Prognostic Factors for Re-Arrest with Shockable Rhythm during Target Temperature Management in Out-Of-Hospital Shockable Cardiac Arrest Patients

Association between the number of prehospital defibrillation attempts and a sustained return of spontaneous circulation: a retrospective, multicentre, registry-based study

BACKGROUND

Currently, there is no consensus on the number of defibrillation attempts that should be made before transfer to a hospital in patients with out-of-hospital cardiac arrest (OHCA). This study aimed to evaluate the association between the number of defibrillations and a sustained prehospital return of spontaneous circulation (ROSC).

METHODS

A retrospective analysis of a multicentre, prospectively collected, registry-based study in Republic of Korea was conducted for OHCA patients with prehospital defibrillation. The primary outcome was sustained prehospital ROSC, and the secondary outcome was a good neurological outcome at hospital discharge, defined as Cerebral Performance Category score 1 or 2. Cumulative incidence of sustained prehospital ROSC and good neurological outcome according to number of defibrillations were examined. Multivariable logistic regression analysis was used to examine whether the number of defibrillations was independently associated with the outcomes.

RESULTS

Excluding 172 patients with missing data, a total of 1983 OHCA patients who received prehospital defibrillation were included. The median time from arrest to first defibrillation was 10 (IQR 7-15) min. The numbers of patients with sustained prehospital ROSC and good neurological outcome were 738 (37%) and 549 (28%), respectively. Sustained ROSC rates decreased as the number of defibrillation attempts increased from the first to the sixth (16%, 9%, 5%, 3%, 2% and 1%, respectively). The cumulative sustained ROSC rate, and good neurological outcome rate from initial defibrillation to sixth defibrillation were 16%, 25%, 30%, 34%, 36%, 36% and 11%, 18%, 22%, 25%, 26%, 27%, respectively. With adjustment for clinical characteristics and time to defibrillation, a higher number of defibrillations was independently associated with a lower chance of a sustained ROSC (OR 0.81, 95% CI 0.76 to 0.86) and a lower chance of good neurological outcome (OR 0.86, 95% CI 0.80 to 0.92).

CONCLUSIONS

We observed no significant increase in ROSC after five defibrillations, and no absolute increase in ROSC after seven defibrillations. These data provide a starting point for determination of the optimal defibrillation strategy prior to consideration for prehospital extracorporeal cardiopulmonary resuscitation (ECPR) or conveyance to a hospital with an ECPR capability.

TRIAL REGISTRATION NUMBER

NCT03222999.

Bedside monitoring of hypoxic ischemic brain injury using low-field, portable brain magnetic resonance imaging after cardiac arrest

BACKGROUND

Assessment of brain injury severity is critically important after survival from cardiac arrest (CA). Recent advances in low-field MRI technology have permitted the acquisition of clinically useful bedside brain imaging. Our objective was to deploy a novel approach for evaluating brain injury after CA in critically ill patients at high risk for adverse neurological outcome.

METHODS

This retrospective, single center study involved review of all consecutive portable MRIs performed as part of clinical care for CA patients between September 2020 and January 2022. Portable MR images were retrospectively reviewed by a blinded board-certified neuroradiologist (S.P.). Fluid-inversion recovery (FLAIR) signal intensities were measured in select regions of interest.

RESULTS

We performed 22 low-field MRI examinations in 19 patients resuscitated from CA (68.4% male, mean [standard deviation] age, 51.8 [13.1] years). Twelve patients (63.2%) had findings consistent with HIBI on conventional neuroimaging radiology report. Low-field MRI detected findings consistent with HIBI in all of these patients. Low-field MRI was acquired at a median (interquartile range) of 78 (40-136) hours post-arrest. Quantitatively, we measured FLAIR signal intensity in three regions of interest, which were higher amongst patients with confirmed HIBI. Low-field MRI was completed in all patients without disruption of intensive care unit equipment monitoring and no safety events occurred.

CONCLUSION

In a critically ill CA population in whom MR imaging is often not feasible, low-field MRI can be deployed at the bedside to identify HIBI. Low-field MRI provides an opportunity to evaluate the time-dependent nature of MRI findings in CA survivors.

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.