The Role of Inflammatory Cytokines in Cardiac Arrest.

INTRODUCTION: Post-cardiac arrest syndrome (PCAS) is characterized by systemic ischemia/reperfusion injury, anoxic brain injury, and post-arrest myocardial dysfunction superimposed on a precipitating pathology. The role of inflammatory cytokines in cardiac arrest remains unclear. AIMS: We aimed to describe, with an emphasis on clinical applications, what is known about the role of inflammatory cytokines in cardiac arrest. DATA SOURCES: A PubMed literature review was performed for relevant articles. Only articles in English that studied cytokines in patients with cardiac arrest were included. RESULTS: Cytokines play a crucial role in the pathogenesis of PCAS. Following cardiac arrest, the large release of circulating cytokines mediates the ischemia/reperfusion injury, brain dysfunction, and myocardial dysfunction seen. Interleukins, tumor necrosis factor, and matrix metalloproteinases all play a unique prognostic role in PCAS. High levels of inflammatory cytokines have been associated with mortality and/or poor neurologic outcomes. Interventions to modify the systemic inflammation seen in PCAS continue to be heavily studied. Currently, the only approved medical intervention for comatose patients following cardiac arrest is targeted temperature management. Medical agents, including minocycline and sodium sulfide, have demonstrated promise in animal models. CONCLUSIONS: The role of inflammatory cytokines for both short- and long-term outcomes is an important area for future investigation.

Association of post-resuscitation inflammatory response with favorable neurologic outcomes in adults with in-hospital cardiac arrest.

BACKGROUND: Early prediction of mortality in adults after in-hospital cardiac arrest (IHCA) remains vital to optimizing treatment strategies. Inflammatory cytokines specific to early prognostication in this population have not been well studied. We evaluated whether novel inflammatory cytokines obtained from adults with IHCA helped predict favorable neurologic outcome. METHODS: The study population included adults with IHCA who underwent ACLS-guided resuscitation between March 2014 and May 2019 at an academic tertiary medical center. Peripheral blood samples were obtained within 6, 24, 48, 72, and 96 h of IHCA and analysis of 15 cytokines were performed. The primary outcome of interest was presence of favorable neurologic outcome at hospital discharge, defined as a Glasgow Outcome Score of 4 or 5. RESULTS: Of the 105 adults with IHCA studied, 27 (25.7%) were noted to have survival with a favorable neurologic outcome while 78 (74.3%) did not. Patients who survived with favorable neurologic outcome were more often men (88.9% vs 61.5%, p = 0.008) and had higher rates of ventricular tachyarrhythmias as their initial rhythm (34.6% vs 11.7%, p = 0.018). Levels of interleukin (IL)-6, IL-8, IL-10, and Tumor Necrosis Factor (TNF)-R1 within 6 or 24 h were significantly lower in patients with favorable neurologic outcome compared with those who had unfavorable neurologic outcome. In multivariable analysis, IL-10 levels within 6 h was the only independent predictor of favorable neurologic outcomes [odds ratio (OR) 0.895, 95% confidence interval 0.805-0.996, p = 0.041]. CONCLUSION: In this contemporary observational study of adults with IHCA receiving ACLS-guided resuscitative and post-resuscitative care, inflammatory cytokines specific to early prognostication in adults with IHCA exist. Further larger scale studies examining the association of these inflammatory cytokines with prognosis are warranted.

Impact of right ventricular dysfunction on mortality in adults with cardiac arrest undergoing coronary angiogram.

OBJECTIVE: We sought to identify the impact of echocardiographic right ventricular (RV) systolic dysfunction on mortality in adults with cardiac arrest (CA). METHODS: The study population included 147 adults hospitalized with CA who underwent both echocardiogram and coronary angiogram at an academic tertiary medical center. The primary outcome of interest was all-cause in-hospital mortality. RESULTS: Of the 147 patients studied, 20 (13.6%) had evidence of RV systolic dysfunction while 127 (86.4%) did not. Patients with RV dysfunction had higher rates of prior surgical and percutaneous coronary revascularization. They also had higher rates of mechanical ventilation, therapeutic hypothermia, vasopressor and inotrope use, and a trend towards higher rates of mechanical support. Coronary angiogram revealed higher rates of multivessel disease, right coronary artery intervention, and glycoprotein IIb-IIIa inhibitor use in those with RV dysfunction, alongside with lower echocardiographic left ventricular ejection fraction. In-hospital mortality rates were higher in adults with RV dysfunction compared to those without (55% vs 11%, p < 0.001). In multivariate analysis, RV dysfunction was the strongest independent predictor of higher mortality [odds ratio 4.71, 95% confidence interval 1.27-17.50]. CONCLUSIONS: In this observational contemporary study, RV dysfunction was independently associated with higher mortality in adults with CA undergoing coronary angiogram. RV dysfunction may be useful for risk stratification and management in this high-mortality population.

Relationship Between the Subcostal and Right Lateral Ultrasound Views of Inferior Vena Cava Collapse: Implications for Clinical Use of Ultrasonography.

BACKGROUND: The collapsibility index of the inferior vena cava is traditionally visualized from the subcostal region in the sagittal plane, referred to here as cIVCSS. Alternatively, the collapsibility index of the inferior vena cava can be visualized from the right midaxillary line in the coronal plane, referred to here as cIVCRC. It is unclear whether values of cIVCRC are comparable with values of cIVCSS because the inferior vena cava collapses asymmetrically into an elliptical form, quantified as the flat ratio of the inferior vena cava (F-IVC). This study aimed (1) to establish if cIVCRC is concordant or discordant to cIVCSS, and (2) to describe how this concordance or discordance is related to F-IVC. METHODS: This single-center cross-sectional study enrolled 110 spontaneously breathing patients. Values of cIVCRC were compared with cIVCSS. Performance of cIVCRC ≥ 42% in predicting fluid responsiveness, defined as cIVCSS ≥ 42%, was assessed. F-IVC was also correlated to the difference between cIVCSS and cIVCRC. RESULTS: cIVCRC ≥ 42% was 61.5% sensitive (95% CI, 31.58%-86.14%) and 67.1% specific (95% CI, 55.81%-77.06%) for predicting cIVCSS ≥ 42%. cIVCRC underestimated cIVCSS. The degree of discordance between cIVCRC and cIVCSS was proportional to the value of F-IVC. CONCLUSIONS: cIVCRC and cIVCSS measures are discordant, where cIVCRC underestimates cIVCSS. The degree of discordance is directly proportional to the value of F-IVC. Therefore, we recommend that cIVCRC ≥ 42% be used to rule in, but not to rule out, fluid responsivity. Wherever possible, F-IVC should be assessed to understand the clinical relevance of cIVCRC.