Post-Cardiac Arrest Syndrome

Vagal nerve stimulation in myocardial ischemia/reperfusion injury: from bench to bedside

The identification of acute cardioprotective strategies against myocardial ischemia/reperfusion (I/R) injury that can be applied in the catheterization room is currently an unmet clinical need and several interventions evaluated in the past at the pre-clinical level have failed in translation. Autonomic imbalance, sustained by an abnormal afferent signalling, is a key component of I/R injury. Accordingly, there is a strong rationale for neuromodulation strategies, aimed at reducing sympathetic activity and/or increasing vagal tone, in this setting. In this review we focus on cervical vagal nerve stimulation (cVNS) and on transcutaneous auricular vagus nerve stimulation (taVNS); the latest has the potential to overcome several of the issues of invasive cVNS, including the possibility of being used in an acute setting, while retaining its beneficial effects. First, we discuss the pathophysiology of I/R injury, that is mostly a consequence of the overproduction of reactive oxygen species. Second, we describe the functional anatomy of the parasympathetic branch of the autonomic nervous system and the most relevant principles of bioelectronic medicine applied to electrical vagal modulation, with a particular focus on taVNS. Then, we provide a detailed and comprehensive summary of the most relevant pre-clinical studies of invasive and non-invasive VNS that support its strong cardioprotective effect whenever there is an acute or chronic cardiac injury and specifically in the setting of myocardial I/R injury. The potential benefit in the emerging field of post cardiac arrest syndrome (PCAS) is also mentioned. Indeed, electrical cVNS has a strong anti-adrenergic, anti-inflammatory, antioxidants, anti-apoptotic and pro-angiogenic effect; most of the involved molecular pathways were already directly confirmed to take place at the cardiac level for taVNS. Pre-clinical data clearly show that the sooner VNS is applied, the better the outcome, with the possibility of a marked infarct size reduction and almost complete left ventricular reverse remodelling when VNS is applied immediately before and during reperfusion. Finally, we describe in detail the limited but very promising clinical experience of taVNS in I/R injury available so far.

Pre-hospital care after return of spontaneous circulation: Are we achieving our targets?

Background

Early restoration of normal physiology when return of spontaneous circulation (ROSC) is obtained after an out-of-hospital cardiac arrest (OHCA) reduces the risk of developing post-cardiac arrest syndrome (PCAS). This study aims to investigate if (and to which extent) this can be achieved within the scope of practice of standard emergency medical services (EMS) crews.

Methods

A prospective mixed-methods quantitative and qualitative cohort study was performed including adult patients with a non-traumatic OHCA presented to a university hospital emergency department (ED) in the Netherlands after pre-hospital ROSC was obtained. Primary endpoint was the percentage of patients with deranged physiology post-ROSC in whom EMS crews were able to reach recommended treatment targets.

Results

During a 32-month period, 160 patients presenting with ROSC after OHCA were included. Median (IQR) pre-hospital treatment duration was 40 (34-51) minutes. When deranged physiology was present (n = 133), it could be restored by EMS crews in 29% of the patients. Although average etCO2 and SpO2 improved gradually over time during pre-hospital treatment, recommended treatment targets could not be achieved in respectively 55% (30/55) and 43% (20/46) of the patients. Similarly, airway problems (24/46, 52%), hypotension (20/23, 87%) and post-anoxic agitation (16/43, 37%) could often not be resolved by EMS crews. The ability to restore normal physiology by EMS could not be predicted based on patient characteristics or in-arrest variables.

Conclusion

Deranged physiology after an OHCA is commonly encountered, and often difficult to treat within the scope of practice of regular EMS crews. Involvement of advanced critical care teams with a wider scope of practice at an early stage may contribute to a better outcome for these patients.

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

BACKGROUND

The post-cardiac arrest syndrome (PCAS) after out-of-hospital cardiac arrest (OHCA) is characterized by a series of pathological events, including inflammation. In the randomized "STERoid for OHCA" (STEROHCA) trial, prehospital high-dose glucocorticoid decreased interleukin (IL) 6 and C-reactive protein levels following resuscitated OHCA. The aim of this predefined sub-study was to assess the inflammatory response the first three days of admission.

METHODS

The STEROHCA trial enrolled 137 OHCA patients randomized to either a single prehospital injection of methylprednisolone 250 mg or placebo. Inflammatory markers, including pro- and anti-inflammatory cytokines, were analyzed in plasma samples, from 0-, 24-, 48-, and 72 h post-admission. Mixed-model analyses were applied using log-transformed data to assess group differences.

RESULTS

The 137 patients included in this sub-study had a median age of 67 years (57 to 74), and the 180-day survival rates were 75% (n = 51/68) and 64% (n = 44/69) in the glucocorticoid and placebo group, respectively. A total of 130 (95%) patients had at least one plasma sample available. The anti-inflammatory cytokine IL-10 was increased at hospital admission in the glucocorticoid group (ratio 2.74 (1.49-5.05), p = 0.006), but the intervention showed the strongest effect after 24 h, decreasing pro-inflammatory levels of IL-6 (ratio 0.06 (0.03-0.10), p < 0.001), IL-8 (ratio 0.53 (0.38-0.75), p < 0.001), macrophage chemokine protein-1 (MCP-1, ratio 0.02 (0.13-0.31), p < 0.001), macrophage inflammatory protein-1-beta (MIP-1b, ratio 0.28 (0.18-0.45), p < 0.001), and tumor necrosis factor-α (TNF-α, ratio 0.6 (0.4-0.8), p = 0.01).

CONCLUSION

Administering high-dose glucocorticoid treatment promptly after resuscitation from OHCA influenced the inflammatory response with a reduction in several systemic proinflammatory cytokines after 24 h.

TRIAL REGISTRATION

EudraCT number: 2020-000855-11; submitted March 30, 2020. URL: https://www.

CLINICALTRIALS

gov; Unique Identifier: NCT04624776.

Wolf Creek XVII Part 8: Neuroprotection

Introduction

Post-cardiac arrest brain injury (PCABI) is the primary determinant of clinical outcomes for patients who achieve return of spontaneous circulation after cardiac arrest (CA). There are limited neuroprotective therapies available to mitigate the acute pathophysiology of PCABI.

Methods

Neuroprotection was one of six focus topics for the Wolf Creek XVII Conference held on June 14-17, 2023 in Ann Arbor, Michigan, USA. Conference invitees included international thought leaders and scientists in the field of CA resuscitation from academia and industry. Participants submitted via online survey knowledge gaps, barriers to translation, and research priorities for each focus topic. Expert panels used the survey results and their own perspectives and insights to create and present a preliminary unranked list for each category that was debated, revised and ranked by all attendees to identify the top 5 for each category.

Results

Top 5 knowledge gaps included developing therapies for neuroprotection; improving understanding of the pathophysiology, mechanisms, and natural history of PCABI; deploying precision medicine approaches; optimizing resuscitation and CPR quality; and determining optimal timing for and duration of interventions. Top 5 barriers to translation included patient heterogeneity; nihilism & lack of knowledge about cardiac arrest; challenges with the translational pipeline; absence of mechanistic biomarkers; and inaccurate neuro-triage and neuroprognostication. Top 5 research priorities focused on translational research and trial optimization; addressing patient heterogeneity and individualized interventions; improving understanding of pathophysiology and mechanisms; developing mechanistic and outcome biomarkers across post-CA time course; and improving implementation of science and technology.

Conclusion

This overview can serve as a guide to transform the care and outcome of patients with PCABI. Addressing these topics has the potential to improve both research and clinical care in the field of neuroprotection for PCABI.

Effect of prehospital high-dose glucocorticoid on hemodynamics in patients resuscitated from out-of-hospital cardiac arrest: a sub-study of the STEROHCA trial

BACKGROUND

Following resuscitated out-of-hospital cardiac arrest (OHCA), inflammatory markers are significantly elevated and associated with hemodynamic instability and organ dysfunction. Vasopressor support is recommended to maintain a mean arterial pressure (MAP) above 65 mmHg. Glucocorticoids have anti-inflammatory effects and may lower the need for vasopressors. This study aimed to assess the hemodynamic effects of prehospital high-dose glucocorticoid treatment in resuscitated comatose OHCA patients.

METHODS

The STEROHCA trial was a randomized, placebo-controlled, phase 2 trial comparing one prehospital injection of methylprednisolone 250 mg with placebo immediately after resuscitated OHCA. In this sub-study, we included patients who remained comatose at admission and survived until intensive care unit (ICU) admission. The primary outcome was cumulated norepinephrine use from ICU admission until 48 h reported as mcg/kg/min. Secondary outcomes included hemodynamic status characterized by MAP, heart rate, vasoactive-inotropic score (VIS), and the VIS/MAP-ratio as well as cardiac function assessed by pulmonary artery catheter measurements. Linear mixed-model analyses were performed to evaluate mean differences between treatment groups at all follow-up times.

RESULTS

A total of 114 comatose OHCA patients were included (glucocorticoid: n = 56, placebo: n = 58) in the sub-study. There were no differences in outcomes at ICU admission. From the time of ICU admission up to 48 h post-admission, patients in the glucocorticoid group cumulated a lower norepinephrine use (mean difference - 0.04 mcg/kg/min, 95% CI - 0.07 to - 0.01, p = 0.02). Moreover, after 12-24 h post-admission, the glucocorticoid group demonstrated a higher MAP with mean differences ranging from 6 to 7 mmHg (95% CIs from 1 to 12), a lower VIS (mean differences from - 4.2 to - 3.8, 95% CIs from - 8.1 to 0.3), and a lower VIS/MAP ratio (mean differences from - 0.10 to - 0.07, 95% CIs from - 0.16 to - 0.01), while there were no major differences in heart rate (mean differences from - 4 to - 3, 95% CIs from - 11 to 3). These treatment differences between groups were also present 30-48 h post-admission but to a smaller extent and with increased statistical uncertainty. No differences were found in pulmonary artery catheter measurements between groups.

CONCLUSIONS

Prehospital treatment with high-dose glucocorticoid was associated with reduced norepinephrine use in resuscitated OHCA patients.

TRIAL REGISTRATION

EudraCT number: 2020-000855-11; submitted March 30, 2020. URL: https://www.

CLINICALTRIALS

gov ; Unique Identifier: NCT04624776.

Management of Patients After Cardiac Arrest

Cardiac arrest remains a significant cause of morbidity and mortality, although contemporary care now enables potential survival with good neurologic outcome. The core acute management goals for survivors of cardiac arrest are to provide organ support, sustain adequate hemodynamics, and evaluate the underlying cause of the cardiac arrest. In this article, the authors review the current state of knowledge and clinical intensive care unit practice recommendations for patients after cardiac arrest, particularly focusing on important areas of uncertainty, such as targeted temperature management, neuroprognostication, coronary evaluation, and hemodynamic targets.

Neurological outcomes and quality of life in post-cardiac arrest patients with return of spontaneous circulation supported by ECMO: A retrospective case series

Post-cardiac arrest brain injury constitutes a significant contributor to morbidity and mortality, leading to cognitive impairment and subsequent disability. Individuals within this patient cohort grapple with uncertainty regarding the potential advantages of extracorporeal life support (ECMO) cannulation. This study elucidates the neurological outcomes and quality of life of post-cardiac arrest patients who attained spontaneous circulation and underwent ECMO cannulation. This is a retrospective case study within a local context, the research involved 32 patients who received ECMO support following an intrahospital cardiac arrest with return of spontaneous circulation (ROSC). An additional 32 patients experienced cardiac arrest with ROSC before undergoing cannulation. The average age was 41 years, with the primary causes of cardiac arrest identified as acute coronary syndrome (46.8%), pulmonary thromboembolism (21.88%), and hypoxemia (18.7%). The most prevalent arrest rhythm was asystole (37.5%), followed by ventricular fibrillation (34.4%). The mean SOFA score was 7 points (IQR 6.5-9), APACHE II score was 12 (IQR 9-16), RESP score was -1 (IQR -1 to -4) in cases of respiratory ECMO, and SAVE score was -3 (IQR -5 to 2) in cases of cardiac ECMO. Overall survival was 71%, and at 6 months, the Barthel score was 75 points, modified Rankin score was 2, cerebral performance categories score was 1, and the SF-12 had an average score of 30. Notably, there were no significant associations between the time, cause, or rhythm of cardiac arrest and neurological outcomes. Importantly, cardiac arrest is not a contraindication for ECMO cannulation. A meticulous assessment of candidates who have achieved spontaneous circulation after cardiac arrest, considering the absence of early signs of poor neurological prognosis, is crucial in patient selection. Larger prospective studies are warranted to validate and extend these findings.

Reviving Hope: A Comprehensive Review of Post-resuscitation Care in Pediatric ICUs After Cardiac Arrest

This comprehensive review thoroughly examines post-resuscitation care in pediatric ICUs (PICUs) following cardiac arrest. The analysis encompasses adherence to resuscitation guidelines, advances in therapeutic interventions, and the nuanced management of neurological, cardiovascular, and respiratory considerations during the immediate post-resuscitation phase. Delving into the complexities of long-term outcomes, cognitive and developmental considerations, and rehabilitation strategies, the review emphasizes the importance of family-centered care for pediatric survivors. A call to action is presented, urging continuous education, research initiatives, and quality improvement efforts alongside strengthened multidisciplinary collaboration and advocacy for public awareness. Through implementing these principles, healthcare providers and systems can collectively contribute to ongoing advancements in pediatric post-resuscitation care, ultimately improving outcomes and fostering a culture of excellence in pediatric critical care.