.4%, P<0.05). The logistic regression analysis showed that the difference between after and before ROSC in ETCO2 (ΔETCO2) and the difference between after and before ROCS in area under the curve of POP (ΔAUCp) were independently associated with sustained ROSC (odds ratio [OR]=0.931, 95% confidence interval [95% CI] 0.881-0.984, P=0.011 and OR=0.998, 95% CI 0.997-0.999, P<0.001). The area under the receiver operating characteristic curve of ΔETCO2, ΔAUCp, and the combination of both to predict unsustained ROSC were 0.752 (95% CI 0.660-0.844), 0.883 (95% CI 0.818-0.948), and 0.902 (95% CI 0.842-0.962), respectively.

CONCLUSION

Patients with unsustained ROSC have a poor prognosis. The combination of ΔETCO2 and ΔAUCp showed significant predictive value for unsustained ROSC.

Dynamic Course of Clinical State Transitions in Patients Undergoing Advanced Life Support after Out-of-Hospital Cardiac Arrest

OBJECTIVES

Studies of out-of-hospital cardiac arrest generally document the presenting (pulseless electrical activity [PEA], ventricular fibrillation/tachycardia (VF/VT), asystole), and the final states (resuming stable spontaneous circulation [s-ROSC], being declared dead). Only a few studies described the transitions between clinical states during advanced life support (ALS). The aim of this study was to describe and analyze the dynamics of state transitions during ALS.

METHODS

A retrospective analysis of 464 OHCA events was conducted. Any observed state and its corresponding changing time were documented through continuous electrocardiographic and trans-thoracic impedance recording.

RESULTS

When achieved, most s-ROSCs were obtained by 30 min, regardless of the presenting state. After this time point, the persistence of any transient state was associated with a great probability of being declared dead. The most probable change for VF/VT or PEA at any time was the transition to asystole (36.4% and 34.4%, respectively); patients in asystole at any time had a 70% probability of death. Patients achieving s-ROSC mostly came from a VF/VT state.In most cases, the presenting rhythm tended to persist over time during ALS. Asystole was the most stable state; a higher degree of instability was observed when the presenting rhythms were VF/VT or PEA. Transient ROSC episodes occurred mainly as the first transition after the presenting state, especially for initial PEA.

CONCLUSIONS

An understanding of the dynamic course of clinical state transitions during ALS may allow treatment strategies to be tailored in patients affected by OHCA.

Saline versus Plasma Solution-A in Initial Resuscitation of Patients with Out-of-Hospital Cardiac Arrest: A Randomized Clinical Trial

BACKGROUND

Although saline is commonly used during cardiopulmonary resuscitation (CPR) or post-cardiac arrest care, it has detrimental effects. This trial aimed to evaluate the efficacy of a balanced crystalloid solution (Plasma Solution-A [PS]) in out-of-hospital cardiac arrest (OHCA) patients and compare it with the efficacy of saline.

METHODS

A randomized, unblinded clinical trial was conducted using PS and saline for intravenous fluid administration during CPR and post-cardiac arrest care of non-traumatic OHCA patients admitted to the emergency department of a tertiary university hospital. Patients received saline (saline group) or PS (PS group) within 24 h of hospital arrival. The primary outcomes were changes in arterial pH, bicarbonate, base excess (BE), and chloride levels within 24 h. The secondary outcomes were clinical outcomes including mortality.

RESULTS

Of the 364 patients, data from 27 and 26 patients in the saline and PS groups, respectively, were analyzed. Analysis using a linear mixed model revealed a significant difference in BE change over time between the groups (treatment-by-time p = 0.044). Increase in BE and bicarbonate levels from 30 min to 2 h was significantly greater (p = 0.044 and p = 0.024, respectively) and the incidence of hyperchloremia was lower (p < 0.001) in the PS group than in the saline group. However, there was no difference in clinical outcomes.

CONCLUSION

Use of PS for resuscitation resulted in a faster improvement in BE and bicarbonate, especially in the early phase of post-cardiac arrest care, and lower hyperchloremia incidence than the use of saline, without differences in clinical outcomes, in OHCA patients.

Association between a Post-Resuscitation Care Bundle and the Odds of Field Rearrest after Successful Resuscitation from Out-of-Hospital Cardiac Arrest: A Pre/Post Study

OBJECTIVES

Rearrest after successful resuscitation from out-of-hospital cardiac arrest (OHCA) is common and is associated with worse patient outcomes. However, little is known about the effect of interventions designed to prevent rearrest. We assessed the association between a prehospital care protocol for immediate management after return of spontaneous circulation (ROSC) and rates of field rearrest and survival to discharge in patients with prehospital ROSC.

METHODS

This was a retrospective study of adult patients with OHCA and field ROSC within a large EMS system before (April 2017-August 2018) and after (April 2019-February 2020) implementation of a structured prehospital post-ROSC care protocol. The protocol was introduced in September 2018 and provided on-scene stabilization direction including guidance on ventilation and blood pressure support. Field data and hospital outcomes were used to compare the frequency of field rearrest, hospital survival, and survival with good neurologic outcome before and after protocol implementation. Logistic regression was used to assess the association between the post-implementation period and these outcomes, and odds ratios were reported. The association between individual interventions on these outcomes was also explored.

RESULTS

There were 2,706 patients with ROSC after OHCA in the pre-implementation period and 1,780 patients in the post-implementation period. The rate of prehospital rearrest was 43% pre-implementation vs 45% post-implementation (RD 2%, 95% CI -1, 4%). In the adjusted analysis, introduction of the protocol was not associated with decreased odds of rearrest (OR 0.87, 95% CI 0.73, 1.04), survival to hospital discharge (OR 1.01, 95% CI 0.81, 1.24), or survival with good neurologic outcome (OR 0.81, 95% CI 0.61, 1.06). Post-implementation, post-ROSC administration of saline and push-dose epinephrine increased from 11% to 25% (RD 14%, 95% CI 11, 17%) and from 3% to 12% (RD 9% 95% CI 7, 11%), respectively. In an exploratory analysis, push-dose epinephrine was associated with a decreased odds of rearrest (OR 0.68, 95% CI 0.50, 0.94).

CONCLUSIONS

Introduction of a post-ROSC care protocol for patients with prehospital ROSC after OHCA was not associated with reduced odds of field rearrest. When elements of the care bundle were considered individually, push-dose epinephrine was associated with decreased odds of rearrest.

Association of prehospital post-resuscitation peripheral oxygen saturation with survival following out-of-hospital cardiac arrest

BACKGROUND

Hypoxia and hyperoxia following resuscitation from out-of-hospital cardiac arrest (OHCA)may cause harm by exacerbating secondary brain injury. Our objective was to retrospectively examine theassociationof prehospital post-ROSC hypoxia and hyperoxia with the primary outcome of survival to discharge home.

METHODS

We utilized the 2019-2021 ESO Data Collaborative public use research datasets for this study (ESO, Austin, TX). Average prehospital SpO₂, lowest recorded prehospital SpO₂, and hypoxia dose were calculated for each patient. Theassociationof these measures with survival was explored using multivariable logistic regression. We also evaluated theassociationof American Heart Association (AHA) and European Resuscitation Council (ERC) recommended post-ROSC SpO₂ target ranges with outcome.

RESULTS

After application of exclusion criteria, 19,023 patients were included in this study. Of these, 52.3% experienced at least one episode of post-ROSC hypoxia (lowest SpO₂ < 90%) and 19.6% experienced hyperoxia (average SpO₂ > 98%). In comparison to normoxic patients, patients who were hypoxic on average (AHA aOR: 0.31 [0.25, 0.38]; ERC aOR: 0.34 [0.28, 0.42]) and patients who had a hypoxic lowest recorded SpO₂ (AHA aOR: 0.48 [0.39, 0.59]; ERC aOR: 0.52 [0.42, 0.64]) had lower adjusted odds of survival. Patients who had a hyperoxic average SpO₂ (AHA aOR: 0.75 [0.59, 0.96]; ERC aOR: 0.68 [0.53, 0.88]) and patients who had a hyperoxic lowest recorded SpO₂ (AHA aOR: 0.66 [0.48, 0.92]; ERC aOR: 0.65 [0.46, 0.92]) also had lower adjusted odds of survival.

CONCLUSION

Prehospital post-ROSC hypoxia and hyperoxia were associated with worse outcomes in this dataset.

Rearrest during hospitalisation in adult comatose out-of-hospital cardiac arrest patients: Risk factors and prognostic impact, and predictors of favourable long-term outcomes

BACKGROUND

Rearrest occurs commonly after initial resuscitation following out-of-hospital cardiac arrest (OHCA). We determined (1) the predictors of rearrest during hospitalisation that can be identified in the hours immediately after OHCA, (2) the association between rearrest and favourable long-term outcomes, and (3) the predictors of favourable long-term outcomes in rearrest patients.

METHODS

Conditional multivariable logistic regression analyses were performed using the Korean Hypothermia Network prospective registry data, which included details of adult OHCA patients treated with targeted temperature management at 22 teaching hospitals in South Korea.

RESULTS

Among the 1,233 patients, 260 (21.1%) experienced rearrest. Of the 192 patients resuscitated from first rearrest, 33 (17.2%) achieved 6-month favourable outcomes. Arrhythmia, heart failure, ST-segment elevation, lower initial Glasgow coma scale (GCS) motor score, higher initial lactate level, and antiarrhythmic drug use within 1 h were independently associated with rearrest. Higher lactate level and antiarrhythmic drug use were associated with shockable first rearrest, while arrhythmia, heart failure, ST-segment elevation, and lower GCS motor score were associated with non-shockable first rearrest. Rearrest was independently associated with a lower likelihood of 6-month favourable outcomes (P = 0.003). Initial shockable rhythm after OHCA, absence of diabetes, shorter cumulative time to restoration of spontaneous circulation, coronary angiography, and hypophosphataemia within 7 d were independently associated with 6-month favourable outcomes in the patients resuscitated from first rearrest.

CONCLUSIONS

Rearrest during hospitalisation after OHCA was inversely associated with 6-month favourable outcomes. We identified several risk factors for rearrest and prognostic factors for patients resuscitated from first rearrest.