Postcardiac arrest syndrome: from immediate resuscitation to long-term outcome

Fifteen-minute consultation: A guide to paediatric post-resuscitation care following return of spontaneous circulation

Paediatric resuscitation is a key skill for anyone in medicine who is involved in the care of children. Basic and advance paediatric life support courses are crucial in teaching those skills nationwide in a way that is memorable, protocolised and standardised. These courses are vital in the dissemination and upkeep of both theoretical and practical knowledge of paediatric resuscitation, with their primary aim being the return of spontaneous circulation. While sustaining life is important, preserving a life with quality, one with good functional and neurological outcomes should be the gold standard of any resuscitative attempt. Good neurological outcomes are dependent, in large part, on how well the postresuscitation stage is managed. This stage does not start in the intensive care unit, it starts at the point at which spontaneous circulation has been reinstated. The aim of this paper is to provide a basic overview of the main strategies that should be followed in order to minimise secondary brain injury after successful resuscitation attempts.

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 hours) 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 hours, 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 (β=-3.38, 95% CI= -5.71, -0.85). Females had better neurological scores compared to males after adjusting for estrone (β=1.27, 95% CI= 0.01, 2.53) and estradiol (β=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.

Survival, but not the severity of hypoxic-ischemic encephalopathy, is associated with higher mean arterial blood pressure after cardiac arrest: a retrospective cohort study

Background

This study investigates the association between the mean arterial blood pressure (MAP), vasopressor requirement, and severity of hypoxic-ischemic encephalopathy (HIE) after cardiac arrest (CA).

Methods

Between 2008 and 2017, we retrospectively analyzed the MAP 200 h after CA and quantified the vasopressor requirements using the cumulative vasopressor index (CVI). Through a postmortem brain autopsy in non-survivors, the severity of the HIE was histopathologically dichotomized into no/mild and severe HIE. In survivors, we dichotomized the severity of HIE into no/mild cerebral performance category (CPC) 1 and severe HIE (CPC 4). We investigated the regain of consciousness, causes of death, and 5-day survival as hemodynamic confounders.

Results

Among the 350 non-survivors, 117 had histopathologically severe HIE while 233 had no/mild HIE, without differences observed in the MAP (73.1 vs. 72.0 mmHg, pgroup = 0.639). Compared to the non-survivors, 211 patients with CPC 1 and 57 patients with CPC 4 had higher MAP values that showed significant, but clinically non-relevant, MAP differences (81.2 vs. 82.3 mmHg, pgroup < 0.001). The no/mild HIE non-survivors (n = 54), who regained consciousness before death, had higher MAP values compared to those with no/mild HIE (n = 179), who remained persistently comatose (74.7 vs. 69.3 mmHg, pgroup < 0.001). The no/mild HIE non-survivors, who regained consciousness, required fewer vasopressors (CVI 2.1 vs. 3.6, pgroup < 0.001). Independent of the severity of HIE, the survivors were weaned faster from vasopressors (CVI 1.0).

Conclusions

Although a higher MAP was associated with survival in CA patients treated with a vasopressor-supported MAP target above 65 mmHg, the severity of HIE was not. Awakening from coma was associated with less vasopressor requirements. Our results provide no evidence for a MAP target above the current guideline recommendations that can decrease the severity of HIE.

Predictors of mortality and transfusion requirements in venoarterial extracorporeal membrane oxygenation patients

OBJECTIVE

The aim of this study was to evaluate the prognostic impact of variables, including thrombocytopenia and the amount of platelet transfusion, for predicting survival in venoarterial extracorporeal membrane oxygenation (ECMO) recipients. Additionally, we aimed to identify the predictors of increased transfusion requirement during venoarterial ECMO support.

METHODS

All patients who received venoarterial ECMO between December 2008 and March 2020 were retrospectively analyzed. Univariate and multivariate Cox regressions were used to evaluate in-hospital mortality according to variables including thrombocytopenia and daily average of platelet concentrate transfusion. Stepwise multiple linear regression analysis was used to identify independent predictors for transfusion requirements.

RESULTS

Analysis of 218 patients demonstrated severe thrombocytopenia as an independent predictor of in-hospital mortality (hazard ratio = 2.840, 95% CI: 1.593-5.063, P < .001), along with age, pre-ECMO cardiac arrest, and pH. In contrast, the amount of platelet transfusion was not associated with in-hospital mortality. Multiple variables, including the type of indication for ECMO were associated with transfusion requirements.

CONCLUSION

Our findings identified severe thrombocytopenia as an independent prognostic factor of in-hospital mortality. However, daily average platelet transfusion was not associated with survival outcomes. Additionally, our study identified predictive variables of increased transfusion requirements.

Acute liver failure after out-of-hospital cardiac arrest: An observational study

RATIONALE

Apart from hypoxic hepatitis (HH), the hepatic consequences of out-of-hospital cardiac arrest (OHCA) have been little studied. This cohort study aimed to investigate the characteristics of liver dysfunction resulting from OHCA and its association with outcomes.

METHODS

Among the conventional static liver function tests used to define acute liver failure (ALF), we determined which one correlated more closely with the reference indocyanine green (ICG) clearance test in a series of OHCA patients from the CYRUS trial (NCT01595958). Subsequently, we assessed whether ALF, in addition to HH (i.e., acute liver injury), was an independent risk factor for death in a large cohort of OHCA patients admitted to two intensive care units between 2007 and 2017.

RESULTS

ICG clearance, available for 22 patients, was impaired in 17 (77.3%) cases. Prothrombin time (PT) ratio was the only static liver function test that correlated significantly (r = -0.66, p < 0.01) with ICG clearance and was therefore used to define ALF, with the usual cutoff of < 50%. Of the 418 patients included in the analysis (sex ratio: 1.4; median age: 64 [53-75] years; non-shockable rhythm: 73%), 67 (16.0%) presented with ALF, and 61 (14.6%) had HH at admission. On day 28, 337 (80.6%) patients died. Following multivariate analysis, ALF at admission, OHCA occurring at home, absence of bystander, non-cardiac cause of OHCA, low-flow duration ≥ 20 min, and SOFA score excluding liver subscore at admission were independently associated with day 28 mortality.

CONCLUSIONS

ALF occurred frequently after OHCA and, unlike HH, was independently associated with day 28 mortality.

Effectiveness of Vasopressin Against Cardiac Arrest: A Systematic Review of Systematic Reviews

PURPOSE

This systematic review (SR) of SRs evaluates the effectiveness of vasopressin alone or in combination with other drugs in improving the outcomes of cardiac arrest (CA).

METHODS

Using a three-step approach, we searched five databases to identify all relevant SRs. Two reviewers independently selected suitable studies, assessed study quality, and extracted relevant data. If an outcome was reported by multiple SRs, a re-meta-analysis was conducted as needed; otherwise, a narrative analysis was performed.

RESULTS

Twelve SRs covering 16 original studies were included in this review. The meta-analysis results revealed a significant increase in survival to hospital admission for patients with in-hospital CA (IHCA) or out-of-hospital CA (OHCA) receiving vasopressin alone compared with that for those receiving epinephrine alone. Furthermore, the return of spontaneous circulation (ROSC) was significantly increased in patients with OHCA receiving vasopressin with epinephrine compared with that in those receiving epinephrine alone. Compared with patients with IHCA receiving epinephrine with placebo, those receiving vasopressin, steroids, and epinephrine (VSE) exhibited significant increases in ROSC, survival to hospital discharge, favorable neurological outcomes, mean arterial pressure, renal failure-free days, coagulation failure-free days, and insulin requirement.

CONCLUSION

VSE is the most effective drug combination for improving the short- and long-term outcomes of IHCA. It is recommended to use VSE in patients with IHCA. Future studies should investigate the effectiveness of VSE against OHCA and CA of various etiologies, the types and standard dosages of steroids for cardiac resuscitation, and the effectiveness of vasopressin-steroid in improving CA outcomes.

Cardiac arrest related lung edema: examining the role of downtimes in transpulmonary thermodilution analysis

Pulmonary edema and its association with low flow times has been observed in postcardiac arrest patients. However, diagnosis of distinct types of lung pathology is difficult.The aim of this study was to investigate pulmonary edema by transpulmonary thermodilution (TPTD) after out-of-hospital cardiac arrest (OHCA), and the correlation to downtimes. In this retrospective single-center study consecutive patients with return of spontaneous circulation (ROSC) following OHCA, age ≥ 18, and applied TPTD were enrolled. According to downtimes, patients were divided into a short and a long no-flow-time group, and data of TPTD were analysed. We identified 45 patients (n = 25 short no-flow time; n = 20 long no-flow time) who met the inclusion criteria. 24 h after ROSC, the extra vascular lung water index (EVLWI) was found to be lower in the group with short no-flow time compared to the group with long no-flow time (10.7 ± 3.5 ml/kg vs. 12.8 ± 3.9 ml/kg; p = 0.08) and remained at a similar level 48 h (10.9 ± 4.3 ml/kg vs. 12.9 ± 4.9 ml/kg; p = 0.25) and 72 h (11.1 ± 5.0 ml/kg vs. 13.9 ± 7.7 ml/kg; p = 0.27) post-ROSC. We found a statistically significant and moderate correlation between no-flow duration and EVLWI 48 h (r = 0.51; p = 0.002) and 72 h (r = 0.54; p = 0.004) post-ROSC. Pulmonary vascular permeability index (PVPI) was not correlated with downtimes. Our observation underlines the presence of cardiac arrest-related lung edema by determination of EVLWI. The duration of no-flow times is a relevant factor for increased extravascular lung water index.

Cardiac power output is associated with cardiovascular related mortality in the ICU in post-cardiac arrest patients

AIM

Although brain injury is the main determinant of poor outcome following cardiac arrest (CA), cardiovascular failure is the leading cause of death within the first days after CA. However, it remains unclear which hemodynamic parameter is most suitable for its early recognition. We investigated the association of cardiac power output (CPO) with early mortality in intensive care unit (ICU) after CA and with mortality related to post-CA cardiovascular failure.

METHODS

Retrospective analysis of adult comatose survivors of CA admitted to the ICU of a University Hospital. Exclusion criteria were treatment with extracorporeal cardiopulmonary resuscitation, ECMO or intra-aortic balloon pump. We retrieved CA characteristics; we recorded mean arterial pressure, cardiac output, CPO (as derived parameter) and the vasoactive-inotropic score for the first 72 hours after ROSC, at intervals of 8 hours. ICU death was defined as related to post-CA cardiovascular failure when death occurred as a direct consequence of shock, secondary CA or fatal arrhythmia, or related to neurological injury if this led to withdrawal of life-sustaining therapy or brain death.

RESULTS

Among the 217 patients (median age 66 years, 65% male, 61.8% out-of-hospital CA), 142 (65.4%) died in ICU: 99 (69.7%) patients died from neurological injury and 43 (30.3%) from cardiovascular-related causes. Comparing the evolution over time of CPO between survivors and non-survivors, a statistically significant difference was found only at +8 hours after CA (p = 0.0042). In multivariable analysis, CPO at 8-hour was significantly associated with cardiovascular-related mortality (p = 0.007).

CONCLUSIONS

In post-CA patients, the 8-hour CPO is an independent factor associated with ICU cardiovascular-related mortality.

Electroencephalography Prediction of Neurological Outcomes After Hypoxic-Ischemic Brain Injury: A Systematic Review and Meta-Analysis

Background. Predicting neurological outcomes after hypoxic-ischemic brain injury (HIBI) is difficult. Objective. Electroencephalography (EEG) can identify acute and subacute brain abnormalities after hypoxic brain injury and predict HIBI recovery. We examined EEG's ability to predict neurologic outcomes following HIBI. Method. A PRISMA-compliant search was conducted in the Medline, Embase, Cochrane, and Central databases until January 2023. EEG-predicted neurological outcomes in HIBI patients were selected from relevant perspective and retrospective cohort studies. RevMan did meta-analysis, while QDAS2 assessed research quality. Results. Eleven studies with 3761 HIBI patients met the inclusion and exclusion criteria. We aggregated study-level estimates of sensitivity and specificity for EEG patterns determined a priori using random effect bivariate and univariate meta-analysis when appropriate. Positive indicators and anatomical area heterogeneity impacted prognosis accuracy. Funnel plots analyzed publication bias. Significant heterogeneity of greater than 80% was among the included studies with P < 0.001. The area under the curve was 0.94, the threshold effect was P < 0.001, and the sensitivity and specificity, with 95% confidence intervals, were 0.91 (0.84-0.99) and 0.86 (0.75-0.97). EEG detects status epilepticus and burst suppression with good sensitivity, specificity, and little probability of false-negative impairment result attribution. Study quality varied by domain, but patient flow and timing were well conducted in all. Conclusion. EEG can predict the outcome of HIBI with good prognostic accuracy, but more standardized cross-study protocols and descriptions of EEG patterns are needed to better evaluate its prognostic use for patients with HIBI.

Serum proteome profiles in patients treated with targeted temperature management after out-of-hospital cardiac arrest

BACKGROUND

Definition of temporal serum proteome profiles after out-of-hospital cardiac arrest may identify biological processes associated with severe hypoxia-ischaemia and reperfusion. It may further explore intervention effects for new mechanistic insights, identify candidate prognostic protein biomarkers and potential therapeutic targets. This pilot study aimed to investigate serum proteome profiles from unconscious patients admitted to hospital after out-of-hospital cardiac arrest according to temperature treatment and neurological outcome.

METHODS

Serum samples at 24, 48, and 72 h after cardiac arrest at three centres included in the Target Temperature Management after out-of-hospital cardiac arrest trial underwent data-independent acquisition mass spectrometry analysis (DIA-MS) to find changes in serum protein concentrations associated with neurological outcome at 6-month follow-up and targeted temperature management (TTM) at 33 °C as compared to 36 °C. Neurological outcome was defined according to Cerebral Performance Category (CPC) scale as "good" (CPC 1-2, good cerebral performance or moderate disability) or "poor" (CPC 3-5, severe disability, unresponsive wakefulness syndrome, or death).

RESULTS

Of 78 included patients [mean age 66 ± 12 years, 62 (80.0%) male], 37 (47.4%) were randomised to TTM at 36 °C. Six-month outcome was poor in 47 (60.3%) patients. The DIA-MS analysis identified and quantified 403 unique human proteins. Differential protein abundance testing comparing poor to good outcome showed 19 elevated proteins in patients with poor outcome (log₂-fold change (FC) range 0.28-1.17) and 16 reduced proteins (log₂(FC) between - 0.22 and - 0.68), involved in inflammatory/immune responses and apoptotic signalling pathways for poor outcome and proteolysis for good outcome. Analysis according to level of TTM showed a significant protein abundance difference for six proteins [five elevated proteins in TTM 36 °C (log₂(FC) between 0.33 and 0.88), one reduced protein (log₂(FC) - 0.6)] mainly involved in inflammatory/immune responses only at 48 h after cardiac arrest.

CONCLUSIONS

Serum proteome profiling revealed an increase in inflammatory/immune responses and apoptosis in patients with poor outcome. In patients with good outcome, an increase in proteolysis was observed, whereas TTM-level only had a modest effect on the proteome profiles. Further validation of the differentially abundant proteins in response to neurological outcome is necessary to validate novel biomarker candidates that may predict prognosis after cardiac arrest.

Predicting poor neurological outcomes following out-of-hospital cardiac arrest using neuron-specific enolase and neurofilament light chain in patients with and without haemolysis

Aims

Hypoxic-ischaemic brain injury following out-of-hospital cardiac arrest (OHCA) is a common complication and a major cause of death. Neuron-specific enolase (NSE) and neurofilament light chain (NfL) are released after brain injury and elevated concentrations of both are associated with poor neurological outcome. We explored the influence of haemolysis on the prognostic performance of NSE and NfL.

Methods and results

The study is based on post hoc analyses of a randomized, single-centre, double-blinded, controlled trial (IMICA), where comatose OHCA patients of presumed cardiac cause were included. Free-haemoglobin was measured at admission to quantify haemolysis. NSE and NfL were measured after 48 h to estimate the extent of brain injury. Montreal Cognitive Assessment score (MoCA) was assessed to evaluate neurocognitive impairments. Seventy-three patients were included and divided into two groups by the median free-haemoglobin at admission. No group differences in mortality or poor neurological outcome were observed. The high-admission free-haemoglobin group had a significantly higher concentration of NSE compared to the low-admission free-haemoglobin group (27.4 µmol/L vs. 19.6 µmol/L, P = 0.03), but no differences in NfL. The performance of NSE and NfL in predicting poor neurological outcome were high for both, but NfL was numerically higher [area under the ROC (AUROC) 0.90 vs. 0.96, P = 0.09]. Furthermore, NfL, but not NSE, was inversely correlated with MoCA score, R2 = 0.21, P = 0.006.

Conclusion

High free-haemoglobin at admission was associated with higher NSE concentration after 48 h, but, the performance of NSE and NfL in predicting poor neurological outcome among OHCA patients were good regardless of early haemolysis. Only elevated NfL concentrations were associated with cognitive impairments.

Serum neurofilament light chain as a predictive marker of neurologic outcome after cardiac arrest: a meta-analysis

OBJECTIVE

Recently, an increasing number of studies have suggested using serum neurofilament light (NfL) chain to predict the neurologic outcome after cardiac arrest. However, the predictive ability of this approach remains inconclusive. Meta-analysis was performed on related studies to assess the ability of serum NfL to predict the neurologic outcome after cardiac arrest.

MATERIALS AND METHODS

PubMed, ScienceDirect and Embase were systematically searched from the date of their inception until June 2022. Data were extracted to calculate the area under the receiver operating characteristic curve (AUC), the sensitivity, the specificity and the publication bias to evaluate the predictive power of serum NfL using Stata 14.0.

RESULTS

Nine studies were included in the present meta-analysis. Seven studies involving 1296 participants reported serum NfL 24 h post arrest for predicting the neurological outcome, and the AUC was 0.92 (77% sensitivity and 96% specificity). Seven studies involving 1020 participants reported serum NfL 48 h post arrest for predicting the neurological outcome, and the AUC was 0.94 (78% sensitivity and 98% specificity). Four studies involving 804 participants reported serum NfL 72 h post arrest for predicting the neurological outcome, and the AUC was 0.96 (90% sensitivity and 98% specificity). No significant publication bias was observed among the included studies.

CONCLUSION

The present meta-analysis results support the potential use of serum NfL as an early biomarker of neurologic outcome, especially 72 h post arrest.

Efficacy of acupuncture for cardiopulmonary cerebral resuscitation: A systematic review and meta-analysis

Background

Cerebral resuscitation is one of the main therapeutic aims in the treatment of cardiac arrest (CA) patients who experience a return of spontaneous circulation (ROSC). However, the therapeutic effects of current treatments are not ideal. The purpose of this study was to evaluate the efficacy of neurological function of acupuncture combined with conventional cardiopulmonary cerebral resuscitationthe (CPCR) for patients after ROSC.

Methods

Seven electronic databases and other related websites were searched to identify studies on acupuncture combined with conventional CPCR for patients after ROSC. R software was used to conduct a meta-analysis, and the outcomes that could not be pooled were analyzed using a descriptive analysis.

Results

Seven RCTs involving 411 participants who had experienced ROSC were eligible for inclusion. The main acupoints were Neiguan (PC6), Shuigou (DU26), Baihui (DU20), Yongquan (KI1), and Sanyinjiao (SP6). Compared to conventional CPCR, acupuncture combined with conventional CPCR led to significantly higher Glasgow Coma Scale (GCS) scores on day 3 (mean difference (MD)=0.89, 95% CI: 0.43, 1.35, I² = 0%), day 5 (MD = 1.21, 95% CI: 0.27, 2.15; I² = 0%), and day 7 (MD = 1.92, 95% CI: 1.35, 2.50; I² = 0%).

Conclusion

Acupuncture-assisted conventional CPCR may have a potential role in improving neurological function in CA patients after ROSC, but the certainty of evidence is very low and more high-quality studies are required.

Protocol registration

This review was registered at the International Prospective Registry of Systematic Reviews (PROSPERO): CRD42021262262.

A complete, evidence-based review on novichok poisoning based on epidemiological aspects and clinical management

Background: The whole world has learned about the existence of a highly toxic neuro-paralytic substance called Novichok. A wide range of neuro-paralytic toxins were used during the wars of decades ago, which also had harmful and irreversible effects. Fortunately, the establishment of conventions prohibiting the use of these weapons prevented the adverse clinical consequences of these compounds. What we did in the present study was to evaluate the clinical features of Novichok, how to manage exposure to it, and to evaluate the prognostic aspects associated with this poisoning agent. Methods: The manuscript especial databases including Medline, Web of knowledge, Google scholar, and Scopus were deeply searched by the two blinded investigators for all eligible studies based on the considered keywords. Initially 98 articles were initially collected by database searching that considering eligibility criteria, 83 articles were finally eligible for the final assessment. There is a lack of clinical trials and case-cohort studies on general population about treatment and side effects when it comes to human nerve agents and most of the data in our search is based on animal studies. Results: In evaluating various clinical, auto physiological and prognostic aspects of exposure to these substances, special attention was necessary to the following points. First, Novichok agents are considered more potent than other toxic agents. Pathophysiologically, these agents irreversibly bind acetylcholinesterase and produce a rapid cholinergic toxidrome which is responsible for the clinical manifestations as well as the potential dangerous and life threatening side effects caused by these agents. Uniquely, these agents are thought to also target every neuron in the central and peripheral nervous system. As a managerial and therapeutic approach, early and timely treatment of its related complication along with prevents massive exposure and decontamination in addition to rapid resuscitation can prohibit debilitating neuropathy and death due to facing it. Conclusion: The present review highlights the importance of recognizing the potential acute toxic effects of Novichok agents, diagnostic and therapeutic approaches (life-saving antidotal therapy) to complications and ultimately the application of guidelines to improve the prognosis of exposure to these agents for both victims and medical community.

Cytokine hemoadsorption with CytoSorb® in post-cardiac arrest syndrome, a pilot randomized controlled trial

BACKGROUND

Hemoadsorption (HA) might mitigate the systemic inflammatory response associated with post-cardiac arrest syndrome (PCAS) and improve outcomes. Here, we investigated the feasibility, safety and efficacy of HA with CytoSorb® in cardiac arrest (CA) survivors at risk of PCAS.

METHODS

In this pilot randomized controlled trial, we included patients admitted to our intensive care unit following CA and likely to develop PCAS: required norepinephrine (> 0.2 µg/kg/min), and/or had serum lactate > 6 mmol/l and/or a time-to-return of spontaneous circulation (ROSC) > 25 min. Those requiring ECMO or renal replacement therapy were excluded. Eligible patients were randomly allocated to either receive standard of care (SOC) or SOC plus HA. Hemoadsorption was performed as stand-alone therapy for 24 h, using CytoSorb® and regional heparin-protamine anticoagulation. We collected feasibility, safety and clinical data as well as serial plasma cytokines levels within 72 h of randomization.

RESULTS

We enrolled 21 patients, of whom 16 (76%) had out-of-hospital CA. Median (IQR) time-to-ROSC was 30 (20, 45) minutes. Ten were assigned to the HA group and 11 to the SOC group. Hemoadsorption was initiated in all patients allocated to the HA group within 18 (11, 23) h of ICU admission and conducted for a median duration of 21 (14, 24) h. The intervention was well tolerated except for a trend for a higher rate of aPTT elevation (5 (50%) vs 2 (18%) p = 0.18) and mild (100-150 G/L) thrombocytopenia at day 1 (5 (50%) vs 2 (18%) p = 0.18). Interleukin (IL)-6 plasma levels at randomization were low (< 100 pg/mL) in 10 (48%) patients and elevated (> 1000 pg/mL) in 6 (29%). The median relative reduction in IL-6 at 48 h was 75% (60, 94) in the HA group versus 5% (- 47, 70) in the SOC group (p = 0.06).

CONCLUSIONS

In CA survivors at risk of PCAS, HA was feasible, safe and was associated with a nonsignificant reduction in cytokine plasma levels. Future trials are needed to further define the role of HA after CA. Those studies should include cytokine assessment to enrich the study population.

TRIAL REGISTRATION

NCT03523039, registered 14 May 2018.

Post-Cardiac Arrest: Mechanisms, Management, and Future Perspectives

Cardiac arrest is an important public health issue, with a survival rate of approximately 15 to 22%. A great proportion of these deaths occur after resuscitation due to post-cardiac arrest syndrome, which is characterized by the ischemia-reperfusion injury that affects the role body. Understanding physiopathology is mandatory to discover new treatment strategies and obtain better results. Besides improvements in cardiopulmonary resuscitation maneuvers, the great increase in survival rates observed in recent decades is due to new approaches to post-cardiac arrest care. In this review, we will discuss physiopathology, etiologies, and post-resuscitation care, emphasizing targeted temperature management, early coronary angiography, and rehabilitation.

Anemia before in-hospital cardiac arrest and survival from cardio-pulmonary resuscitation-a retrospective cohort study

BACKGROUND

Multiple patient-related variables have been associated with reduced rates of survival to hospital discharge (SHD) after in-hospital cardiac arrest (IHCA). As opposed to most of these, anemia may be reversible. This retrospective single-center study aims to examine the relationship between prearrest hemoglobin levels, comorbidities, and survival after cardiopulmonary resuscitation (CPR) among patients with non-traumatic IHCA. Patients were classified as anemic (hemoglobin < 10 g/dL) or non-anemic (hemoglobin ≥ 10 g/dL) based on their lowest hemoglobin measurement in the 48 h preceding the arrest. The primary outcome was SHD. The secondary outcome was return of spontaneous circulation (ROSC).

RESULTS

Of 1515 CPR reports screened, 773 patients were included. Half of the patients (50.5%, 390) were classified as anemic. Anemic patients had higher Charlson Comorbidity Indices (CCIs), less cardiac causes, and more metabolic causes for the arrest. An inverse association was found between CCI and lowest hemoglobin. Overall, 9.1% (70 patients) achieved SHD and 49.5% (383) achieved ROSC. Similar rates of SHD (7.3 vs. 10.7%, p = 0.118) and ROSC (49.5 vs. 51.0%, p = 0.688) were observed in anemic and non-anemic patients. These findings remained consistent after adjustment for comorbidities, in sensitivity analyses on the independent variable (i.e., hemoglobin) and on potential confounders and in subgroups based on sex or blood transfusion in the 72 h preceding the arrest.

CONCLUSIONS

Prearrest hemoglobin levels lower than 10 g/dL were not associated with lower rates of SHD or ROSC in IHCA patients after controlling for comorbidities. Further studies are required to confirm our findings and to establish whether post-arrest hemoglobin levels reflect the severity of the inflammatory post-resuscitation processes.

Incidence, Outcomes, and Risk Factors for Preincision Cardiac Arrest in Cardiac Surgery Patients

BACKGROUND

We examined the incidence, postoperative outcomes, and patient-related factors associated with preincision cardiac arrest in patients undergoing cardiac surgery.

METHODS

We retrospectively examined adult patients undergoing elective or urgent cardiac surgery at the Cleveland Clinic between 2008 and 2019. The incidence of preincision cardiac arrest, defined as arrest between induction of general anesthesia and surgical incision, was reported. In a secondary analysis, we assessed the association between preincision cardiac arrest and major postoperative outcomes. In a tertiary analysis, we used adjusted linear regression models to explore the association between preincision cardiac arrest and prespecified patient risk factors, including severe left main coronary artery stenosis, left ventricular ejection fraction, moderate/severe right ventricular dysfunction, low-flow low-gradient aortic stenosis, and moderate/severe pulmonary hypertension.

RESULTS

Preincision cardiac arrests occurred in 75 of 41,238 (incidence of 0.18%; 95% CI, 0.17-0.26) patients who had elective or urgent cardiac surgery. Successful cardiopulmonary resuscitation with return of spontaneous circulation or bridge to cardiopulmonary bypass occurred in 74 of 75 (98.6%) patients. Patients who experienced preincision cardiac arrest had significantly higher in-hospital mortality than those who did not (11% vs 2%; odds ratio [OR] (95% CI), 4.14 (1.94-8.84); P < .001). They were also more likely to suffer postoperative respiratory failure (46% vs 13%; OR [95% CI], 3.94 [2.40-6.47]; P < .001), requirement for renal replacement therapy (11% vs 2%; OR [95% CI], 3.90 [1.82-8.35]; P < .001), neurologic deficit (7% vs 2%; OR [95% CI], 2.49 (1.00-6.21); P = .05), and longer median hospital stay (15 vs 8 days; hazard ratio (HR) [95% CI], 0.68 [0.55-0.85]; P < .001). Reduced left ventricular ejection fraction (per 5% decrease) (OR [95% CI], 1.13 [1.03-1.22]; P = .006) and moderate/severe pulmonary hypertension (OR [95% CI], 3.40 [1.95-5.90]; P < .001) were identified as independent risk factors for cardiac arrest.

CONCLUSIONS

Cardiac arrest after anesthetic induction is rare in cardiac surgical patients in our investigation. Though most patients are rescued, morbidity and mortality remain higher. Reduced left ventricular ejection fraction and moderate/severe pulmonary hypertension are associated with greater risk for preincision cardiac arrest.

Serum total cholesterol level as a potential predictive biomarker for neurological outcomes in cardiac arrest survivors who underwent target temperature management

Cholesterol is an essential substance to maintain cell membranes. Low levels of total cholesterol (TC) are associated with poor prognosis in critically ill patients. Cardiac arrest-induced whole-body ischemia and reperfusion injury cause a sepsis-like syndrome. The Cholesterol level in post-cardiac arrest patients may indicate the degree of endotoxemia or inflammation caused by ischemic and reperfusion injury. We aimed to investigate the association of TC levels with neurologic outcome of out-of-hospital cardiac arrest (OHCA) survivors who underwent target temperature management (TTM). This was a retrospective single-center observational study from May 2018 to April 2021 on a cohort of 106 patients. TC levels were determined in samples obtained immediately and at 24, 48, and 72 hours after the return of spontaneous circulation (ROSC). The primary outcome was poor neurologic outcome at 3 months after ROSC. Poor neurologic outcome was defined by cerebral performance categories 3 to 5. Sixty patients had a poor neurologic outcome. TC levels were significantly lower in the poor neurologic outcome group at each time point. The TC levels for predicting poor neurologic outcome had a sensitivity of 80.8%, with 67.6% specificity at 48 hours (TC48) after ROSC. The areas under the curve value of TC48 was 0.771 (0.670-0.853), with a cutoff value of 114 mg/dL. TC level at 48 hours after ROSC was a helpful marker for the 3-month poor neurologic outcome. This might be an easily accessible predictive marker of neurologic outcome in OHCA survivors treated with TTM.

Cerebrospinal fluid features in comatose survivors of cardiac arrest: A pilot study

INTRODUCTION

Lumbar puncture is among the investigations used to identify various neurological conditions, including some that can cause cardiac arrest (CA). However, CA per se may alter cerebrospinal fluid (CSF) characteristics. Few studies have investigated CSF findings after CA. In this descriptive work, we assessed the frequency and risk factors of abnormal CSF findings after CA and the contribution of CSF analysis to the etiological diagnosis.

MATERIALS AND METHODS

We retrospectively studied data from prospectively established databases of consecutive patients who were admitted to two French ICUs in 2007-2016 with sustained return of spontaneous circulation (ROSC) after CA and who underwent lumbar puncture as an etiological investigation.

RESULTS

Of 1984 patients with sustained ROSC, 55 (2.7%) underwent lumbar puncture and were included. Lumbar puncture identified a neurological cause of CA in 2/55 (3.6%) patients. Nonspecific CSF abnormalities were noted in 37/53 (69.8%) patients. By multivariate analysis, postresuscitation shock was positively associated with CSF abnormalities (OR, 6.92; 95% confidence interval [95%CI], 1.62-37.26; P = 0.013). A no-flow time above 6 minutes (OR, 0.19; 95%CI, 0.03-1.11; P = 0.076) and a respiratory cause of CA (OR, 2.91; 95%CI, 0.53-23.15; P = 0.24) were not statistically associated with CSF abnormalities. Nonspecific CSF abnormalities were not significantly associated with poor outcomes (Cerebral Performance Category ≥3; P = 0.06).

CONCLUSIONS

Lumbar puncture, although infrequently performed, may contribute to the etiological diagnosis of CA, albeit rarely. Nonspecific CSF abnormalities seem common after CA, notably with postresuscitation shock, and may be related to blood-brain barrier disruption. These findings may help to interpret CSF findings after CA. Further studies are warranted to assess our results.

Delirium in ICU Patients after Cardiac Arrest: A Scoping Review

Introduction: The incidence of delirium in the intensive care unit is high, although it may differ according to the specific characteristics of the unit. Despite the rapid development of research on delirium in recent years, the pathophysiological mechanisms leading to the clinical presentation of delirium are still subject to hypotheses. The aim of this review was to describe the incidence of delirium in cardiac arrest survivors and the clinical impact of delirium on patient outcomes. Methods: A scoping review was conducted in the second quarter of 2022. The number of articles retrieved during each search test was limited to studies conducted between 2010 and 2020. Strict inclusion and exclusion criteria were applied. The last search was conducted in May 2022. Results: A total of 537 records was initially obtained from the databases. After discarding duplicates, selecting titles and abstracts, and then analyzing full-text articles, 7 studies met the inclusion criteria. The incidence of delirium in the cardiac arrest survivor population ranged from 8% to as high as 100%. The length of stay in ICU and hospital was significantly longer in patients with delirium than those without. Ninety-eight percent of patients had cognitive or perceptual impairment and psychomotor impairment. Of the seven studies included in the analysis, the RASS, CAM, and NuDesc scales were used to diagnose delirium. Potential risk factors that may influence the duration of delirium include age and time since resuscitation; propofol use shortened the duration of delirium. Conclusion: the incidence of delirium in ICU patients who survived CA is high. Cardiac arrest is an additional predisposing factor for delirium. In cardiac arrest survivors, the occurrence of delirium prolongs the duration of ICU and hospital stay and adversely affects functional outcomes. The most common type of delirium among this population was hypoactive delirium. A large percentage of patients manifested symptoms such as cognitive or perception impairment, psychomotor impairment, and impaired concentration and attention.

Myocardial dysfunction after cardiac arrest: tips and pitfalls

Postcardiac arrest shock (PCAS) is defined by hemodynamic instability occurring in the first hours after cardiac arrest (CA) and is a major cause of mortality among patients hospitalized after CA. It includes vasoplegia and myocardial dysfunction. This postcardiac arrest myocardial dysfunction is supposed to recover within the 3 days. However, there are many unknowns regarding its definition, its prognosis value and its management. In this review dedicated to emergency physicians, we choose to address tips and pitfalls they should know regarding this prevalent syndrome.

Immediate complete revascularization showed better outcome in out-of-hospital cardiac arrest survivors with left main or triple-vessel coronary diseases

This study aimed to evaluate the prevalence of left main or triple vessel coronary artery disease (CAD) in comatose out-of-hospital cardiac arrest (OHCA) survivors and assessed their outcome based on the revascularization strategy. This multicenter, retrospective, observational registry-based study was conducted at 9 Korean tertiary care hospitals. Adult comatose OHCA survivors with left main or triple vessel CAD documented by immediate (≤ 2 h) coronary angiography after return of spontaneous circulation between 2011 and 2019 were included. The primary outcome was neurologically intact survival at 1-month. Among 727 OHCA patients, 150 (25%) had left main or triple vessel CAD and underwent complete (N = 32), incomplete (N = 78), and no immediate (N = 40) revascularization, respectively. The rate of neurologically intact survival at 1 month was significantly different among the groups (53%, 32%, and 23% for complete, incomplete, and no immediate revascularization groups, respectively; P = 0.02). After adjustment using the inverse probability of treatment weighting, complete revascularization was associated with neurologically intact survival at 1 month (odds ratio, 2.635; P = 0.01). Left main or triple vessel CAD is not uncommon in OHCA patients. The complete revascularization was associated with better outcome. Further clinical trials to confirm the best revascularization strategy are needed.

Ischemic injury of the upper gastrointestinal tract after out-of-hospital cardiac arrest: a prospective, multicenter study

Background

The consequences of cardiac arrest (CA) on the gastro-intestinal tract are poorly understood. We measured the incidence of ischemic injury in the upper gastro-intestinal tract after Out-of-hospital CA (OHCA) and determined the risk factors for and consequences of gastrointestinal ischemic injury according to its severity.

Methods

Prospective, non-controlled, multicenter study in nine ICUs in France and Belgium conducted from November 1, 2014 to November 30, 2018. Included patients underwent an esophago-gastro-duodenoscopy 2 to 4 d after OHCA if still intubated and the presence of ischemic lesions of the upper gastro-intestinal tract was determined by a gastroenterologist. Lesions were a priori defined as severe if there was ulceration or necrosis and moderate if there was mucosal edema or erythema. We compared clinical and cardiac arrest characteristics of three groups of patients (no, moderate, and severe lesions) and identified variables associated with gastrointestinal ischemic injury using multivariate regression analysis. We also compared the outcomes (organ failure during ICU stay and neurological status at hospital discharge) of the three groups of patients.

Results

Among the 214 patients included in the analysis, 121 (57%, 95% CI 50–63%) had an upper gastrointestinal ischemic lesion, most frequently on the fundus. Ischemic lesions were severe in 55/121 (45%) patients. In multivariate regression, higher adrenaline dose during cardiopulmonary resuscitation (OR 1.25 per mg (1.08–1.46)) was independently associated with increased odds of severe upper gastrointestinal ischemic lesions; previous proton pump inhibitor use (OR 0.40 (0.14–1.00)) and serum bicarbonate on day 1 (OR 0.89 (0.81–0.97)) were associated with lower odds of ischemic lesions. Patients with severe lesions had a higher SOFA score during the ICU stay and worse neurological outcome at hospital discharge.

Conclusions

More than half of the patients successfully resuscitated from OHCA had upper gastrointestinal tract ischemic injury. Presence of ischemic lesions was independently associated with the amount of adrenaline used during resuscitation. Patients with severe lesions had higher organ failure scores during the ICU stay and a worse prognosis.

Clinical Trial RegistrationNCT02349074.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-03939-9.

Metformin Protects Against Cardiac and Renal Damage in Diabetic Cardiac Arrest Patients

INTRODUCTION

Metformin is a first-line diabetic therapy that improves survival in a wide number of ischemic pathologies. We tested the association of metformin with markers of cardiac and renal injury in diabetic post-arrest patients.

METHODS

We performed a retrospective analysis of clinical outcomes in diabetic cardiac arrest patients with and without metformin therapy at a single academic medical center. We used generalized linear models to test the independent association of metformin, insulin, and other hypoglycemic agents with peak 24-hour serum creatinine and peak 24-hour serum troponin.

RESULTS

Metformin prescription at the time of SCA was independently associated with lower 24-hour peak serum troponin and lower 24-hour peak serum creatinine when compared to non-metformin patients.

CONCLUSION

Metformin pretreatment may offer cardiac and renal protection for diabetic patients during sudden cardiac arrest.

Olanzapine-Induced Therapeutic Hypothermia Attenuates Renal Injury in Rats after Asphyxial Cardiac Arrest and Resuscitation

Return of spontaneous circulation (ROSC) through cardiopulmonary resuscitation (CPR) after cardiac arrest (CA) causes post-cardiac arrest syndrome (PCAS) due to dysfunction in various organs, which provokes acute kidney injury because of renal ischemia-reperfusion injury. Therapeutic hypothermia (TH) can reduce PCAS after CA and ROSC. However, it needs to be more sophisticated and effective. Hence, we aimed to elucidate the protective effects of olanzapine-induced TH against renal injury in asphyxial CA-induced rats. Every rat’s body temperature was maintained at 33 °C for 6 h after administering olanzapine post-CA and ROSC. Olanzapine-induced TH dramatically increased the survival rate of the rats and ameliorated renal tissue damage. Moreover, it suppressed oxidative stress responses through preservation of mitochondrial function and endoplasmic reticulum stress as the main contributor of oxidative stress. Notably, these actions of olanzapine-induced TH were mediated through the Sirt3-related signaling pathway, including the maintenance of Sirt3 and FOXO3a protein expression and the activation of AMPKα and superoxide dismutase 1 (SOD2, a mitochondrial antioxidant). This study is the first to disclose the protective effects of olanzapine-induced TH against renal injury after CA and ROSC, suggesting that olanzapine-induced TH could be utilized for treating CA followed by ROSC.

Omecamtiv mecarbil treatment improves post-resuscitation cardiac function and neurological outcome in a rat model

Background

Myocardial dysfunction is a major cause of poor outcomes in the post-cardiac arrest period. Omecamtiv mecarbil (OM) is a selective small molecule activator of cardiac myosin that prolongs myocardial systole and increases stroke volume without apparent effects on myocardial oxygen demand. OM administration is safe and improves cardiac function in patients with acute heart failure. Whether OM improves post-resuscitation myocardial dysfunction remains unclear. This study investigated the effect of OM treatment on post-resuscitation myocardial dysfunction and outcomes.

Methods and results

Adult male rats were resuscitated after 9.5 min of asphyxia-induced cardiac arrest. OM and normal saline was continuously intravenously infused after return of spontaneous circulation (ROSC) at 0.25 mg/kg/h for 4 h in the experimental group and control group, respectively (n = 20 in each group). Hemodynamic parameters were measured hourly and monitored for 4 h after cardiac arrest. Recovery of neurological function was evaluated by neurological functioning scores (0–12; favorable: 11–12) for rats 72 h after cardiac arrest. OM treatment prolonged left ventricular ejection time and improved post-resuscitation cardiac output. Post-resuscitation heart rate and left ventricular systolic function (dp/dt₄₀) were not different between groups. Kaplan-Meier analysis showed non-statistically higher 72-h survival in the OM group (72.2% [13/18] and 58.8% [10/17], p = 0.386). The OM group had a higher chance of having favorable neurological outcomes in surviving rats 72 h after cardiac arrest (84.6% [11/13] vs. 40% [4/10], p = 0.026). The percentage of damaged neurons was lower in the OM group in a histology study at 72 h after cardiac arrest (55.5±2.3% vs. 76.2±10.2%, p = 0.004).

Conclusions

OM treatment improved post-resuscitation myocardial dysfunction and neurological outcome in an animal model. These findings support further pre-clinical studies to improve outcomes in post-cardiac arrest care.

Efficacy of combination triple therapy with vasopressin, steroid, and epinephrine in cardiac arrest: a systematic review and meta-analysis of randomized-controlled trials

Background

This study investigated whether combination therapy with vasopressin, steroid, and epinephrine (VSE) improves in-hospital survival and return of spontaneous circulation (ROSC) during and after resuscitation in-hospital cardiac arrest (CA).

Materials and methods

Various databases were explored from inception until October 2021 for relevant published clinical trials and cohort studies.

Results

Three clinical trials were included. Pooled analysis suggested that VSE was significantly associated with increased ROSC in patients with in-hospital CA (IHCA) (odds ratio (OR): 2.281, 95% confidence interval (CI): 1.304–3.989, P value = 0.004). Meta-analysis of two studies (368 patients) demonstrated a significant difference in the reduction of mean arterial pressure (MAP) during and 15–20 min after cardiopulmonary resuscitation (standardized mean difference (SMD): 1.069, 95% CI: 0.851–1.288, P value < 0.001), renal failure free days (SMD = 0.590; 95% CI: 0.312–0.869 days; P value < 0.001), and coagulation failure free days (SMD = 0.403; 95% CI: 0.128–0.679, P value = 0.004). However, no significant difference was observed for survival-to-discharge ratio (OR: 2.082, 95% CI: 0.638–6.796, P value = 0.225) and ventilator free days (SMD = 0.201, 95% CI: − 0.677, 1.079 days; P value = 0.838).

Conclusions

VSE combination therapy during and after IHCA may have beneficial effects in terms of the ROSC, renal and circulatory failure free days, and MAP.

Prospero registration: CRD42020178297 (05/07/2020).

Supplementary Information

The online version contains supplementary material available at 10.1186/s40560-022-00597-5.

The association of early diarrhea after successful resuscitation following out-of-hospital cardiac arrest with neurological outcome: A retrospective observational study

Gastrointestinal ischemia with reperfusion tissue injury contributes to post-cardiac arrest syndrome. We hypothesized that diarrhea is a symptom of intestinal ischemia/reperfusion injury and investigated whether the occurrence of early diarrhea (≤12 hours) after successful cardiopulmonary resuscitation is associated with an unfavorable neurological outcome.We analyzed data from the Vienna Clinical Cardiac Arrest Registry. Inclusion criteria comprised ≥18 years of age, a witnessed, non-traumatic out-of-hospital cardiac arrest, return of spontaneous circulation (ROSC), initial shockable rhythm, and ST-segment elevation in electrocardiogram after ROSC with consecutive coronary angiography. Patients with diarrhea caused by other factors (e.g., infections, antibiotic treatment, or chronic diseases) were excluded. The primary endpoint was neurological function between patients with or without "early diarrhea" (≤12 hours after ROSC) according to cerebral performance categories.We included 156 patients between 2005 and 2012. The rate of unfavorable neurologic outcome was higher in patients with early diarrhea (67% vs 37%). In univariate analysis, the crude odds ratio for unfavorable neurologic outcome was 3.42 (95% confidence interval, 1.11-10.56, P = .03) for early diarrhea. After multivariate adjustment for traditional prognostication markers the odds ratio of early diarrhea was 5.90 (95% confidence interval, 1.28-27.06, P = .02).In conclusion, early diarrhea within 12 hours after successful cardiopulmonary resuscitation was associated with an unfavorable neurological outcome.

Effect of therapeutic hypothermia against renal injury in a rat model of asphyxial cardiac arrest: Α focus on the survival rate, pathophysiology and antioxidant enzymes

Although multi-organ dysfunction is associated with the survival rate following cardiac arrest (CA), the majority of studies to date have focused on hearts and brains, and few studies have considered renal failure. The objective of the present study, therefore, was to examine the effects of therapeutic hypothermia on the survival rate, pathophysiology and antioxidant enzymes in rat kidneys following asphyxial CA. Rats were sacrificed one day following CA. The survival rate, which was estimated using Kaplan-Meier analysis, was 42.9% one day following CA. However, hypothermia, which was induced following CA, significantly increased the survival rate (71.4%). In normothermia rats with CA, the serum blood urea nitrogen level was significantly increased one day post-CA. In addition, the serum creatinine level was significantly increased one day post-CA. However, in CA rats exposed to hypothermia, the levels of urea nitrogen and creatinine significantly decreased following CA. Histochemical staining revealed a significant temporal increase in renal injury after the normothermia group was subjected to CA. However, renal injury was significantly decreased in the hypothermia group. Immunohistochemical analysis of the kidney revealed a significant decrease in antioxidant enzymes (copper-zinc superoxide dismutase, manganese superoxide dismutase, glutathione peroxidase and catalase) with time in the normothermia group. However, in the hypothermia group, these enzymes were significantly elevated following CA. Collectively, the results revealed that renal dysfunction following asphyxial CA was strongly associated with the early survival rate and therapeutic hypothermia reduced renal injury via effective antioxidant mechanisms.

Therapeutic Effects of Risperidone against Spinal Cord Injury in a Rat Model of Asphyxial Cardiac Arrest: A Focus on Body Temperature, Paraplegia, Motor Neuron Damage, and Neuroinflammation

Cardiac arrest (CA) causes severe spinal cord injury and evokes spinal cord disorders including paraplegia. It has been reported that risperidone, an antipsychotic drug, effectively protects neuronal cell death from transient ischemia injury in gerbil brains. However, until now, studies on the effects of risperidone on spinal cord injury after asphyxial CA (ACA) and cardiopulmonary resuscitation (CPR) are not sufficient. Therefore, this study investigated the effect of risperidone on hind limb motor deficits and neuronal damage/death in the lumbar part of the spinal cord following ACA in rats. Mortality, severe motor deficits in the hind limbs, and the damage/death (loss) of motor neurons located in the anterior horn were observed two days after ACA/CPR. These symptoms were significantly alleviated by risperidone (an atypical antipsychotic) treatment after ACA. In vehicle-treated rats, the immunoreactivities of tumor necrosis factor-alpha (TNF-α) and interleukin 1-beta (IL-1β), as pro-inflammatory cytokines, were increased, and the immunoreactivities of IL-4 and IL-13, as anti-inflammatory cytokines, were reduced with time after ACA/CPR. In contrast, in risperidone-treated rats, the immunoreactivity of the pro-inflammatory cytokines was significantly decreased, and the anti-inflammatory cytokines were enhanced compared to vehicle-treated rats. In brief, risperidone treatment after ACA/CPR in rats significantly improved the survival rate and attenuated paralysis, the damage/death (loss) of motor neurons, and inflammation in the lumbar anterior horn. Thus, risperidone might be a therapeutic agent for paraplegia by attenuation of the damage/death (loss) of spinal motor neurons and neuroinflammation after ACA/CPR.

Updates on the Management of Neurologic Complications of Post-Cardiac Arrest Resuscitation

Sudden cardiac arrest (SCA) is one of the leading causes of mortality and morbidity in the United States, and survivors are frequently left with severe disability. Of the 10% successfully resuscitated from SCA, only around 10% of these live with a favorable neurologic outcome. Survivors of SCA commonly develop post-cardiac arrest syndrome (PCAS). PCAS is composed of neurologic, myocardial, and systemic injury related to inadequate perfusion and ischemia-reperfusion injury with free radical formation and an inflammatory cascade. While targeted temperature management is the cornerstone of therapy, other intensive care unit-based management strategies include monitoring and treatment of seizures, cerebral edema, and increased intracranial pressure, as well as prevention of further neurologic injury. In this review, we discuss the scientific evidence, recent updates, future prospects, and knowledge gaps in the treatment of post-cardiac arrest patients.

Cerebral and myocardial mitochondrial injury differ in a rat model of cardiac arrest and cardiopulmonary resuscitation

Brain mitochondria are more sensitive to global ischemia compared to heart mitochondria. Complex I in the electron transport chain (ETC) is sensitive to ischemic injury and is a major control point of the rate of ADP stimulated oxygen consumption. The purpose of this study was to explore whether changes in cerebral and myocardial mitochondria differ after cardiac arrest. Animals were randomized into 4 groups (n = 6): 1) Sham 2) VF 3) VF+CPR 4) ROSC 1hr. Ventricular Fibrillation (VF) was induced through a guide wire advanced from the right jugular vein into the ventricle and untreated for 8 min. Resuscitation was attempted with a 4J defibrillation after 8 min of cardiopulmonary resuscitation (CPR). Brain mitochondria and cardiac mitochondrial subpopulations were isolated. Calcium retention capacity was measured to assess susceptibility to mitochondrial permeability transition pore opening. ADP stimulated oxygen consumption and ETC activity assays were performed. Brain mitochondria are far more sensitive to injury during cardiac arrest and resuscitation compared to cardiac mitochondria. Complex I is highly sensitive to injury in brain mitochondria. With markedly decreased calcium retention capacity, mitochondria contribute to cerebral reperfusion injury. Therapeutic preservation of cerebral mitochondrial activity and mitochondrial function during cardiac arrest may improve post-resuscitation neurologic function.

Changes of renal histopathology and the role of Nrf2/HO-1 in asphyxial cardiac arrest model in rats

PURPOSE

To investigate the role of Nrf2/HO-1 in renal histopathological ailments time-dependently in asphyxial cardiac arrest (CA) rat model.

METHODS

Eighty-eight Sprague Dawley male rats were divided into five groups of eight rats each. Asphyxial CA was induced in all the experimental rats except for the sham group. The rats were sacrificed at 6 hours, 12 hours, one day and two days post-CA. Serum blood urea nitrogen (BUN), creatinine (Crtn) and malondialdehyde from the renal tissues were evaluated. Hematoxylin and eosin and periodic acid-Schiff staining were done to evaluate the renal histopathological changes in the renal cortex. Furthermore, Nrf2/HO-1 immunohistochemistry (ihc) and western blot analysis were performed after CA.

RESULTS

The survival rate of rats decreased in a time-dependent manner: 66.6% at 6 hours, 50% at 12 hours, 38.1% in one day, and 25.8% in two days. BUN and serum Crtn markedly increased in CA-operated groups. Histopathological ailments of the renal cortical tissues increased significantly from 6 hours until two days post-CA. Furthermore, Nrf2/HO-1 expression level significantly increased at 6 hours, 12 hours, and one day.

CONCLUSIONS

The survival rate decreased time-dependently, and Nrf/HO-1 expression increased from 6 hours with the peak times at 12 hours, and one day post-CA.

Change of Hemoglobin Levels in the Early Post-cardiac Arrest Phase Is Associated With Outcome

Background: The post-cardiac arrest (CA) phase is characterized by high fluid requirements, endothelial activation and increased vascular permeability. Erythrocytes are large cells and may not leave circulation despite massive capillary leak. We hypothesized that dynamic changes in hemoglobin concentrations may reflect the degree of vascular permeability and may be associated with neurologic function after CA.

Methods: We included patients ≥18 years, who suffered a non-traumatic CA between 2013 and 2018 from the prospective Vienna Clinical Cardiac Arrest Registry. Patients without return of spontaneous circulation (ROSC), with extracorporeal life support, with any form of bleeding, undergoing surgery, receiving transfusions, without targeted temperature management or with incomplete datasets for multivariable analysis were excluded. The primary outcome was neurologic function at day 30 assessed by the Cerebral Performance Category scale. Differences of hemoglobin concentrations at admission and 12 h after ROSC were calculated and associations with neurologic function were investigated by uni- and multivariable logistic regression.

Results: Two hundred and seventy-five patients were eligible for analysis of which 143 (52%) had poor neurologic function. For every g/dl increase in hemoglobin from admission to 12 h the odds of poor neurologic function increased by 26% (crude OR 1.26, 1.07–1.49, p = 0.006). The effect remained unchanged after adjustment for fluid balance and traditional prognostication markers (adjusted OR 1.27, 1.05–1.54, p = 0.014).

Conclusion: Increasing hemoglobin levels in spite of a positive fluid balance may serve as a surrogate parameter of vascular permeability and are associated with poor neurologic function in the early post-cardiac arrest period.

Efficacy of Glucocorticoid Administration in Patients with Cardiac Arrest: A Systematic Review of Clinical Studies

BACKGROUND

The pathophysiology of cardiac arrest (CA) involves over-activation of systemic inflammatory responses, relative adrenal insufficiency, and glycocalyx damage. Corticosteroids have beneficial effects in preventing the perturbation of the endothelial glycocalyx.

OBJECTIVES

The aim of this systematic review was to determine the efficacy of glucocorticoids in patients with cardiac arrest.

METHODS

We searched PubMed, Scopus, ISI Web of Science, Google Scholar and Cochrane central register for relevant clinical trials and cohort studies until September 2019.

RESULTS

We retrieved 7 peer-reviewed published studies for the systematic review. Two studies were clinical trials evaluating 147 patients, while five illustrated cohort design, evaluating 196,192 patients. In total, 196,339 patients were assessed. There was limited evidence and conflicting results to establish a correlation between glucocorticoids and the survival of patients suffering from cardiac arrest. However, the link between these medications and survival-to-admission, survival-to discharge, and 1-year survival rates was strong and consistent in observational studies.

CONCLUSION

The clinical evidence regarding the efficacy and safety of glucocorticoids in CA is limited to observational studies with inconsistent methodology and few clinical trials with small sample size. Nevertheless, it seems that glucocorticoid supplementation during and after cardiopulmonary resuscitation (CPR) may have significant effects in terms of survival-to-admission, survival to discharge, 1-year survival rates and an improved return of spontaneous circulation (ROSC) rate, especially in patients with hemodynamic instability and cardiovascular diseases (i.e., refractory hemodynamic shock). Future studies with high-quality, large-scale, long-term intervention and precise baseline characteristics are needed to evaluate the exact effective dose, duration, and efficacy of glucocorticoids in CA.

European Resuscitation Council and European Society of Intensive Care Medicine guidelines 2021: post-resuscitation care

The European Resuscitation Council (ERC) and the European Society of Intensive Care Medicine (ESICM) have collaborated to produce these post-resuscitation care guidelines for adults, which are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. The topics covered include the post-cardiac arrest syndrome, diagnosis of cause of cardiac arrest, control of oxygenation and ventilation, coronary reperfusion, haemodynamic monitoring and management, control of seizures, temperature control, general intensive care management, prognostication, long-term outcome, rehabilitation and organ donation.

European Resuscitation Council and European Society of Intensive Care Medicine Guidelines 2021: Post-resuscitation care

The European Resuscitation Council (ERC) and the European Society of Intensive Care Medicine (ESICM) have collaborated to produce these post-resuscitation care guidelines for adults, which are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. The topics covered include the post-cardiac arrest syndrome, diagnosis of cause of cardiac arrest, control of oxygenation and ventilation, coronary reperfusion, haemodynamic monitoring and management, control of seizures, temperature control, general intensive care management, prognostication, long-term outcome, rehabilitation, and organ donation.

Association between Novel Marker (Platelet-Lymphocyte Ratio, Neutrophil-Lymphocyte Ratio, and Delta Neutrophil Index) and Outcomes in Sudden Cardiac Arrest Patients

Purpose

It is important that clinicians accurately predict the outcome of patients with sudden cardiac arrest (SCA). The complete blood count (CBC) is an easy and inexpensive test that provides information on blood content. Platelet-lymphocyte ratio (PLR), neutrophil-lymphocyte ratio (NLR), and delta neutrophil index (DNI) are relatively novel biomarkers that have been used in the prognosis of various diseases. We aimed to determine the usefulness of PLR, NLR, and DNI in predicting the outcomes of SCA.

Materials and Methods

This retrospective observational study was performed on patients with SCA. Patients who visited the tertiary university hospital from January 2015 to December 2019 were targeted. The inclusion criteria were all nontraumatic adult out-hospital cardiac arrest patients. We analyzed DNI, PLR, and NLR based on the CBC results of all enrolled patients. The exclusion criteria were as follows: no data on laboratory study, traumatic arrest, age < 18 years, and a history of leukemia, myelodysplastic syndrome, and myelofibrosis. The primary outcome was assessed as return of spontaneous circulation (ROSC), the secondary outcome as survival to discharge, and the tertiary outcome as neurological outcome.

Results

From January 1, 2015, to December 31, 2019, 739 patients were enrolled. ROSC was seen in 324 patients, of whom 60 had survival to discharge and 24 had good neurological outcome at the time of discharge (cerebral performance categories (CPCs) 1-2). The PLR of the ROSC group was 42.41 (range: 4.21–508.7), which was higher than that of the No-ROSC group (p=0.006). The DNI value of the survival group was 0.00 (range: 0.00–40.9), which was lower than that of the nonsurvival group.

Conclusions

Patients with SCA and subsequent ROSC had higher PLR and NLR, while those with survival to discharge had lower DNI values than those with nonsurvival to discharge (p=0.005).

The outcome of in- and out-hospital cardiopulmonary arrest in the older population: a scoping review

Aim

We aimed to collect the available evidence on outcome regarding survival and quality of life after CPR following both IHCA and OHCA in the older population.

Findings

Hospital survival rates following IHCA and OHCA in the older population improved in the recent decade, though do not exceed 28.5% and 11.1%, respectively. The effect of age on outcome remains controversial and age should not be used as the sole decision criterium whether to initiate CPR.

Message

Future research should study frailty and resilience as an independent predictor regardless of age, and add broader, extensive QoL measures as outcome variables.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41999-021-00454-y.

Purpose

We aimed to collect the available evidence on outcome regarding survival and quality of life after cardiopulmonary resuscitation (CPR) following both in-hospital cardiac arrest (IHCA) and out-of-hospital cardiac arrest (OHCA) in the older population.

Methods

A scoping review was performed studying published reviews after 2008, focusing on outcome of CPR in patients aged ≥ 70 years following IHCA and OHCA. In addition, 11 (IHCA) and 19 (OHCA) eligible studies published after the 2 included reviews were analyzed regarding: return of spontaneous circulation, survival until hospital discharge, long-term survival, neurological outcome, discharge location or other measurements for quality of life (QoL).

Results

The survival until hospital discharge ranged between 11.6 and 28.5% for IHCA and 0–11.1% for OHCA, and declined with increasing age. The same trend was seen regarding 1-year survival rates with 5.7–25.0% and 0–10% following IHCA and OHCA, respectively. A good neurological outcome defined as a Cerebral Performance Category (CPC) 1–2 was found in 11.5–23.6% (IHCA) and up to 10.5% (OHCA) of all patients. However, the proportion of CPC 1–2 among patients surviving until hospital discharge was 82–93% (IHCA) and 77–91.6% (OHCA). Few studies included other QoL measures as an outcome variable. Other risk factors aside from age were identified, including nursing home residency, comorbidity, non-shockable rhythm, non-witnessed arrest. The level of frailty was not studied as a predictor of arrest outcome in the included studies.

Conclusions

Hospital survival rates following IHCA and OHCA in the older population improved in the recent decade, though do not exceed 28.5% and 11.1%, respectively. The effect of age on outcome remains controversial and age should not be used as the sole decision criterium whether to initiate CPR. Future research should study frailty and resilience as an independent predictor regardless of age, and add broader, extensive QoL measures as outcome variables.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41999-021-00454-y.

A descriptive analysis of cross-sectional imaging findings in patients after non-traumatic sudden cardiac arrest

Introduction

Cross-sectional imaging is frequently obtained after sudden cardiac arrest (SCA) to determine the aetiology. Although imaging studies may reveal acute and/or chronic findings that may impact downstream medical management, lack of standardized guidelines results in significant practice variability. We aimed to perform a descriptive analysis and to report on radiographic findings after SCA.

Methods

This was a retrospective observational descriptive study that included all adult SCA patients who presented to our emergency department (ED) over a 6-year period, achieved sustained return of spontaneous circulation, and subsequently received cross-sectional imaging while in the ED. Each imaging study was reviewed and graded based on a predefined scale, and significant radiographic findings were tabulated.

Results

1573 patients were identified, and 452 patients remained after applying predefined exclusion criteria. A total of 298, 184, and 113 computed tomography (CT) studies were performed of the head, chest, and abdomen, respectively. For head, chest, and abdominal imaging, 13 (4.4%), 23 (12.5%), and 6 (5.3%) studies had radiographic findings that likely contributed to SCA, respectively. Altogether, 42 (7.1%) radiographic studies had findings that likely contributed to SCA. Eighty (13.4%) studies (head [n = 38, 12.8%], chest [n = 26, 14.1%], abdomen [n = 16, 14.2%]) resulted in a change of clinical care (e.g. specialty consultation or procedures).

Conclusion

Given the clinical uncertainty and relative instability during the post-SCA phase, cross-sectional imaging frequently reveals important acute and chronic diagnostic findings.

Energy Expenditure and Shivering Severity During Targeted Temperature Management at 36°C After Cardiac Arrest: A Case Series

Patients undergoing targeted temperature management (TTM) after cardiac arrest are at risk for shivering, which increases energy expenditure (EE) and may attenuate TTM benefits. This article reports patterns of EE for patients with and without shivering who received TTM at 36°C after cardiac arrest. Based on 96 case assessments, there were 14 occasions when more than one 15-minute interval period was required to appropriately modify the Bedside Shivering Assessment Scale (BSAS) score. Investigators noted that although higher EE was related to higher BSAS scores, there may be opportunities for earlier detection of shivering.

Post-resuscitation shock: recent advances in pathophysiology and treatment

A post-resuscitation shock occurs in 50–70% of patients who had a cardiac arrest. It is an early and transient complication of the post-resuscitation phase, which frequently leads to multiple-organ failure and high mortality. The pathophysiology of post-resuscitation shock is complex and results from the whole-body ischemia–reperfusion process provoked by the sequence of circulatory arrest, resuscitation manoeuvers and return of spontaneous circulation, combining a myocardial dysfunction and sepsis features, such as vasoplegia, hypovolemia and endothelial dysfunction. Similarly to septic shock, the hemodynamic management of post-resuscitation shock is based on an early and aggressive hemodynamic management, including fluid administration, vasopressors and/or inotropes. Norepinephrine should be considered as the first-line vasopressor in order to avoid arrhythmogenic effects of other catecholamines and dobutamine is the most established inotrope in this situation. Importantly, the optimal mean arterial pressure target during the post-resuscitation shock still remains unknown and may probably vary according to patients. Mechanical circulatory support by extracorporeal membrane oxygenation can be necessary in the most severe patients, when the neurological prognosis is assumed to be favourable. Other symptomatic treatments include protective lung ventilation with a target of normoxia and normocapnia and targeted temperature management by avoiding the lowest temperature targets. Early coronary angiogram and coronary reperfusion must be considered in ST-elevation myocardial infarction (STEMI) patients with preserved neurological prognosis although the timing of coronary angiogram in non-STEMI patients is still a matter of debate. Further clinical research is needed in order to explore new therapeutic opportunities regarding inflammatory, hormonal and vascular dysfunction.

NSE as a predictor of death or poor neurological outcome after non-shockable cardiac arrest due to any cause: Ancillary study of HYPERION trial data

PURPOSE

Prognostication of hypoxic-ischaemic brain injury after resuscitation from cardiac arrest is based on a multimodal approach including biomarker assays. Our goal was to assess whether plasma NSE helps to predict day-90 death or poor neurological outcome in patients resuscitated from cardiac arrest in non-shockable rhythm.

METHODS

All included patients participated in the randomised multicentre HYPERION trial. Serum blood samples were taken 24, 48, and 72 h after randomisation; pre-treated, aliquoted, and frozen at -80 °C at the study sites; and shipped to a central biology laboratory, where the NSE assays were performed. Primary outcome was neurological status at day 90 assessed by Cerebral Performance Category (1 or 2 versus. 3, 4 or 5).

RESULTS

NSE was assayed in 235 assessable blood samples from 101 patients. In patients with good versus poor outcomes, median NSE values at 24, 48, and 72 h were 22.6 [95%CI, 14.6;27.3] ng/mL versus 33.6 [20.5;90.0] ng/mL (p < 0.04), 18.1 [11.7;29.7] ng/mL versus 76.8 [21.5;206.6] ng/mL (p < 0.0029), and 9 [6.1;18.6] ng/mL versus 80.5 [22.9;236.1] ng/mL (p < 0.001), respectively. NSE at 48 and 72 h predicted the neurological outcome with areas under the receiver-operating curve of 0.79 [95%CI, 0.69;0.96] and 0.9 [0.81;0.96], respectively. NSE levels did not differ significantly between the groups managed at 33°C and 37°C (p = 0.59).

CONCLUSIONS

Data from a multicentre trial on cardiac arrest with a non-shockable rhythm due to any cause confirm that NSE values at 72 h are associated with 90-day outcome. NSE levels did not differ significantly according to the targeted temperature.

REGISTRATION IDENTIFIER

ClinicalTrial NCT02722473.

A walk through the progression of resuscitation medicine

Cardiac arrest (CA) is a sudden and devastating disease process resulting in more deaths in the United States than many cancers, metabolic diseases, and even car accidents. Despite such a heavy mortality burden, effective treatments have remained elusive. The past century has been productive in establishing the guidelines for resuscitation, known as cardiopulmonary resuscitation (CPR), as well as developing a scientific field whose aim is to elucidate the underlying mechanisms of CA and develop therapies to save lives. CPR has been successful in reinitiating the heart after arrest, enabling a survival rate of approximately 10% in out-of-hospital CA. Although current advanced resuscitation methods, including hypothermia and extracorporeal membrane oxygenation, have improved survival in some patients, they are unlikely to significantly improve the national survival rate any further without a paradigm shift. Such a change is possible with sustained efforts in the basic and clinical sciences of resuscitation and their implementation. This review seeks to discuss the current landscape in resuscitation medicine-how we got here and where we are going.

Stearic acid methyl ester affords neuroprotection and improves functional outcomes after cardiac arrest

Cardiac arrest causes neuronal damage and functional impairments that can result in learning/memory dysfunction after ischemia. We previously identified a saturated fatty acid (stearic acid methyl ester, SAME) that was released from the superior cervical ganglion (sympathetic ganglion). The function of stearic acid methyl ester is currently unknown. Here, we show that SAME can inhibit the detrimental effects of global cerebral ischemia (i.e. cardiac arrest). Treatment with SAME in the presence of asphyxial cardiac arrest (ACA) revived learning and working memory deficits. Similarly, SAME-treated hippocampal slices after oxygen-glucose deprivation inhibited neuronal cell death. Moreover, SAME afforded neuroprotection against ACA in the CA1 region of the hippocampus, reduced ionized calcium-binding adapter molecule 1 expression and inflammatory cytokines/chemokines, with restoration in mitochondria respiration. Altogether, we describe a unique and uncharted role of saturated fatty acids in the brain that may have important implications against cerebral ischemia.