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

Abstract

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.

Intra-Arrest Therapeutic Hypothermia and Neurologic Outcome in Patients Admitted after Out-of-Hospital Cardiac Arrest: A Post Hoc Analysis of the Princess Trial

“…The main findings from this post hoc analysis are in line with previous publications [ 14 , 15 ]; however, these findings also provide additional evidence to the existing literature. In particular, we evaluated the effects of TNEC only in admitted patients [ 16 ].…”

“…The lack of statistically significant differences between groups might suggest that this analysis was underpowered; as such, future trials’ design and sample size calculation should consider these findings to develop an adequate cohort to test the effectiveness of TNEC in this setting. As in previous publications, most of the benefits of intra-arrest cooling was observed in patients with an initial shockable rhythm [ 13 , 14 , 15 ]. Interestingly, these data do not coincide with those from a previous randomized trial, showing an improvement in neurological outcome when TTM was applied in comatose survivors after cardiac arrest with non-shockable rhythm, when compared to targeted normothermia [ 7 ].…”

“…In a phase-III RCT (PRINCESS), 677 unconscious OHCA patients were randomized to receive either TNEC during CPR or cooling started after hospital arrival [ 14 ]; the proportion of patients achieving good neurological outcome at 90 days was similar between the groups. In a pooled analysis of individual data from these two trials, TNEC was associated with a significant increase in favorable neurological outcome in out-of-hospital cardiac arrest patients with initial shockable rhythms [ 15 ].…”

Update kardiopulmonale Reanimation

“…So mag bei Patienten mit beobachtetem Kreislaufstillstand, durch-geführter Laienreanimation und eher kurzer Reanimationsdauer eine reine Fiebervermeidungsstrategie gegenüber einer Hypothermietherapie nicht von Nachteil sein. Andererseits gibt es weiterhin ausreichend Hinweise, dass Patienten mit einem hohen Risiko für eine hypoxischischämische Enzephalopathie von einer hochqualitativen und frühzeitig eingeleiteten Hypothermietherapie profitieren können [23,24].…”

Strategies of Advanced Airway Management in Out-of-Hospital Cardiac Arrest during Intra-Arrest Hypothermia: Insights from the PRINCESS Trial

“…Targeted temperature management remains an important intervention that may influence survival with good neurological function among cardiac arrest patients [ 16 ]. In particular, intra-arrest cooling using trans-nasal evaporative cooling may provide some benefits on neurologic recovery in patients with initial shockable rhythms (i.e., ventricular fibrillation or pulseless ventricular tachycardia) [ 17 , 18 , 19 ]. Trans-nasal evaporative intra-arrest cooling has emerged as a promising therapeutic strategy in OHCA [ 18 , 20 , 21 ].…”