Effect of targeted temperature management on systemic inflammatory responses after out-of-hospital cardiac arrest: A prospective cohort study.

BACKGROUND: Interleukin (IL)-6 is a major inflammatory cytokine that predicts mortality after out-of-hospital cardiac arrest (OHCA). Targeted temperature management (TTM) is associated with improved all-cause mortality in patients with OHCA. However, the effect of TTM on IL-6 production remains unclear. This study investigated whether TTM has additional anti-inflammatory effects after OHCA. METHODS: This prospective cohort study included a total of 141 hospitalized patients with OHCA who were treated between January 2015 and June 2023. The study was conducted in the intensive care unit of China Medical University Hospital, Taichung. Postcardiac arrest care included TTM or the control approach (no TTM). The primary outcomes included the 90-day mortality rate and neurologic outcomes after OHCA. Differences between the TTM and control groups were examined using Student t test, chi-square test, and Kaplan-Meier survival curve analysis. Multivariate analysis of variance model was used to examine interaction effects. RESULTS: Plasma IL-6 and IL-6/soluble IL-6 receptor complex levels were measured at 6 and 24 hours after resuscitation. IL-6 and IL-6/soluble IL-6 receptor complex production was lower in the TTM group than in the control group (-50.0% vs +136.7%, P < .001; +26.3% vs +102.40%, P < .001, respectively). In addition, the 90-day mortality rate and poor neurologic outcomes were lower in the TTM group than in the control group (36.8% vs 63.0%, relative risk 0.39, 95% confidence interval 0.24-0.64, P < .001; 65.5% vs 81.5%, relative risk 0.80, 95% confidence interval 0.66-0.98, P = .04). CONCLUSION: TTM improves both the mortality rate and neurologic outcomes in patients resuscitated from OHCA, possibly by reducing IL-6-induced proinflammatory responses.

Sex hormone trajectories and association to outcomes after out-of-hospital cardiac arrest.

BACKGROUND: Outcomes and susceptibility to out-of-hospital cardiac arrest (OHCA) are known to differ by sex, yet little is known about changes in sex hormones after OHCA. We sought to determine the trajectory of sex hormones after OHCA and their association to survival and neurological outcome. METHODS: Plasma samples were collected from those that survived to hospital admission at four time points (1, 6, 24, and 48 h) and estrone, estradiol, progesterone, and testosterone concentrations were quantified via liquid chromatography-mass spectrometry. Trends in hormones were plotted over time by sex and outcomes. The association between sex, hormone levels with survival and neurological outcome (cerebral performance category 1-2 indicating good outcome and 3-5 for poor outcome) were determined using generalized estimating equation models. RESULTS: Of the 94 OHCA patients, 50 were males and 44 females, with a mean age of 61.3 (+15.7) years. Despite older age and lower BCPR in females compared to males, females had higher proportion of good neurological outcome compared to males. Over the 48 h, estrone increased, testosterone decreased, and estradiol and progesterone remained flat. Survivors had lower levels of estrone at all time points but only at early time points for estradiol, progesterone and testosterone. Lower estrone level predicted survival at discharge, even after adjusting for time, sex, age, and hormones independently (ß = -3.38, 95% CI = -5.71, -0.85). Females had better neurological scores compared to males after adjusting for estrone (ß = 1.27, 95% CI = 0.01, 2.53) and estradiol (ß = 2.92, 95% CI = 1.13, 4.70). CONCLUSIONS: Survivors and those with favorable neurological outcome had lower trend in estrone. The sex hormone estrone, present in both males and females, may be a predictor of survival. When adjusted for estrogens, female sex had better neurological recovery compared to males. The difference in neurological outcome by sex is not explained by estrogens. However, these finding open the door for exploration of other sex-specific pathways in resuscitation after OHCA.

Inflammatory response after prehospital high-dose glucocorticoid to patients resuscitated from out-of-hospital cardiac arrest: A sub-study of the STEROHCA trial.

BACKGROUND: The post-cardiac arrest syndrome (PCAS) after out-of-hospital cardiac arrest (OHCA) is characterized by a series of pathological events, including inflammation. In the randomized "STERoid for OHCA" (STEROHCA) trial, prehospital high-dose glucocorticoid decreased interleukin (IL) 6 and C-reactive protein levels following resuscitated OHCA. The aim of this predefined sub-study was to assess the inflammatory response the first three days of admission. METHODS: The STEROHCA trial enrolled 137 OHCA patients randomized to either a single prehospital injection of methylprednisolone 250 mg or placebo. Inflammatory markers, including pro- and anti-inflammatory cytokines, were analyzed in plasma samples, from 0-, 24-, 48-, and 72 h post-admission. Mixed-model analyses were applied using log-transformed data to assess group differences. RESULTS: The 137 patients included in this sub-study had a median age of 67 years (57 to 74), and the 180-day survival rates were 75% (n = 51/68) and 64% (n = 44/69) in the glucocorticoid and placebo group, respectively. A total of 130 (95%) patients had at least one plasma sample available. The anti-inflammatory cytokine IL-10 was increased at hospital admission in the glucocorticoid group (ratio 2.74 (1.49-5.05), p = 0.006), but the intervention showed the strongest effect after 24 h, decreasing pro-inflammatory levels of IL-6 (ratio 0.06 (0.03-0.10), p < 0.001), IL-8 (ratio 0.53 (0.38-0.75), p < 0.001), macrophage chemokine protein-1 (MCP-1, ratio 0.02 (0.13-0.31), p < 0.001), macrophage inflammatory protein-1-beta (MIP-1b, ratio 0.28 (0.18-0.45), p < 0.001), and tumor necrosis factor-α (TNF-α, ratio 0.6 (0.4-0.8), p = 0.01). CONCLUSION: Administering high-dose glucocorticoid treatment promptly after resuscitation from OHCA influenced the inflammatory response with a reduction in several systemic proinflammatory cytokines after 24 h. TRIAL REGISTRATION: EudraCT number: 2020-000855-11; submitted March 30, 2020. URL: https://www. CLINICALTRIALS: gov; Unique Identifier: NCT04624776.

The association between serum free fatty acid levels and neurological outcomes in out-of-hospital cardiac arrest patients: A prospective observational study.

Free fatty acids (FFA) are a known risk factor in the development of sudden cardiac death. However, the relationship between FFA and the outcome of out-of-hospital cardiac arrest (OHCA) patients remains unclear. We aimed to examine the association between FFA and neurological outcomes in OHCA patients. This prospective observational study included adult (≥18 years) OHCA patients between February 2016 and December 2022. We measured serial FFA levels within 1 hour after ROSC and at 6, 12, 24, 48, and 72 hours after the return of spontaneous circulation (ROSC). The primary outcome was neurological outcome at 6 months. A poor neurological outcome was defined by cerebral performance categories 3, 4, and 5. A total of 147 patients were included. Of them, 104 (70.7%) had poor neurological outcomes, whereby the median FFA levels within 1 hour after ROSC (0.72 vs 1.01 mol/L), at 6 hours (1.19 vs 1.90 mol/L), 12 hours (1.20 vs 1.66 mol/L), and 24 hours (1.20 vs 1.95 mol/L) after ROSC were significantly lower than in good outcome group. The FFA levels at 6 hours (odds ratio, 0.583; 95% confidence interval, 0.370-0.919; P = .020), and 12 hours (odds ratio, 0.509; 95% confidence interval, 0.303-0.854; P = .011) after ROSC were independently associated with poor neurological outcomes. The lower FFA levels at 6 hours and 12 hours after ROSC were associated with poor neurological outcomes in patients with OHCA. FFA may reflect oxidative metabolism as well as oxidative stress.

Association of hyperfibrinolysis with poor prognosis in refractory circulatory arrest: implications for extracorporeal cardiopulmonary resuscitation.

BACKGROUND: Identifying candidates for extracorporeal cardiopulmonary resuscitation (eCPR) is challenging, and novel predictive markers are urgently needed. Hyperfibrinolysis is linked to tissue hypoxia and is associated with poor outcomes in out-of-hospital cardiac arrest (OHCA). Rotational thromboelastometry (ROTEM) can detect or rule out hyperfibrinolysis, and could, therefore, provide decision support for initiation of eCPR. We explored early detection of hyperfibrinolysis in patients with refractory OHCA referred for eCPR. METHODS: We analysed ROTEM results and resuscitation parameters of 57 adult patients with ongoing OHCA who presented to our ICU for eCPR evaluation. RESULTS: Hyperfibrinolysis, defined as maximum lysis ≥15%, was present in 36 patients (63%) and was associated with higher serum lactate, lower arterial blood pH, and increased low-flow intervals. Of 42 patients who achieved return of circulation, 28 had a poor 30-day outcome. The incidence of hyperfibrinolysis was higher in the poor outcome group compared with patients with good outcomes (75% [21 of 28] vs 7.1% [1 of 14]; P<0.001). The ratio of EXTEM A5 to lactate concentration showed good predictive value in detecting hyperfibrinolysis (AUC of 0.89 [95% confidence interval 0.8-1]). CONCLUSIONS: Hyperfibrinolysis was common in patients with refractory cardiac arrest, and was associated with poor prognosis. The combination of high lactate with early clot firmness values, such as EXTEM A5, appears promising for early detection of hyperfibrinolysis. This finding could facilitate decisions to perform eCPR, particularly for patients with prolonged low-flow duration but lacking hyperfibrinolysis.

Utilization of Multi-Parameter Blood Gas Analysis in Prehospital Emergency Medicine-A Scoping Review.

BACKGROUND: Prehospital blood gas analysis (BGA) is an evolving field that offers the potential for early identification and management of critically ill patients. However, the utility and accuracy of prehospital BGA are subjects of ongoing debate. OBJECTIVES: We aimed to provide a comprehensive summary of the current literature on prehospital BGA, including its indications, methods, and feasibility. METHODS: We performed a scoping review of prehospital BGA. A thorough search of the PubMed, Embase, and Web of Science databases was conducted to identify relevant studies focusing on prehospital BGA in adult patients. RESULTS: Fifteen studies met the inclusion criteria. Prehospital BGA was most frequently performed in patients in out-of-hospital cardiac arrest, followed by traumatic and nontraumatic cases. The parameters most commonly analyzed were pH, pCO2, pO2, and lactate. Various sampling methods, including arterial, venous, and intraosseous, were reported for prehospital BGA. While prehospital BGA shows promise in facilitating early identification of critical patients and guiding resuscitation efforts, logistical challenges are to be considered. The handling of preclinical BGA is described as feasible and useful in most of the included studies. CONCLUSION: Prehospital BGA holds significant potential for enhancing patient care in the prehospital setting, though technical challenges need to be considered. However, further research is required to establish optimal indications and demonstrate the benefits for prehospital BGA in specific clinical contexts.

Circulating glycocalyx shedding products as biomarkers for evaluating prognosis of patients with out-of-hospital cardiac arrest after return of spontaneous circulation.

The endothelial glycocalyx is damaged in postcardiac arrest syndrome (PCAS), but the prognostic value is unknown. We aimed to observe the expression and prognostic value of glycocalyx shedding products, including syndecan-1 (SDC-1), hyaluronan (HA), and heparan sulfate (HS) in PCAS. Data on clinical and 28-day outcomes of seventy-one consecutive patients with out-of-hospital cardiac arrest (OHCA) after the return of spontaneous circulation (ROSC) were collected. SDC-1, HA, and HS were measured on days 0, 1, and 3 after ROSC. Thirty healthy individuals were controls. Glycocalyx shedding was observed in human umbilical vein endothelial cells (HUVECs) stimulated during hypoxia and reoxygenation in vitro. Within 4 h of ROSC, SDC-1 and HA levels, significantly increased. In the 28-day non-survivors, HA levels showed a gradual upward trend, SDC-1 remained at a high level, and HS levels first increased, then decreased. Kaplan-Meier curves and binary logistic regression analysis showed the prognostic value of SDC-1 levels on days 0, 1, and 3, HA levels on days 1 and 3, and HS levels on day 1. Only HS levels on day 1 showed a prognostic value for 28-day neurological outcomes. SDC-1 and HA levels were positively correlated with the no-flow time. In vitro, HUVECs showed shedding of SDC-1 and HS during a prolonged duration of hypoxia. After ROSC, SDC-1, HA, and HS levels may predict the 28-day survival after PCAS, and HS levels are associated with functional outcomes.

Lactate-to-albumin ratio and cholesterol levels predict neurological outcome in cardiac arrest survivors.

BACKGROUND: Out-of-hospital cardiac arrest (OHCA) increases lactate levels and reduces albumin levels on admission and tends to lead to a poor neurological prognosis. In our experience, reduced cholesterol levels predict poor neurological prognosis. However, the relationship between cholesterol levels and neurological prognosis in OHCA survivors remains unclear. METHODS: This retrospective observational study included data from January 2015 to June 2023 on 219 OHCA survivors at our intensive care unit. Patients were categorized into two groups based on cerebral functional classification (CPC) scores: Group A (CPC score of 1 or 2), including patients with a favorable neurological outcome, and Group B (CPC scores of 3 to 5), comprising those with a poor neurological outcome. We analyzed their lactate, albumin levels, and lipid profiles measured at 6 h after resuscitation. A model to predict the neurological prognosis of admission of OHCA survivors was developed. RESULTS: Approximately 40% of the patients had favorable neurological outcomes at the 30-day follow-up. The lactate-to-albumin ratio (LAR) was significantly lower in Group A than in Group B (3.1 vs. 5.0 mmol/dag, p < 0.001). However, the albumin, total cholesterol, and high-density lipoprotein (HDL) cholesterol levels were significantly higher in Group A than in Group B (3.6 vs. 2.9 g/dL, 166.1 vs. 131.4 mg/dL, and 38.8 vs. 29.7 mg/dL, respectively, p < 0.001). Favorable neurological outcome was indicated at the following thresholds: LAR < 3.7 mmol/dag, albumin level > 3.1 g/dL, total cholesterol level > 146.4 mg/dL, and HDL-cholesterol level > 31.9 mg/dL. These findings underscore the high sensitivity and negative predictive value of the biomarkers. Furthermore, the area under the curve values for LAR, albumin, total cholesterol, and HDL-cholesterol levels were 0.70, 0.75, 0.71, and 0.71, respectively. The corresponding odds ratios were 3.37, 7.08, 3.67, and 3.94, respectively. CONCLUSIONS: The LAR, albumin, total cholesterol, and HDL-cholesterol levels measured on admission may predict neurological prognosis in OHCA survivors. Thus, routine practice should include the measurement of these biomarkers at 6 h after resuscitation, especially in patients with a lactate level of > 5 mmol/L. TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT02633358.

Effects of mild hypercapnia on myocardial injury after out-of-hospital cardiac arrest. A sub-study of the TAME trial.

PURPOSE: Mild hypercapnia did not improve neurological outcomes for resuscitated out-of-hospital cardiac arrest (OHCA) patients in the Targeted Therapeutic Mild Hypercapnia After Resuscitated Cardiac Arrest (TAME) trial. However, the effects of hypercapnic acidosis on myocardial injury in patients with cardiac arrest is unexplored. We investigated whether mild hypercapnia compared to normocapnia, following emergency coronary intervention, increased myocardial injury in comatose OHCA-patients with AMI. METHODS: Single-centre, prospective, pre-planned sub-study of the TAME trial. Patients were randomised to targeted mild hypercapnia (PaCO2 = 6.7-7.3 kPa) or normocapnia (PaCO2 = 4.7-6.0 kPa) for 24 h. Myocardial injury was assessed with high-sensitive cardiac troponin T (hs-cTnT) measured at baseline, 24, 48 and 72 h. Haemodynamics were assessed with right heart catheterisation and blood-gas analyses every 4th hour for 48 h. RESULTS: We included 125 OHCA-patients. 57 (46%) had an AMI, with 31 and 26 patients randomised to hypercapnia and normocapnia, respectively. Median peak hs-cTnT in AMI-patients was 58% lower in the hypercapnia-group: 2136 (IQR: 861-4462) versus 5165 ng/L (IQR: 2773-7519), p = 0.007. Lower average area under the hs-cTnT curve was observed in the hypercapnia-group: 2353 (95% CI 1388-3319) versus 4953 ng/L (95% CI 3566-6341), P-group = 0.002. Hypercapnia was associated with increased cardiac power output (CPO) and lower lactate levels in patients with AMI (P-group < 0.05). hs-cTnT, lactate and CPO were not significantly different between intervention groups in OHCA-patients without AMI (p > 0.05). CONCLUSIONS: Mild hypercapnia was not associated with increased myocardial injury in resuscitated OHCA-patients. In AMI-patients, mild hypercapnia was associated with lower hs-cTnT and lactate, and improved cardiac performance. TRIAL REGISTRATION NUMBER: NCT03114033.

Vitamin D deficiency as a risk factor for sudden cardiac arrest: A multicenter case-control study.

BACKGROUND AND AIMS: Vitamin D is known to influence the risk of cardiovascular disease, which is a recognized risk factor for sudden cardiac arrest (SCA). However, the relationship between vitamin D and SCA is not well understood. Therefore, this study aims to investigate the association between vitamin D and SCA in out-of-hospital cardiac arrest (OHCA) patients compared to healthy controls. METHODS AND RESULTS: Using the Phase II Cardiac Arrest Pursuit Trial with Unique Registration and Epidemiologic Surveillance (CAPTURES II) registry, a 1:1 propensity score-matched case-control study was conducted between 2017 and 2020. Serum 25-hydroxyvitamin D (vitamin D) levels in patients with OHCA (454 cases) and healthy controls (454 cases) were compared after matching for age, sex, cardiovascular risk factors, and lifestyle behaviors. The mean vitamin D levels were 14.5 ± 7.6 and 21.3 ± 8.3 ng/mL among SCA cases and controls, respectively. Logistic regression analysis was used adjusting for cardiovascular risk factors, lifestyle behaviors, corrected serum calcium levels, and estimated glomerular filtration rate (eGRF). The adjusted odds ratio (aOR) for vitamin D was 0.89 (95% confidence interval [CI] 0.87-0.91). The dose-response relationship demonstrated that vitamin D deficiency was associated with SCA incidence (severe deficiency, aOR 10.87, 95% CI 4.82-24.54; moderate deficiency, aOR 2.24, 95% CI 1.20-4.20). CONCLUSION: Vitamin D deficiency was independently and strongly associated with an increased risk of SCA, irrespective of cardiovascular and lifestyle factors, corrected calcium levels, and eGFR.

A metabolic profile of xenon and metabolite associations with 6-month mortality after out-of-hospital cardiac arrest: A post-hoc study of the randomised Xe-Hypotheca trial.

PURPOSE: Out-of-hospital cardiac arrest (OHCA) carries a relatively poor prognosis and requires multimodal prognostication to guide clinical decisions. Identification of previously unrecognized metabolic routes associated with patient outcome may contribute to future biomarker discovery. In OHCA, inhaled xenon elicits neuro- and cardioprotection. However, the metabolic effects remain unknown. MATERIALS AND METHODS: In this post-hoc study of the randomised, 2-group, single-blind, phase 2 Xe-Hypotheca trial, 110 OHCA survivors were randomised 1:1 to receive targeted temperature management (TTM) at 33°C with or without inhaled xenon during 24 h. Blood samples for nuclear magnetic resonance spectroscopy metabolic profiling were drawn upon admission, at 24 and 72 h. RESULTS: At 24 h, increased lactate, adjusted hazard-ratio 2.25, 95% CI [1.53; 3.30], p<0.001, and decreased branched-chain amino acids (BCAA) leucine 0.64 [0.5; 0.82], p = 0.007, and valine 0.37 [0.22; 0.63], p = 0.003, associated with 6-month mortality. At 72 h, increased lactate 2.77 [1.76; 4.36], p<0.001, and alanine 2.43 [1.56; 3.78], p = 0.001, and decreased small HDL cholesterol ester content (S-HDL-CE) 0.36 [0.19; 0.68], p = 0.021, associated with mortality. No difference was observed between xenon and control groups. CONCLUSIONS: In OHCA patients receiving TTM with or without xenon, high lactate and alanine and decreased BCAAs and S-HDL-CE associated with increased mortality. It remains to be established whether current observations on BCAAs, and possibly alanine and lactate, could reflect neural damage via their roles in the metabolism of the neurotransmitter glutamate. Xenon did not significantly alter the measured metabolic profile, a potentially beneficial attribute in the context of compromised ICU patients. TRIAL REGISTRATION: Trial Registry number: ClinicalTrials.gov Identifier: NCT00879892.

High-sensitivity troponin T for detection of culprit lesions in patients with out-of-hospital cardiac arrest.

BACKGROUND: Patients with an out-of-hospital cardiac arrest (OHCA) often undergo coronary angiography, although a culprit lesion is found in only 30%-40% of patients. The aim of this study was to investigate high-sensitivity troponin T (hsTnT) levels in post cardiac arrest patients with and without coronary culprit lesions; factors affecting hsTnT levels after return of spontaneous circulation (ROSC); and the diagnostic ability of hsTnT in identifying patients with culprit lesions. We hypothesized that peak hsTnT levels were higher during the initial 48 h after cardiac arrest in patients with a coronary culprit lesion. METHODS: This was a retrospective observational study, which included patients admitted to the Intensive Care Unit after an OHCA and who received a coronary angiography. Peak values and dynamic changes in hsTnT were analyzed in relation to the presence of a culprit lesion at coronary angiography. RESULTS: A total of 238 patients were studied, of whom 140 had a culprit lesion. HsTnT levels during the initial 48 h were higher in patients with culprit lesions, longer time to ROSC and an unwitnessed cardiac arrest. At 6 to 12 h after ROSC, a hsTnT cut-off level of 1690 ng/L had a sensitivity of 64% and specificity of 84% to identify a culprit lesion. In patients without ST-elevations, hsTnT measured between 6 and 12 h after ROSC had a specificity above 90%, with a sensitivity of 46%. CONCLUSION: HsTnT levels after cardiac arrest are higher in patients with coronary culprit lesions. Presence of a culprit lesion, witnessed status and the duration of CPR are important factors affecting hsTnT levels. Repeated measurement of hsTnT within the first 12 h after admission improved diagnostic accuracy but the value of hsTnT as a predictor of culprit lesions early after OHCA is limited.

Biomarkers for neuroprognostication after standard versus extracorporeal cardiopulmonary resuscitation - A sub-analysis of Prague-OHCA study.

BACKGROUND: Limited evidence exists for prognostic performance of biomarkers in patients resuscitated from out-of-hospital cardiac arrest (OHCA) with extracorporeal CPR (ECPR). We hypothesized that (1) the time course and (2) prognostic performance of biomarkers might differ between CPR and ECPR in a sub-analysis of Prague-OHCA study. METHODS: Patients received either CPR (n = 164) or ECPR (n = 92). The primary outcome was favorable neurologic survival at 180 days [cerebral performance category (CPC) 1-2]. Secondary outcomes included biomarkers of neurologic injury, inflammation and hemocoagulation. RESULTS: Favorable neurologic outcome was not different between groups: CPR 29.3% vs. ECPR 21.7%; p = 0.191. Biomarkers exhibited similar trajectories in both groups, with better values in patients with CPC 1-2. Procalcitonin (PCT) was higher in ECPR group at 24-72 h (all p < 0.01). Neuron-specific enolase (NSE), C-reactive protein and neutrophil-to-lymphocyte ratio did not differ between groups. Platelets, D-dimers and fibrinogen were lower in ECPR vs. CPR groups at 24-72 h (all p < 0.001). ROC analysis (24-48-72 h) showed the best performance of NSE in both CPR and ECPR groups (AUC 0.89 vs. 0.78; 0.9 vs. 0.9; 0.91 vs. 0.9). PCT showed good performance specifically in ECPR (0.72 vs. 0.84; 0.73 vs. 0.87; 0.73 vs. 0.86). Optimal cutoff points of NSE and PCT were higher in ECPR vs. CPR. CONCLUSIONS: Biomarkers exhibited similar trajectories although absolute values tended to be higher in ECPR. NSE had superior performance in both groups. PCT showed a good performance specifically in ECPR. Additional biomarkers may have modest incremental value. Prognostication algorithms should reflect the resuscitation method.

Lactate and lactate clearance as predictors of one-year survival in extracorporeal cardiopulmonary resuscitation - An international, multicentre cohort study.

AIM: Extracorporeal cardiopulmonary resuscitation (ECPR) can be considered in selected patients with refractory cardiac arrest. Given the risk of patient futility and high resource utilisation, identifying ECPR candidates, who would benefit from this therapy, is crucial. Previous ECPR studies investigating lactate as a potential prognostic marker have been small and inconclusive. In this study, it was hypothesised that the lactate level (immediately prior to initiation of ECPR) and lactate clearance (within 24 hours after ECPR initiation) are predictors of one-year survival in a large, multicentre study cohort of ECPR patients. METHODS: Adult patients with refractory cardiac arrest at three German and four Danish tertiary cardiac care centres between 2011 and 2021 were included. Pre-ECPR lactate and 24-hour lactate clearance were divided into three equally sized tertiles. Multivariable logistic regression analyses and Kaplan-Meier analyses were used to analyse survival outcomes. RESULTS: 297 adult patients with refractory cardiac arrest were included in this study, of which 65 (22%) survived within one year. The pre-ECPR lactate level and 24-hour lactate clearance were level-dependently associated with one-year survival: OR 5.40 [95% CI 2.30-13.60] for lowest versus highest pre-ECPR lactate level and OR 0.25 [95% CI 0.09-0.68] for lowest versus highest 24-hour lactate clearance. Results were confirmed in Kaplan-Meier analyses (each p log rank < 0.001) and subgroup analyses. CONCLUSION: Pre-ECPR lactate levels and 24 hour-lactate clearance after ECPR initiation in patients with refractory cardiac arrest were level-dependently associated with one-year survival. Lactate is an easily accessible and quickly available point-of-care measurement which might be considered as an early prognostic marker when considering initiation or continuation of ECPR treatment.

Mild Hypercapnia or Normocapnia after Out-of-Hospital Cardiac Arrest.

BACKGROUND: Guidelines recommend normocapnia for adults with coma who are resuscitated after out-of-hospital cardiac arrest. However, mild hypercapnia increases cerebral blood flow and may improve neurologic outcomes. METHODS: We randomly assigned adults with coma who had been resuscitated after out-of-hospital cardiac arrest of presumed cardiac or unknown cause and admitted to the intensive care unit (ICU) in a 1:1 ratio to either 24 hours of mild hypercapnia (target partial pressure of arterial carbon dioxide [Paco2], 50 to 55 mm Hg) or normocapnia (target Paco2, 35 to 45 mm Hg). The primary outcome was a favorable neurologic outcome, defined as a score of 5 (indicating lower moderate disability) or higher, as assessed with the use of the Glasgow Outcome Scale-Extended (range, 1 [death] to 8, with higher scores indicating better neurologic outcome) at 6 months. Secondary outcomes included death within 6 months. RESULTS: A total of 1700 patients from 63 ICUs in 17 countries were recruited, with 847 patients assigned to targeted mild hypercapnia and 853 to targeted normocapnia. A favorable neurologic outcome at 6 months occurred in 332 of 764 patients (43.5%) in the mild hypercapnia group and in 350 of 784 (44.6%) in the normocapnia group (relative risk, 0.98; 95% confidence interval [CI], 0.87 to 1.11; P = 0.76). Death within 6 months after randomization occurred in 393 of 816 patients (48.2%) in the mild hypercapnia group and in 382 of 832 (45.9%) in the normocapnia group (relative risk, 1.05; 95% CI, 0.94 to 1.16). The incidence of adverse events did not differ significantly between groups. CONCLUSIONS: In patients with coma who were resuscitated after out-of-hospital cardiac arrest, targeted mild hypercapnia did not lead to better neurologic outcomes at 6 months than targeted normocapnia. (Funded by the National Health and Medical Research Council of Australia and others; TAME ClinicalTrials.gov number, NCT03114033.).

Association Between EEG Patterns and Serum Neurofilament Light After Cardiac Arrest: A Post Hoc Analysis of the TTM Trial.

BACKGROUND AND OBJECTIVES: EEG is widely used for prediction of neurologic outcome after cardiac arrest. To better understand the relationship between EEG and neuronal injury, we explored the association between EEG and neurofilament light (NfL) as a marker of neuroaxonal injury, evaluated whether highly malignant EEG patterns are reflected by high NfL levels, and explored the association of EEG backgrounds and EEG discharges with NfL. METHODS: We performed a post hoc analysis of the Target Temperature Management After Out-of-Hospital Cardiac Arrest trial. Routine EEGs were prospectively performed after the temperature intervention ≥36 hours postarrest. Patients who awoke or died prior to 36 hours postarrest were excluded. EEG experts blinded to clinical information classified EEG background, amount of discharges, and highly malignant EEG patterns according to the standardized American Clinical Neurophysiology Society terminology. Prospectively collected serum samples were analyzed for NfL after trial completion. The highest available concentration at 48 or 72 hours postarrest was used. RESULTS: A total of 262/939 patients with EEG and NfL data were included. Patients with highly malignant EEG patterns had 2.9 times higher NfL levels than patients with malignant patterns and NfL levels were 13 times higher in patients with malignant patterns than those with benign patterns (95% CI 1.4-6.1 and 6.5-26.2, respectively; effect size 0.47; p < 0.001). Both background and the amount of discharges were independently strongly associated with NfL levels (p < 0.001). The EEG background had a stronger association with NfL levels than EEG discharges (R2 = 0.30 and R2 = 0.10, respectively). NfL levels in patients with a continuous background were lower than for any other background (95% CI for discontinuous, burst-suppression, and suppression, respectively: 2.26-18.06, 3.91-41.71, and 5.74-41.74; effect size 0.30; p < 0.001 for all). NfL levels did not differ between suppression and burst suppression. Superimposed discharges were only associated with higher NfL levels if the EEG background was continuous. DISCUSSION: Benign, malignant, and highly malignant EEG patterns reflect the extent of brain injury as measured by NfL in serum. The extent of brain injury is more strongly related to the EEG background than superimposed discharges. Combining EEG and NfL may be useful to better identify patients misclassified by single methods. TRIAL REGISTRATION INFORMATION: ClinicalTrials.gov NCT01020916.

Blood-brain barrier disruption as a cause of various serum neuron-specific enolase cut-off values for neurological prognosis in cardiac arrest patients.

We compared the cut-off and prognostic value of serum neuron-specific enolase (NSE) between groups with and without severe blood-brain barrier (BBB) disruption to reveal that a cause of various serum NSE cut-off value for neurological prognosis is severe BBB disruption in out-of-hospital cardiac arrest (OHCA) patients underwent target temperature management (TTM). This was a prospective, single-centre study conducted from January 2019 to June 2021. Severe BBB disruption was indicated using cerebrospinal fluid-serum albumin quotient values > 0.02. The area under the receiver operating characteristic curve of serum NSE obtained on day 3 of hospitalisation to predict poor outcomes was used. In patients with poor neurologic outcomes, serum NSE in those with severe BBB disruption was higher than in those without (P = 0.006). A serum NSE cut-off value of 40.4 µg/L for poor outcomes in patients without severe BBB disruption had a sensitivity of 41.7% and a specificity of 96.0%, whereas a cut-off value of 34.6 µg/L in those with severe BBB disruption had a sensitivity of 86.4% and a specificity of 100.0%. We demonstrated that the cut-off and prognostic value of serum NSE were heterogeneous, depending on severe BBB disruption in OHCA patients treated with TTM.

The role of the lactate/albumin ratio in predicting survival outcomes in patients resuscitated after out-of-hospital cardiac arrest: A preliminary report.

OBJECTIVE: To investigate the effect of lactate/albumin (L/A) ratio on survival to discharge in patients who have had out-of-hospital cardiac arrest (OHCA). METHODS: We analyzed adult patients (aged ≥18 years) who were admitted to our hospital's emergency department (ED) due to OHCA between January 2018 and June 2020 and who achieved return of spontaneous circulation after successful resuscitation. Blood lactate and albumin concentrations were obtained within the first 10 min after admission to the ED. Patients were grouped according to clinical outcomes. The primary outcome was survival until hospital discharge. The groups were then statistically compared. RESULTS: In this study, 235 OHCA patients were analyzed, 42 (17.9%) of whom had survived until discharge. The L/A ratio was higher in the non-survivor group than in the survivor group (2.0 (interquartile range: 1.4-2.8) vs 1.4 (0.9-1.9); P < 0.001). A low L/A ratio was significantly associated with survival at discharge (odds ratio: 2.55; 95% confidence interval (CI): 3.24-11.08; P < 0.001). In the prediction of survival to discharge, the area under the curve (AUC) for the L/A ratio (AUC: 0.823) was higher than that for lactate (AUC: 0.762) or albumin (AUC: 0.722) alone. Moreover, the predictive value of L/A ratio for survival to discharge might significantly improve when the cutoff value is higher than 1.62. CONCLUSION: The L/A ratio is more valuable than the lactate or albumin levels alone in predicting survival to discharge. Our findings indicate that a combination of these parameters might increase the predictability of survival to discharge in OHCA patients.