Brain monitoring after cardiac arrest

Purpose of reviewTo describe the available neuromonitoring tools in patients who are comatose after resuscitation from cardiac arrest because of hypoxic-ischemic brain injury (HIBI).Recent findingsElectroencephalogram (EEG) is useful for detecting seizures and guiding antiepileptic treatment. Moreover, specific EEG patterns accurately identify patients with irreversible HIBI. Cerebral blood flow (CBF) decreases in HIBI, and a greater decrease with no CBF recovery indicates poor outcome. The CBF autoregulation curve is narrowed and right-shifted in some HIBI patients, most of whom have poor outcome. Parameters derived from near-infrared spectroscopy (NIRS), intracranial pressure (ICP) and transcranial Doppler (TCD), together with brain tissue oxygenation, are under investigation as tools to optimize CBF in patients with HIBI and altered autoregulation. Blood levels of brain biomarkers and their trend over time are used to assess the severity of HIBI in both the research and clinical setting, and to predict the outcome of postcardiac arrest coma. Neuron-specific enolase (NSE) is recommended as a prognostic tool for HIBI in the current postresuscitation guidelines, but other potentially more accurate biomarkers, such as neurofilament light chain (NfL) are under investigation.Neuromonitoring provides essential information to detect complications, individualize treatment and predict prognosis in patients with HIBI.Peer reviewe

The impact of COVID-19 on the epidemiology, outcome and management of cardiac arrest

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Does this comatose survivor of cardiac arrest have a poor prognosis?

Neurological prognostication in comatose survivors of cardiac arrest requires a multimodal approach combining clinical and diagnostic tests. Most patients with good outcomes recover consciousness within 72–120 h of arrest, and therefore the suggested timing for prognostication is 72 h from ROSC, or later. Results of earlier prognostic tests, such as status myoclonus and NSE levels, should also be considered at this time point. A careful clinical neurological examination is the cornerstone of prognostic assessment [and it should be performed after major confounders, (e.g. residual sedation,neuromuscular blockade, metabolic derangements) have been excluded.Although absent or extensormotor responses to pain are not specific for predicting a poor neurological outcome, they are highly sensitive for identifying those patients who require neurological prognostication

Prognostication after cardiac arrest

Hypoxic-ischaemic brain injury (HIBI) is the main cause of death in patients who are comatose after resuscitation from cardiac arrest. A poor neurological outcome-defined as death from neurological cause, persistent vegetative state, or severe neurological disability-can be predicted in these patients by assessing the severity of HIBI. The most commonly used indicators of severe HIBI include bilateral absence of corneal and pupillary reflexes, bilateral absence of N 2 O waves of short-latency somatosensory evoked potentials, high blood concentrations of neuron specific enolase, unfavourable patterns on electroencephalogram, and signs of diffuse HIBI on computed tomography or magnetic resonance imaging of the brain. Current guidelines recommend performing prognostication no earlier than 72 h after return of spontaneous circulation in all comatose patients with an absent or extensor motor response to pain, after having excluded confounders such as residual sedation that may interfere with clinical examination. A multimodal approach combining multiple prognostication tests is recommended so that the risk of a falsely pessimistic prediction is minimised

Early Neurological ASsessment with pupillometrY during Cardiac Arrest REsuscitation (EASY-CARE): protocol for an observational multicentre prospective study

IntroductionOut-of-hospital cardiac arrest is burdened with a high rate of ineffective resuscitation and poor neurological outcome among survivors. To date, there are few perfusion assessment tools during cardiopulmonary resuscitation and none of them provide reliable data. Despite the lack of information, physicians must decide whether to extend or terminate resuscitation efforts.Method and analysisThis is a multicentre prospective, observational cohort study, involving adult patients, victims of unexpected out-of-hospital cardiac arrest. Early Neurological ASsessment with pupillometrY during Cardiac Arrest Resuscitation aims to primarily describe the reliability of quantitative pupillometry through use of the Neurological Pupillary Index (NPi) during the manoeuvre of cardiopulmonary resuscitation, as a predictor of the return of spontaneous circulation. The second objective is to seek and describe the association between the NPi and neurological outcome in the surviving cohort. Patients will be excluded if they are less than 18 years of age, have sustained traumatic brain injury, cerebrovascular emergencies, direct injury to the eyes or have pupil anomalies. Neurological outcome will be collected at intensive care unit discharge, at 30 days, 6 months and at 1 year. The Glasgow Coma Scale (GCS) will be used in the emergency department; modified Rankin Score will be adopted for neurological assessment; biomarkers and neurophysiology exams will be collected as well.Ethics and disseminationThe study has been approved by Ethics Committee of Milano. Local committee acceptance is required for each of the centres involved in the clinical and follow-up data collection. Data will be disseminated to the scientific community through original articles submitted to peer-reviewed journals and abstracts to conferences.Trial registration numberNCT05192772

Neurologic prognostication: Neurologic examination and current guidelines

Clinical examination is paramount for prognostication in patients who are comatose after resuscitation from cardiac arrest. At 72 hours from recovery of spontaneous circulation (ROSC), an absent or extensor motor response to pain (M ≤ 2) is a very sensitive, but not specific predictor of poor neurologic outcome. Bilaterally absent pupillary or corneal reflexes are less sensitive, but highly specific predictors. Besides the clinical examination, investigations such as somatosensory evoked potentials (SSEPs), electroencephalography (EEG), blood levels of neuron-specific enolase (NSE), or imaging studies can be used for neuroprognostication. In patients who have not been treated using targeted temperature management (TTM), the 2006 Practice Parameter of the American Academy of Neurology suggested a unimodal approach for prognostication within 72 hours from ROSC, based on status myoclonus (SM) within 24 hours, SSEP, or NSE at 24 to 72 hours and ocular reflexes or M ≤ 2 at 72 hours. The 2015 guidelines from the European Resuscitation Council and the European Society of Intensive Care Medicine suggest a multimodal prognostication algorithm, to be used in both TTM-treated and non-TTM-treated patients with M ≤ 2 at ≥ 72 hours from ROSC. Ocular reflexes (pupillary and corneal) and SSEPs should be used first, followed by a combination of other predictors (SM, EEG, NSE, imaging) if results of the first predictors are normal

Does a combination of ≥2 abnormal tests vs. the ERC-ESICM stepwise algorithm improve prediction of poor neurological outcome after cardiac arrest? A post-hoc analysis of the ProNeCA multicentre study.

BACKGROUND Bilaterally absent pupillary light reflexes (PLR) or N20 waves of short-latency evoked potentials (SSEPs) are recommended by the 2015 ERC-ESICM guidelines as robust, first-line predictors of poor neurological outcome after cardiac arrest. However, recent evidence shows that the false positive rates (FPRs) of these tests may be higher than previously reported. We investigated if testing accuracy is improved when combining PLR/SSEPs with malignant electroencephalogram (EEG), oedema on brain computed tomography (CT), or early status myoclonus (SM). METHODS Post-hoc analysis of ProNeCA multicentre prognostication study. We compared the prognostic accuracy of the ERC-ESICM prognostication strategy vs. that of a new strategy combining ≥2 abnormal results from any of PLR, SSEPs, EEG, CT and SM. We also investigated if using alternative classifications for abnormal SSEPs (absent-pathological vs. bilaterally-absent N20) or malignant EEG (ACNS-defined suppression or burst-suppression vs. unreactive burst-suppression or status epilepticus) improved test sensitivity. RESULTS We assessed 210 adult comatose resuscitated patients of whom 164 (78%) had poor neurological outcome (CPC 3-5) at six months. FPRs and sensitivities of the ≥2 abnormal test strategy vs. the ERC-ESICM algorithm were 0[0-8]% vs. 7 [1-18]% and 49[41-57]% vs. 63[56-71]%, respectively (p < .0001). Using alternative SSEP/EEG definitions increased the number of patients with ≥2 concordant test results and the sensitivity of both strategies (67[59-74]% and 54[46-61]% respectively), with no loss of specificity. CONCLUSIONS In comatose resuscitated patients, a prognostication strategy combining ≥2 among PLR, SSEPs, EEG, CT and SM was more specific than the 2015 ERC-ESICM prognostication algorithm for predicting 6-month poor neurological outcome

In‐Depth Extracorporeal Cardiopulmonary Resuscitation in Adult Out‐of‐Hospital Cardiac Arrest

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Delayed awakening after cardiac arrest: prevalence and risk factors in the Parisian registry

PURPOSE: Although prolonged unconsciousness after cardiac arrest (CA) is a sign of poor neurological outcome, limited evidence shows that a late recovery may occur in a minority of patients. We investigated the prevalence and the predictive factors of delayed awakening in comatose CA survivors treated with targeted temperature management (TTM). METHODS: Retrospective analysis of the Parisian Region Out-of-Hospital CA Registry (2008-2013). In adult comatose CA survivors treated with TTM, sedated with midazolam and fentanyl, time to awakening was measured starting from discontinuation of sedation at the end of rewarming. Awakening was defined as delayed when it occurred after more than 48 h. RESULTS: A total of 326 patients (71 % male, mean age 59 ± 16 years) were included, among whom 194 awoke. Delayed awakening occurred in 56/194 (29 %) patients, at a median time of 93 h (IQR 70-117) from discontinuation of sedation. In 5/56 (9 %) late awakeners, pupillary reflex and motor response were both absent 48 h after sedation discontinuation. In multivariate analysis, age over 59 years (OR 2.1, 95 % CI 1.0-4.3), post-resuscitation shock (OR 2.6 [1.3-5.2]), and renal insufficiency at admission (OR 3.1 [1.4-6.8]) were associated with significantly higher rates of delayed awakening. CONCLUSIONS: Delayed awakening is common among patients recovering from coma after CA. Renal insufficiency, older age, and post-resuscitation shock were independent predictors of delayed awakening. Presence of unfavorable neurological signs at 48 h after rewarming from TTM and discontinuation of sedation did not rule out recovery of consciousness in late awakeners

The present and future of cardiac arrest care : international experts reach out to caregivers and healthcare authorities

The purpose of this review is to describe the epidemiology of out-of-hospital cardiac arrest (OHCA), disparities in organisation and outcome, recent advances in treatment and ongoing controversies. We also outline the standard of care that should be provided by the critical care specialist and propose future directions for cardiac arrest research. Narrative review with contributions from international resuscitation experts. Although it is recognised that survival rates from OHCA are increasing there is considerable scope for improvement and many countries have implemented national strategies in an attempt to achieve this goal. More resources are required to enable high-quality randomised trials in resuscitation. Increasing international collaboration should facilitate resuscitation research and knowledge translation. The International Liaison Committee on Resuscitation (ILCOR) has adopted a continuous evidence review process, which facilitate the implementation of resuscitation interventions proven to improve patient outcomes.Peer reviewe