Effect of intra-arrest trans-nasal evaporative cooling in out-of-hospital cardiac arrest: a pooled individual participant data analysis

Background

Randomized trials have shown that trans-nasal evaporative cooling initiated during CPR (i.e. intra-arrest) effectively lower core body temperature in out-of-hospital cardiac arrest patients. However, these trials may have been underpowered to detect significant differences in neurologic outcome, especially in patients with initial shockable rhythm.

Methods

We conducted a post hoc pooled analysis of individual data from two randomized trials including 851 patients who eventually received the allocated intervention and with available outcome (“as-treated” analysis). Primary outcome was survival with favourable neurological outcome at hospital discharge (Cerebral Performance Category [CPC] of 1–2) according to the initial rhythm (shockable vs. non-shockable). Secondary outcomes included complete neurological recovery (CPC 1) at hospital discharge.

Results

Among the 325 patients with initial shockable rhythms, favourable neurological outcome was observed in 54/158 (34.2%) patients in the intervention and 40/167 (24.0%) in the control group (RR 1.43 [confidence intervals, CIs 1.01–2.02]). Complete neurological recovery was observed in 40/158 (25.3%) in the intervention and 27/167 (16.2%) in the control group (RR 1.57 [CIs 1.01–2.42]). Among the 526 patients with initial non-shockable rhythms, favourable neurological outcome was in 10/259 (3.8%) in the intervention and 13/267 (4.9%) in the control group (RR 0.88 [CIs 0.52–1.29]; p = 0.67); survival and complete neurological recovery were also similar between groups. No significant benefit was observed for the intervention in the entire population.

Conclusions

In this pooled analysis of individual data, intra-arrest cooling was associated with a significant increase in favourable neurological outcome in out-of-hospital cardiac arrest patients with initial shockable rhythms. Future studies are needed to confirm the potential benefits of this intervention in this subgroup of patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-021-03583-9.

European first responder systems and differences in return of spontaneous circulation and survival after out-of-hospital cardiac arrest: A study of registry cohorts

BACKGROUND

In Europe, survival-rates after out-of-hospital cardiac arrest (OHCA) vary widely between regions. Whether a system dispatching First Responders (FRs; main FR-types: firefighters, police officers, citizen-responders) is present or not may be associated with survival-rates. This study aimed to assess the association between having a dispatched FR-system and rates of return of spontaneous circulation (ROSC) and survival across Europe.

METHODS

Results of an inventory of dispatched FR-systems for OHCA in Europe were combined with aggregate ROSC and survival data from the EuReCa-TWO study and additionally collected data. Regression analysis (weighted on number of patients included per region) was performed to study the association between having a dispatched FR-system and ROSC and survival-rates to hospital discharge in the total population and in patients with shockable initial rhythm, witnessed OHCA and bystander cardiopulmonary resuscitation (CPR; Utstein comparator group). For regions without a dispatched FR-system, the theoretical survival-rate if a dispatched FR-system would have existed was estimated.

FINDINGS

We included 27 European regions. There were 15,859 OHCAs in the total group and 2,326 OHCAs in the Utstein comparator group. Aggregate ROSC and survival-rates were significantly higher in regions with an FR-system compared to regions without (ROSC: 36% [95%CI 35%-37%] vs. 24% [95%CI 23%-25%]; P<0.001; survival in total population [N=15.859]: 13% [95%CI 12%-15%] vs. 5% [95%CI 4%-6%]; P<0.001; survival in Utstein comparator group [N=2326]: 33% [95%CI 30%-36%] vs. 18% [95%CI 16%-20%]; P<0.001), and in regions with more than one FR-type compared to regions with only one FR-type. All main FR-types were associated with higher survival-rates (all P<0.050).

INTERPRETATION

European regions with dispatched FRs showed higher ROSC and survival-rates than regions without.

FUNDING

This project/work has received funding from the European Union's Horizon 2020 research and innovation programme under acronym ESCAPE-NET, registered under grant agreement No 733381 (IO, HLT and MTB) and the European Union's COST programme under acronym PARQ, registered under grant agreement No CA19137 (IO, DC, HLT, MTB). HLT and MTB were supported by a grant from the Netherlands CardioVascular Research Initiative, Dutch Heart Foundation, Dutch Federation of University Medical Centres, Netherlands Organization for Health Research and Development, Royal Netherlands Academy of Sciences - CVON2017-15 RESCUED (HLT), and CVON2018-30 Predict2 (HLT and MTB).

ABCDE cognitive aid tool in patient assessment - development and validation in a multicenter pilot simulation study

Background

The so called ABCDE approach (Airway-Breathing-Circulation-Disability-Exposure) is a golden standard of patient assessment. The efficacy of using cognitive aids (CA) in resuscitation and peri-arrest situations remains an important knowledge gap. This work aims to develop an ABCDE CA tool (CAT) and study its potential benefits in patient condition assessment.

Methods

The development of the ABCDE CAT was done by 3 rounds of modified Delphi method performed by the members of the Advanced Life Support Science and Education Committee of the European Resuscitation Council.

A pilot multicentre study on 48 paramedic students performing patient assessment in pre-post cohorts (without and with the ABCDA CAT) was made in order to validate and evaluate the impact of the tool in simulated clinical scenarios.

The cumulative number and proper order of steps in clinical assessment in simulated scenarios were recorded and the time of the assessment was measured.

Results

The Delphi method resulted in the ABCDE CAT. The use of ABCDE CAT was associated with more performed assessment steps (804: 868; OR = 1.17, 95% CI: 1.02 to 1.35, p = 0.023) which were significantly more frequently performed in proper order (220: 338; OR = 1.68, 95% CI: 1.40 to 2.02, p < 0.0001). The use of ABCDE CAT did not prolong the time of patient assessment.

Conclusion

The cognitive aid for ABCDE assessment was developed. The use of this cognitive aid for ABCDE helps paramedics to perform more procedures, more frequently in the right order and did not prolong the patient assessment in advanced life support and peri-arrest care.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12873-020-00390-3.

Time to intra-arrest therapeutic hypothermia in out-of-hospital cardiac arrest patients and its association with neurologic outcome: a propensity matched sub-analysis of the PRINCESS trial

PURPOSE

To study the association between early initiation of intra-arrest therapeutic hypothermia and neurologic outcome in out-of-hospital cardiac arrest.

METHODS

A prespecified sub-analysis of the PRINCESS trial (NCT01400373) that randomized 677 bystander-witnessed cardiac arrests to transnasal evaporative intra-arrest cooling initiated by emergency medical services or cooling started after hospital arrival. Early cooling (intervention) was defined as intra-arrest cooling initiated < 20 min from collapse (i.e., ≤ median time to cooling in PRINCESS). Propensity score matching established comparable control patients. Primary outcome was favorable neurologic outcome, Cerebral Performance Category (CPC) 1-2 at 90 days. Complete recovery (CPC 1) was among secondary outcomes.

RESULTS

In total, 300 patients were analyzed and the proportion with CPC 1-2 at 90 days was 35/150 (23.3%) in the intervention group versus 24/150 (16%) in the control group, odds ratio (OR) 1.92, 95% confidence interval (CI) 0.95-3.85, p = .07. In patients with shockable rhythm, CPC 1-2 was 29/57 (50.9%) versus 17/57 (29.8%), OR 3.25, 95%, CI 1.06-9.97, p = .04. The proportion with CPC 1 at 90 days was 31/150 (20.7%) in the intervention group and 17/150 (11.3%) in controls, OR 2.27, 95% CI 1.12-4.62, p = .02. In patients with shockable rhythms, the proportion with CPC 1 was 27/57 (47.4%) versus 12/57 (21.1%), OR 5.33, 95% CI 1.55-18.3, p = .008.

CONCLUSIONS

In the whole study population, intra-arrest cooling initiated < 20 min from collapse compared to cooling initiated at hospital was not associated with improved favorable neurologic outcome. In the subgroup with shockable rhythms, early cooling was associated with improved favorable outcome and complete recovery.

First-response treatment after out-of-hospital cardiac arrest: a survey of current practices across 29 countries in Europe

Background

In Europe, survival rates after out-of-hospital cardiac arrest (OHCA) vary widely. Presence/absence and differences in implementation of systems dispatching First Responders (FR) in order to arrive before Emergency Medical Services (EMS) may contribute to this variation. A comprehensive overview of the different types of FR-systems used across Europe is lacking.

Methods

A mixed-method survey and information retrieved from national resuscitation councils and national EMS services were used as a basis for an inventory. The survey was sent to 51 OHCA experts across 29 European countries.

Results

Forty-seven (92%) OHCA experts from 29 countries responded to the survey. More than half of European countries had at least one region with a FR-system. Four categories of FR types were identified: (1) firefighters (professional/voluntary); (2) police officers; (3) citizen-responders; (4) others including off-duty EMS personnel (nurses, medical doctors), taxi drivers. Three main roles for FRs were identified: (a) complementary to EMS; (b) part of EMS; (c) instead of EMS. A wide variation in FR-systems was observed, both between and within countries.

Conclusions

Policies relating to FRs are commonly implemented on a regional level, leading to a wide variation in FR-systems between and within countries. Future research should focus on identifying the FR-systems that most strongly influence survival. The large variation in local circumstances across regions suggests that it is unlikely that there will be a ‘one-size fits all’ FR-system for Europe, but examining the role of FRs in the Chain of Survival is likely to become an increasingly important aspect of OHCA research.

Effect of Trans-Nasal Evaporative Intra-arrest Cooling on Functional Neurologic Outcome in Out-of-Hospital Cardiac Arrest: The PRINCESS Randomized Clinical Trial

IMPORTANCE

Therapeutic hypothermia may increase survival with good neurologic outcome after cardiac arrest. Trans-nasal evaporative cooling is a method used to induce cooling, primarily of the brain, during cardiopulmonary resuscitation (ie, intra-arrest).

OBJECTIVE

To determine whether prehospital trans-nasal evaporative intra-arrest cooling improves survival with good neurologic outcome compared with cooling initiated after hospital arrival.

DESIGN, SETTING, AND PARTICIPANTS

The PRINCESS trial was an investigator-initiated, randomized, clinical, international multicenter study with blinded assessment of the outcome, performed by emergency medical services in 7 European countries from July 2010 to January 2018, with final follow-up on April 29, 2018. In total, 677 patients with bystander-witnessed out-of-hospital cardiac arrest were enrolled.

INTERVENTIONS

Patients were randomly assigned to receive trans-nasal evaporative intra-arrest cooling (n = 343) or standard care (n = 334). Patients admitted to the hospital in both groups received systemic therapeutic hypothermia at 32°C to 34°C for 24 hours.

MAIN OUTCOMES AND MEASURES

The primary outcome was survival with good neurologic outcome, defined as Cerebral Performance Category (CPC) 1-2, at 90 days. Secondary outcomes were survival at 90 days and time to reach core body temperature less than 34°C.

RESULTS

Among the 677 randomized patients (median age, 65 years; 172 [25%] women), 671 completed the trial. Median time to core temperature less than 34°C was 105 minutes in the intervention group vs 182 minutes in the control group (P < .001). The number of patients with CPC 1-2 at 90 days was 56 of 337 (16.6%) in the intervention cooling group vs 45 of 334 (13.5%) in the control group (difference, 3.1% [95% CI, -2.3% to 8.5%]; relative risk [RR], 1.23 [95% CI, 0.86-1.72]; P = .25). In the intervention group, 60 of 337 patients (17.8%) were alive at 90 days vs 52 of 334 (15.6%) in the control group (difference, 2.2% [95% CI, -3.4% to 7.9%]; RR, 1.14 [95% CI, 0.81-1.57]; P = .44). Minor nosebleed was the most common device-related adverse event, reported in 45 of 337 patients (13%) in the intervention group. The adverse event rate within 7 days was similar between groups.

CONCLUSIONS AND RELEVANCE

Among patients with out-of-hospital cardiac arrest, trans-nasal evaporative intra-arrest cooling compared with usual care did not result in a statistically significant improvement in survival with good neurologic outcome at 90 days.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01400373.

Novel patterns of left ventricular mechanical activity during experimental cardiac arrest in pigs

We conducted an experimental study to evaluate the presence of coordinated left ventricular mechanical myocardial activity (LVMA) in two types of experimentally induced cardiac arrest: ventricular fibrillation (VF) and pulseless electrical activity (PEA). Twenty anesthetized domestic pigs were randomized 1:1 either to induction of VF or PEA. They were left in nonresuscitated cardiac arrest until the cessation of LVMA and microcirculation. Surface ECG, presence of LVMA by transthoracic echocardiography and sublingual microcirculation were recorded. One minute after induction of cardiac arrest, LVMA was identified in all experimental animals. In the PEA group, rate of LVMA was of 106+/-12/min. In the VF group, we identified two patterns of LVMA. Six animals exhibited contractions of high frequency (VFhigh group), four of low frequency (VFlow group) (334+/-12 vs. 125+/-32/min, p<0.001). A time from cardiac arrest induction to asystole (19.2+/-7.2 vs. 7.3+/-2.2 vs. 8.3+/-5.5 min, p=0.003), cessation of LVMA (11.3+/-5.6 vs. 4.4+/-0.4 vs. 7.4+/-2.9 min, p=0.027) and cessation of microcirculation (25.3+/-12.6 vs. 13.4+/-2.4 vs. 23.2+/-8.7 min, p=0.050) was significantly longer in VFlow group than in VFhigh and PEA group, respectively. Thus, LVMA is present in both VF and PEA type of induced cardiac arrest and moreover, VF may exhibit various patterns of LVMA.

Determinants of occurrence and survival after sudden cardiac arrest-A European perspective: The ESCAPE-NET project

AIMS

The ESCAPE-NET project ("European Sudden Cardiac Arrest network- towards Prevention, Education and New Effective Treatments") aims to study: (1) risk factors and mechanisms for the occurrence of sudden cardiac arrest (SCA) in the population, and (2) risk factors and treatment strategies for survival after SCA on a European scale.

METHODS

This is an Horizon2020 funded program of the European Union, performed by a European public-private consortium of 16 partners across 10 EU countries. There are 11 deep-phenotyped SCA cohorts for the study of risk factors and treatment strategies for survival after SCA, and 5 deep-phenotyped observational prospective population cohorts for the study of risk factors for occurrence of SCA. Personalized risk scores for predicting SCA onset and for predicting survival after SCA will be derived and validated.

RESULTS

The 11 clinical studies with SCA cases comprise 85,790 SCA cases; the 5 observational prospective population cohorts include 53,060 subjects. A total of 15,000 SCA samples will be genotyped for common and rare variants at the Helmholtz Zentrum München (Germany) using the Illumina Global Screening Array which contains > 770,000 SNPs, and after imputation, a database of an estimated > 9 million variants will be available for genome wide association studies. Standardization of risk factors definition and outcomes is ongoing. An Executive Committee has been created along with a Collaboration Policy document.

CONCLUSION

ESCAPE-NET will complement ongoing efforts on SCA outside Europe and within Europe including the EuReCa project.

Comparison of cold crystalloid and colloid infusions for induction of therapeutic hypothermia in a porcine model of cardiac arrest

Introduction

Large-volume cold intravenous infusion of crystalloids has been used for induction of therapeutic hypothermia after cardiac arrest. However, the effectiveness of cold colloids has not been evaluated. Therefore, we performed an experimental study to investigate the cooling effect of cold normal saline compared to colloid solution in a porcine model of ventricular fibrillation.

Methods

Ventricular fibrillation was induced for 15 minutes in 22 anesthetized domestic pigs. After spontaneous circulation was restored, the animals were randomized to receive either 45 ml/kg of 1°C cold normal saline (Group A, 9 animals); or 45 ml/kg of 1°C cold colloid solution (Voluven®, 6% hydroxyethyl starch 130/0.4 in 0.9% NaCl) during 20 minutes (Group B, 9 animals); or to undergo no cooling intervention (Group C, 4 animals). Then, the animals were observed for 90 minutes. Cerebral, rectal, intramuscular, pulmonary artery, and subcutaneous fat body temperatures (BT) were recorded. In the mechanical ex-vivo sub study we added a same amount of cold normal saline or colloid into the bath of normal saline and calculated the area under the curve (AUC) for induced temperature changes.

Results

Animals treated with cold fluids achieved a significant decrease of BT at all measurement sites, whereas there was a consistent significant spontaneous increase in group C. At the time of completion of infusion, greater decrease in pulmonary artery BT and cerebral BT in group A compared to group B was detected (−2.1 ± 0.3 vs. -1.6 ± 0.2°C, and −1.7 ± 0.4 vs. -1.1 ± 0.3°C, p < 0.05, respectively). AUC analysis of the decrease of cerebral BT revealed a more vigorous cooling effect in group A compared to group B (−91 ± 22 vs. -68 ± 23°C/min, p = 0.046). In the mechanical sub study, AUC analysis of the induced temperature decrease of cooled solution revealed that addition of normal saline led to more intense cooling than colloid solution (−7155 ± 647 vs. -5733 ± 636°C/min, p = 0.008).

Conclusions

Intravenous infusion of cold normal saline resulted in more intense decrease of cerebral and pulmonary artery BT than colloid infusion in this porcine model of cardiac arrest. This difference is at least partially related to the various specific heat capacities of the coolants.

Out-of-hospital cardiac arrest from air embolism during sexual intercourse: Case report and review of the literature

We report the successful resuscitation of a 38-year-old woman in cardiac arrest following heterosexual intercourse 7 days after spontaneous abortion and an instrumental uterine evacuation. The collapse was thought to be due to venous air embolism (VAE). Her survival neurologically intact was attributed to appropriate first aid, pre-hospital and subsequent hospital intensive care. Neither a case of an out-of-hospital air embolism where the patient made a good recovery, nor a case of miscarriage followed by collapse from air embolism has been reported in the literature. Air embolism is a very infrequent cause of out-of-hospital cardiac arrest with a high mortality rate. Predominant causal reasons are severe penetrating neck or thoracic injuries and sexual activities in pregnancy, when air can pass into the damaged veins in the wall of the uterus and lead to total obstruction in the heart. Diagnostics and management techniques for venous air embolism are discussed. Air embolism should be included in the differential diagnosis for all young women in cardiac arrest, particularly when occurring during sexual activity. Instructions in risks of sexual intercourse during pregnancy and the puerperium should become part of pregnant women's education.