Treating Rhythmic and Periodic EEG Patterns in Comatose Survivors of Cardiac Arrest

Abstract

BACKGROUNDWhether the treatment of rhythmic and periodic electroencephalographic (EEG) patterns in comatose survivors of cardiac arrest improves outcomes is uncertain. METHODSWe conducted an open-label trial of suppressing rhythmic and periodic EEG patterns detected on continuous EEG monitoring in comatose survivors of cardiac arrest. Patients were randomly assigned in a 1:1 ratio to a stepwise strategy of antiseizure medications to suppress this activity for at least 48 consecutive hours plus standard care (antiseizure-treatment group) or to standard care alone (control group); standard care included targeted temperature management in both groups. The primary outcome was neurologic outcome according to the score on the Cerebral Performance Category (CPC) scale at 3 months, dichotomized as a good outcome (CPC score indicating no, mild, or moderate disability) or a poor outcome (CPC score indicating severe disability, coma, or death). Secondary outcomes were mortality, length of stay in the intensive care unit (ICU), and duration of mechanical ventilation. RESULTSWe enrolled 172 patients, with 88 assigned to the antiseizure-treatment group and 84 to the control group. Rhythmic or periodic EEG activity was detected a median of 35 hours after cardiac arrest; 98 of 157 patients (62%) with available data had myoclonus. Complete suppression of rhythmic and periodic EEG activity for 48 consecutive hours occurred in 49 of 88 patients (56%) in the antiseizure-treatment group and in 2 of 83 patients (2%) in the control group. At 3 months, 79 of 88 patients (90%) in the antiseizure-treatment group and 77 of 84 patients (92%) in the control group had a poor outcome (difference, 2 percentage points; 95% confidence interval, −7 to 11; P = 0.68). Mortality at 3 months was 80% in the antiseizure-treatment group and 82% in the control group. The mean length of stay in the ICU and mean duration of mechanical ventilation were slightly longer in the antiseizure-treatment group than in the control group. CONCLUSIONSIn comatose survivors of cardiac arrest, the incidence of a poor neurologic outcome at 3 months did not differ significantly between a strategy of suppressing rhythmic and periodic EEG activity with the use of antiseizure medication for at least 48 hours plus standard care and standard care alone. (Funded by the Dutch Epilepsy Foundation; TELSTAR ClinicalTrials.gov number, NCT02056236.

Neurocritical Care Updates in Cerebrovascular Disease

“…Aggressive treatment of electroencephalographic abnormalities post-CA was similarly disappointing: TEL-STAR (Treatment of Electroencephalographic Status Epilepticus After Cardiopulmonary Resuscitation) randomized 172 patients to standard care with or without complete suppression of rhythmic/periodic electroencephalographic activity for 48 hours. 14 Despite suppression in 56% within the treatment group (versus 2% with standard care), there was no difference in outcome or mortality. However, >60% of the patients had myoclonus which, depending on the electrographic phenotype, may have skewed the population towards unfavorable outcomes regardless of treatment.…”

Adult Critical Care Electroencephalography Monitoring for Seizures: A Narrative Review

“…However, this association is less common when compared to lateralized (LPDs) and bilateral independent periodic discharges (BIPD) (49). Furthermore, the most common etiologies associated with GPDs are often seen in acute brain injury, ischemic/hemorrhagic stroke, and hypoxic-ischemic brain injury (HIBI) patients (50).…”

“…Since the prevalence of seizures is high in HIBI patients, a recent multicenter clinical trial known as the treatment of electroencephalographic status epilepticus after cardiopulmonary resuscitation trail (TELSTAR) was conducted to determine the degree of treatment required by this unique cohort (50,98). This was a multicenter clinical trial that randomized open-label treatment assignments and blinded end-point evaluation of 172 adult post-cardiac arrest patients in 11 ICUs in Europe.…”

“…Mortality at 3 months was 80% in the treatment group and 82% in the control group. The authors highlight limitations to their study that included the trial physicians' ability to withdraw life-sustaining treatment after the 48-h treatment period, the study treating several different patterns that are not clearly ictal in nature, and finally the difficulty in evaluating a sick population who had poor outcomes at the onset (50,98).…”

Not all rhythmicities and periodicities in coma electroencephalography are fatal—When simplification becomes dangerous

“…The multicenter (11 intensive care unit [ICU] centers) TELSTAR Trial, 1 published in The New England Journal of Medicine on Feb 24, 2022, with the Title “Treating Rhythmic and Periodic EEG Patterns in Comatose Survivors of Cardiac Arrest,” investigated whether intensive, stepwise antiseizure and sedative treatment to suppress rhythmic and periodic patterns (RPPs) found on the electroencephalography (EEG) monitoring would change the outcomes in patients with persistent coma once resuscitated from cardiac arrest (CA). The authors included adult patients monitored with continuous EEG initiated less than 24 h after return of spontaneous circulation (ROSC) and revealing any RPPs.…”