The design of the PRINCESS 2 trial: A randomized trial to study the impact of ultrafast hypothermia on complete neurologic recovery after out-of-hospital cardiac arrest with initial shockable rhythm.

BACKGROUND: Delayed hypothermia, initiated after hospital arrival, several hours after cardiac arrest with 8-10 hours to reach the target temperature, is likely to have limited impact on overall survival. However, the effect of ultrafast hypothermia, i.e., delivered intra-arrest or immediately after return of spontaneous circulation (ROSC), on functional neurologic outcome after out-of-hospital cardiac arrest (OHCA) is unclear. In two prior trials, prehospital trans-nasal evaporative intra-arrest cooling was safe, feasible and reduced time to target temperature compared to delayed cooling. Both studies showed trends towards improved neurologic recovery in patients with shockable rhythms. The aim of the PRINCESS2-study is to assess whether cooling, initiated either intra-arrest or immediately after ROSC, followed by in-hospital hypothermia, significantly increases survival with complete neurologic recovery as compared to standard normothermia care, in OHCA patients with shockable rhythms. METHODS/DESIGN: In this investigator-initiated, randomized, controlled trial, the emergency medical services (EMS) will randomize patients at the scene of cardiac arrest to either trans-nasal cooling within 20 minutes from EMS arrival with subsequent hypothermia at 33°C for 24 hours after hospital admission (intervention), or to standard of care with no prehospital or in-hospital cooling (control). Fever (>37,7°C) will be avoided for the first 72 hours in both groups. All patients will receive post resuscitation care and withdrawal of life support procedures according to current guidelines. Primary outcome is survival with complete neurologic recovery at 90 days, defined as modified Rankin scale (mRS) 0-1. Key secondary outcomes include survival to hospital discharge, survival at 90 days and mRS 0-3 at 90 days. In total, 1022 patients are required to detect an absolute difference of 9% (from 45 to 54%) in survival with neurologic recovery (80% power and one-sided α=0,025, ß=0,2) and assuming 2,5% lost to follow-up. Recruitment starts in Q1 2024 and we expect maximum enrolment to be achieved during Q4 2024 at 20-25 European and US sites. DISCUSSION: This trial will assess the impact of ultrafast hypothermia applied on the scene of cardiac arrest, as compared to normothermia, on 90-day survival with complete neurologic recovery in OHCA patients with initial shockable rhythm. TRIAL REGISTRATION: NCT06025123.

Early ECPR for out-of-hospital cardiac arrest: Best practice in 2018.

Extracorporeal CPR is a second line treatment for refractory cardiac arrest, as written in the latest International Guidelines. Optimal timing, patient selection, location and method of implementation vary across the world. The objective here is to present an international consensus on the pillars of an ECPR program. The major aspect the group agrees on in that ECPR should be implemented within 60 minutes of collapse. With this in mind, the program should be built according to local resources knowing that the optimal team will require pre-established specific roles with personnel dedicated to resuscitation and others to ECPR.

Traumatic cardiac arrest: should advanced life support be initiated?

BACKGROUND: Several studies recommend not initiating advanced life support in traumatic cardiac arrest (TCA), mainly owing to the poor prognosis in several series that have been published. This study aimed to analyze the survival of the TCA in our series and to determine which factors are more frequently associated with recovery of spontaneous circulation (ROSC) and complete neurologic recovery (CNR). METHODS: This is a cohort study (2006-2009) of treatment benefits. RESULTS: A total of 167 TCAs were analyzed. ROSC was obtained in 49.1%, and 6.6% achieved a CNR. Survival rate by age groups was 23.1% in children, 5.7% in adults, and 3.7% in the elderly (p < 0.05). There was no significant difference in ROSC according to which type of ambulance arrived first, but if the advanced ambulance first, 9.41% achieved a CNR, whereas only 3.7% if the basic ambulance first. We found significant differences between the response time and survival with a CNR (response time was 6.9 minutes for those who achieved a CNR and 9.2 minutes for those who died). Of the patients, 67.5% were in asystole, 25.9% in pulseless electrical activity (PEA), and 6.6% in VF. ROSC was achieved in 90.9% of VFs, 60.5% of PEAs, and 40.2% of those in asystole (p < 0.05), and CNR was achieved in 36.4% of VFs, 7% of PEAs, and 2.7% of those in asystole (p < 0.05). The mean (SD) quantity of fluid replacement was greater in ROSC (1,188.8 [786.7] mL of crystalloids and 487.7 [688.9] mL of colloids) than in those without ROSC (890.4 [622.4] mL of crystalloids and 184.2 [359.3] mL of colloids) (p < 0.05). CONCLUSION: In our series, 6.6% of the patients survived with a CNR. Our data allow us to state beyond any doubt that advanced life support should be initiated in TCA patients regardless of the initial rhythm, especially in children and those with VF or PEA as the initial rhythm and that a rapid response time and aggressive fluid replacement are the keys to the survival of these patients. LEVEL OF EVIDENCE: Therapeutic study, level IV; epidemiologic study, level III.

Epidemiologic intervention framework of a prehospital emergency medical service.

OBJECTIVES: To describe and analyze the characteristics of prehospital medical assistance provided by the Madrid Municipal Emergency and Civil Rescue & Protection Service (SAMUR); and, based on the epidemiologic knowledge so gained, to prioritize public health intervention strategies. METHODS: A retrospective cross-sectional analysis of all medical services performed by the SAMUR-Protección Civil in 2001 and 2002. Study variables included causes, response times, hour, day of the week, month, mobile resource, Municipal District, and pathology. For analysis purposes, the relevant data were linked to Access 97 via Open Database Connectivity. Statistical analysis was performed using the SPSS computer software package, with Spearman's correlation coefficient and analysis of variance. Values were deemed statistically significant at p < 0.05. RESULTS: The study population comprised the 97,937 and 101,438 interventions undertaken in 2001 and 2002, respectively. Mean daily activity in 2002 involved 278 alerts (standard deviation: 46), 95% confidence interval: 273-282. Distributions of the interventions were similar for 2001 and 2002, with peak activity from 1 to 2 pm and 8 to 9 pm, and minimum activity from 6 to 7 am. Activity was at its most intense on Saturdays. The magnitude of the association between the two years by day of the week was 96% (p < 0.001). The Central Municipal District (Centro) triggered 17,875 emergency actions. The prevalent pathology was traumatologic, followed by cardiovascular. CONCLUSIONS: Epidemiologic description enabled the characteristics of the prehospital assistance procedure to be comprehensively ascertained and quantified. False alarms assume special relevance due to their implications. Emergency medical alerts with a psychosocial component are on the increase, something that must be controlled.