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

Analysis of Cerebral CT Based on Supervised Machine Learning as a Predictor of Outcome After Out-of-Hospital Cardiac Arrest

BACKGROUND AND OBJECTIVES

In light of limited intensive care capacities and a lack of accurate prognostic tools to advise caregivers and family members responsibly, this study aims to determine whether automated cerebral CT (CCT) analysis allows prognostication after out-of-hospital cardiac arrest.

METHODS

In this monocentric, retrospective cohort study, a supervised machine learning classifier based on an elastic net regularized logistic regression model for gray matter alterations on nonenhanced CCT obtained after cardiac arrest was trained using 10-fold cross-validation and tested on a hold-out sample (random split 75%/25%) for outcome prediction. Following the literature, a favorable outcome was defined as a cerebral performance category of 1-2 and a poor outcome of 3-5. The diagnostic accuracy was compared with established and guideline-recommended prognostic measures within the sample, that is, gray matter-white matter ratio (GWR), neuron-specific enolase (NSE), and neurofilament light chain (NfL) in serum.

RESULTS

Of 279 adult patients, 132 who underwent CCT within 14 days of cardiac arrest with good imaging quality were identified. Our approach discriminated between favorable and poor outcomes with an area under the curve (AUC) of 0.73 (95% CI 0.59-0.82). Thus, the prognostic power outperformed the GWR (AUC 0.66, 95% CI 0.56-0.76). The biomarkers NfL, measured at days 1 and 2, and NSE, measured at day 2, exceeded the reliability of the imaging markers derived from CT (AUC NfL day 1: 0.87, 95% CI 0.75-0.99; AUC NfL day 2: 0.90, 95% CI 0.79-1.00; AUC NSE day: 2 0.78, 95% CI 0.62-0.94).

DISCUSSION

Our data show that machine learning-assisted gray matter analysis of CCT images offers prognostic information after out-of-hospital cardiac arrest. Thus, CCT gray matter analysis could become a reliable and time-independent addition to the standard workup with serum biomarkers sampled at predefined time points. Prospective studies are warranted to replicate these findings.

Improving Outcomes After Post-Cardiac Arrest Brain Injury: A Scientific Statement From the International Liaison Committee on Resuscitation

This scientific statement presents a conceptual framework for the pathophysiology of post-cardiac arrest brain injury, explores reasons for previous failure to translate preclinical data to clinical practice, and outlines potential paths forward. Post-cardiac arrest brain injury is characterized by 4 distinct but overlapping phases: ischemic depolarization, reperfusion repolarization, dysregulation, and recovery and repair. Previous research has been challenging because of the limitations of laboratory models; heterogeneity in the patient populations enrolled; overoptimistic estimation of treatment effects leading to suboptimal sample sizes; timing and route of intervention delivery; limited or absent evidence that the intervention has engaged the mechanistic target; and heterogeneity in postresuscitation care, prognostication, and withdrawal of life-sustaining treatments. Future trials must tailor their interventions to the subset of patients most likely to benefit and deliver this intervention at the appropriate time, through the appropriate route, and at the appropriate dose. The complexity of post-cardiac arrest brain injury suggests that monotherapies are unlikely to be as successful as multimodal neuroprotective therapies. Biomarkers should be developed to identify patients with the targeted mechanism of injury, to quantify its severity, and to measure the response to therapy. Studies need to be adequately powered to detect effect sizes that are realistic and meaningful to patients, their families, and clinicians. Study designs should be optimized to accelerate the evaluation of the most promising interventions. Multidisciplinary and international collaboration will be essential to realize the goal of developing effective therapies for post-cardiac arrest brain injury.

Heart rate variability for neuro-prognostication after CA: insight from the Parisian registry

BACKGROUND

Hypoxic ischemic brain injury (HIBI) induced by cardiac arrest (CA) seems to predominate in cortical areas and to a lesser extent in the brainstem. These regions play key roles in modulating the activity of the autonomic nervous system (ANS), that can be assessed through analyses of heart rate variability (HRV). The objective was to evaluate the prognostic value of various HRV parameters to predict neurological outcome after CA.

METHODS

Retrospective monocentric study assessing the prognostic value of HRV markers and their association with HIBI severity. Patients admitted for CA who underwent EEG for persistent coma after CA were included. HRV markers were computed from 5 minutes signal of the ECG lead of the EEG recording. HRV indices were calculated in the time-, frequency-, and non-linear domains. Frequency-domain analyses differentiated very low frequency (VLF 0.003-0.04Hz), low frequency (LF 0.04-0.15Hz), high frequency (HF 0.15-0.4Hz), and LF/HF ratio. HRV indices were compared to other prognostic markers: pupillary light reflex, EEG, N20 on somatosensory evoked potentials (SSEP) and biomarkers (neuron specific enolase-NSE). Neurological outcome at 3 months was defined as unfavorable in case of best CPC 3-4-5.

RESULTS

Between 2007 and 2021, 199 patients were included. Patients were predominantly male (64%), with a median age of 60 [48.9-71.7] years. 76% were out-of-hospital CA, and 30% had an initial shockable rhythm. Neurological outcome was unfavorable in 73%. Compared to poor outcome, patients with a good outcome had higher VLF (0.21 vs 0.09 ms2/Hz, p<0.01), LF (0.07 vs 0.04 ms2/Hz, p=0.003), and higher LF/HF ratio (2.01 vs 1.01, p=0.008). Several non-linear domain indices were also higher in the good outcome group, such as SD2 (15.1 vs 10.2, p = 0.016) and DFA α1 (1.03 vs 0.78, p = 0.002). These indices also differed depending on the severity of EEG pattern and abolition of pupillary light reflex. These time-frequency and non-linear domains HRV parameters were predictive of poor neurological outcome, with high specificity despite a low sensitivity.

CONCLUSION

In comatose patients after CA, some HRV markers appear to be associated with unfavorable outcome, EEG severity and PLR abolition, although the sensitivity of these HRV markers remains limited.

Comparative cost-effectiveness of termination of resuscitation rules for patients transported in cardiac arrest

AIM

To compare the cost-effectiveness of termination-of-resuscitation (TOR) rules for patients transported in cardiac arrest.

METHODS

The economic analyses evaluated cost-effectiveness of alternative TOR rules for OHCA from a National Health Service (NHS) and personal social services (PSS) perspective over a lifetime horizon. A systematic review was used to identify the different TOR rules included in the analyses. Data from the OHCAO outcomes registry, trial data and published literature were used to compare outcomes for the different rules identified. The economic analyses estimated discounted NHS and PSS costs and quality-adjusted life-years (QALYs) for each TOR rule, based on which incremental cost-effectiveness ratios (ICERs) were calculated.

RESULTS

The systematic review identified 33 TOR rules and the economic analyses assessed the performance of 29 of these TOR rules plus current practice. The most cost-effective strategies were the European Resuscitation Council (ERC) termination of resuscitation rule (ICER of £8,111), the Korean Cardiac Arrest Research Consortium 2 (KOC 2) termination of resuscitation rule (ICER of £17,548), and the universal Basic Life Support (BLS) termination of resuscitation rule (ICER of £19,498,216). The KOC 2 TOR rule was cost-effective at the established cost-effectiveness threshold of £20,000-£30,000 per QALY.

CONCLUSION

The KOC 2 rule is the most cost-effective at established cost-effectiveness thresholds used to inform health care decision-making in the UK. Further research on economic implications of TOR rules is warranted to support constructive discussion on implementing TOR rules.

Associations between initial heart rhythm and self-reported health among cardiac arrest survivors - A nationwide registry study

BACKGROUND

Non-shockable initial rhythm is a known risk factor for high mortality at cardiac arrest (CA). However, knowledge on its association with self-reported health in CA survivors is still incomplete.

AIM

To examine the associations between initial rhythm and self-reported health in CA survivors.

METHODS

This nationwide study used data from the Swedish Register for Cardiopulmonary Resuscitation 3-6 months post CA. Health status was measured using EQ-5D-5L and psychological distress by the Hospital Anxiety and Depression Scale (HADS). Kruskal-Wallis test was used to examine differences in self-reported health between groups of different initial rhythms. To control for potential confounders, age, sex, place of CA, aetiology, witnessed status, time to CPR, time to defibrillation, and neurological function were included as covariates in multiple regression analyses for continuous and categorical outcomes.

RESULTS

The study included 1783 adult CA survivors. Overall, the CA survivors reported good health status and symptoms of anxiety or depression were uncommon (13.7% and 13.9% respectively). Survivors with PEA and asystole reported significantly more problems in all dimensions of health status (p = 0.037 to p < 0.001), anxiety (p = 0.034), and depression (p = 0.017) compared to VT/VF. Overall, these differences did not remain in the adjusted regression analyses.

CONCLUSIONS

Initial rhythm is not associated with self-reported health when potential confounders are controlled. Initial rhythm seems to be an indicator of unfavourable factors causing the arrest, or factors related to characteristics and treatment. Therefore, initial rhythm may be used as a proxy for identifying patients at risk for poor outcomes such as worse health status and psychological distress.

Managing hemolysis in serum neuron-specific enolase measurements - an automated algorithm for routine practice

Neuron-specific enolase (NSE) derived from neurons and peripheral neuroendocrine cells is a biomarker for neuroendocrine tumors and for prognostication in comatose cardiac arrest survivors. However, as platelets and erythrocytes contain NSE, hemolysis causes falsely elevated NSE. We used native serum and hemolysate derived from the same patients to make serial dilutions, and subsequently measured NSE (mNSE) and hemolytic index (HI) in each dilution. An algorithm suitable for the laboratory information system was developed based on the mNSE, HI and the estimated gradient of hemolytic interference from 30 patients. We estimated the associated uncertainty of the corrected NSE (cNSE) results based on the observed range of the gradient and derived an equation for cNSE for samples with limited hemolysis (i.e. 5 < HI ≤ 30): cNSE = mNSE - HI × (0.34 ± 0.23) µg/L. By semi-quantitatively grading the contribution from limited hemolysis, a texted result noting the hemolysis-associated degree of uncertainty can accompany the cNSE result. The major challenge of hemolysis when using serum NSE as a biomarker can be managed using an automated algorithm for correction of NSE results based on degree of hemolysis. However, laboratorians and clinicians should be aware of the limitations associated with in vivo hemolysis.

Prediction of outcomes after cardiac arrest by a generative artificial intelligence model

Aims

To investigate the prognostic accuracy of a non-medical generative artificial intelligence model (Chat Generative Pre-Trained Transformer 4 - ChatGPT-4) as a novel aspect in predicting death and poor neurological outcome at hospital discharge based on real-life data from cardiac arrest patients.

Methods

This prospective cohort study investigates the prognostic performance of ChatGPT-4 to predict outcomes at hospital discharge of adult cardiac arrest patients admitted to intensive care at a large Swiss tertiary academic medical center (COMMUNICATE/PROPHETIC cohort study). We prompted ChatGPT-4 with sixteen prognostic parameters derived from established post-cardiac arrest scores for each patient. We compared the prognostic performance of ChatGPT-4 regarding the area under the curve (AUC), sensitivity, specificity, positive and negative predictive values, and likelihood ratios of three cardiac arrest scores (Out-of-Hospital Cardiac Arrest [OHCA], Cardiac Arrest Hospital Prognosis [CAHP], and PROgnostication using LOGistic regression model for Unselected adult cardiac arrest patients in the Early stages [PROLOGUE score]) for in-hospital mortality and poor neurological outcome.

Results

Mortality at hospital discharge was 43% (n = 309/713), 54% of patients (n = 387/713) had a poor neurological outcome. ChatGPT-4 showed good discrimination regarding in-hospital mortality with an AUC of 0.85, similar to the OHCA, CAHP, and PROLOGUE (AUCs of 0.82, 0.83, and 0.84, respectively) scores. For poor neurological outcome, ChatGPT-4 showed a similar prediction to the post-cardiac arrest scores (AUC 0.83).

Conclusions

ChatGPT-4 showed a similar performance in predicting mortality and poor neurological outcome compared to validated post-cardiac arrest scores. However, more research is needed regarding illogical answers for potential incorporation of an LLM in the multimodal outcome prognostication after cardiac arrest.

Good outcome prediction after out-of-hospital cardiac arrest: A prospective multicenter observational study in Korea (the KORHN-PRO registry)

AIM

To assess the ability of clinical examination, biomarkers, electrophysiology and brain imaging, individually or in combination to predict good neurological outcomes at 6 months after CA.

METHODS

This was a retrospective analysis of the Korean Hypothermia Network Prospective Registry 1.0, which included adult out-of-hospital cardiac arrest (OHCA) patients (≥18 years). Good outcome predictors were defined as both pupillary light reflex (PLR) and corneal reflex (CR) at admission, Glasgow Coma Scale Motor score (GCS-M) >3 at admission, neuron-specific enolase (NSE) <17 µg/L at 24-72 h, a median nerve somatosensory evoked potential (SSEP) N20/P25 amplitude >4 µV, continuous background without discharges on electroencephalogram (EEG), and absence of anoxic injury on brain CT and diffusion-weighted imaging (DWI).

RESULTS

A total of 1327 subjects were included in the final analysis, and their median age was 59 years; among them, 412 subjects had a good neurological outcome at 6 months. GCS-M >3 at admission had the highest specificity of 96.7% (95% CI 95.3-97.8), and normal brain DWI had the highest sensitivity of 96.3% (95% CI 92.9-98.4). When the two predictors were combined, the sensitivities tended to decrease (ranging from 2.7-81.1%), and the specificities tended to increase, ranging from81.3-100%. Through the explorative variation of the 2021 European Resuscitation Council (ERC) and the European Society of Intensive Care Medicine (ESICM) prognostication strategy algorithms, good outcomes were predicted, with a specificity of 83.2% and a sensitivity of 83.5% in patients by the algorithm.

CONCLUSIONS

Clinical examination, biomarker, electrophysiology, and brain imaging predicted good outcomes at 6 months after CA. When the two predictors were combined, the specificity further improved. With the 2021 ERC/ESICM guidelines, the number of indeterminate patients and the uncertainty of prognostication can be reduced by using a good outcome prediction algorithm.

An Update on Brain Death/Death by Neurologic Criteria since the World Brain Death Project

The World Brain Death Project (WBDP) is a 2020 international consensus statement that provides historical background and recommendations on brain death/death by neurologic criteria (BD/DNC) determination. It addresses 13 topics including: (1) worldwide variance in BD/DNC, (2) the science of BD/DNC, (3) the concept of BD/DNC, (4) minimum clinical criteria for BD/DNC determination, (5) beyond minimum clinical BD/DNC determination, (6) pediatric and neonatal BD/DNC determination, (7) BD/DNC determination in patients on ECMO, (8) BD/DNC determination after treatment with targeted temperature management, (9) BD/DNC documentation, (10) qualification for and education on BD/DNC determination, (11) somatic support after BD/DNC for organ donation and other special circumstances, (12) religion and BD/DNC: managing requests to forego a BD/DNC evaluation or continue somatic support after BD/DNC, and (13) BD/DNC and the law. This review summarizes the WBDP content on each of these topics and highlights relevant work published from 2020 to 2023, including both the 192 citing publications and other publications on BD/DNC. Finally, it reviews questions for future research related to BD/DNC and emphasizes the need for national efforts to ensure the minimum standards for BD/DNC determination described in the WBDP are included in national BD/DNC guidelines and due consideration is given to the recommendations about social and legal aspects of BD/DNC determination.

Emergent Management of Hypoxic-Ischemic Brain Injury

OBJECTIVE

This article outlines interventions used to improve outcomes for patients with hypoxic-ischemic brain injury after cardiac arrest.

LATEST DEVELOPMENTS

Emergent management of patients after cardiac arrest requires prevention and treatment of primary and secondary brain injury. Primary brain injury is minimized by excellent initial resuscitative efforts. Secondary brain injury prevention requires the detection and correction of many pathophysiologic processes that may develop in the hours to days after the initial arrest. Key physiologic parameters important to secondary brain injury prevention include optimization of mean arterial pressure, cerebral perfusion, oxygenation and ventilation, intracranial pressure, temperature, and cortical hyperexcitability. This article outlines recent data regarding the treatment and prevention of secondary brain injury. Different patients likely benefit from different treatment strategies, so an individualized approach to treatment and prevention of secondary brain injury is advisable. Clinicians must use multimodal sources of data to prognosticate outcomes after cardiac arrest while recognizing that all prognostic tools have shortcomings.

ESSENTIAL POINTS

Neurologists should be involved in the postarrest care of patients with hypoxic-ischemic brain injury to improve their outcomes. Postarrest care requires nuanced and patient-centered approaches to the prevention and treatment of primary and secondary brain injury and neuroprognostication.

[Open questions with respect to extracorporeal circulatory support 2024]

The use of extracorporeal circulatory support, both for cardiogenic shock and during resuscitation, still presents many unanswered questions. The inclusion and exclusion criteria for such a resource-intensive treatment must be clearly defined, considering that these criteria are directly associated with the type and location of treatment. For example, it is worth questioning the viability of an extracorporeal resuscitation program in areas where it is impossible to achieve low-flow times under 60 min due to local limitations. Additionally, the best approach for further treatment, including whether it is necessary to regularly relieve the left ventricle, must be explored. To find answers to some of these questions, large-scale, multicenter, randomized studies and registers must be performed. Until then this treatment must be carefully considered before use.

Real-time feedback on chest compression efficacy by hands-free carotid Doppler in a porcine model

Aim

Current guidelines for cardiopulmonary resuscitation (CPR) recommend a one-size-fits-all approach in relation to the positioning of chest compressions. We recently developed RescueDoppler, a hands-free Doppler ultrasound device for continuous monitoring of carotid blood flow velocity during CPR. The aim of the present study is to investigate whether RescueDoppler via real-time hemodynamic feedback, could identify both optimal and suboptimal compression positions.

Methods

In this model of animal cardiac arrest, we induced ventricular fibrillation in five domestic pigs. Manual chest compressions were performed for ten seconds at three different positions on the sternum in random order and repeated six times. We analysed Time Average Velocity (TAV) with chest compression position as a fixed effect and animal, position, and sequential time within animals as random effects. Furthermore, we compared TAV to invasive blood pressure from the contralateral carotid artery.

Results

We were able to detect changes in TAV when altering positions. The positions with the highest (range 19 to 48 cm/s) and lowest (6-25 cm/s) TAV were identified in all animals, with corresponding peak pressure 50-81 mmHg, and 46-64 mmHg, respectively. Blood flow velocity was, on average, highest at the middle position (TAV 33 cm/s), but with significant variability between animals (SD 2.8) and positions within the same animal (SD 9.3).

Conclusion

RescueDoppler detected TAV changes during CPR with alternating chest compression positions, identifying the position yielding maximal TAV. Future clinical studies should investigate if RescueDoppler can be used as a real-time hemodynamical feedback device to guide compression position.

Using generative artificial intelligence in bibliometric analysis: 10 years of research trends from the European Resuscitation Congresses

Aims

The aim of this study is to use generative artificial intelligence to perform bibliometric analysis on abstracts published at European Resuscitation Council (ERC) annual scientific congress and define trends in ERC guidelines topics over the last decade.

Methods

In this bibliometric analysis, the WebHarvy software (SysNucleus, India) was used to download data from the Resuscitation journal's website through the technique of web scraping. Next, the Chat Generative Pre-trained Transformer 4 (ChatGPT-4) application programming interface (Open AI, USA) was used to implement the multinomial classification of abstract titles following the ERC 2021 guidelines topics.

Results

From 2012 to 2022 a total of 2491 abstracts have been published at ERC congresses. Published abstracts ranged from 88 (in 2020) to 368 (in 2015). On average, the most common ERC guidelines topics were Adult basic life support (50.1%), followed by Adult advanced life support (41.5%), while Newborn resuscitation and support of transition of infants at birth (2.1%) was the least common topic. The findings also highlight that the Basic Life Support and Adult Advanced Life Support ERC guidelines topics have the strongest co-occurrence to all ERC guidelines topics, where the Newborn resuscitation and support of transition of infants at birth (2.1%; 52/2491) ERC guidelines topic has the weakest co-occurrence.

Conclusion

This study demonstrates the capabilities of generative artificial intelligence in the bibliometric analysis of abstract titles using the example of resuscitation medicine research over the last decade at ERC conferences using large language models.

The detrimental effects of intestinal injury mediated by inflammation are limited in cardiac arrest patients: A prospective cohort study

Background

Ischaemic intestines could be a driver of critical illness through an inflammatory response. We have previously published reports on a biomarker for intestinal injury, plasma Intestinal Fatty Acid Binding Protein (IFABP), and inflammatory biomarkers after out-of-hospital cardiac arrest (OHCA). In this post-hoc study we explored the potential indirect effects of intestinal injury mediated through the inflammatory response on organ dysfunction and mortality.

Methods

We measured IFABP and twenty-one inflammatory biomarkers in 50 patients at admission to intensive care unit after OHCA. First, we stratified patients on median IFABP and compared biomarkers between "low" and "high" IFABP. Second, by causal mediation analysis, we assessed effects of IFABP through the two most important inflammatory biomarkers, interleukin (IL)-6 and terminal complement complex (TCC), on day two circulatory variables, Sequential Organ Failure Assessment (SOFA)-score, and 30-day mortality.

Results

Cytokines and complement activation were higher in the high IFABP group. In mediation analysis, patients on the 75th percentile of IFABP, compared to the 25th percentile, had 53% (95% CI, 33-74; p < 0.001) higher risk of dying, where 13 (95% CI, 3-23; p = 0.01) percentage points were mediated through an indirect effect of IL-6. Similarly, the indirect effect of IFABP through IL-6 on SOFA-score was significant, but smaller than potential other effects. Effects through IL-6 on circulatory variables, and all effects through TCC, were not statistically significant and/or small.

Conclusion

Effects of intestinal injury mediated through inflammation on organ dysfunction and mortality were limited. Small, but significant, effects through IL-6 were noted.Trial registration: ClinicalTrials.gov: NCT02648061.

Oxygenation during general anesthesia in pediatric patients: A retrospective observational study

STUDY OBJECTIVE

Protocols are used in intensive care and emergency settings to limit the use of oxygen. However, in pediatric anesthesiology, such protocols do not exist. This study aimed to investigate the administration of oxygen during pediatric general anesthesia and related these values to PaO2, SpO2 and SaO2.

DESIGN

Retrospective observational study.

SETTING

Tertiary pediatric academic hospital, from June 2017 to August 2020.

PATIENTS

Patients aged 0-18 years who underwent general anesthesia for a diagnostic or surgical procedure with tracheal intubation and an arterial catheter for regular blood withdrawal were included. Patients on cardiopulmonary bypass or those with missing data were excluded. Electronic charts were reviewed for patient characteristics, type of surgery, arterial blood gas analyses, and oxygenation management.

INTERVENTIONS

No interventions were done.

MEASUREMENTS

Primary outcome defined as FiO2, PaO2 and SpO2 values were interpreted using descriptive analyses, and the correlation between PaO2 and FiO2 was determined using the weighted Spearman correlation coefficient.

MAIN RESULTS

Data of 493 cases were obtained. Of these, 267 were excluded for various reasons. Finally, 226 cases with a total of 645 samples were analyzed. The median FiO2 was 36% (IQR 31 to 43), with a range from 20% to 97%, and the median PaO2 was 23.6 kPa (IQR 18.6 to 28.1); 177 mmHg (IQR 140 to 211). The median SpO2 level was 99% (IQR 98 to 100%). The study showed a moderately positive association between PaO2 and FiO2 (r = 0.52, p < 0.001). 574 of 645 samples (89%) contained a PaO2 higher than 13.3 kPa; 100 mmHg.

CONCLUSIONS

Oxygen administration during general pediatric anesthesia is barely regulated. Hyperoxemia is observed intraoperatively in approximately 90% of cases. Future research should focus on outcomes related to hyperoxemia.

Impact of Blood Pressure Targets in Patients With Heart Failure Undergoing Postresuscitation Care: A Subgroup Analysis From a Randomized Controlled Trial

BACKGROUND

To assess the effect of targeting higher or lower blood pressure during postresucitation intensive care among comatose patients with out-of-hospital cardiac arrest with a history of heart failure.

METHODS

The BOX trial (Blood Pressure and Oxygenation Targets After Out-of-Hospital Cardiac Arrest) was a randomized, controlled, double-blinded, multicenter study comparing titration of vasopressors toward a mean arterial pressure (MAP) of 63 versus 77 mm Hg during postresuscitation intensive care. Patients with a history of heart failure were included in this substudy. Pulmonary artery catheters were inserted shortly after admission. History of heart failure was assessed through chart review of all included patients. The primary outcome was cardiac index during the first 72 hours. Secondary outcomes were left ventricular ejection fraction, heart rate, stroke volume, renal replacement therapy and all-cause mortality at 365 days.

RESULTS

A total of 134 patients (17% of the BOX cohort) had a history of heart failure (patients with left ventricular ejection fraction, ≤40%: 103 [77%]) of which 71 (53%) were allocated to a MAP of 77 mm Hg. Cardiac index at intensive care unit arrival was 1.77±0.11 L/min·m-2 in the MAP63-group and 1.78±0.17 L/min·m-2 in the MAP77, P=0.92. During the next 72 hours, the mean difference was 0.15 (95% CI, -0.04 to 0.35) L/min·m-2; Pgroup=0.22. Left ventricular ejection fraction and stroke volume was similar between the groups. Patients allocated to MAP77 had significantly elevated heart rate (mean difference 6 [1-12] beats/min, Pgroup=0.03). Vasopressor usage was also significantly increased (P=0.006). At 365 days, 69 (51%) of the patients had died. The adjusted hazard ratio for 365 day mortality was 1.38 (0.84-2.27), P=0.20 and adjusted odds ratio for renal replacement therapy was 2.73 (0.84-8.89; P=0.09).

CONCLUSIONS

In resuscitated patients with out-of-hospital cardiac arrest with a history of heart failure, allocation to a higher blood pressure target resulted in significantly increased heart rate in the higher blood pressure-target group. However, no certain differences was found for cardiac index, left ventricular ejection fraction or stroke volume.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03141099.

Resting state EEG relates to short- and long-term cognitive functioning after cardiac arrest

BACKGROUND

Approximately half of cardiac arrest survivors have persistent cognitive impairment. Guidelines recommend early screening to identify patients at risk for cognitive impairment, but there is no consensus on the best screening method. We aimed to identify quantitative EEG measures relating with short- and long-term cognitive function after cardiac arrest for potential to cognitive outcome prediction.

METHODS

We analyzed data from a prospective longitudinal multicenter cohort study designed to develop a prediction model for cognitive outcome after cardiac arrest. For the current analysis, we used twenty-minute EEG registrations from 80 patients around one week after cardiac arrest. We calculated power spectral density, normalized alpha-to-theta ratio (nATR), peak frequency, and center of gravity (CoG) of this peak frequency. We related these with global cognitive functioning (scores on the Montreal Cognitive Assessment (MoCA)) at one week, three and twelve months follow-up with multivariate mixed effect models, and with performance on standard neuropsychological examination at twelve months using Pearson correlation coefficients.

RESULTS

Each individual EEG parameter related to MoCA at one week (βnATR = 7.36; P < 0.01; βpeak frequency = 1.73, P < 0.01; βCoG = -9.88, P < 0.01). The nATR also related with the MoCA at three months ((βnATR = 2.49; P 0.01). No EEG metrics significantly related to the MoCA score at twelve months. nATR and peak frequency related with memory performance at twelve months. Results were consistent in sensitivity analyses.

CONCLUSION

Early resting-state EEG parameters relate with short-term global cognitive functioning and with memory function at one year after cardiac arrest. Additional predictive values in multimodal prediction models need further study.

Nutritional support in the cardiac intensive care unit

Optimal care of critically ill patients in the cardiac intensive care unit includes adequate nutritional support. This review highlights the high prevalence of malnutrition in acute heart failure, acute coronary syndrome, cardiogenic shock, and post-cardiac arrest and its adverse impact on prognosis. There is a lack of robust evidence regarding appropriate nutritional support in this patient population. Initiation of nutritional support with a comprehensive assessment of the patient's nutritional status is critical. High-risk cardiac patients who are not critically ill can receive oral nutrition adapted to individual risk factors or deficiencies, although overfeeding should be avoided in the acute phase. For critically ill patients at risk of or with malnutrition on admission, general principles include initiation of nutritional support within 48 h of admission, preference for enteral over parenteral nutrition, preference for hypocaloric nutrition in the first week of intensive care unit admission, and adequate micronutrient supplementation. Enteral nutrition in haemodynamically unstable patients carries a risk, albeit low, of intestinal ischaemia. In the case of malnutrition, the risk of refeeding syndrome should always be considered.

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.

Factors associated with fever after cardiac arrest: A post-hoc analysis of the FINNRESUSCI study

BACKGROUND

Fever after cardiac arrest may impact outcome. We aimed to assess the incidence of fever in post-cardiac arrest patients, factors predicting fever and its association with functional outcome in patients treated without targeted temperature management (TTM).

METHODS

The FINNRESUSCI observational cohort study in 2010-2011 included intensive care unit (ICU)-treated out-of-hospital cardiac arrest (OHCA) patients from all five Finnish university hospitals and 14 of 15 central hospitals. This post hoc analysis included those FINNRESUSCI study patients who were not treated with TH. We defined fever as at least one temperature measurement of ≥37.8°C within 72 h of ICU admission. The primary outcome was favourable functional outcome at 12 months, defined as cerebral performance category (CPC) of 1 or 2. Binary logistic regression models including witnessed arrest, bystander cardiopulmonary resuscitation (CPR), initial rhythm and delay of return of spontaneous circulation were used to compare the functional outcomes of the groups.

RESULTS

There were 67,428 temperature measurements from 192 patients, of whom 89 (46%) experienced fever. Twelve-month CPC was missing in 7 patients, and 51 (28%) patients had favourable functional outcome at 12 months. The patients with shockable initial rhythms had a lower incidence of fever within 72 h of ICU admission (28% vs. 72%, p < .01), and the patients who experienced fever had a longer median return of spontaneous circulation (ROSC) delay (20 [IQR 10-30] vs. 14 [IQR 9-22] min, p < .01). Only initial non-shockable rhythm (OR 2.99, 95% CI 1.51-5.94) was associated with increased risk of fever within the first 72 h of ICU admission. Neither time in minutes nor area (minutes  ×  degree celsius over threshold) over 37°C, 37.5°C, 38°C, 38.5°C, 39°C, 39.5°C or 40°C were significantly different in those with favourable functional outcome compared to those with unfavourable functional outcome within the first 24, 48 or 72 h from ICU admission. Fever was not associated with favourable functional outcome at 12 months (OR 0.90, 95% CI 0.44-1.84).

CONCLUSIONS

Half of OHCA patients not treated with TTM developed fever. We found no association between fever and outcome.

Lower versus higher blood pressure targets in comatose patients resuscitated from out-of-hospital cardiac arrest-Protocol for a secondary Bayesian analysis of the box trial

BACKGROUND

The management of blood pressure targets during intensive care after out-of-hospital cardiac arrest (OHCA) remains a topic of debate. The blood Pressure and Oxygenation Targets After OHCA (BOX) trial explored the efficacy of two different blood pressure targets in 789 patients during intensive care after OHCA. In the primary frequentist analysis, no statistically significant differences were found for neurological outcome after 90 days.

METHODS

This protocol outlines secondary Bayesian analyses of 365-day all-cause mortality and two secondary outcomes: neurological outcome after 365 days, and plasma neuron-specific enolase, a biomarker of brain injury, after 48 h. We will employ adjusted Bayesian logistic and linear regressions, presenting results as relative and absolute differences with 95% confidence intervals. We will use weakly informative priors for the primary analyses, and skeptical and evidence-based priors (where available) in sensitivity analyses. Exact probabilities for any benefit/harm will be presented for all outcomes, along with probabilities of clinically important benefit/harm (risk differences larger than 2%-points absolute) and no clinically important differences for the binary outcomes. We will assess whether heterogeneity of treatment effects on mortality is present according to lactate at admission, time to return of spontaneous circulation, primary shockable rhythm, age, hypertension, and presence of ST-elevation myocardial infarction.

DISCUSSION

This secondary analysis of the BOX trial aim to complement the primary frequentist analysis by quantifying the probabilities of beneficial or harmful effects of different blood pressure targets. This approach seeks to provide clearer insights for researchers and clinicians into the effectiveness of these blood pressure management strategies in acute medical conditions, particularly focusing on mortality, neurological outcomes, and neuron-specific enolase.

Blood-brain barrier permeability for the first 24 hours in hypoxic-ischemic brain injury following cardiac arrest

BACKGROUND

This study aimed to explore the changes in blood-brain barrier (BBB) permeability and intracranial pressure (ICP) for the first 24 h after the return of spontaneous circulation (ROSC) and their association with injury severity of cardiac arrest.

METHODS

This prospective study analysed the BBB permeability assessed using the albumin quotient (Qa) and ICP every 2 h for the first 24 h after ROSC. The injury severity of cardiac arrest was assessed using Pittsburgh Cardiac Arrest Category (PCAC) scores. The primary outcome was the time course of changes in the BBB permeability and ICP for the first 24 h after ROSC and their association with injury severity (PCAC scores of 1-4).

RESULTS

Qa and ICP were measured 274 and 197 times, respectively, in 32 enrolled patients. Overall, the BBB permeability increased progressively over time after ROSC, and then it increased significantly at 18 h after ROSC compared with the baseline. In contrast, the ICP revealed non-significant changes for the first 24 h after ROSC. The Qa in the PCAC 2 group was < 0.01, indicating normal or mild BBB disruption at all time points, whereas the PCAC 3 and 4 groups showed a significant increase in BBB permeability at 14 and 22 h, and 12 and 14 h after ROSC, respectively.

CONCLUSION

BBB permeability increased progressively over time for the first 24 h after ROSC despite post-resuscitation care, whereas ICP did not change over time. BBB permeability has an individual pattern when stratified by injury severity.

The experiences of cardiac arrest survivors and their key supporters following cardiac arrest: A systematic review and meta-ethnography

AIM

To review qualitative studies on the experience of sudden cardiac arrest survival from the perspective of both survivors and their key supporters, including family/close friends.

METHODS

A seven-step meta-ethnography and synthesis of qualitative evidence was undertaken, informed by the Meta-Ethnography Reporting Guidelines (eMERGe). Four major databases were searched (Medline, EMBASE, CINAHL, PsycINFO; January 1995-January 2022, updated July 2023) for qualitative studies exploring survivors' and/or key supporters' experiences of cardiac arrest survival. The Critical Appraisal Skills Programme checklist and Grading of Recommendations Assessment, Development and Evaluation - Confidence in Evidence from Reviews of Qualitative Research (GRADE-CERQual) were applied to evaluate the overall confidence in research findings. Constructs were identified from each paper, informing theme and sub-theme development.

RESULTS

From 15,917 unique titles/abstracts and 196 full-text articles, 32 met the inclusion criteria. Three themes captured the survivors' experiences: 1) Making sense of my cardiac arrest; 2) Learning to trust my body and mind; and 3) Re-evaluating my life. A further three themes reflected key supporters' experiences: 1) Emotional turmoil; 2) Becoming a carer: same person but different me; and 3) Engaging with a new and unknown world. However, limited data and some methodological weaknesses in included studies reduced confidence in several themes. The findings were conceived within the overarching concept of 'negotiating a new normal'.

CONCLUSIONS

The enduring psychosocial and physical sequelae of cardiac arrest survival substantially impacts the lives of survivors and their key supporters, requiring negotiation of their 'new normality'. The need for sense-making, physical and psychological recovery, and the new roles for key supporters should be strong considerations in the development of future interventions.

Acute Lung Injury after Cardiopulmonary Resuscitation: A Narrative Review

Although cardiopulmonary resuscitation (CPR) includes lifesaving maneuvers, it might be associated with a wide spectrum of iatrogenic injuries. Among these, acute lung injury (ALI) is frequent and yields significant challenges to post-cardiac arrest recovery. Understanding the relationship between CPR and ALI is determinant for refining resuscitation techniques and improving patient outcomes. This review aims to analyze the existing literature on ALI following CPR, emphasizing prevalence, clinical implications, and contributing factors. The review seeks to elucidate the pathogenesis of ALI in the context of CPR, assess the efficacy of CPR techniques and ventilation strategies, and explore their impact on post-cardiac arrest outcomes. CPR-related injuries, ranging from skeletal fractures to severe internal organ damage, underscore the complexity of managing post-cardiac arrest patients. Chest compression, particularly when prolonged and vigorous, i.e., mechanical compression, appears to be a crucial factor contributing to ALI, with the concept of cardiopulmonary resuscitation-associated lung edema (CRALE) gaining prominence. Ventilation strategies during CPR and post-cardiac arrest syndrome also play pivotal roles in ALI development. The recognition of CPR-related lung injuries, especially CRALE and ALI, highlights the need for research on optimizing CPR techniques and tailoring ventilation strategies during and after resuscitation.

Blood Pressure Management for Hypotensive Patients in Intensive Care and Perioperative Cardiovascular Settings

Blood pressure is a critical physiological parameter, particularly in the context of cardiac intensive care and perioperative settings. As a primary indicator of organ perfusion, the maintenance of adequate blood pressure is imperative for the assurance of sufficient tissue oxygen delivery. Among critically ill and major surgery patients, the continuous monitoring of blood pressure is performed as a standard practice for patients. Nonetheless, uncertainties remain regarding blood pressure goals, and there is no consensus regarding blood pressure targets. This review describes the determinants of blood pressure, examine the influence of blood pressure on organ perfusion, and synthesize the current clinical evidence from various intensive care and perioperative settings to provide a concise guidance for daily clinical practice.

Outcome prediction of cardiac arrest with automatically computed gray-white matter ratio on computed tomography images

BACKGROUND

This study aimed to develop an automated method to measure the gray-white matter ratio (GWR) from brain computed tomography (CT) scans of patients with out-of-hospital cardiac arrest (OHCA) and assess its significance in predicting early-stage neurological outcomes.

METHODS

Patients with OHCA who underwent brain CT imaging within 12 h of return of spontaneous circulation were enrolled in this retrospective study. The primary outcome endpoint measure was a favorable neurological outcome, defined as cerebral performance category 1 or 2 at hospital discharge. We proposed an automated method comprising image registration, K-means segmentation, segmentation refinement, and GWR calculation to measure the GWR for each CT scan. The K-means segmentation and segmentation refinement was employed to refine the segmentations within regions of interest (ROIs), consequently enhancing GWR calculation accuracy through more precise segmentations.

RESULTS

Overall, 443 patients were divided into derivation N=265, 60% and validation N=178, 40% sets, based on age and sex. The ROI Hounsfield unit values derived from the automated method showed a strong correlation with those obtained from the manual method. Regarding outcome prediction, the automated method significantly outperformed the manual method in GWR calculation (AUC 0.79 vs. 0.70) across the entire dataset. The automated method also demonstrated superior performance across sensitivity, specificity, and positive and negative predictive values using the cutoff value determined from the derivation set. Moreover, GWR was an independent predictor of outcomes in logistic regression analysis. Incorporating the GWR with other clinical and resuscitation variables significantly enhanced the performance of prediction models compared to those without the GWR.

CONCLUSIONS

Automated measurement of the GWR from non-contrast brain CT images offers valuable insights for predicting neurological outcomes during the early post-cardiac arrest period.

Plasma glial fibrillary acidic protein and tau: predictors of neurological outcome after cardiac arrest

BACKGROUND

The purpose was to evaluate glial fibrillary acidic protein (GFAP) and total-tau in plasma as predictors of poor neurological outcome after out-of-hospital (OHCA) and in-hospital cardiac arrest (IHCA), including comparisons with neurofilament light (NFL) and neuron-specific enolase (NSE).

METHODS

Retrospective multicentre observational study of patients admitted to an intensive care unit (ICU) in three hospitals in Sweden 2014-2018. Blood samples were collected at ICU admission, 12 h, and 48 h post-cardiac arrest. Poor neurological outcome was defined as Cerebral Performance Category 3-5 at 2-6 months after cardiac arrest. Plasma samples were retrospectively analysed for GFAP, tau, and NFL. Serum NSE was analysed in clinical care. Prognostic performances were tested with the area under the receiver operating characteristics curve (AUC).

RESULTS

Of the 428 included patients, 328 were OHCA, and 100 were IHCA. At ICU admission, 12 h and 48 h post-cardiac arrest, GFAP predicted neurological outcome after OHCA with AUC (95% CI) 0.76 (0.70-0.82), 0.86 (0.81-0.90) and 0.91 (0.87-0.96), and after IHCA with AUC (95% CI) 0.77 (0.66-0.87), 0.83 (0.74-0.92) and 0.83 (0.71-0.95). At the same time points, tau predicted outcome after OHCA with AUC (95% CI) 0.72 (0.66-0.79), 0.75 (0.69-0.81), and 0.93 (0.89-0.96) and after IHCA with AUC (95% CI) 0.61 (0.49-0.74), 0.68 (0.56-0.79), and 0.77 (0.65-0.90). Adding the change in biomarker levels between time points did not improve predictive accuracy compared to the last time point. In a subset of patients, GFAP at 12 h and 48 h, as well as tau at 48 h, offered similar predictive value as NSE at 48 h (the earliest time point NSE is recommended in guidelines) after both OHCA and IHCA. The predictive performance of NFL was similar or superior to GFAP and tau at all time points after OHCA and IHCA.

CONCLUSION

GFAP and tau are promising biomarkers for neuroprognostication, with the highest predictive performance at 48 h after OHCA, but not superior to NFL. The predictive ability of GFAP may be sufficiently high for clinical use at 12 h after cardiac arrest.

Early versus late advanced airway management for adult patients with out-of-hospital cardiac arrest: A time-dependent propensity score-matched analysis

OBJECTIVE

The objective was to investigate whether early advanced airway management during the entire resuscitation period is associated with favorable neurological outcomes and survival in patients with out-of-hospital cardiac arrest (OHCA).

METHODS

We performed a retrospective cohort study of patients with OHCA aged ≥18 years enrolled in OHCA registry in Japan who received advanced airway management during cardiac arrest between June 2014 and December 2020. To address resuscitation time bias, we performed risk set matching analyses in which patients who did and did not receive advanced airway management were matched at the same time point (min) using the time-dependent propensity score; further, we compared early (≤10 min) and late (>10 min) advanced airway management. The primary and secondary outcome measures were favorable neurological outcomes using Cerebral Performance Category scores and survival at 1 month after cardiac arrest.

RESULTS

Of the 41,101 eligible patients, 21,446 patients received early advanced airway management. Thus, risk set matching was performed with a total of 42,866 patients. In the main analysis, early advanced airway management was significantly associated with favorable neurological outcomes (risk ratio [RR] 0.997, 95% confidence interval [CI] 0.995-0.999) and survival (RR 0.990, 95% CI 0.986-0.994) at 1 month after cardiac arrest. In the sensitivity analysis with early advanced airway management defined as ≤5 min and ≤20 min, the results were comparable.

CONCLUSIONS

Although early advanced airway management was statistically significant for improved neurological outcomes and survival at 1 month after cardiac arrest, the RR was very close to 1, indicating that the timing of advanced airway management has minimal impact on clinical outcomes, and decisions should be made based on the individual needs of the patient.

Observer-reported cognitive decline in out-of-hospital cardiac arrest survivors and its association with long-term survivor and relative outcomes

AIM

Long-term cognitive decline after out-of-hospital cardiac arrest (OHCA) is still poorly understood. This study describes long-term observer-reported cognitive decline among Danish OHCA survivors, including differences in years since the event, and investigates characteristics and self-reported outcomes associated with observer-reported cognitive decline.

METHODS

Adults who survived an OHCA from 2016 to 2019, and their relatives, completed the national DANish Cardiac Arrest Survivorship survey. Relatives completed the Informant Questionnaire on Cognitive Decline in the Elderly, Cardiac Arrest version (IQCODE-CA), the Hospital Anxiety and Depression Scale (HADS) and the World Health Organisation-Five Well-being index; and survivors completed the Two Simple Questions (everyday activities and mental recovery), the Modified Fatigue Impact Scale, HADS, and the Short World Health Organisation Disability Assessment Schedule 2.0. Potential associations between survivor characteristics and the IQCODE-CA were investigated using a multivariable logistic regression model. Self-reported outcomes among survivors and relatives, and the association with IQCODE-CA scores were investigated using separate logistic regression models.

RESULTS

Total median IQCODE-CA score was 3.04 (IQR: 3.00-3.27), with 47% having possible cognitive decline (score ≥ 3.04), consistent across time groups. Increasing age (OR 0.98, 95% CI: 0.97-0.99) and worse self-reported mental and physical outcomes for survivors and relatives, except 'everyday activities' were significantly associated with possible cognitive decline among survivors.

CONCLUSIONS

Nearly half of OHCA survivors may suffer long-term cognitive decline. Worse self-reported mental and physical outcomes among survivors and their relatives are associated with potential cognitive decline emphasising the need for post-OHCA care to include systematic neurocognitive assessment, tailored support and effective rehabilitation.

2021 European Resuscitation Council/European Society of Intensive Care Medicine Algorithm for Prognostication of Poor Neurological Outcome After Cardiac Arrest-Can Entry Criteria Be Broadened?

OBJECTIVES

To explore broadened entry criteria of the 2021 European Resuscitation Council/European Society of Intensive Care Medicine (ERC/ESICM) algorithm for neuroprognostication including patients with ongoing sedation and Glasgow Coma Scale-Motor score (GCS-M) scores 4-5.

DESIGN

Retrospective multicenter observational study.

SETTING

Four ICUs, Skane, Sweden.

PATIENTS

Postcardiac arrest patients managed at targeted temperature 36°C, 2014-2018. Neurologic outcome was assessed after 2-6 months according to the Cerebral Performance Category scale.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

In 794 included patients, median age was 69.5 years (interquartile range, 60.6-77.0 yr), 241 (30.4%) were female, 550 (69.3%) had an out-of-hospital cardiac arrest, and 314 (41.3%) had a shockable rhythm. Four hundred ninety-five patients were dead at follow-up, 330 of 495 died after a decision on withdrawal of life-sustaining therapies. At 72 hours after cardiac arrest 218 patients remained unconscious. The entry criteria of the original algorithm (GCS-M 1-3) was fulfilled by 163 patients and 115 patients with poor outcome were identified, with false positive rate (FPR) of 0% (95% CI, 0-79.4%) and sensitivity of 71.0% (95% CI, 63.6-77.4%). Inclusion of patients with ongoing sedation identified another 13 patients with poor outcome, generating FPR of 0% (95% CI, 0-65.8%) and sensitivity of 69.6% (95% CI, 62.6-75.8%). Inclusion of all unconscious patients (GCS-M 1-5), regardless of sedation, identified one additional patient, generating FPR of 0% (95% CI, 0-22.8) and sensitivity of 62.9% (95% CI, 56.1-69.2). The few patients with true negative prediction (patients with good outcome not fulfilling guideline criteria of a poor outcome) generated wide 95% CI for FPR.

CONCLUSION

The 2021 ERC/ESICM algorithm for neuroprognostication predicted poor neurologic outcome with a FPR of 0%. Broadening inclusion criteria to include all unconscious patients regardless of ongoing sedation identified an additional small number of patients with poor outcome but did not affect the FPR. Results are limited by high rate of withdrawal of life-sustaining therapies and few patients with true negative prediction.

Association between quantitative analysis of cerebral edema using CT imaging and neurological outcomes in cardiac arrest survivors

BACKGROUND

To determine if the density distribution proportion of Hounsfield unit (HUdp) in head computed tomography (HCT) images can be used to quantitatively measure cerebral edema in survivors of out-of-hospital cardiac arrest (OHCA).

METHODS

This retrospective observational study included adult comatose OHCA survivors who underwent HCT within 6 h (first) and 72-96 h (second), all performed using the same CT scanner. Semi-automated quantitative analysis was used to identify differences in HUdp at specific HU ranges across the intracranial component based on neurological outcome. Cerebral edema was defined as the increased displacement of the sum of HUdp values (ΔHUdp) at a specific range between two HCT scans. Poor neurological outcome was defined as cerebral performance categories 3-5 at 6 months after OHCA.

RESULTS

Twenty-three (42%) out of 55 patients had poor neurological outcome. Significant HUdp differences were observed between good and poor neurological outcomes in the second HCT scan at HU = 1-14, 23-35, and 39-56 (all P < 0.05). Only the ΔHUdp = 23-35 range showed a significant increase and correlation in the poor neurological outcome group (4.90 vs. -0.72, P < 0.001) with the sum of decreases in the other two ranges (r = 0.97, P < 0.001). Multivariate logistic regression analysis demonstrated a significant association between ΔHUdp = 23-35 range and poor neurological outcomes (adjusted OR, 1.12; 95% CI: 1.02-1.24; P = 0.02).

CONCLUSION

In this cohort study, the increased displacement in ΔHUdp = 23-35 range is independently associated with poor neurological outcome and provides a quantitative assessment of cerebral edema formation in OHCA survivors.

Delayed Deterioration of Electroencephalogram in Patients with Cardiac Arrest: A Cohort Study

BACKGROUND

The aim of this study was to assess the prevalence of delayed deterioration of electroencephalogram (EEG) in patients with cardiac arrest (CA) without early highly malignant patterns and to determine their associations with clinical findings.

METHODS

This was a retrospective study of adult patients with CA admitted to the intensive care unit (ICU) of a university hospital. We included all patients with CA who had a normal voltage EEG, no more than 10% discontinuity, and absence of sporadic epileptic discharges, periodic discharges, or electrographic seizures. Delayed deterioration was classified as the following: (1) epileptic deterioration, defined as the appearance, at least 24 h after CA, of sporadic epileptic discharges, periodic discharges, and status epilepticus; or (2) background deterioration, defined as increasing discontinuity or progressive attenuation of the background at least 24 h after CA. The end points were the incidence of EEG deteriorations and their association with clinical features and ICU mortality.

RESULTS

We enrolled 188 patients in the analysis. The ICU mortality was 46%. Overall, 30 (16%) patients presented with epileptic deterioration and 9 (5%) patients presented with background deterioration; of those, two patients presented both deteriorations. Patients with epileptic deterioration more frequently had an out-of-hospital CA, and higher time to return of spontaneous circulation and less frequently had bystander resuscitation than others. Patients with background deterioration showed a predominantly noncardiac cause, more frequently developed shock, and had multiple organ failure compared with others. Patients with epileptic deterioration presented with a higher ICU mortality (77% vs. 41%; p < 0.01) than others, whereas all patients with background deterioration died in the ICU.

CONCLUSIONS

Delayed EEG deterioration was associated with high mortality rate. Epileptic deterioration was associated with worse characteristics of CA, whereas background deterioration was associated with shock and multiple organ failure.

Grey-to-White Matter Ratio Values in Early Head Computed Tomography (CT) as a Predictor of Neurologic Outcomes in Survivors of Out-of-Hospital Cardiac Arrest Based on Severity of Hypoxic-Ischemic Brain Injury

BACKGROUND

Hypoxic-ischemic brain injury (HIBI) is a common complication of out-of-hospital cardiac arrest (OHCA).

OBJECTIVES

We investigated whether grey-to-white matter ratio (GWR) values, measured using early head computed tomography (HCT), were associated with neurologic outcomes based on the severity of HIBI in survivors of OHCA.

METHODS

This retrospective multicenter study included adult comatose OHCA survivors who underwent an HCT scan within 2 h after the return of spontaneous circulation. HIBI severity was assessed using the revised post-Cardiac Arrest Syndrome for Therapeutic hypothermia (rCAST) scale (low, moderate, and severe). Poor neurologic outcomes were defined as Cerebral Performance Categories 3 to 5 at 6 months after OHCA.

RESULTS

Among 354 patients, 27% were women and 224 (63.3%) had poor neurologic outcomes. The distribution of severity was 19.5% low, 47.5% moderate, and 33.1% severe. The area under the receiver operating curves of the GWR values for predicting rCAST severity (low, moderate, and severe) were 0.52, 0.62, and 0.79, respectively. The severe group had significantly higher predictive performance than the moderate group (p = 0.02). Multivariate logistic regression analysis revealed a significant association between GWR values and poor neurologic outcomes in the moderate group (adjusted odds ratio = 0.012, 95% CI 0.0-0.54, p = 0.02).

CONCLUSIONS

In this cohort study, GWR values measured using early HCT demonstrated variations in predicting neurologic outcomes based on HIBI severity. Furthermore, GWR in the moderate group was associated with poor neurologic outcomes.

Qualitative Exploration of Anesthesia Providers' Perceptions Regarding Philips Visual Patient Avatar in Clinical Practice

The Philips Visual Patient Avatar, a user-centered visualization technology, offers an alternative approach to patient monitoring. Computer-based simulation studies indicate that it increases diagnostic accuracy and confidence, while reducing perceived workload. About three months after the technology's integration into clinical practice, we conducted an assessment among anesthesia providers to determine their views on its strengths, limitations, and overall perceptions. This single-center qualitative study at the University Hospital of Zurich examined anesthesia providers' perceptions of the Philips Visual Patient Avatar after its implementation. The study included an online survey to identify medical personnel's opinions on the technology's strengths and areas for improvement, which were analyzed using thematic analysis. A total of 63 of the 377 invited anesthesia providers (16.7%) responded to the survey. Overall, 163 comments were collected. The most prevalent positive themes were good presentation of specific parameters (16/163; 9.8%) and quick overview/rapid identification of problems (15/163; 9.2%). The most common perceived area for improvement was the ability to adjust the visualization thresholds of Visual Patient Avatar, which represent the physiological upper and lower vital-sign limits (33/163; 20.3%). The study showed that users consider Philips Visual Patient Avatar a valuable asset in anesthesia, allowing for easier identification of underlying problems. However, the study also revealed a user desire for the ability to freely adjust the thresholds of the Visual Patient Avatar by the handling caregivers, which were fixed to the departmental standard during the study.

Feasibility of quality indicators on prehospital advanced airway management in a physician-staffed emergency medical service: survey-based assessment of the provider point of view

OBJECTIVE

We aimed to determine the feasibility of quality indicators (QIs) for prehospital advanced airway management (PAAM) from a provider point of view.

DESIGN

The study is a survey based feasibility assessment following field testing of QIs for PAAM.

SETTING

The study was performed in two physician staffed emergency medical services in Switzerland.

PARTICIPANTS

42 of the 44 emergency physicians who completed at least one case report form (CRF) dedicated to the collection of the QIs on PAAM between 1 January 2019 and 31 December 2021 participated in the study.

INTERVENTION

The data required to calculate the 17 QIs was systematically collected through a dedicated electronic CRF.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcomes were provider-related feasibility criteria: relevance and acceptance of the QIs, as well as reliability of the data collection. Secondary outcomes were effort to collect specific data and to complete the CRF.

RESULTS

Over the study period, 470 CRFs were completed, with a median of 11 per physician (IQR 4-17; range 1-48). The median time to complete the CRF was 7 min (IQR 3-16) and was considered reasonable by 95% of the physicians. Overall, 75% of the physicians assessed the set of QIs to be relevant, and 74% accepted that the set of QIs assessed the quality of PAAM. The reliability of data collection was rated as good or excellent for each of the 17 QIs, with the lowest rated for the following 3 QIs: duration of preoxygenation, duration of laryngoscopy and occurrence of desaturation during laryngoscopy.

CONCLUSIONS

Collection of QIs on PAAM appears feasible. Electronic medical records and technological solutions facilitating automatic collection of vital parameters and timing during the procedure could improve the reliability of data collection for some QIs. Studies in other services are needed to determine the external validity of our results.

Coma Prognostication After Acute Brain Injury: A Review

Importance

Among the most impactful neurologic assessments is that of neuroprognostication, defined here as the prediction of neurologic recovery from disorders of consciousness caused by severe, acute brain injury. Across a range of brain injury etiologies, these determinations often dictate whether life-sustaining treatment is continued or withdrawn; thus, they have major implications for morbidity, mortality, and health care costs. Neuroprognostication relies on a diverse array of tests, including behavioral, radiologic, physiological, and serologic markers, that evaluate the brain's functional and structural integrity.

Observations

Prognostic markers, such as the neurologic examination, electroencephalography, and conventional computed tomography and magnetic resonance imaging (MRI), have been foundational in assessing a patient's current level of consciousness and capacity for recovery. Emerging techniques, such as functional MRI, diffusion MRI, and advanced forms of electroencephalography, provide new ways of evaluating the brain, leading to evolving schemes for characterizing neurologic function and novel methods for predicting recovery.

Conclusions and Relevance

Neuroprognostic markers are rapidly evolving as new ways of assessing the brain's structural and functional integrity after brain injury are discovered. Many of these techniques remain in development, and further research is needed to optimize their prognostic utility. However, even as such efforts are underway, a series of promising findings coupled with the imperfect predictive value of conventional prognostic markers and the high stakes of these assessments have prompted clinical guidelines to endorse emerging techniques for neuroprognostication. Thus, clinicians have been thrust into an uncertain predicament in which emerging techniques are not yet perfected but too promising to ignore. This review illustrates the current, and likely future, landscapes of prognostic markers. No matter how much prognostic markers evolve and improve, these assessments must be approached with humility and individualized to reflect each patient's values.

Critical care nurses' experiences of caring challenges during post-resuscitation period: a qualitative content analysis

BACKGROUND

Patients in the post-resuscitation period experience critical conditions and require high-quality care. Identifying the challenges that critical care nurses encounter when caring for resuscitated patients is essential for improving the quality of their care.

AIM

This study aimed to identify the challenges encountered by critical care nurses in providing care during the post-resuscitation period.

METHODS

A qualitative study was conducted using semi-structured interviews. Sixteen nurses working in the intensive care units of three teaching hospitals were selected through purposive sampling. The Data collected were analyzed using qualitative content analysis.

RESULTS

Participants experienced individual, interpersonal, and organizational challenges when providing post-resuscitation care. The most significant challenges include inadequate clinical knowledge and experience, poor management and communication skills, lack of support from nurse managers, role ambiguity, risk of violence, and inappropriate attitudes of physicians towards nurses' roles. Additionally, nurses expressed a negative attitude towards resuscitated patients.

CONCLUSION

Critical care nurses face several challenges in providing care for resuscitated patients. To enhance the quality of post-resuscitation care, address the challenges effectively and improve long-time survival it is crucial to implement interventions such as In-service education, post-resuscitation briefing, promotion of interprofessional collaboration among healthcare teams, providing sufficient human resources, clarifying nurses' roles in the post-resuscitation period and increasing support from nursing managers.

Characteristics of the most severely ill and injured patients in a Norwegian helicopter emergency medical service: a retrospective cohort study

BACKGROUND

Physician-staffed helicopter emergency medical services (HEMS) are dispatched to a variety of incidents, ranging from less serious to life-threatening. The skillset of a physician may be important to provide appropriate care for the most critically ill and severely injured patients. A better understanding of these patients may therefore be important to optimize dispatch criteria, training, and equipment setups for HEMS units. The aim of this study was to describe the characteristics of patients with the national advisory committee on aeronautics (NACA) score 5 and 6, primarily by diagnostic group and interventions performed.

METHODS

Retrospective cohort study on aggregated data from the HEMS-base in Trondheim, Norway. All patients with NACA score 5 and 6 in the 10-year period from 2013 to 2022 were included. Patients with return of spontaneous circulation (ROSC) after successful cardiopulmonary resuscitation were described separately from non-cardiac arrest patients.

RESULTS

Out of 9546 patient encounters, 2598 patients were included, with 1640 in the NACA 5 and 958 in NACA 6 group. Patient age was median 63 (interquartile range 45-74) and 64% of the patients were male. Post-ROSC patients accounted for 24% of patients. Of the non-cardiac arrest patients, the most frequent aetiology was trauma (16%), cardiac (15%), neurologic (14%) and respiratory (11%). The most common physician-requiring advanced interventions were general anaesthesia (22%), intubation (21%), invasive blood pressure monitoring (21%) and ventilator treatment (18%). The mean number of advanced interventions per mission were consistent during the study period (1,78, SD 0,25).

CONCLUSION

Twenty-seven percent of all HEMS dispatches were to NACA 5 and 6 patients. Twenty-four percent of these were post-ROSC patients. Sixty-three percent of all patients received at least one advanced physician-requiring intervention and the average number of interventions were consistent during the last 10 years. Hence, the competence a physician-staffed HEMS resource provide is utilized in a high number of critically ill and injured patients.

A multidisciplinary guideline-based approach to improving the sudden cardiac arrest care pathway: The Copenhagen framework

Although recommended in the European Resuscitation Council (ERC) and European Society of Intensive Care Medicine (ESICM) Guidelines, a framework for delivering post-cardiac arrest care in a systematic manner in dedicated high-volume cardiac arrest centers is lacking in the existing literature. To our knowledge, the Copenhagen Framework is the only established framework of its kind. The framework comprises management of out-of-hospital cardiac arrest (OHCA) survivors, and follow-up, and rehabilitation. The framework also incorporates research projects on cardiac arrest survivors and their close family members. The overall aim of this paper is to describe a framework made in order to bridge the gaps between international recommendations and delivering high-quality post-resuscitation clinical care, improving the continuity of care for OHCA survivors, access to post-CA rehabilitation, a seamless transition to everyday life, and ultimately patient outcomes in the future.

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.

Methylene blue as an adjuvant during cardiopulmonary resuscitation: an experimental study in rats

INTRODUCTION

Methylene Blue (MB) has been shown to attenuate oxidative, inflammatory, myocardial, and neurological lesions during ischemia-reperfusion and has great potential during cardiac arrest. This study aimed to determine the effects of MB combined with epinephrine during cardiac arrest on myocardial and cerebral lesions.

METHOD

Thirty-eight male Wistar rats were randomly assigned to four groups: the sham group (SH, n = 5), and three groups subjected to cardiac arrest (n = 11/group) and treated with EPI 20 µg.kg-1 (EPI), EPI 20 µg.kg-1 + MB 2 mg.kg-1 (EPI + MB), or saline 0.9% 0.2 ml (CTL). Ventricular fibrillation was induced by direct electrical stimulation in the right ventricle for 3 minutes, and anoxia was maintained for 5 minutes. Cardiopulmonary Resuscitation (CPR) consisted of medications, ventilation, chest compressions, and defibrillation. After returning to spontaneous circulation, animals were observed for four hours. Blood gas, troponin, oxidative stress, histology, and TUNEL staining measurements were analyzed. Groups were compared using generalized estimating equations.

RESULTS

No differences in the Returning of Spontaneous Circulation (ROSC) rate were observed among the groups (EPI: 63%, EPI + MB: 45%, CTL: 40%, p = 0.672). The mean arterial pressure immediately after ROSC was higher in the EPI+MB group than in the CTRL group (CTL: 30.5 [5.8], EPI: 63 [25.5], EPI+MB: 123 [31] mmHg, p = 0.007). Serum troponin levels were high in the CTL group (CTL: 130.1 [333.8], EPI: 3.70 [36.0], EPI + MB: 43.7 [116.31] ng/mL, p < 0.05).

CONCLUSION

The coadministration of MB and epinephrine failed to yield enhancements in cardiac or brain lesions in a rodent model of cardiac arrest.