Infectious complications in out-of-hospital cardiac arrest patients in the therapeutic hypothermia era*:

PROACTIVE SCREENING ALGORITHM FOR EARLY-ONSET PNEUMONIA IN PATIENTS WITH OUT-OF-HOSPITAL CARDIAC ARREST: A BEFORE-AFTER IMPLEMENTATION STUDY

ABSTRACT

Introduction : Early-onset pneumonia (EOP) occurs in around 50% of critically ill patients with out-of-hospital cardiac arrest (OHCA) and is associated with increased morbidity. Prompt diagnosis of EOP in these patients is difficult because of targeted temperature management and the postcardiac arrest syndrome. We hypothesized that an algorithm for proactive screening of EOP would improve patient outcomes. Methods : We conducted a single-center observational study comparing the outcomes of mechanically ventilated adult patients with OHCA, before (study period 1) and after (study period 2) implementation of an algorithm for proactive diagnosis of EOP, including an early distal pulmonary specimen. An inverse probability treatment weighted multivariable regression was performed to identify independent parameters associated with duration of mechanical ventilation. A subgroup analysis was conducted in patients alive on day 5 after intensive care unit admission. Results : Over the 4-year study period, 190 patients (99 and 91 for study periods 1 and 2, respectively) were enrolled. The overall incidence of EOP was 57.4% and was similar between both study periods. Although there was no difference in the time interval to antibiotic initiation, study period 2 was independently associated with higher SpO 2 /FiO 2 ratios on days 3 and 4. We also observed a decrease in mechanical ventilation time in study period 2 (4.5 [1-11.3] vs. 3 [2-5.8] days; P = 0.07), and this reached statistical significance in the subgroup analysis of patients alive at day 5 (10 [5-17] vs. 5 [3-9] days, P = 0.01). Conclusion: In critically ill patients with OHCA, proactive diagnosis of EOP was not associated with a significant change in the time to antibiotic initiation. Further research is warranted to better define optimal diagnosis and management of EOP in this setting.

Can Biomarkers Correctly Predict Ventilator-associated Pneumonia in Patients Treated With Targeted Temperature Management After Cardiac Arrest? An Exploratory Study of the Multicenter Randomized Antibiotic (ANTHARTIC) Study

IMPORTANCE

Ventilator-associated pneumonia (VAP) frequently occurs in patients with cardiac arrest. Diagnosis of VAP after cardiac arrest remains challenging, while the use of current biomarkers such as C-reactive protein (CRP) or procalcitonin (PCT) is debated.

OBJECTIVES

To evaluate biomarkers' impact in helping VAP diagnosis after cardiac arrest.

DESIGN SETTING AND PARTICIPANTS

This is a prospective ancillary study of the randomized, multicenter, double-blind placebo-controlled ANtibiotherapy during Therapeutic HypothermiA to pRevenT Infectious Complications (ANTHARTIC) trial evaluating the impact of antibiotic prophylaxis to prevent VAP in out-of-hospital patients with cardiac arrest secondary to shockable rhythm and treated with therapeutic hypothermia. An adjudication committee blindly evaluated VAP according to predefined clinical, radiologic, and microbiological criteria. All patients with available biomarker(s), sample(s), and consent approval were included.

MAIN OUTCOMES AND MEASURES

The main endpoint was to evaluate the ability of biomarkers to correctly diagnose and predict VAP within 48 hours after sampling. The secondary endpoint was to study the combination of two biomarkers in discriminating VAP. Blood samples were collected at baseline on day 3. Routine and exploratory panel of inflammatory biomarkers measurements were blindly performed. Analyses were adjusted on the randomization group.

RESULTS

Among 161 patients of the ANTHARTIC trial with available biological sample(s), patients with VAP (n = 33) had higher body mass index and Acute Physiology and Chronic Health Evaluation II score, more unwitnessed cardiac arrest, more catecholamines, and experienced more prolonged therapeutic hypothermia duration than patients without VAP (n = 121). In univariate analyses, biomarkers significantly associated with VAP and showing an area under the curve (AUC) greater than 0.70 were CRP (AUC = 0.76), interleukin (IL) 17A and 17C (IL17C) (0.74), macrophage colony-stimulating factor 1 (0.73), PCT (0.72), and vascular endothelial growth factor A (VEGF-A) (0.71). Multivariate analysis combining novel biomarkers revealed several pairs with p value of less than 0.001 and odds ratio greater than 1: VEGF-A + IL12 subunit beta (IL12B), Fms-related tyrosine kinase 3 ligands (Flt3L) + C-C chemokine 20 (CCL20), Flt3L + IL17A, Flt3L + IL6, STAM-binding protein (STAMBP) + CCL20, STAMBP + IL6, CCL20 + 4EBP1, CCL20 + caspase-8 (CASP8), IL6 + 4EBP1, and IL6 + CASP8. Best AUCs were observed for CRP + IL6 (0.79), CRP + CCL20 (0.78), CRP + IL17A, and CRP + IL17C.

CONCLUSIONS AND RELEVANCE

Our exploratory study shows that specific biomarkers, especially CRP combined with IL6, could help to better diagnose or predict early VAP occurrence in cardiac arrest patients.

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.

Critical Care Management of Patients After Cardiac Arrest: A Scientific Statement from the American Heart Association and Neurocritical Care Society

The critical care management of patients after cardiac arrest is burdened by a lack of high-quality clinical studies and the resultant lack of high-certainty evidence. This results in limited practice guideline recommendations, which may lead to uncertainty and variability in management. Critical care management is crucial in patients after cardiac arrest and affects outcome. Although guidelines address some relevant topics (including temperature control and neurological prognostication of comatose survivors, 2 topics for which there are more robust clinical studies), many important subject areas have limited or nonexistent clinical studies, leading to the absence of guidelines or low-certainty evidence. The American Heart Association Emergency Cardiovascular Care Committee and the Neurocritical Care Society collaborated to address this gap by organizing an expert consensus panel and conference. Twenty-four experienced practitioners (including physicians, nurses, pharmacists, and a respiratory therapist) from multiple medical specialties, levels, institutions, and countries made up the panel. Topics were identified and prioritized by the panel and arranged by organ system to facilitate discussion, debate, and consensus building. Statements related to postarrest management were generated, and 80% agreement was required to approve a statement. Voting was anonymous and web based. Topics addressed include neurological, cardiac, pulmonary, hematological, infectious, gastrointestinal, endocrine, and general critical care management. Areas of uncertainty, areas for which no consensus was reached, and future research directions are also included. Until high-quality studies that inform practice guidelines in these areas are available, the expert panel consensus statements that are provided can advise clinicians on the critical care management of patients after cardiac arrest.

Critical Care Management of Patients After Cardiac Arrest: A Scientific Statement From the American Heart Association and Neurocritical Care Society

The critical care management of patients after cardiac arrest is burdened by a lack of high-quality clinical studies and the resultant lack of high-certainty evidence. This results in limited practice guideline recommendations, which may lead to uncertainty and variability in management. Critical care management is crucial in patients after cardiac arrest and affects outcome. Although guidelines address some relevant topics (including temperature control and neurological prognostication of comatose survivors, 2 topics for which there are more robust clinical studies), many important subject areas have limited or nonexistent clinical studies, leading to the absence of guidelines or low-certainty evidence. The American Heart Association Emergency Cardiovascular Care Committee and the Neurocritical Care Society collaborated to address this gap by organizing an expert consensus panel and conference. Twenty-four experienced practitioners (including physicians, nurses, pharmacists, and a respiratory therapist) from multiple medical specialties, levels, institutions, and countries made up the panel. Topics were identified and prioritized by the panel and arranged by organ system to facilitate discussion, debate, and consensus building. Statements related to postarrest management were generated, and 80% agreement was required to approve a statement. Voting was anonymous and web based. Topics addressed include neurological, cardiac, pulmonary, hematological, infectious, gastrointestinal, endocrine, and general critical care management. Areas of uncertainty, areas for which no consensus was reached, and future research directions are also included. Until high-quality studies that inform practice guidelines in these areas are available, the expert panel consensus statements that are provided can advise clinicians on the critical care management of patients after cardiac arrest.

Temperature Control After Cardiac Arrest: A Narrative Review

Cardiac arrest (CA) is a critical public health issue affecting more than half a million Americans annually. The main determinant of outcome post-CA is hypoxic-ischemic brain injury (HIBI), and temperature control is currently the only evidence-based, guideline-recommended intervention targeting secondary brain injury. Temperature control is a key component of a post-CA care bundle; however, conflicting evidence challenges its wide implementation across the vastly heterogeneous population of CA survivors. Here, we critically appraise the available literature on temperature control in HIBI, detail how the evidence has been integrated into clinical practice, and highlight the complications associated with its use and the timing of neuroprognostication after CA. Future clinical trials evaluating different temperature targets, rates of rewarming, duration of cooling, and identifying which patient phenotype benefits from different temperature control methods are needed to address these prevailing knowledge gaps.

Association Between Procalcitonin Level at 72 Hours After Cardiac Arrest and Neurological Outcomes in Cardiac Arrest Survivors

The association between procalcitonin (PCT) level measured 72 hours after cardiac arrest (CA) and neurological outcomes is unknown. We aimed to examine the association of serial PCT levels up to 72 hours with neurological outcomes in patients who underwent targeted temperature management (TTM) after CA. This retrospective observational study included adult comatose patients with CA undergoing TTM (33℃ for 24 hours) at the Chonnam National University Hospital in Gwangju, Korea, between January 2018 and December 2020. PCT levels were measured at admission and at 24, 48, and 72 hours after CA. The presence of early-onset infections (within 7 days after CA) was confirmed by reviewing clinical, radiological, and microbiological data. The primary outcome was poor neurological outcomes at 6 months and was defined by cerebral performance category 3-5. Among the CA survivors, 118 were included and 67 (56.8%) had poor neurological outcomes. The PCT level at 72 hours in the poor outcome group (3.01 [0.88-12.71]) was higher than that in good outcome group (0.56 [0.18-1.32]). The multivariate analysis revealed that the PCT level at 72 hours (adjusted odds ratio 1.241; 95% confidence interval, 1.059-1.455) was independently associated with poor neurological outcomes, showed good performance for poor outcomes (area under the receiver operating characteristic curve of 0.823), and was not associated with early-onset infections. The PCT level at 72 hours after CA can be helpful in predicting prognosis, and it did not correlate with early-onset infections in the study.

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

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

Pulmonary inflammatory response and immunomodulation to multiple trauma and hemorrhagic shock in pigs

BACKGROUND

Patients suffering from severe trauma experience substantial immunological stress. Lung injury is a known risk factor for the development of posttraumatic complications, but information on the long-term course of the pulmonary inflammatory response and treatment with mild hypothermia are scarce.

AIM

To investigate the pulmonary inflammatory response to multiple trauma and hemorrhagic shock in a porcine model of combined trauma and to assess the immunomodulatory properties of mild hypothermia.

METHODS

Following induction of trauma (blunt chest trauma, liver laceration, tibia fracture), two degrees of hemorrhagic shock (45 and 50%) over 90 (n = 30) and 120 min. (n = 20) were induced. Animals were randomized to hypothermia (33°C) or normothermia (38°C). We evaluated bronchoalveolar lavage (BAL) fluid and tissue levels of cytokines and investigated changes in microRNA- and gene-expression as well as tissue apoptosis.

RESULTS

We observed a significant induction of Interleukin (IL) 1β, IL-6, IL-8, and Cyclooxygenase-2 mRNA in lung tissue. Likewise, an increased IL-6 protein concentration could be detected in BAL-fluid, with a slight decrease of IL-6 protein in animals treated with hypothermia. Lower IL-10 protein levels in normothermia and higher IL-10 protein concentrations in hypothermia accompanied this trend. Tissue apoptosis increased after trauma. However, intervention with hypothermia did not result in a meaningful reduction of pro-inflammatory biomarkers or tissue apoptosis.

CONCLUSION

We observed signs of a time-dependent pulmonary inflammation and apoptosis at the site of severe trauma, and to a lower extent in the trauma-distant lung. Intervention with mild hypothermia had no considerable effect during 48 hours following trauma.

Sex-Based Differences in 30-Day Readmissions After Cardiac Arrest: Analysis of the Nationwide Readmissions Database

Background There are limited data on the sex-based differences in the outcome of readmission after cardiac arrest. Methods and Results Using the Nationwide Readmissions Database, we analyzed patients hospitalized with cardiac arrest between 2010 and 2015. Based on International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes, we identified comorbidities, therapeutic interventions, and outcomes. Multivariable logistic regression was performed to assess the independent association between sex and outcomes. Of 835 894 patients, 44.4% (n=371 455) were women, of whom 80.7% presented with pulseless electrical activity (PEA)/asystole. Women primarily presented with PEA/asystole (80.7% versus 72.4%) and had a greater comorbidity burden than men, as assessed using the Elixhauser Comorbidity Score. Thirty-day readmission rates were higher in women than men in both PEA/asystole (20.8% versus 19.6%) and ventricular tachycardia/ventricular fibrillation arrests (19.4% versus 17.1%). Among ventricular tachycardia/ventricular fibrillation arrest survivors, women were more likely than men to be readmitted because of noncardiac causes, predominantly infectious, respiratory, and gastrointestinal illnesses. Among PEA/asystole survivors, women were at higher risk for all-cause (adjusted odds ratio [aOR], 1.07; [95% CI, 1.03-1.11]), cardiac-cause (aOR, 1.15; [95% CI, 1.06-1.25]), and noncardiac-cause (aOR, 1.13; [95% CI, 1.04-1.22]) readmission. During the index hospitalization, women were less likely than men to receive therapeutic procedures, including coronary angiography and targeted therapeutic management. While the crude case fatality rate was higher in women, in both ventricular tachycardia/ventricular fibrillation (51.8% versus 47.4%) and PEA/asystole (69.3% versus 68.5%) arrests, sex was not independently associated with increased crude case fatality after adjusting for differences in baseline characteristics. Conclusions Women are at increased risk of readmission following cardiac arrest, independent of comorbidities and therapeutic interventions.

Association of multiple rib fractures with the frequency of pneumonia in the post-resuscitation period

Purpose

Successful cardiopulmonary resuscitation is associated with a high incidence of chest wall injuries. However, few studies have examined chest wall injury as a risk factor for respiratory complications after cardiopulmonary resuscitation. Therefore, herein, we investigated the association of multiple rib fractures on the incidence of post-resuscitation pneumonia.

Methods

This single-centre retrospective cohort study enrolled adult, nontraumatic, out-of-hospital cardiac arrest patients who maintained circulation for more than 48 h between June 2015 and May 2019. Rib fractures were evaluated by computed tomography on the day of hospital admission. The association with newly developed pneumonia within 7 days of hospitalisation was analysed using a Fine-Gray proportional hazards regression model adjusted for the propensity score of multiple rib fractures estimated from age, sex, presence of witnessed status, bystander CPR, initial rhythm, and total CPR time and for previously reported risk factors for pneumonia (therapeutic hypothermia and prophylactic antibiotics).

Results

Overall, 683 patients with out-of-hospital cardiac arrest were treated; 87 eligible cases were enrolled for analysis. Thirty-two (36.8%) patients had multiple rib fractures identified on computed tomography, and 35 (40.2%) patients developed pneumonia. The presence of multiple rib fractures was significantly associated with a higher incidence of pneumonia, consistently both with and without adjustment for background factors (unadjusted hazard ratio 4.63, 95% confidence interval: 2.35–9.13, p < 0.001; adjusted hazard ratio 4.03, 95% confidence interval: 2.08–7.82, p < 0.001).

Conclusions

Multiple rib fractures are independently associated with the development of pneumonia after successful resuscitation.

The immunology of the post-cardiac arrest syndrome

Patients successfully resuscitated from cardiac arrest often have brain injury, myocardial dysfunction, and systemic ischemia-reperfusion injury, collectively termed the post-cardiac arrest syndrome (PCAS). To improve outcomes, potential therapies must be able to be administered early in the post-arrest course and provide broad cytoprotection, as ischemia-reperfusion injury affects all organ systems. Our understanding of the immune system contributions to the PCAS has expanded, with animal models detailing biologically plausible mechanisms of secondary injury, the protective effects of available immunomodulatory drugs, and how immune dysregulation underlies infection susceptibility after arrest. In this narrative review, we discuss the dysregulated immune response in PCAS, human trials of targeted immunomodulation therapies, and future directions for immunomodulation following cardiac arrest.

Salivary Alpha Amylase Bronchial Measure for Early Aspiration Pneumonia Diagnosis in Patients Treated With Therapeutic Hypothermia After Out-of-hospital Cardiac Arrest

Background

Aspiration pneumonia is the most common respiratory complication following out-of-hospital cardiac arrests (OHCA). Alpha-amylase (α-amylase) in pulmonary secretions is a biomarker of interest in detecting inhalation. The main goal of this study is to evaluate the performance of bronchoalveolar levels of α-amylase in early diagnosis of aspiration pneumonia, in patients admitted to intensive care unit (ICU) after OHCA.

Methods

This is a prospective single-center trial, led during 5 years (July 2015 to September 2020). We included patients admitted to ICU after OHCA. A protected specimen bronchial brushing and a mini-bronchoalveolar lavage (mini-BAL) were collected during the first 6 h after admission. Dosage of bronchial α-amylase and standard bacterial analysis were performed. Investigators confirmed pneumonia diagnosis using clinical, radiological, and microbiological criteria. Every patient underwent targeted temperature management.

Results

88 patients were included. The 34% (30 patients) developed aspiration pneumonia within 5 days following admission. The 55% (17) of pneumonias occurred during the first 48 h. The 57% of the patients received a prophylactic antibiotic treatment on their admission day. ICU mortality was 50%. Median value of bronchial α-amylase did not differ whether patients had aspiration pneumonia (15 [0–94]) or not (3 [0–61], p = 0,157). Values were significantly different concerning early-onset pneumonia (within 48 h) [19 (7–297) vs. 3 (0–82), p = 0,047]. If one or more microorganisms were detected in the initial mini-BAL, median value of α-amylase was significantly higher [25 (2–230)] than in sterile cultures (2 [0–43], p = 0,007). With an 8.5 IU/L cut-point, sensitivity and specificity of α-amylase value for predicting aspiration pneumonia during the first 2 days were respectively 74 and 62%. True positive and negative rates were respectively 44 and 86%. The area under the ROC curve was 0,654 (CI 95%; 0,524–0,785). Mechanical ventilation duration, length of ICU stay, and mortality were similar in both groups.

Conclusion

In our study, dosage of bronchial α-amylase was not useful in predicting aspiration pneumonia within the first 5 days after ICU admission for OHCA. Performance in predicting early-onset pneumonia was moderate.

Increased risk of ventilator-associated pneumonia in patients after cardiac arrest treated with mild therapeutic hypothermia

Background

We aimed at investigating the incidence, characteristics and outcome of ventilator‐associated pneumonia (VAP) in patients after cardiac arrest (CA) and its potential association with mild therapeutic hypothermia (MTH). We hypothesized, that MTH might increase the risk of VAP.

Methods

Prospective observational study including comatose adult patients after successful resuscitation from out‐of‐hospital or in‐hospital CA with presumed cardiac cause admitted to ICU and treated with MTH at 33°C for 24 h or normothermia (NT) with treatment of fever ≥38°C by pharmacological means. The primary outcome measure was the development of VAP. VAP diagnosis included mechanical ventilation >48 h combined with clinical and radiologic criteria. For a microbiologically confirmed VAP (mcVAP), a positive respiratory culture was required.

Results

About 23% of 171 patients developed VAP, 6% presented with mcVAP. VAP was associated with increased ICU‐LOS (9 (IQR 5–14) vs. 6 (IQR 3–9) days; p < .01), ventilator‐dependent days (6 (IQR 4–9) vs. 4 (IQR 2–7) days; p < .01) and duration of antibiotic treatment (9 (IQR 5–13) vs. 5 (IQR 2–9) days; p < .01), but not with mortality (OR 0.88 (95% CI: 0.43–1.81); p = .74). Patients treated with MTH (47%) presented higher VAP (30% vs. 17%; p = .04) and mcVAP rates (11% vs. 2%; p = .03). MTH was associated with VAP in multivariable logistic regression analysis with an OR of 2.67 (95% CI: 1.22–5.86); p = .01.

Conclusions

VAP appears to be a common complication in patients after CA, accompanied by more ventilator‐dependent days, prolonged antibiotic treatment, and ICU‐LOS. Treatment with MTH is significantly associated with development of VAP.

Study of risk factors for healthcare-associated infections in acute cardiac patients using categorical principal component analysis (CATPCA)

Using categorical principal component analysis, we aimed to determine the relationship between health care-associated infections (HAIs) and diagnostic categories (DCs) in patients with acute heart disease using data collected in the Spanish prospective ENVIN-HELICS intensive care registry over a 10-year period (2005–2015). A total of 69,876 admissions were included, of which 5597 developed HAIs. Two 2-component CATPCA models were developed. In the first model, all cases were included; the first component was determined by the duration of the invasive devices, the ICU stay, the APACHE II score and the HAIs; the second component was determined by the type of admission (medical or surgical) and by the DCs. No clear association between DCs and HAIs was found. Cronbach’s alpha was 0.899, and the variance accounted for (VAF) was 52.5%. The second model included only admissions that developed HAIs; the first component was determined by the duration of the invasive devices and the ICU stay; the second component was determined by the inflammatory response, the mortality in the ICU and the HAIs. Cronbach’s alpha value was 0.855, and VAF was 46.9%. These findings highlight the role of exposure to invasive devices in the development of HAIS in patients with acute heart disease.

Chest wall injuries due to cardiopulmonary resuscitation and the effect on in-hospital outcomes in survivors of out-of-hospital cardiac arrest

BACKGROUND

This study aimed to assess the prevalence of chest wall injuries due to cardiopulmonary resuscitation for out-of-hospital cardiac arrest (OHCA) and to compare in-hospital outcomes in patients with versus without chest wall injuries.

METHODS

A retrospective cohort study of all intensive care unit (ICU)-admitted patients who underwent cardiopulmonary resuscitation for OHCA between January 1, 2007, and December 2019 was performed. The primary outcome was the occurrence of chest wall injuries, as diagnosed on chest computed tomography. Chest wall injury characteristics such as rib fracture location, type, and dislocation were collected. Secondary outcomes were in-hospital outcomes and subgroup analysis of patients with good neurological recovery to identify those who could possibly benefit from the surgical stabilization of rib fractures.

RESULTS

Three hundred forty-four patients were included, of which 291 (85%) sustained chest wall injury. Patients with chest wall injury had a median of 8 fractured ribs (P25-P75, 4-10 ribs), which were most often undisplaced (on chest computed tomography) (n = 1,574 [72.1%]), simple (n = 1,948 [89.2%]), and anterior (n = 1,785 [77.6%]) rib fractures of ribs 2 to 7. Eight patients (2.3%) had a flail segment, and 136 patients (39.5%) had an anterior flail segment. Patients with chest wall injury had fewer ventilator-free days (0 days [P25-P75, 0-16 days] vs. 13 days [P25-P75, 2-22 days]; p = 0.006) and a higher mortality rate (n = 102 [54.0%] vs. n = 8 [22.2%]; p < 0.001) than those without chest wall injury. For the subgroup of patients with good neurological recovery, the presence of six or more rib fractures or a single displaced rib fracture was associated with longer hospital and ICU length of stay, respectively.

CONCLUSION

Cardiopulmonary resuscitation-related chest wall injuries in survivors of OHCA and especially rib fractures are common. Patients with chest wall injury had fewer ventilator-free days and a higher mortality rate. Patients with good neurological recovery might represent a subgroup of patients who could benefit from surgical stabilization of rib fractures.

LEVEL OF EVIDENCE

Therapeutic, level IV; Epidemiological, Level IV.

The prevalence of bacteremia in out of hospital cardiac arrest patients presenting to the emergency department of a tertiary care hospital

BACKGROUND

Out-of-hospital cardiac arrest (OHCA) remains one of the most common causes of death. There is a scarcity of evidence concerning the prevalence of bacteraemia in cardiac arrest patients presenting to the Emergency Department (ED). We aimed to determine the prevalence of bacteraemia in OHCA patients presenting to the ED, as well as study the association between bacteraemia and in-hospital mortality in OHCA patients. In addition, the association between antibiotic use during resuscitation and in-hospital mortality was examined.

METHODS AND RESULTS

This was a study of 200 adult OHCA patients who presented to the ED between 2015 and 2019. Bacteraemia was confirmed if at least one of the blood culture bottles grew a non-skin flora pathogen or if two blood culture bottles grew a skin flora pathogen from two different sites. The prevalence of bacteraemia was 46.5%. Gram positive bacteria, specifically Staphylococcus species, were the most common pathogens isolated from the bacteremic group. 42 patients survived to hospital admission. The multivariate analysis revealed that there was no association between bacteraemia and hospital mortality in OHCA patients (OR = 1.3, 95% CI= 0.2-9.2) with a p-value of .8. There was no association between antibiotic administration during resuscitation and hospital mortality (OR = 0.6, 95% CI= 0.1 - 3.8) with a p-value of .6.

CONCLUSION

In our study, the prevalence of bacteraemia among OHCA patients presenting to the ED was found to be 46.5%. Bacteremic and non-bacteremic OHCA patients had similar initial baseline characteristics and laboratory parameters except for higher serum creatinine and BUN in the bacteremic group. In OHCA patients who survived their ED stay there was no association between hospital mortality and bacteraemia or antibiotic administration during resuscitation. There is a need for randomised controlled trials with a strong patient oriented primary outcome to better understand the association between in-hospital mortality and bacteraemia or antibiotic administration in OHCA patients.KEY MESSAGESWe aimed to determine the prevalence of bacteraemia in OHCA patients presenting to the Emergency Department. In our study, we found that 46.5% of patients presenting to our ED with OHCA were bacteremic.Bacteremic and non-bacteremic OHCA patients had similar initial baseline characteristics and laboratory parameters except for higher serum creatinine and BUN in the bacteremic group.We found no association between bacteraemia and hospital mortality. There was no association between antibiotic administration during resuscitation and hospital mortality.There is a need for randomised controlled trials with a strong patient oriented primary outcome to better understand the association between in-hospital mortality and bacteraemia or antibiotic administration in OHCA patients.

Blood Cultures and Appropriate Antimicrobial Administration after Achieving Sustained Return of Spontaneous Circulation in Adults with Nontraumatic Out-of-Hospital Cardiac Arrest

We aimed to determine the incidence of bacteremia and prognostic effects of prompt administration of appropriate antimicrobial therapy (AAT) on nontraumatic out-of-hospital cardiac arrest (OHCA) patients achieving a sustained return of spontaneous circulation (sROSC), compared with non-OHCA patients. In the multicenter case-control study, nontraumatic OHCA adults with bacteremia episodes after achieving sROSC were defined as case patients, and non-OHCA patients with community-onset bacteremia in the emergency department were regarded as control patients. Initially, case patients had a higher bacteremia incidence than non-OHCA visits (231/2171, 10.6% vs. 10,430/314,620, 3.3%; p < 0.001). Compared with the matched control (2288) patients, case (231) patients experienced more bacteremic episodes due to low respiratory tract infections, fewer urosepsis events, fewer Escherichia coli bacteremia, and more streptococcal and anaerobes bacteremia. Antimicrobial-resistant organisms, such as methicillin-resistant Staphylococcus aureus and extended-spectrum beta-lactamase-producing Enterobacteriaceae, were frequently evident in case patients. Notably, each hour delay in AAT administration was associated with an average increase of 10.6% in crude 30-day mortality rates in case patients, 0.7% in critically ill control patients, and 0.3% in less critically ill control patients. Conclusively, the incidence and characteristics of bacteremia differed between the nontraumatic OHCA and non-OHCA patients. The incorporation of blood culture samplings and rapid AAT administration as first-aids is essential for nontraumatic OHCA patients after achieving sROSC.

Diagnostic yield of routine daily blood culture in patients on veno-arterial extracorporeal membrane oxygenation

BACKGROUND

Bloodstream infections (BSIs) are frequent on veno-arterial extracorporeal membrane oxygenation (V-A ECMO). Performing routine blood cultures (BCs) may identify early paucisymptomatic BSIs. We investigated the contribution of systematic daily BCs to detect BSIs on V-A ECMO.

METHODS

This was a retrospective study including all adult patients requiring V-A ECMO and surviving more than 24 h. Our protocol included routine daily BCs, from V-A ECMO insertion up to 5 days after withdrawal; other BCs were performed on-demand.

RESULTS

On the 150 V-A ECMO included, 2146 BCs were performed (1162 routine and 984 on-demand BCs); 190 (9%) were positive, including 68 contaminants. Fifty-one (4%) routine BCs revealed BSIs; meanwhile, 71 (7%) on-demand BCs revealed BSIs (p = 0.005). Performing routine BCs was negatively associated with BSIs diagnosis (OR 0.55, 95% CI [0.38; 0.81], p = 0.002). However, 16 (31%) BSIs diagnosed by routine BCs would have been missed by on-demand BCs. Independent variables for BSIs diagnosis after routine BCs were: V-A ECMO for cardiac graft failure (OR 2.43, 95% CI [1.20; 4.92], p = 0.013) and sampling with on-going antimicrobial therapy (OR 2.15, 95% CI [1.08; 4.27], p = 0.029) or renal replacement therapy (OR 2.05, 95% CI [1.10; 3.81], p = 0.008). Without these three conditions, only two BSIs diagnosed with routine BCs would have been missed by on-demand BCs sampling.

CONCLUSIONS

Although routine daily BCs are less effective than on-demand BCs and expose to contamination and inappropriate antimicrobial therapy, a policy restricted to on-demand BCs would omit a significant proportion of BSIs. This argues for a tailored approach to routine daily BCs on V-A ECMO, based on risk factors for positivity.

Opioid-Associated Out-of-Hospital Cardiac Arrest: Distinctive Clinical Features and Implications for Health Care and Public Responses: A Scientific Statement From the American Heart Association

Opioid overdose is the leading cause of death for Americans 25 to 64 years of age, and opioid use disorder affects >2 million Americans. The epidemiology of opioid-associated out-of-hospital cardiac arrest in the United States is changing rapidly, with exponential increases in death resulting from synthetic opioids and linear increases in heroin deaths more than offsetting modest reductions in deaths from prescription opioids. The pathophysiology of polysubstance toxidromes involving opioids, asphyxial death, and prolonged hypoxemia leading to global ischemia (cardiac arrest) differs from that of sudden cardiac arrest. People who use opioids may also develop bacteremia, central nervous system vasculitis and leukoencephalopathy, torsades de pointes, pulmonary vasculopathy, and pulmonary edema. Emergency management of opioid poisoning requires recognition by the lay public or emergency dispatchers, prompt emergency response, and effective ventilation coupled to compressions in the setting of opioid-associated out-of-hospital cardiac arrest. Effective ventilation is challenging to teach, whereas naloxone, an opioid antagonist, can be administered by emergency medical personnel, trained laypeople, and the general public with dispatcher instruction to prevent cardiac arrest. Opioid education and naloxone distributions programs have been developed to teach people who are likely to encounter a person with opioid poisoning how to administer naloxone, deliver high-quality compressions, and perform rescue breathing. Current American Heart Association recommendations call for laypeople and others who cannot reliably establish the presence of a pulse to initiate cardiopulmonary resuscitation in any individual who is unconscious and not breathing normally; if opioid overdose is suspected, naloxone should also be administered. Secondary prevention, including counseling, opioid overdose education with take-home naloxone, and medication for opioid use disorder, is important to prevent recurrent opioid overdose.

Necessity of early and continuous monitoring for possible infectious complications in children undergoing therapeutic hypothermia

AIM

Since therapeutic hypothermia (TH) is known for its inhibitory effects on leucocyte migration and cytokine synthesis, our aim was to underline the necessity of early monitoring for potential immunomodulatory risks.

METHODS

Using a 13-year retrospective case-control study at the paediatric intensive care unit (PICU) of the Medical University in Vienna, all newborn infants and children receiving TH were screened and compared with a diagnosis-matched control group undergoing conventional normothermic treatment (NT). TH was accomplished by using a non-invasive cooling device. Target temperature was 32-34°C. Children with evident infections, a medical history of an immunodeficiency or undergoing immunosuppressive therapy, were excluded.

RESULTS

During the observational period, 108 patients were screened, 27 of which underwent TH. Culture-proven infections occurred in 22% of the TH group compared with 4% of the normothermic controls (P = .1). From the second day following PICU admission, median C-reactive protein (CRP) values were higher in the TH group (day two P = .002, day three P = .0002, day six P = .008).

CONCLUSION

Children undergoing TH showed earlier and higher increases in CRP levels when compared to normothermic controls. These data underline the necessity of early and continuous monitoring for possible infectious complications.

Cheap and simple, could it get even cooler? Mild hypothermia and COVID-19

Purpose

The pathophysiology theories of COVID-19 attach the injury of target organs to faulty immune responses and occasionally hyper-inflammation. The damage frequently extends beyond the respiratory system, accompanying cardiovascular, renal, central nervous system, and/or coagulation derangements. Tumor necrosis factor-α (TNF-α) and interleukins (IL)-1 and − 6 suppression may improve outcomes, as experimentally shown. Targeted therapies have been proposed, but mild therapeutic hypothermia—a more multifaceted approach—could be suitable.

Findings

According to evidence derived from previous applications, therapeutic hypothermia diminishes the release of IL-1, IL-6, and TNF-α in serum and at the tissue level. PaCO2 is reduced and the PaO2/FiO2 ratio is increased, possibly lasting after rewarming. Cooling might mitigate both ventilator and infectious-induced lung injury, and suppress microthrombi development, enhancing V/Q mismatch. Improvements in microhemodynamics and tissue O2 diffusion, along with the ischemia-tolerance heightening of tissues, could be reached. Arrhythmia incidence diminishes. Moreover, hypothermia may address the coagulopathy, promoting normalization of both hypo- and hyper-coagulability patterns, which are apparently sustained after a return to normothermia.

Conclusions

As per prior therapeutic hypothermia literature, the benefits regarding inflammatory response and organic damage might be seen. Following the safety-cornerstones of the technique, the overall infection rate and infection-related mortality are not expected to rise, and increased viral replication does not seem to be a concern. Therefore, the possibility of a low cost and widely available therapy being capable of improving COVID-19 outcomes deserves further study.

Post-cardiac arrest care and targeted temperature management: A consensus of scientific statement from the Taiwan Society of Emergency & Critical Care Medicine, Taiwan Society of Critical Care Medicine and Taiwan Society of Emergency Medicine

BACKGROUND

Post-cardiac arrest care is critically important in bringing cardiac arrest patients to functional recovery after the detrimental event. More high quality studies are published and evidence is accumulated for the post-cardiac arrest care in the recent years. It is still a challenge for the clinicians to integrate these scientific data into the real clinical practice for such a complicated intensive care involving many different disciplines.

METHODS

With the cooperation of the experienced experts from all disciplines relevant to post-cardiac arrest care, the consensus of the scientific statement was generated and supported by three major scientific groups for emergency and critical care in post-cardiac arrest care.

RESULTS

High quality post-cardiac arrest care, including targeted temperature management, early evaluation of possible acute coronary event and intensive care for hemodynamic and respiratory care are inevitably needed to get full recovery for cardiac arrest. Management of these critical issues were reviewed and proposed in the consensus CONCLUSION: The goal of the statement is to provide help for the clinical physician to achieve better quality and evidence-based care in post-cardiac arrest period.

Pathophysiology and clinical consequences of arterial blood gases and pH after cardiac arrest

Post cardiac arrest syndrome is associated with high morbidity and mortality, which is related not only to a poor neurological outcome but also to respiratory and cardiovascular dysfunctions. The control of gas exchange, and in particular oxygenation and carbon dioxide levels, is fundamental in mechanically ventilated patients after resuscitation, as arterial blood gases derangement might have important effects on the cerebral blood flow and systemic physiology.

In particular, the pathophysiological role of carbon dioxide (CO₂) levels is strongly underestimated, as its alterations quickly affect also the changes of intracellular pH, and consequently influence metabolic energy and oxygen demand. Hypo/hypercapnia, as well as mechanical ventilation during and after resuscitation, can affect CO₂ levels and trigger a dangerous pathophysiological vicious circle related to the relationship between pH, cellular demand, and catecholamine levels. The developing hypocapnia can nullify the beneficial effects of the hypothermia. The aim of this review was to describe the pathophysiology and clinical consequences of arterial blood gases and pH after cardiac arrest.

According to our findings, the optimal ventilator strategies in post cardiac arrest patients are not fully understood, and oxygen and carbon dioxide targets should take in consideration a complex pattern of pathophysiological factors. Further studies are warranted to define the optimal settings of mechanical ventilation in patients after cardiac arrest.

Post-resuscitation shock: recent advances in pathophysiology and treatment

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

Targeted Temperature Management at 33 Versus 36 Degrees: A Retrospective Cohort Study

OBJECTIVES

To determine the association between targeted temperature management goal temperature of 33°C versus 36°C and neurologic outcome after out-of-hospital cardiac arrest.

DESIGN

This was a retrospective, before-and-after, cohort study.

SETTING

Urban, academic, level 1 trauma center from 2010 to 2017.

PATIENTS

Adults with nontraumatic out-of-hospital cardiac arrest who received targeted temperature management.

INTERVENTIONS

Our primary exposure was targeted temperature management goal temperature, which was changed from 33°C to 36°C in April of 2014 at the study hospital. Primary outcome was neurologically intact survival to discharge. Secondary outcomes included hospital mortality and care processes.

MEASUREMENTS AND MAIN RESULTS

Of 782 out-of-hospital cardiac arrest patients transported to the study hospital, 453 (58%) received targeted temperature management. Of these, 258 (57%) were treated during the 33°C period (targeted temperature management 33°C) and 195 (43%) were treated during the 36°C period (targeted temperature management 36°C). Patients treated during targeted temperature management 33°C were older (57 vs 52 yr; p < 0.05) and had more arrests of cardiac etiology (45% vs 35%; p < 0.05), but otherwise had similar baseline characteristics, including initial cardiac rhythm. A total of 40% of patients treated during targeted temperature management 33°C survived with favorable neurologic outcome, compared with 30% in the targeted temperature management 36°C group (p < 0.05). After adjustment for demographic and cardiac arrest characteristics, targeted temperature management 33°C was associated with increased odds of neurologically intact survival to discharge (odds ratio, 1.79; 95% CI, 1.09-2.94). Targeted temperature management 33°C was not associated with significantly improved hospital mortality. Targeted temperature management was implemented faster (1.9 vs 3.5 hr from 911 call; p < 0.001) and more frequently in the emergency department during the targeted temperature management 33°C period (87% vs 55%; p < 0.001).

CONCLUSIONS

Comatose, adult out-of-hospital cardiac arrest patients treated during the targeted temperature management 33°C period had higher odds of neurologically intact survival to hospital discharge compared with those treated during the targeted temperature management 36°C period. There was no significant difference in hospital mortality.

Infections in out-of-hospital and in-hospital post-cardiac arrest patients

This study aims to describe infectious complications in both out-of-hospital cardiac arrest (OHCA) and in-hospital cardiac arrest (IHCA) patients with sustained return of spontaneous circulation (ROSC) and to compare differences in antimicrobial treatment and outcomes between the two groups. This was a retrospective, single-center, observational study. Adult patients (≥ 18 years) with OHCA or IHCA who had sustained ROSC between December 2007 to March 2015 were included. Blood, urine, sputum, and other fluid cultures, as well as radiologic imaging, were obtained at the discretion of the treating clinical teams. 275 IHCA and 318 OHCA patients were included in the analysis. We found evidence of infection in 181 IHCA and 168 OHCA patients. Significant differences were found between the IHCA and OHCA group in terms of initial rhythm, duration of arrest (10 min vs. 20, p = < 0.001), targeted temperature management (30% vs. 73%, p = < 0.001), and post-arrest infection rates (66% vs 53%, p = 0.001). 95% of IHCA and 82% of OHCA patients received antimicrobial treatment in the post-cardiac arrest period. The source of infection in both groups was largely respiratory, followed by urinary. Gram-positive cocci and gram-negative rods were the most common organisms identified among subjects with culture-proven bacteremia. Infections in the post-arrest period were common in both OHCA and IHCA. We found significantly more infections in IHCA compared to OHCA patients. The most common infection category was respiratory and the most common organism isolated from sputum cultures was Staphylococcus aureus coagulase-positive. The incidence of culture-positive bacteremia was similar in both OHCA and IHCA cohorts but overall lower than previously reported.

State-of-the-art considerations in post-arrest care

Cardiac arrest has a high rate of morbidity and mortality. Several advances in post-cardiac arrest management can improve outcome, but are time-dependent, placing the emergency physician in a critical role to both recognize the need for and initiate therapy. We present a novel perspective of both the workup and therapeutic interventions geared toward the emergency physician during the first few hours of care. We describe how the immediate care of a post-cardiac arrest patient is resource intensive and requires simultaneous evaluation for the underlying cause and intensive management to prevent further end organ damage, particularly of the central nervous system. The goal of the initial focused assessment is to rapidly determine if any reversible causes of cardiac arrest are present and to intervene when possible. Interventions performed in this acute period are aimed at preventing additional brain injury through optimizing hemodynamics, providing ventilatory support, and by using therapeutic hypothermia when indicated. After the initial phase of care, disposition is guided by available resources and the clinician's judgment. Transfer to a specialized cardiac arrest center is prudent in centers that do not have significant support or experience in the care of these patients.

Presepsin As a Biomarker for Evaluating Prognosis and Early Innate Immune Response of Out-of-Hospital Cardiac Arrest Patients After Return of Spontaneous Circulation

OBJECTIVES

After return of spontaneous circulation, patients who experienced out-of-hospital cardiac arrest present an impaired innate immune response that resembles sepsis. Presepsin, a new biomarker for sepsis, has not been studied in out-of-hospital cardiac arrest patients. This study explored the role of presepsin in evaluating the prognosis and early innate immune alteration of out-of-hospital cardiac arrest patients after return of spontaneous circulation by observing presepsin levels, CD14, and human leukocyte antigen-DR expression on monocytes.

DESIGN

Retrospective analysis.

SETTING

The emergency department of an urban university tertiary hospital.

PARTICIPANTS

One hundred sixty-five out-of-hospital cardiac arrest patients with return of spontaneous circulation more than 12 hours, and 100 healthy individuals.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Plasma presepsin and procalcitonin levels were tested after resuscitation (day 0) and on days 1 and 3 after return of spontaneous circulation. Presepsin levels were higher in out-of-hospital cardiac arrest patients than in healthy individuals. In the first 3 days, presepsin and procalcitonin levels were persistently lower in 28-day survivors and patients with favorable neurologic outcome patients than in 28-day nonsurvivors and patients with unfavorable neurologic outcome. On days 0, 1, and 3, different cut-off values of presepsin showed prognostic value for 28-day mortality and favorable neurologic outcomes similar to procalcitonin. CD14 and human leukocyte antigen-DR expression on monocytes were analyzed by flow cytometry. Compared with controls, CD14 expression in out-of-hospital cardiac arrest patients increased on day 1 and began to decrease on day 3, whereas human leukocyte antigen-DR+ monocyte percentages decreased on days 1 and 3. Presepsin and procalcitonin had a low positive correlation with CD14 expression and a strong negative correlation with human leukocyte antigen-DR+ monocyte percentages on day 1.

CONCLUSIONS

Plasma presepsin concentrations are independent prognostic factors for out-of-hospital cardiac arrest patients after return of spontaneous circulation and are correlated with abnormal CD14 and human leukocyte antigen-DR expression on monocytes. Monitoring presepsin levels may be helpful for evaluating the prognosis and impaired innate immune response in the early period after return of spontaneous circulation.

Microbiological profile of nosocomial infections following cardiac arrest: Insights from the targeted temperature management (TTM) trial

AIMS

Infectious complications frequently occur in intensive care unit patients admitted after out-of-hospital cardiac arrest. There is debate on the effects of temperature management on the incidence of infections, as well as on the efficacy and choice of antibiotic prophylaxis. In this substudy of the targeted temperature management (TTM) trial, we describe the microbiological profile of infectious complications in patients with cardiac arrest and examined the impact of TTM at 33 °C compared to TTM at 36 °C. Furthermore we aimed to determine the association between antibiotic prophylaxis and the incidence of infections.

METHODS

This is a posthoc analysis of the TTM cohort. Microbiological data was retrospectively collected for the first 14-days of ICU-admission. Logistic regression was used to determine the relationship between antibiotic prophylaxis and pneumonia adjusted for mortality.

RESULTS

Of 696 patients included in this analysis, 158 (23%) developed pneumonia and 28 (4%) had bacteremia with a clinically relevant pathogen. Staphylococcus aureus was the most common pathogen isolated in patients with pneumonia (23%) and in patients with bacteremia (24%). Gram-negative pathogens were most common overall. TTM did not have an impact on the microbiological profile. The use of antibiotic prophylaxis was significantly associated with a reduced risk of infection (OR 0.59, 95%CI 0.43-0.79, p = 0.0005). This association remained significant after correcting for confounders (OR 0.64, 95%CI 0.46-0.90; p = 0.01). The association is not present in a model after correction for clustering within centers (aOR 0.55, 95%CI 0.20-1.47, p = 0.22). Adjustment for mortality did not influence the outcome.

CONCLUSION

Gram-negative pathogens are the most common causes of nosocomial infections following cardiac arrest. TTM does not impact the microbiological profile. It remains unclear whether patients in ICUs using antibiotic prophylaxis have a reduced risk of pneumonia and bacteremia that is unrelated to center effects.

Acute respiratory failure and inflammatory response after out-of-hospital cardiac arrest: results of the Post-Cardiac Arrest Syndrome (PCAS) pilot study

BACKGROUND

Although the lungs are potentially highly susceptible to post-cardiac arrest syndrome injury, the issue of acute respiratory failure after out-of-hospital cardiac arrest has not been investigated. The objectives of this analysis were to determine the prevalence of acute respiratory failure after out-of-hospital cardiac arrest, its association with post-cardiac arrest syndrome inflammatory response and to clarify its importance for early mortality.

METHODS

The Post-Cardiac Arrest Syndrome (PCAS) pilot study was a prospective, observational, six-centre project (Poland 2, Denmark 1, Spain 1, Italy 1, UK 1), studying patients resuscitated after out-of-hospital cardiac arrest of cardiac origin. Primary outcomes were: (a) the profile of organ failure within the first 72 hours after out-of-hospital cardiac arrest; (b) in-hospital and short-term mortality, up to 30 days of follow-up. Respiratory failure was defined using a modified version of the Berlin acute respiratory distress syndrome definition. Inflammatory response was defined using leukocytes (white blood cells), platelet count and C-reactive protein concentration. All parameters were assessed every 24 hours, from admission until 72 hours of stay.

RESULTS

Overall, 148 patients (age 62.9±15.27 years; 27.7% women) were included. Acute respiratory failure was noted in between 50 (33.8%) and 75 (50.7%) patients over the first 72 hours. In-hospital and short-term mortality was 68 (46.9%) and 72 (48.6%), respectively. Inflammation was significantly associated with the risk of acute respiratory failure, with the highest cumulative odds ratio of 748 at 72 hours (C-reactive protein 1.035 (1.001-1.070); 0.043, white blood cells 1.086 (1.039-1.136); 0.001, platelets 1.004 (1.001-1.007); <0.005). Early acute respiratory failure was related to in-hospital mortality (3.172, 95% confidence interval 1.496-6.725; 0.002) and to short-term mortality (3.335 (1.815-6.129); 0.0001).

CONCLUSIONS

An inflammatory response is significantly associated with acute respiratory failure early after out-of-hospital cardiac arrest. Acute respiratory failure is associated with a worse early prognosis after out-of-hospital cardiac arrest.

Postresuscitation Care after Out-of-hospital Cardiac Arrest: Clinical Update and Focus on Targeted Temperature Management

Out-of-hospital cardiac arrest is a major cause of mortality and morbidity worldwide. With the introduction of targeted temperature management more than a decade ago, postresuscitation care has attracted increased attention. In the present review, we discuss best practice hospital management of unconscious out-of-hospital cardiac arrest patients with a special focus on targeted temperature management. What is termed post-cardiac arrest syndrome strikes all organs and mandates access to specialized intensive care. All patients need a secured airway, and most patients need hemodynamic support with fluids and/or vasopressors. Furthermore, immediate coronary angiography and percutaneous coronary intervention, when indicated, has become an essential part of the postresuscitation treatment. Targeted temperature management with controlled sedation and mechanical ventilation is the most important neuroprotective strategy to take. Targeted temperature management should be initiated as quickly as possible, and according to international guidelines, it should be maintained at 32° to 36°C for at least 24 h, whereas rewarming should not increase more than 0.5°C per hour. However, uncertainty remains regarding targeted temperature management components, warranting further research into the optimal cooling rate, target temperature, duration of cooling, and the rewarming rate. Moreover, targeted temperature management is linked to some adverse effects. The risk of infection and bleeding is moderately increased, as is the risk of hypokalemia and magnesemia. Circulation needs to be monitored invasively and any deviances corrected in a timely fashion. Outcome prediction in the individual patient is challenging, and a self-fulfilling prophecy poses a real threat to early prognostication based on clinical assessment alone. Therefore, delayed and multimodal prognostication is now considered a key element of postresuscitation care. Finally, modern postresuscitation care can produce good outcomes in the majority of patients but requires major diagnostic and therapeutic resources and specific training. Hence, recent international guidelines strongly recommend the implementation of regional prehospital resuscitation systems with integrated and specialized cardiac arrest centers.

Pneumonia and Extracorporeal Cardiopulmonary Resuscitation Followed by Targeted Temperature Management in Patients With Out-of-Hospital Cardiac Arrest - Retrospective Cohort Study

Background: We examined the association between initiation of extracorporeal cardiopulmonary resuscitation (ECPR) and the incidence of infectious complications, such as pneumonia, sepsis, and bacteremia, after out-of-hospital cardiac arrest (OHCA) in patients who received targeted temperature management (TTM). Methods and Results: This retrospective study used data from hospital medical records of patients with OHCA treated with TTM who had been admitted to St. Luke's International Hospital between April 2006 and December 2018. The primary endpoint was the association between the type of CPR and the incidence of early onset pneumonia in the intensive care unit (ICU; between 48 h and 7 days of hospitalization). Univariate and multivariate logistic regression analyses were performed for the primary endpoints. After applying the inclusion/exclusion criteria, 254 patients were included in the analyses; of these, 52 were enrolled in the ECPR group, and 202 were enrolled in the CCPR group. Median age was 58 years, 88.5% were male, prophylactic antibiotics were used in 80.3%, and favorable neurological outcomes were observed in 51.9%. On multivariate analysis, ECPR (odds ratio [OR], 2.78; 95% CI: 1.16-6.66; P=0.037) was significantly associated with the development of early onset pneumonia. Conclusions: ECPR was an independent predictor of pneumonia after OHCA in patients who received TTM.

Prevention of Early Ventilator-Associated Pneumonia after Cardiac Arrest

BACKGROUND

Patients who are treated with targeted temperature management after out-of-hospital cardiac arrest with shockable rhythm are at increased risk for ventilator-associated pneumonia. The benefit of preventive short-term antibiotic therapy has not been shown.

METHODS

We conducted a multicenter, double-blind, randomized, placebo-controlled trial involving adult patients (>18 years of age) in intensive care units (ICUs) who were being mechanically ventilated after out-of-hospital cardiac arrest related to initial shockable rhythm and treated with targeted temperature management at 32 to 34°C. Patients with ongoing antibiotic therapy, chronic colonization with multidrug-resistant bacteria, or moribund status were excluded. Either intravenous amoxicillin-clavulanate (at doses of 1 g and 200 mg, respectively) or placebo was administered three times a day for 2 days, starting less than 6 hours after the cardiac arrest. The primary outcome was early ventilator-associated pneumonia (during the first 7 days of hospitalization). An independent adjudication committee determined diagnoses of ventilator-associated pneumonia.

RESULTS

A total of 198 patients underwent randomization, and 194 were included in the analysis. After adjudication, 60 cases of ventilator-associated pneumonia were confirmed, including 51 of early ventilator-associated pneumonia. The incidence of early ventilator-associated pneumonia was lower with antibiotic prophylaxis than with placebo (19 patients [19%] vs. 32 [34%]; hazard ratio, 0.53; 95% confidence interval, 0.31 to 0.92; P = 0.03). No significant differences between the antibiotic group and the control group were observed with respect to the incidence of late ventilator-associated pneumonia (4% and 5%, respectively), the number of ventilator-free days (21 days and 19 days), ICU length of stay (5 days and 8 days if patients were discharged and 7 days and 7 days if patients had died), and mortality at day 28 (41% and 37%). At day 7, no increase in resistant bacteria was identified. Serious adverse events did not differ significantly between the two groups.

CONCLUSIONS

A 2-day course of antibiotic therapy with amoxicillin-clavulanate in patients receiving a 32-to-34°C targeted temperature management strategy after out-of-hospital cardiac arrest with initial shockable rhythm resulted in a lower incidence of early ventilator-associated pneumonia than placebo. No significant between-group differences were observed for other key clinical variables, such as ventilator-free days and mortality at day 28. (Funded by the French Ministry of Health; ANTHARTIC ClinicalTrials.gov number, NCT02186951.).

Targeted Temperature Management for In-Hospital Cardiac Arrest: 6 Years of Experience

Targeted temperature management (TTM) is widely used for postcardiac arrest management of patients with out-of-hospital cardiac arrest. However, the use of TTM for patients with in-hospital cardiac arrest (IHCA) is controversial. The aim of this study was to investigate the role of TTM in the management of patients with IHCA. The medical records of all IHCA patients who were resuscitated and returned to spontaneous circulation from January 2011 to December 2016 were reviewed. After excluding patients with new do not resuscitate orders and those who died within 24 hours, 262 patients were eligible for analysis. Thirty-five of the 262 patients (13.3%) received TTM after IHCA. Patients who received TTM and standard supportive care (SSC) had similar baseline epidemiological status. The TTM patients were older and had a longer cardiac pulmonary resuscitation duration; however, the differences were not statistically significant. The 28-day survival rate was not significantly different between groups (12/35 in the TTM group [34%] vs. 114/225 in the SSC group [50%], p = 0.079). In the patients with good neurological status before arrest (Glasgow-Pittsburgh cerebral performance category [GP-CPC] scores: 1-2), there was no significant difference in the 28-day survival between groups (11/26 in the TTM group [42.3%] vs. 81/154 [52.6%] in the SSC group; p = 0.332). In this subgroup, the TTM patients had poorer neurological outcomes at discharge (GP-CPC score 1-2) than the SSC patients (1/26 in the TTM group [3.8%] vs. 57/154 in the SSC group [37%]; p = 0.001). TTM was not associated with better 28-day survival than usual care among the patients with IHCA in this study, and the TTM patients had less favorable neurological outcomes at discharge. Randomized clinical trials are needed to assess the efficacy of TTM for IHCA patients.

Prophylactic antibiotic use following cardiac arrest: A systematic review and meta-analysis

OBJECTIVE

To evaluate the effect of prophylactic/ early antibiotics (intervention group) compared with clinically driven/ delayed antibiotics (control group) on patient and infectious outcomes in adult cardiac arrest patients admitted to hospital.

DATA SOURCES

We searched MEDLINE (1946-current), EMBASE (1947-current) and the Cochrane library (inception-current) on 8th May 2018. Additional citations were identified through forward and backward citation tracking.

STUDY SELECTION

Two reviewers independently screened titles, abstracts, and full-texts. We included observational and interventional primary research studies with a concurrent or retrospective control group that were relevant to our study objective.

DATA EXTRACTION

We extracted data using a piloted data extraction form. Risk of bias was assessed using the Cochrane tool for randomised controlled trials or the GRADE tool for risk of bias in observational studies. Overall evidence quality for each outcome was assessed using the GRADE system.

DATA SYNTHESIS

Databases searches and citation tracking identified 6825 citations, of which ten citations containing 11 studies (3 randomised controlled trials, 8 observational studies) were eligible for inclusion. Data were summarised in meta-analyses using random-effect models. The intervention was not associated with increased survival (odds ratio 1.16, 95% CI 0.97-1.40), survival with good neurological outcome (odds ratio 2.25, 95% CI 0.93-5.45), critical care length of stay (mean difference -0.6, 95% CI -3.6 to 2.4) or incidence of pneumonia (odds ratio 0.58, 95% CI 0.23-1.46). Findings were generally consistent between observational studies and randomised controlled trials.

CONCLUSIONS

Antibiotic prophylaxis following cardiac arrest is not associated with a change in key clinical outcomes. Further high-quality trials may be needed to address this important clinical question. Review registration: PROSPERO CRD42016039358.

Targeted Temperature Management and Postcardiac arrest Care

Despite recent advances, care of the post-cardiac arrest patient remains a challenge. In this article, the authors discuss an approach to the initial care of post-cardiac arrest patients with particular focus on targeted temperature management (TTM). The article starts with history, physiologic rationale, and the major randomized controlled trials that have shaped guidelines for post-cardiac arrest care. It also reviews controversial topics, including TTM for nonshockable rhythms, TTM dose, and surface versus endovascular cooling. The article concludes with a brief review of other key aspects of post-arrest care: coronary angiography, hemodynamic optimization, ventilator management, and prognostication.

Effectiveness of Two Targeted Temperature Management Methods After Pediatric Postcardiac Arrest: A Multicenter International Study

OBJECTIVES

It is currently recommended that after return of spontaneous circulation following cardiac arrest, fever should be prevented using TTM through a servo-controlled system. This technology is not yet available in many global settings, where manual physical measures without servo-control is the only option. Our aim was to compare feasibility, safety and quality assurance of servo-controlled system versus no servo-controlled system cooling, TTM protocols for cooling, maintenance and rewarming following return of spontaneous circulation after cardiac arrest in children.

DESIGN

Prospective, multicenter, nonrandomized, study.

SETTING

PICUs of 20 hospitals in South America, Spain, and Italy, 2012-2014.

PATIENTS

Under 18 years old with a cardiac arrest longer than 2 minutes, in coma and surviving to PICU admission requiring mechanical ventilation were included.

METHODS

TTM to 32-34°C was performed by prospectively designed protocol across 20 centers, with either servo-controlled system or no servo-controlled system methods, depending on servo-controlled system availability. We analyzed clinical data, cardiac arrest, temperature, mechanical ventilation duration, length of hospitalization, complications, survival, and neurologic outcomes at 6 months.

PRIMARY OUTCOME

feasibility, safety and quality assurance of the cooling technique and secondary outcome: survival and Pediatric Cerebral Performance Category at 6 months.

MEASUREMENTS AND MAIN RESULTS

Seventy patients were recruited, 51 of 70 TTM (72.8%) with servo-controlled system. TTM induction, maintenance, and rewarming were feasible in both groups. Servo-controlled system was more effective than no servo-controlled system in maintaining TTM (69 vs 60%; p = 0.004). Servo-controlled system had fewer temperatures above 38.1°C during the 5 days of TTM (0.1% vs 2.9%; p < 0.001). No differences in mortality, complications, length of mechanical ventilation and of stay, or neurologic sequelae were found between the two groups.

CONCLUSIONS

TTM protocol (for cooling, maintenance and rewarming) following return of spontaneous circulation after cardiac arrest in children was feasible and safe with both servo-controlled system and no servo-controlled system techniques. Achieving, maintaining, and rewarming within protocol targets were more effective with servo-controlled system versus no servo-controlled system techniques.

Factors Predicting Bacterial Infection in Out-of-Hospital Cardiac Arrest Patients Undergoing Targeted Temperature Management

The objective of this study was to determine a risk factor for predicting bacterial infection in patients, who survived out-of-hospital cardiac arrest (OHCA), during targeted temperature management (TTM). This prospective registry-based retrospective observational study was conducted from November 2010 to October 2017. We measured several biomarkers such as whole blood cell counts, and levels of C-reactive protein and procalcitonin daily during TTM. The primary outcome was bacterial growth in initial blood or sputum cultures. A total of 116 patients were analyzed in this study. The bacterial growth rate was 32.8% and the procalcitonin levels measured at 24 h from cardiac arrest was significantly higher in the culture-positive group than the culture-negative group (10.6 vs. 2.5 ng/mL, p = 0.017). Area under the receiver operating characteristic curve for procalcitonin obtained after 24 h was 0.727 and the cutoff value was 6.5 ng/mL (odds ratio 9.58 [95% confidential interval, CI 2.21-41.55], p = 0.003). Sensitivity was 71.4% [95% CI 41.9-91.6] and specificity was 79.3% [95% CI 60.3-92.0]. Procalcitonin measured at 24 h from cardiac arrest was associated with bacterial infection in OHCA patients undergoing TTM. Further prospective interventional studies are needed to validate these results.

Critical Care of the Post-Cardiac Arrest Patient

The post-cardiac arrest syndrome is a highly inflammatory state characterized by organ dysfunction, systemic ischemia and reperfusion injury, and persistent precipitating pathology. Early critical care should focus on identifying and treating arrest etiology and minimizing further injury to the brain and other organs by optimizing perfusion, oxygenation, ventilation, and temperature. Patients should be treated with targeted temperature management, although the exact temperature goal is not clear. No earlier than 72 hours after rewarming, prognostication using a multimodal approach should inform discussions with families regarding likely neurologic outcome.

Venoarterial Extracorporeal Membrane Oxygenation Increased Immune Function of Spleen and Decreased Reactive Oxygen Species During Post-Resuscitation

We aimed to investigate the effect of venoarterial extracorporeal membrane oxygenation (VA-ECMO) on immune function of the spleen and reactive oxygen species (ROS) during post-resuscitation in a porcine model. After 8 min of untreated ventricular fibrillation and 6 min of basic life support, pigs were randomized into two groups: Group 1 received VA-ECMO and Group 2 received conventional cardiopulmonary resuscitation. After successful return of spontaneous circulation, the hemodynamic status was determined and blood samples were collected at 0, 1, 2, 4, and 6 h. Surviving pigs were euthanized 6 h after return of spontaneous circulation, their spleens were harvested and the T-cells were separated. Then, we investigated immune function parameters of the spleen and ROS levels. VA-ECMO increased the return of spontaneous circulation and 6 h survival rate after return of spontaneous circulation. Compared with the conventional cardiopulmonary resuscitation group, the VA-ECMO group showed increased superoxide dismutase and decreased malondialdehyde and ROS levels. Furthermore, VA-ECMO was associated with a high rate of CD4+ and CD4+/CD8+, high levels of interleukin 2, interferon γ, and interferon γ/interleukin 4, as well as high proliferation of lymphocytes. The apoptotic rate of T-cells was lower in the VA-ECMO group than it was in the conventional cardiopulmonary resuscitation group. VA-ECMO increased immune function of spleen and decreased ROS levels during post-resuscitation. Further research is expected to illustrate whether the differences in immune responses are due to ROS or some other perfusion related effect on spleen.

Patients with out-of-hospital cardiac arrest show decreased human leucocyte antigen-DR expression on monocytes and B and T lymphocytes after return of spontaneous circulation

Immune disorders are an important feature of patients with out-of-hospital cardiac arrest (OHCA) after return of spontaneous circulation (ROSC). However, the precise immune alterations in patients with OHCA that occur immediately after ROSC are unclear. In this study, we investigated human leucocyte antigen-DR (HLA-DR) expression on circulatory monocytes and B and T lymphocytes. Sixty-eight consecutive patients with OHCA with ROSC >12 hours were enrolled. Clinical data and 28-day survival were recorded. Peripheral blood samples after ROSC days 1 and 3 were analysed to evaluate HLA-DR expression. Fifty healthy individuals were enrolled as controls. Compared with levels in healthy individuals, HLA-DR expression on monocytes and B lymphocytes, but not on T lymphocytes, decreased on days 1 and 3 after ROSC. No significant difference in HLA-DR expression was detected between survivors and non-survivors on day 1. For 41 patients with expression data for days 1 and 3, HLA-DR expression on monocytes and B lymphocytes in non-survivors was lower than that in survivors on day 3. In non-survivors, the mean fluorescence intensities of HLA-DR on B lymphocytes and percentages of HLA-DR+ T lymphocytes were lower on day 3 than on day 1. On days 1 and 3, there were significant correlations between HLA-DR expression on monocytes and B lymphocytes and clinical indicators, such as time to ROSC, adrenaline dose, acute physiology, chronic health evaluation II and the sequential organ failure assessment. The decreases in HLA-DR expression on circulatory monocytes and B and T lymphocytes after ROSC may be involved in the observed immunosuppression in patients with OHCA.