Comatose Cardiac Arrest Patients Research Articles

Additional predictive value of optic nerve sheath diameter for neurological prognosis after cardiac arrest: a prospective cohort study

BackgroundThe goal is to estimate the additional value of ultrasonographic optic nerve sheath diameter (ONSD) measurement on days 1–3, on top of electroencephalography (EEG), pupillary light reflexes (PLR), and somatosensory evoked potentials (SSEP), for neurological outcome prediction of comatose cardiac arrest patients. We performed a prospective longitudinal cohort study in adult comatose patients after cardiac arrest. ONSD was measured on days 1–3 using ultrasound. Continuous EEG, PLR, and SSEP were acquired as standard care. Poor outcome was defined as cerebral performance categories 3–5 at 3–6 months. Logistic regression models were created for outcome prediction based on the established predictors with and without ONSD. Additional predictive value was assessed by increase in sensitivity for poor (at 100% specificity) and good outcome (at 90% specificity).ResultsWe included 100 patients, 54 with poor outcome. Mean ONSD did not differ significantly between patients with good and poor outcome. Sensitivity for predicting poor outcome increased by adding ONSD to EEG and SSEP from 25% to 41% in all patients and from 27% to 50% after exclusion of patients with non-neurological death.ConclusionsONSD on days 1–3 after cardiac arrest holds potential to add to neurological outcome prediction.Trialregistration: clinicaltrials.gov, NCT04084054. Registered 10 September 2019, https://www.clinicaltrials.gov/study/NCT04084054.

Abstract 188: Association Between Mean Arterial Pressure and Neurological Outcomes in Comatose Cardiac Arrest Patients: A Multicenter Observational Study

Aim: The target blood pressure has not been determined in comatose cardiac arrest patients. Therefore, we aimed to investigate the association between mean arterial pressure (MAP) and six-month neurological outcomes in out-of-hospital cardiac arrest (OHCA) survivors who underwent targeted temperature management (TTM). Methods: We analyzed the prospective registry of comatose OHCA survivors who underwent TTM. The arterial blood pressure measured every 1 hr in a 48-hour period after return of spontaneous circulation (ROSC) was recorded between January 2019 and May 2021 in the registry. We calculated the MAP during 48 hr and at every 6 hr. Patients with an MAP < 65 mmHg or missing MAP data for more than 6 hr were excluded. We conducted a multivariable logistic regression analysis to determine the association between MAP and neurological outcomes and conducted a linear mixed models analysis to reveal the interaction between MAP over time and neurological outcomes. The primary outcome was six-month neurological outcomes with Cerebral Performance Category (CPC), which was dichotomized into good (CPC 1 or 2) and poor (CPC 3-5) neurological outcomes. Results: Of the 394 included patients, 255 patients (64.7%) had poor neurological outcomes. MAP did not differ between the neurological outcome groups (poor [89 mmHg, 82-97 mmHg] vs. good [89 mmHg, 84-95 mmHg]; p = 0.498). MAP was not independently associated with poor neurological outcomes (odds ratio, 1.010 [95% confidence intervals, 0.978-1.042]) adjusted with age, sex, body mass index, pre-existing illness (coronary artery disease, diabetes, pulmonary disease, renal impairment), witnessed collapse, first-monitored rhythm, cardiac etiology, downtime, lactate level after ROSC, and sequential organ failure assessment score. Repeated MAP measurements every 6 hr did not differ between the neurological outcome groups (p = 0.403), and the interaction between MAP every 6hr and neurological outcomes was not significant (p = 0.136). Conclusions: MAP during 48 hr after ROSC was not associated with the six-month neurological outcomes. MAP measurements every 6 hr during 48 hr after ROSC did not differ between neurological outcome groups, and the changes in MAP over time were not associated with neurological outcomes.

Increased task-relevant fMRI responsiveness in comatose cardiac arrest patients is associated with improved neurologic outcomes

Early prediction of the recovery of consciousness in comatose cardiac arrest patients remains challenging. We prospectively studied task-relevant fMRI responses in 19 comatose cardiac arrest patients and five healthy controls to assess the fMRI’s utility for neuroprognostication. Tasks involved instrumental music listening, forward and backward language listening, and motor imagery. Task-specific reference images were created from group-level fMRI responses from the healthy controls. Dice scores measured the overlap of individual subject-level fMRI responses with the reference images. Task-relevant responsiveness index (Rindex) was calculated as the maximum Dice score across the four tasks. Correlation analyses showed that increased Dice scores were significantly associated with arousal recovery (P < 0.05) and emergence from the minimally conscious state (EMCS) by one year (P < 0.001) for all tasks except motor imagery. Greater Rindex was significantly correlated with improved arousal recovery (P = 0.002) and consciousness (P = 0.001). For patients who survived to discharge (n = 6), the Rindex’s sensitivity was 75% for predicting EMCS (n = 4). Task-based fMRI holds promise for detecting covert consciousness in comatose cardiac arrest patients, but further studies are needed to confirm these findings. Caution is necessary when interpreting the absence of task-relevant fMRI responses as a surrogate for inevitable poor neurological prognosis.

Cortical somatosensory evoked potential amplitudes and clinical outcome after cardiac arrest: a retrospective multicenter study

ObjectiveBilaterally absent cortical somatosensory evoked potentials (SSEPs) reliably predict poor outcome in comatose cardiac arrest (CA) patients. Cortical SSEP amplitudes are a recent prognostic extension; however, amplitude thresholds, inter-recording, and inter-rater agreement remain uncertain.MethodsIn a retrospective multicenter cohort study, we determined cortical SSEP amplitudes of comatose CA patients using a standardized evaluation pathway. We studied inter-recording agreement in repeated SSEPs and inter-rater agreement by four raters independently determining 100 cortical SSEP amplitudes. Primary outcome was assessed using the cerebral performance category (CPC) upon intensive care unit discharge dichotomized into good (CPC 1–3) and poor outcome (CPC 4–5).ResultsOf 706 patients with SSEPs with median 3 days after CA, 277 (39.2%) had good and 429 (60.8%) poor outcome. Of patients with bilaterally absent cortical SSEPs, one (0.8%) survived with CPC 3 and 130 (99.2%) had poor outcome. Otherwise, the lowest cortical SSEP amplitude in good outcome patients was 0.5 µV. 184 (42.9%) of 429 poor outcome patients had lower cortical SSEP amplitudes. In 106 repeated SSEPs, there were 6 (5.7%) with prognostication-relevant changes in SSEP categories. Following a standardized evaluation pathway, inter-rater agreement was almost perfect with a Fleiss’ kappa of 0.88.InterpretationBilaterally absent and cortical SSEP amplitudes below 0.5 µV predicted poor outcome with high specificity. A standardized evaluation pathway provided high inter-rater and inter-recording agreement. Regain of consciousness in patients with bilaterally absent cortical SSEPs rarely occurs. High-amplitude cortical SSEP amplitudes likely indicate the absence of severe brain injury.

CT perfusion for Assessment of poor Neurological outcome in Comatose Cardiac Arrest Patients (CANCCAP): protocol for a prospective study

IntroductionCardiac arrest remains one of the most common causes of death with the majority occurring outside of hospitals (out of hospital cardiac arrest). Despite advancements in resuscitation management, approximately 50%...

Influence of blood-pressure and oxygen levels on the prognostic value of quantitative pupillometry for comatose cardiac arrest patients - a BOX-trial substudy

Abstract Funding Acknowledgements Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Novo Nordisk Foundation Background Quantitative pupillometry has been implemented in resuscitation guidelines as part of multimodal prognostication in comatose out-of-hospital cardiac arrest (OHCA) patients. Post-resuscitation intensive care allows for different blood-pressure and oxygen targets, but evidence on the implication of these targets on prognostication is limited. Purpose To assess the impact of different blood-pressure and oxygen targets in resuscitated OHCA patients on the prognostic ability of the quantitatively assessed percentage reduction of pupillary size (qPLR, %) and the neurological pupil index (NPi, 0-5). Methods The BOX-trial is a multicenter, double-blind, randomized trial, comparing low (63 mm Hg) versus high (77 mm Hg) mean arterial blood-pressure targets and restrictive (9 to 10 kPa) versus liberal (13 to 14 kPa) partial pressure of arterial oxygen targets in comatose survivors of OHCA. In this predefined, prospective substudy, quantitative pupillometry measurements were obtained from consecutively enrolled patients at 0, 24, 48, 72, 96, and 120 hours after OHCA (t0-t120). The prognostic performance of qPLR and NPi for high and low blood-pressure groups, and liberal and restrictive oxygen target groups were illustrated through the area under the receiver operating characteristic (ROC) curves (AUC). The time point achieving the highest AUC was used for further analyses. AUCs were compared with DeLong’s test. Results The highest AUC for qPLR and NPi were achieved for measurements made 48 hours after OHCA. qPLR produced AUC at 0.79 [95%CI 0.73-0.85] and 0.81 [95%CI 0.75-0.86] for high and low blood-pressure groups, and 0.79 [95%CI 0.73-0.85] and 0.80 [95%CI 0.74-0.86] for liberal and restrictive oxygen target groups, respectively (Fig 1). For NPi AUC were 0.79 [95%CI 0.73-0.85] and 0.78 [95%CI 0.72-0.84] in high and low blood-pressure groups, and 0.77 [95%CI 0.71-0.83] and 0.80 [95%CI 0.75-0.86] in liberal and restrictive oxygen target groups, respectively (Fig 2). No significant difference between any groups, for either blood-pressure or oxygen targets, was found. Conclusion Prognostic value of quantitative pupillometry for predicting outcome in resuscitated OHCA patients was high and consistent across different blood-pressure and oxygen level targets.

Pain pupillary index to prognosticate unfavorable outcome in comatose cardiac arrest patients

BackgroundThe prognostic role of the Pupillary Pain Index (PPI), derived from automated pupillometry, remains unknown in post-anoxic brain injury. MethodsSingle-center retrospective study in adult comatose cardiac arrest (CA) patients. Quantitative PPI and Neurologic Pupil Index (NPi) were concomitantly recorded on day 1 and day 2 after CA. The primary outcome was to assess the prognostic value of PPI to predict 3-month unfavourable outcome (UO, defined as Cerebral Performance Category of 3–5). Secondary outcome was the agreement between PPI and NPi to predict unfavourable outcome. ResultsA total of 102 patients were included; patients with UO (n = 69, 68%) showed a lower NPi (4.2 [3.5–4.5] vs. 4.6 [4.3–4.7]; p < 0.01 on day 1–4.3 [3.8–4.7] vs 4.6 [4.3–4.8] on day 2), and PPI (3 [1–6] vs. 6 [3–7]; p < 0.01 on day 1–3 [1–6] vs 6 [4–8]; p < 0.01 on day 2) than others. A PPI = 1 on day 2 showed a sensitivity of 26 [95% CI 16–38]% and a specificity of 100 [95% CI 89–100]% to predict UO (p = 0.003 vs. NPi ≤ 2). On day 2, a total of 6 patients had concomitant PPI = 1 and NPi ≤ 2, while 12 showed NPi > 2 and PPI = 1; the coefficient of agreement was 0.42. Moreover, NPi and PPI values showed a moderate correlation both on day 1 and day 2. ConclusionsIn this study, PPI = 1 on day 2 could predict UO in comatose CA patients with 100% specificity, but with a low sensitivity (yet higher than NPi). The agreement between PPI and NPi values was moderate.

Severe cerebral edema in substance-related cardiac arrest patients

BackgroundStudies of neurologic outcomes have found conflicting results regarding differences between patients with substance-related cardiac arrests (SRCA) and non-SRCA. We investigate the effects of SRCA on severe cerebral edema development, a neuroimaging intermediate endpoint for neurologic injury. Methods327 out-of-hospital comatose cardiac arrest patients were retrospectively analyzed. Demographics and baseline clinical characteristics were examined. SRCA categorization was based on admission toxicology screens. Severe cerebral edema classification was based on radiology reports. Poor clinical outcomes were defined as discharge Cerebral Performance Category scores > 3. ResultsSRCA patients (N = 86) were younger (P < 0.001), and more likely to have non-shockable rhythms (P < 0.001), be unwitnessed (P < 0.001), lower Glasgow Coma Scale scores (P < 0.001), absent brainstem reflexes (P < 0.05) and develop severe cerebral edema (P < 0.001) than non-SRCA patients (N = 241). Multivariable analyses found younger age (P < 0.001), female sex (P = 0.008), non-shockable rhythm (P = 0.01) and SRCA (P = 0.05) to be predictors of severe cerebral edema development. Older age (P < 0.001), non-shockable rhythm (P = 0.02), severe cerebral edema (P < 0.001), and absent pupillary light reflexes (P = 0.004) were predictors of poor outcomes. SRCA patients had higher proportion of brain deaths (P < 0.001) compared to non-SRCA patients. ConclusionsSRCA results in higher rates of severe cerebral edema development and brain death. The absence of statistically significant differences in discharge outcomes or survival between SRCA and non-SRCA patients may be related to the higher rate of withdrawal of life-sustaining treatment (WLST) in the non-SRCA group. Future neuroprognostic studies may opt to include neuroimaging markers as intermediate measures of neurologic injury which are not influenced by WLST decisions.

Comparing Doppler Echocardiography and Thermodilution for Cardiac Output Measurements in a Contemporary Cohort of Comatose Cardiac Arrest Patients Undergoing Targeted Temperature Management.

Measuring cardiac output is used to guide treatment during postresuscitation care. The aim of this study was to compare Doppler echocardiography (Doppler-CO) with thermodilution using pulmonary artery catheters (PAC-CO) for cardiac output estimation in a large cohort of comatose out-of-hospital cardiac arrest (OHCA) patients undergoing targeted temperature management (TTM). Single-center substudy of 141 patients included in the TTM trial randomly assigned to 33 or 36°C for 24 hours after OHCA. Per protocol, PAC-CO and Doppler-CO were measured simultaneously shortly after admission and again at 24 and 48 hours. Linear correlation was assessed between methods and positive predictive value (PPV) and negative predictive value (NPV) of Doppler to estimate low cardiac output (<3.5 L/min) was calculated. A total of 301 paired cardiac output measurements were available. Average cardiac output was 5.28 ± 1.94 L/min measured by thermodilution and 4.06 ± 1.49 L/min measured by Doppler with a mean bias of 1.22 L/min (limits of agreements -1.92 to 4.36 L/min). Correlation between methods was moderate (R2 = 0.36). Using PAC-CO as the gold standard, PPV of a low cardiac output measurement (<3.5 L/min) by Doppler was 33%. However, the NPV was 92%. Hypothermia at 33°C did not negatively affect the correlations of CO methods. In the lowest quartile of Doppler, 13% had elevated lactate (>2 mmol/L). In the lowest quartile of thermodilution, 36% had elevated lactate (>2 mmol/L). In ventilated OHCA patients, the two methods for estimating cardiac output correlated moderately and there was a consistent underestimation of Doppler-CO. Absolute cardiac output values from Doppler-CO should be interpreted with caution. However, Doppler can be used to exclude low cardiac output with high accuracy. TTM at 33°C did not negatively affect the correlation or bias of cardiac output measurements. ClinicalTrials.gov ID: NCT01020916.

Awakening from post anoxic coma with burst suppression with identical bursts

BackgroundElectroencephalography (EEG) is commonly used after cardiac arrest. Burst suppression with identical bursts (BSIB) has been reported as a perfectly specific predictor of poor outcome but published case series are small. We describe two patients with BSIB who awakened from coma after cardiac arrest. MethodsWe identified two out-of-hospital cardiac arrest (OHCA) patients with coma and BSIB. We determined the etiology of arrest, presenting neurological examination, potential confounders to neurological assessment, neurodiagnostics and time to awakening. We reviewed and interpreted EEGs using 2021 American Clinical Neurophysiology Society guidelines. We quantified identicality of bursts by calculating pairwise correlation coefficients between the first 500 ms of each aligned burst. ResultsIn case one we present a 62-year-old man with OHCA secondary to septic shock. EEG showed burst suppression pattern, with bursts consisted of high amplitude generalized spike waves in lock-step with myoclonus (inter-burst correlation = 0.86). He followed commands 3 days after arrest, when repeat EEG showed a continuous, variable and reactive background without epileptiform activity. Case two was a 49-year-old woman with OHCA secondary to polysubstance overdose. Initial EEG revealed burst suppression with high amplitude generalized polyspike-wave bursts with associated myoclonus. She followed commands on post-arrest day 4, when repeat EEG showed a continuous, variable and reactive background with frequent runs of bifrontal predominant sharply contoured rhythmic delta activity. ConclusionThese cases highlight the perils of prognosticating with a single modality in comatose cardiac arrest patients.

A Review of the Electrophysiological Neuroprognostications after Out of Hospital Cardiac Arrest

This personal opinion review of the potential role for EEG in the multimodal neuroprognostication of comatose cardiac arrest patients, after resuscitation and targeted temperature management, discusses recent findings along with our personal experience from a large single-center cohort of 220 consecutive patients investigated with electrophysiological tests (EEG and SSEP). Although EEG has its limitations, along with all modalities in the multimodal prognostic framework, when timed appropriately and interpreted in a standardized fashion, it can be probabilistic but not deterministic of an individual patient’s neurological prognosis. The EEG phenotype can indicate both good and poor prognoses for a comatose patient on the Intensive Care Unit, which is a distinct advantage of this widely available modality, whilst an SSEP can reliably predict a poor outcome if absent and may also help predict good outcome using amplitude analysis.

The capacity of neurological pupil index to predict absence of somatosensory evoked potentials after cardiac arrest—A study protocol

Anoxic-ischemic brain injury is the most common cause of death after cardiac arrest (CA). Robust methods to detect severe injury with a low false positive rate (FPR) for poor neurological outcome include the pupillary light reflex (PLR) and somatosensory evoked potentials (SSEP). The PLR can be assessed manually or with automated pupillometry which provides the neurological pupil index (NPi). We aim to describe the interrelation between NPi values and the absence of SSEP cortical response and to evaluate the capacity of NPi to predict the absence of cortical SSEP response in comatose patients after CA. A total of 50 patients will be included in an explorative, prospective, observational study of adult (>18years) comatose survivors of CA admitted to intensive care in a university hospital. NPi assessed with a hand-held pupillometer will be compared to SSEP signals recorded >48hours after CA. Primary outcomes are sensitivity, specificity, and odds ratio for NPi to predict bilateral absence of the SSEP N20 signal, with NPi values corresponding to <5% FPRs of SSEP absence. Secondary outcomes are the PLR and SSEP sensitivity, specificity, and odds ratio for poor neurological outcome at hospital discharge and death at 30days. The PLR and SSEP may have a systematic interrelation, and a certain NPi threshold could potentially predict the absence of cortical SSEP response. If this can be concluded from the present study, SSEP testing could be excluded in certain patients to save resources in the multimodal prognostication after CA. Editorial comment The interrelation between loss of the pupillary light reflex (PLR) and the loss of cortical response to a somatosensory evoked potential (SSEP) in comatose cardiac arrest patients is not known. This exploratory prospective study is designed to evaluate whether a specific degree of attenuated PLR, as measured by semiautomated pupillometry, can predict the bilateral loss of cortical SSEP response in severe anoxic/ischemic brain injury. Such an interrelation between the two methods would enable the use of pupillometry rather than the more resource demanding SSEP for neurologic prognostication in post cardiac arrest patients. ClinicalTrials.gov, NCT04720482, Registered 21 January 2021, retrospectively registered.

The first national survey on practices of neurological prognostication after cardiac arrest in China, still a lot to do

To investigate current awareness and practices of neurological prognostication in comatose cardiac arrest (CA) patients. An anonymous questionnaire was distributed to 1600 emergency physicians in 75 hospitals which were selected randomly from China between January and July 2018. 92.1% respondents fulfilled the survey. The predictive value of brain stem reflex, motor response and myoclonus was confirmed by 63.5%, 44.6% and 31.7% respondents, respectively. Only 30.7% knew that GWR value<1.1 indicated poor prognosis and only 8.1% know the most commonly used SSEP N20. Status epilepticus, burst suppression and suppression were considered to predict poor outcome by only 35.0%, 27.4% and 20.9% respondents, respectively. Only 46.7% knew NSE and only 24.7% knew S-100. Only a few respondents knew that neurological prognostication should be performed later than 72hours from CA either in TTM or non-TTM patients. In practice, the most commonly used method was clinical examination (85.4%). Only 67.9% had used brain CT for prognosis and 18.4% for MRI. NSE (39.6%) was a little more widely used than S-100β (18.0%). However, SSEP (4.4%) and EEG (11.4%) were occasionally performed. Neurological prognostication in CA survivors had not been well understood and performed by emergency physicians in China. They were more likely to use clinical examination rather than objective tools, especially SSEP and EEG, which also illustrated that multimodal approach was not well performed in practice.

Reduced EEG montage has a high accuracy in the post cardiac arrest setting

ObjectiveTo study if comatose cardiac arrest patients can be assessed with a reduced number of EEG electrodes. Methods110 routine EEGs from 67 consecutive patients, including both hypothermic and normothermic EEGs were retrospectively assessed by three blinded EEG-experts using two different electrode montages. A standard 19-electrode-montage was compared to the reduced version of the same EEGs, down-sampled to six electrodes (F3, T3, P3, F4, T4, P4). We used intra-rater and inter-observer statistics to assess the reliability of the reduced montage for background features and discharges. ResultsThe reduced montage had almost perfect performance for background continuity (κ 0.80–0.88), including identification of highly malignant backgrounds (burst-suppression/suppression) (κ 0.85–0.94) and benign backgrounds (continuous/nearly continuous) (κ 0.85–0.91). We found substantial performance for identifying rhythmic/periodic discharges (κ 0.79–0.86). The reduced montage had high accuracy for assessment of both highly malignant (sensitivity 91–95%, specificity 94–99%) and benign (sensitivity 89–98%, specificity 91–96%) backgrounds, and periodic/rhythmic patterns (sensitivity 79–100%, specificity 89–99%), compared to the full montage. The inter-observer variability was not increased by the reduced montage. ConclusionReduced EEG had high performance for classifying important background and discharge patterns in this post cardiac arrest cohort. SignificanceOur results support the use of reduced EEG-montage for monitoring comatose cardiac arrest patients.

Serum GFAP and UCH-L1 for the prediction of neurological outcome in comatose cardiac arrest patients

ObjectiveNeurological outcome prediction is crucial early after cardiac arrest. Serum biomarkers released from brain cells after hypoxic-ischaemic injury may aid in outcome prediction. The only serum biomarker presently recommended in the European Resuscitation Council prognostication guidelines is neuron-specific enolase (NSE), but NSE has limitations. In this study, we therefore analyzed the outcome predictive accuracy of the serum biomarkers glial fibrillary acidic protein (GFAP) and ubiquitin C-terminal hydrolase-L1 (UCH-L1) in patients after cardiac arrest. MethodsSerum GFAP and UCH-L1 were collected at 24, 48 and 72 h after cardiac arrest. The primary outcome was neurological function at 6-month follow-up assessed by the cerebral performance category scale (CPC), dichotomized into good (CPC1-2) and poor (CPC3-5). Prognostic accuracies were tested with receiver-operating characteristics by calculating the area under the receiver-operating curve (AUROC) and compared to the AUROC of NSE. Results717 patients were included in the study. GFAP and UCH-L1 discriminated between good and poor neurological outcome at all time-points when used alone (AUROC GFAP 0.88–0.89; UCH-L1 0.85–0.87) or in combination (AUROC 0.90–0.91). The combined model was superior to GFAP and UCH-L1 separately and NSE (AUROC 0.75–0.85) at all time-points. At specificities ≥95%, the combined model predicted poor outcome with a higher sensitivity than NSE at 24 h and with similar sensitivities at 48 and 72 h. ConclusionGFAP and UCH-L1 predicted poor neurological outcome with high accuracy. Their combination may be of special interest for early prognostication after cardiac arrest where it performed significantly better than the currently recommended biomarker NSE.

Standardized EEG analysis to reduce the uncertainty of outcome prognostication after cardiac arrest.

Post-resuscitation guidelines recommend a multimodal algorithm for outcome prediction after cardiac arrest (CA). We aimed at evaluating the prevalence of indeterminate prognosis after application of this algorithm and providing a strategy for improving prognostication in this population. We examined a prospective cohort of comatose CA patients (n = 485) in whom the ERC/ESICM algorithm was applied. In patients with an indeterminate outcome, prognostication was investigated using standardized EEG classification (benign, malignant, highly malignant) and serum neuron-specific enolase (NSE). Neurological recovery at 3months was dichotomized as good (Cerebral Performance Categories [CPC] 1-2) vs. poor (CPC 3-5). Using the ERC/ESICM algorithm, 155 (32%) patients were prognosticated with poor outcome; all died at 3months. Among the remaining 330 (68%) patients with an indeterminate outcome, the majority (212/330; 64%) showed good recovery. In this patient subgroup, absence of a highly malignant EEG by day 3 had 99.5 [97.4-99.9] % sensitivity for good recovery, which was superior to NSE < 33μg/L (84.9 [79.3-89.4] % when used alone; 84.4 [78.8-89] % when combined with EEG, both p < 0.001). Highly malignant EEG had equal specificity (99.5 [97.4-99.9] %) but higher sensitivity than NSE for poor recovery. Further analysis of the discriminative power of outcome predictors revealed limited value of NSE over EEG. In the majority of comatose CA patients, the outcome remains indeterminate after application of ERC/ESICM prognostication algorithm. Standardized EEG background analysis enables accurate prediction of both good and poor recovery, thereby greatly reducing uncertainty about coma prognostication in this patient population.

The association between duration of mechanical ventilation and survival in post cardiac arrest patients

PurposeTo assess the association between the duration of mechanical ventilation during post resuscitation care and 30-day survival after cardiac arrest. MethodsWe conducted a retrospective observational study using data from two national registries. Comatose cardiac arrest patients admitted to general intensive care in Swedish hospitals between 2011 and 2016 were eligible. Based on the median duration of mechanical ventilation for patients who did not survive to hospital discharge, used as a proxy for the endurance of post resuscitation care, the hospitals were divided into four ordered groups for which association with 30-day survival was analyzed. ResultsIn total, 5.113 patients in 56 hospitals were included. Median duration of mechanical ventilation for patients who did not survive to hospital discharge ranged from 17 h in hospital group 1–51 hours in hospital group 4. After adjustment for baseline characteristics, 30-day survival in the entire cohort was positively and independently associated with ordered hospital group: (adjusted odds ratio (95%CI); 1.12 (1.02,1.23); p = 0.02). Thus, hospitals with a longer duration of mechanical ventilation among non-survivors had better survival rate among patients admitted to ICU after a cardiac arrest. However, in a secondary analysis restricted to patients with length of stay in the intensive care unit ≥ 48 h, there was no significant association between 30-day survival and ordered hospital group. ConclusionA tendency for longer duration of post resuscitation care in the ICU was associated with higher 30-day survival in comatose patients admitted to intensive care after cardiac arrest.

Temporal trends in the use of targeted temperature management after cardiac arrest and association with outcome: insights from the Paris Sudden Death Expertise Centre

PurposeRecent doubts regarding the efficacy may have resulted in a loss of interest for targeted temperature management (TTM) in comatose cardiac arrest (CA) patients, with uncertain consequences on outcome. We aimed to identify a change in TTM use and to assess the relationship between this change and neurological outcome.MethodsWe used Utstein data prospectively collected in the Sudden Death Expertise Center (SDEC) registry (capturing CA data from all secondary and tertiary hospitals located in the Great Paris area, France) between May 2011 and December 2017. All cases of non-traumatic OHCA patients with stable return of spontaneous circulation (ROSC) were included. After adjustment for potential confounders, we assessed the relationship between changes over time in the use of TTM and neurological recovery at discharge using the Cerebral Performance Categories (CPC) scale.ResultsBetween May 2011 and December 2017, 3925 patients were retained in the analysis, of whom 1847 (47%) received TTM. The rate of good neurological outcome at discharge (CPC 1 or 2) was higher in TTM patients as compared with no TTM (33% vs 15%, P < 0.001). Gender, age, and location of CA did not change over the years. Bystander CPR increased from 55% in 2011 to 73% in 2017 (P < 0.001) and patients with a no-flow time longer than 3 min decreased from 53 to 38% (P < 0.001). The use of TTM decreased from 55% in 2011 to 37% in 2017 (P < 0.001). Meanwhile, the rate of patients with good neurological recovery remained stable (19 to 23%, P = 0.76). After adjustment, year of CA occurrence was not associated with outcome.ConclusionsWe report a progressive decrease in the use of TTM in post-cardiac arrest patients over the recent years. During this period, neurological outcome remained stable, despite an increase in bystander-initiated resuscitation and a decrease in “no flow” duration.

Abstract 286: Cerebral Microstructure Disruptions are Associated With Poor Neurologic Outcomes in Comatose Cardiac Arrest Patients

Background: For cardiac arrest survivors who are initially comatose after restoration of spontaneous circulation, the extent of brain injury and expected recovery are crucial for management decisions. Advanced diffusion imaging approaches may provide additional insight into microstructural integrity and potential for arousal recovery (AR). Methods: Multi-shell diffusion imaging was acquired in a prospective study. Neurite orientation dispersion (OD), intracellular volume fraction (ICVF), free water fraction (ISO), mean kurtosis (MK), axial kurtosis (AK), radial kurtosis (RK), mean diffusivity (MD), axial diffusivity (AD), radial diffusivity (RD) and fractional anisotropy (FA) were calculated (see Figure). Median whole-brain values in patients with AR by discharge were compared with those with no AR and to controls (ANOVA, post-hoc 2-tailed Wilcoxon test). Multivariable backward stepwise logistic regression was performed to predict AR. Results: 19 patients (mean ±SD 48±23 y, 42% men) and 5 controls (37±19 y, 40% men) were analyzed (10 patients with AR, 9 without). Median [IQR] time-to-MRI was 5 [4-8] days. Patients with no AR had higher AK (P=0.037), and RK (P=.045) than those with AR. Controls exhibited higher FA than either AR (P=.009) or no AR (P=.02), lower MK than no AR (P=.02), lower AK than no AR (P=.02), lower RK than no AR (P=0.02), lower OD than no AR (P=.008), and lower ICVF than no AR (P=.046). AK (P=.049) and ICVF (P=.01) were found in multivariable regression to be significant predictors of AR with 81% area under the receiver operating curve (AUC). Discussion: Advanced diffusion imaging metrics, AK and ICVF, were able to predict which patients were likely to regain consciousness, with 81% AUC. Despite the small sample size, we note statistically significant differences using more sensitive measures of microstructural injury compared to more commonly used diffusivity metrics. Further investigation of advanced diffusion imaging methods is warranted.

P1710Risk of Mortality associated with use of mechanical support devices among comatose cardiac arrest patients

Abstract Background The impact of mechanical circulatory assist devices (MCS) has not been well studied in cardiac arrest survivors. We examined that association of MCS with risk of mortality among comatose cardiac arrest survivors Purpose Compare the survival between different MCS and non MCS groups Methods This is a retrospective cohort study of 1417 comatose adult cardiac arrest survivors that survived for at least 1 day post cardiopulmonary resuscitation. Cox proportional hazard models adjusted for demographics, resuscitation parameters, comorbidities and medications were used to compute hazard ratios for extracorporeal membrane oxygenation (ECMO), ECMO + Impella/intraaortic balloon pump (IABP), IABP and Impella associated with risk of short term 60 day mortality. Kaplan meier's curves were used to demonstrate cumulative survival rate. Results Among 1417 cardiac arrest survivors, MCS was used among 553 (39.1%) patients. After 60 days of follow up, mortality rate was 49.4% in non MCS group, 58.6% in IABP group, 22.9% in Impella group, 40.0% in ECMO only group, 50.0% in ECMO + Impella/IABP group. When compared with no MCS use, only Impella use was associated with decrease risk of short term mortality (HR 0.37; 95% CI 0.16–0.83, p=0.02) while there was no significant association of other forms of MCS with short term mortality. There was no significant association of any MCS with long term mortality. Kaplan-Meier curves demonstrate early benefit of Impella and very early benefit of ECMO (figure 1). Conclusions This is the first large study to report various types of MCS use among comatose cardiac arrest survivors and has shown an indication of benefit with Impella use only in first 60 days post cardiac arrest. Future prospective study may be needed to validate this association Acknowledgement/Funding None