Post-Hypoxic Myoclonus Status following Out-of-Hospital Cardiac Arrest-Does It still Predict a Poor Outcome? A Retrospective Study.

Anne C Brøchner,Finn L Henriksen,Margrethe J Jensen,Søren Mikkelsen,Palle Toft,Jens F Lassen,Peter Lindholm

doi:10.3390/healthcare10010041

Abstract

In patients with out-of-hospital cardiac arrest (OHCA), the initial prehospital treatment and transfer of patients directly to intervention clinics—bypassing smaller hospitals—have improved outcomes in recent years. Despite the improved treatment strategies, some patients develop myoclonic status following OHCA, and this phenomenon is usually considered an indicator of poor outcome. With this study, we wanted to challenge this perception. The regional prehospital database in Odense in the Region of Southern Denmark was searched for patients with OHCA from the period of 2011–2016. All 900 patients presenting with a diagnosis of OHCA were included in the study. Patients surviving to the hospital and presenting with myoclonic status were followed for up to one year. Only 2 out of 38 patients with myoclonic status and status epilepticus verified by an EEG survived more than one year. Eleven out of 36 patients with myoclonic status but without status epilepticus survived for more than one year. We found no evidence that myoclonic status is an unmistakable sign of poor outcome when not associated with EEG-verified status epilepticus. The conclusion for clinicians involved in post-resuscitation care is that myoclonic status is uncomfortable to witness but does not necessarily indicate that further treatment is futile.

Highlights

In Denmark, each year, approximately 5400 patients have an out-of-hospital cardiac arrest (OHCA)
382 patients were included in the study as having obtained return of spontaneous circulation (ROSC) following OHCA
We found that 19.6% of patients surviving OHCA who were subsequently admitted to a university hospital suffered from myoclonic status after admission

Summary

Introduction

In Denmark, each year, approximately 5400 patients have an out-of-hospital cardiac arrest (OHCA). The Danish 30 day-survival following OHCA is 10.4% [1]. Two-thirds of patients with OHCA that have a return of spontaneous circulation (ROSC) subsequently dies in the hospital due to severe neurological injury [2]. Whereas resuscitation guidelines previously focused on survival rates after cardiac arrest in general, the focus has changed from mere survival to survival with acceptable cerebral performance. Some of the early signs of severe neurological harm are the absence of spontaneous breathing, unconsciousness for more than three days despite discontinuation of sedatives, and absence of brainstem reflexes (pupillary reactivity, spontaneous eye positioning and movements, vestibular–ocular reflexes, corneal reflexes, cough, and gag reflexes). Status epilepticus and myoclonus status are conventionally considered as indicators creativecommons.org/licenses/by/

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