Early pneumonia and timing of antibiotic therapy in patients after nontraumatic out-of-hospital cardiac arrest

Microbiological Profiles after Out-of-Hospital Cardiac Arrest: Exploring the Relationship between Infection, Inflammation, and the Potential Effects of Mechanical Circulatory Support

Background: Cardiogenic shock (CS) following an out-of-hospital cardiac arrest (OHCA) poses significant management challenges, exacerbated by inflammatory responses and infectious complications. This study investigates the microbiological profiles and impacts of mechanical circulatory support (MCS) on inflammation and infection in OHCA patients. Methods: We retrospectively analyzed microbiological data from various specimens of 372 OHCA patients, who were treated at the Cardiac Arrest Center of the University Hospital of Marburg from January 2018 to December 2022. Clinical outcomes were evaluated to investigate the potential impact of MCS on infection and inflammation. Results: Of the study cohort, 115 patients received MCS. The microbiological analysis revealed a higher incidence of positive blood cultures in the MCS group vs. the non-MCS group (39% vs. 27.7%, p = 0.037), with predominantly Gram-positive bacteria. Patients with positive microbiological findings had longer in-hospital stays and prolonged periods of mechanical ventilation. The levels of inflammatory markers such as C-reactive protein (CRP) and procalcitonin (PCT) differed, suggesting a more pronounced inflammatory response in MCS patients, especially in the later ICU stages. Notably, despite the higher infection rate in the MCS group, the survival rates did not significantly differ in the two groups. Conclusions: MCS appears to influence the microbiological and inflammatory landscape in OHCA patients, increasing the susceptibility to certain infections but not affecting the overall mortality. This study underscores the complexity of managing post-resuscitation care and highlights the need for tailored therapeutic strategies to effectively mitigate infectious and inflammatory complications.

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.

Antibiotic Initiation Timing and Mortality in Trauma Patients With Ventilator-Associated Pneumonia

BACKGROUND

Early antibiotic initiation is considered a cornerstone in the management of ventilator-associated pneumonia (VAP). However, recent data suggests that early antibiotic initiation may not be necessary in all cases. Additionally, the benefits of early antibiotic administration for infection have not been studied in a dedicated trauma population. This study's aim was to evaluate the impact of antibiotic administration timing on in-hospital mortality in trauma patients with VAP.

METHODS

This retrospective case-control study identified all trauma patients at a single level 1 academic trauma center from 2016 to 2020. Patients with a TQIP-defined VAP were included and stratified into 2 subgroups by in-hospital mortality. Time interval between airway culture and antibiotic initiation was gathered. Baseline measures of injury and illness severity were collected. Univariate analysis of the data was performed.

RESULTS

Forty-five patients met inclusion criteria. Overall, 80% of patients survived admission (n = 36) and 20% of patients did not survive admission (n = 9). There were no significant differences in baseline characteristics or cultured organism between survivors and non-survivors. The median time interval between airway culture and antibiotic initiation was 2 hours (IQR 0-4.5) for survivors, and 0 hours (IQR 0-0) for non-survivors (P = .07). Antibiotics were administered within 1 hour of airway culture for 33.3% of survivors, and 77.8% of non-survivors (P = .02).

CONCLUSIONS

In a population of trauma patients with VAP, survivors had antibiotics initiated in more delayed fashion than non-survivors. These findings question the primacy of early antibiotic administration for suspected infection.

Unveiling Breakthroughs in Post-resuscitation Supportive Care for Out-of-Hospital Cardiac Arrest Survivors: A Narrative Review

Survivors of out-of-hospital cardiac arrest (OHCA) experience significant mortality rates and neurological impairment, potentially attributed to the hypoxic-ischemic injury sustained amid the cardiac arrest episode. Post-resuscitation care plays a crucial role in determining outcomes for survivors of OHCA. Supportive therapies have proven to be influential in shaping these outcomes. However, targeting higher blood pressure or oxygen levels during the post-resuscitative phase has not been shown to offer any mortality or neurological benefits. In terms of maintaining hemodynamic instability after resuscitation, it is recommended to use norepinephrine rather than epinephrine. While extracorporeal cardiopulmonary resuscitation has shown promising results, targeted temperature management has been found ineffective in improving outcomes despite its previous potential. This review also investigates various challenges and barriers associated with the practical implementation of these supportive therapies in clinical settings. The review also highlights areas ripe for future research and proposes potential directions to further enhance post-resuscitation supportive care for OHCA survivors.

Clinical and microbiological features of drowning-associated pneumonia: a retrospective multicentre cohort study

OBJECTIVE

Pneumonia is the most frequent infectious complication in patients who have experienced drowning that requires intensive care unit (ICU) admission. We aimed to describe clinical, microbiological, and therapeutic data as well as predictors and impacts of such pneumonia on patients' outcomes.

METHODS

We conducted a retrospective, multicentre study (2013-2020) of 270 consecutive patients admitted for drowning to 14 ICUs in Western France. Their baseline characteristics and outcomes were compared according to the occurrence of drowning-associated pneumonia (DAP), defined as pneumonia diagnosed within 48 hours of ICU admission. A Cox regression model was used to compare survival on day 28, and logistic regression was used to identify risk factors for DAP. Microbiological characteristics and empirical antibacterial treatment were also analysed.

RESULTS

Among the 270 patients admitted to the ICU for drowning, 101 (37.4%) and 33 (12.2%) experienced pneumonia and microbiologically proven DAP, respectively. The occurrence of pneumonia was associated with higher severity scores at ICU admission (median Simplified Acute Physiology Score II, 34 [interquartile range {IQR}, 25-55] vs. 45 [IQR, 28-67]; p 0.006) and longer ICU length of stay (2 days [IQR, 1-3] vs. 4 days [IQR, 2-7]; p < 0.001). The 28-day mortality rate was higher among these patients (29/101 [28.7%] vs. 26/169 [15.4%]; p 0.013). Microbiologically proven DAP remained associated with higher 28-day mortality after adjustments for cardiac arrest and water salinity (adjusted hazard ratio, 1.86 [95% CI, 1.06-3.28]; p 0.03). A microbiological analysis of respiratory samples showed a high proportion of gram-negative bacilli (23/56; 41.1%), with a high prevalence of amoxicillin-clavulanate resistance (12/33; 36.4%).

CONCLUSIONS

Pneumonia is a common complication in patients admitted in the ICU for drowning and is associated with increased mortality.

Hypothermia and its role in patients with ST-segment-elevation myocardial infarction and cardiac arrest

Background

Patients suffering cardiac arrest resulting from ST-segment-elevation myocardial infarction (STEMI) are at very high risk of death. In addition to reperfusion strategies, therapeutic hypothermia is recommended for cardiac arrest patients who remain unconscious after resuscitation. However, data analysis of the impact of therapeutic hypothermia on survival showed inconsistent results. We aimed to investigate the benefits of therapeutic hypothermia in STEMI patients after cardiopulmonary resuscitation (CPR).

Methods

Patients with STEMI who received CPR were identified after nationwide German inpatient data (2005-2019) were screened. These patients were stratified for therapeutic hypothermia. The impact of hypothermia on mortality and adverse in-hospital outcomes was analyzed.

Results

Overall, 133,070 inpatients with STEMI and CPR (53.3% aged ≥70 years; 34% females) were recorded in Germany between 2005 and 2019, of which 12.3% (16,386 patients) underwent therapeutic hypothermia. Females (23.8 vs. 35.4%, p < 0.001) and patients aged ≥70 years (34.9 vs. 55.9%, p < 0.001) were less frequently treated with therapeutic hypothermia. The in-hospital case fatality rate was lower for STEMI with CPR and subsequent therapeutic hypothermia than for treatment without therapeutic hypothermia (53.5 vs. 66.7%, p < 0.001). Therapeutic hypothermia was independently associated with a reduced in-hospital case fatality rate {OR 0.83 [95% confidence interval (CI) 0.80-0.86], p < 0.001}. In addition, therapeutic hypothermia was associated with an increased risk for stroke (OR 1.37 [95% CI 1.25-1.49], p < 0.001), pneumonia (OR 1.75 [95% CI 1.68-1.82], p < 0.001), and acute kidney injury (OR 2.21 [95% CI 2.07-2.35], p < 0.001).

Conclusion

Therapeutic hypothermia is associated with a survival benefit for STEMI patients after cardiac arrest.

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.

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.

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.

Elevated Plasma Soluble PD-L1 Levels in Out-of-Hospital Cardiac Arrest Patients

Background: A deregulated immune system has been implicated in the pathogenesis of post-cardiac arrest syndrome (PCAS). A soluble form of programmed cell death-1 (PD-1) ligand (sPD-L1) has been found at increased levels in cancer and sustained inflammation, thereby deregulating immune functions. Here, we aim to study the possible involvement of sPD-L1 in PCAS. Methods: Thirty out-of-hospital cardiac arrest (OHCA) patients consecutively admitted to the ER of Mie University Hospital were prospectively enrolled. Plasma concentrations of sPD-L1 were measured by an enzyme-linked immunosorbent assay in blood samples of all 30 OHCA patients obtained during cardiopulmonary resuscitation (CPR). In 13 patients who achieved return-of-spontaneous-circulation (ROSC), sPD-L1 levels were also measured daily in the ICU. Results: The plasma concentrations of sPD-L1 in OHCA were significantly increased; in fact, to levels as high as those observed in sepsis. sPD-L1 levels during CPR correlated with reduced peripheral lymphocyte counts and increased C-reactive protein levels. Of 13 ROSC patients, 7 cases survived in the ICU for more than 4 days. A longitudinal analysis of sPD-L1 levels in the 7 ROSC cases revealed that sPD-L1 levels occurred in parallel with organ failure. Conclusions: This study suggests that ischemia- reperfusion during CPR may aberrantly activate immune and endothelial cells to release sPD-L1 into circulation, which may play a role in the pathogenesis of immune exhaustion and organ failures associated with PCAS.

Early Bronchoscopy Improves Extubation Rates after Out-of-Hospital Cardiac Arrest: A Retrospective Cohort Analysis

BACKGROUND

Patients suffering from out-of-hospital cardiac arrest (OHCA) frequently receive a bronchoscopy after being admitted to the ICU. We investigated the optimal timing and the outcome in these patients.

METHODS

All patients who suffered from OHCA and were treated in our ICU from January 2013 to December 2018 were retrospectively analyzed. The data were collected from the patients' medical files, and included duration of mechanical ventilation, antibiotics, microbiological test results and neurological outcome. The outcome was the effect of early bronchoscopy (≤48 h after administration) on the rate of intubated patients on day five and day seven.

RESULTS

From January 2013 to December 2018, 190 patients were admitted with OHCA. Bronchoscopy was performed in 111 patients out of the 164 patients who survived the first day. Late bronchoscopy >48 h was associated with higher rates of intubation on day five (OR 4.94; 95% CI 1.2-36.72, 86.7% vs. 55.0%, p = 0.036) and day seven (OR 4.96; 95% CI 1.38-24.69; 80.0% vs. 43.3%, p = 0.019).

CONCLUSION

This study shows that patients who suffered from OHCA might have a better outcome if they receive a bronchoscopy early after hospital admission. Our data suggests an association of early bronchoscopy with a shorter intubation period.

Bacterial Pneumonia in Brain-Dead Patients: Clinical Features and Impact on Lung Suitability for Donation

OBJECTIVES

To appraise the epidemiological features of bacterial pneumonia and its impact on lung suitability for donation in brain-dead patients managed with protective ventilatory settings.

DESIGN

Retrospective observational study.

SETTING

Six ICUs from two university-affiliated hospitals.

PATIENTS

Brain-dead adult patients managed in the participating ICUs over a 4-year period.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Among the 231 included patients, 145 (62.8%) were classified as ideal or extended-criteria potential lung donors at ICU admission and the remaining 86 patients having baseline contraindication for donation. Culture-proven aspiration pneumonia and early-onset ventilator-associated pneumonia occurred in 54 patients (23.4%) and 15 patients (6.5%), respectively (overall pneumonia incidence, 29.9%). Staphylococcus aureus and Enterobacterales were the most common pathogens. Using mixed-effects Cox proportional hazard models, age (adjusted hazard ratio, 0.98; 95% CI [0.96-0.99]), anoxic brain injury (3.55 [1.2-10.5]), aspiration (2.29 [1.22-4.29]), and not receiving antimicrobial agents at day 1 (3.56 [1.94-6.53]) were identified as independent predictors of pneumonia occurrence in the whole study population. Analyses restricted to potential lung donors yielded similar results. Pneumonia was associated with a postadmission decrease in the PaO2/FIO2 ratio and lower values at brain death, in the whole study population (estimated marginal mean, 294 [264-323] vs 365 [346-385] mm Hg in uninfected patients; p = 0.0005) as in potential lung donors (299 [248-350] vs 379 [350-408] mm Hg; p = 0.04; linear mixed models). Lungs were eventually retrieved in 31 patients (34.4%) among the 90 potential lung donors with at least one other organ harvested (pneumonia prevalence in lung donors (9.7%) vs nondonors (49.2%); p = 0.0002).

CONCLUSIONS

Pneumonia occurs in one-third of brain-dead patients and appears as the main reason for lung nonharvesting in those presenting as potential lung donors. The initiation of antimicrobial prophylaxis upon the first day of the ICU stay in comatose patients with severe brain injury could enlarge the pool of actual lung donors.

Hyperoxia After Return of Spontaneous Circulation in Cardiac Arrest Patients

Current guidelines emphasize the use of 100% oxygen during cardiopulmonary resuscitation after cardiac arrest. When patients are ventilated for variable periods after return of spontaneous circulation (ROSC), hyperoxia causes increased morbidity and mortality by overproduction of reactive oxygen species. Various patient, volunteer, and animal studies have shown the harmful effects of hyperoxia. This mini-review article aims to expand the potential clinical spectrum of hyperoxia on individual organ systems leading to organ dysfunction. A framework to achieve and maintain normoxia after ROSC is proposed. Despite the harmful considerations of hyperoxia in critically ill patients, additional safety studies including dose-effect, level and onset of the reactive oxygen species effect, and safe hyperoxia applicability period after ROSC, need to be performed in various animal and human models to further elucidate the role of oxygen therapy after cardiac arrest.

Prevention of Complications in the Cardiac Intensive Care Unit: A Scientific Statement From the American Heart Association

Contemporary cardiac intensive care units (CICUs) have an increasing prevalence of noncardiovascular comorbidities and multisystem organ dysfunction. However, little guidance exists to support the development of best-practice principles specific to the CICU. This scientific statement evaluates strategies to avoid the potentially preventable complications encountered within contemporary CICUs, focusing on those that are most applicable to the CICU environment. This scientific statement reviews evidence-based practices derived in non–CICU populations, assesses their relevance to CICU practice, and highlights key knowledge gaps warranting further investigation to attenuate patient risk.

Interleukin-6 Receptor Antibodies for Modulating the Systemic Inflammatory Response after Out-of-Hospital Cardiac Arrest (IMICA): study protocol for a double-blinded, placebo-controlled, single-center, randomized clinical trial

Background

Resuscitated out-of-hospital cardiac arrest (OHCA) patients who remain comatose at admission are at high risk of morbidity and mortality. This has been attributed to the post-cardiac arrest syndrome (PCAS) which encompasses multiple interacting components, including systemic inflammation. Elevated levels of circulating interleukin-6 (IL-6), a pro-inflammatory cytokine, is associated with worse outcomes in OHCA patients, including higher vasopressor requirements and higher mortality rates. In this study, we aim to reduce systemic inflammation after OHCA by administering a single infusion of tocilizumab, an IL-6 receptor antibody approved for use for other indications.

Methods

Investigator-initiated, double-blinded, placebo-controlled, single-center, randomized clinical trial in comatose OHCA patients admitted to an intensive cardiac care unit. Brief inclusion criteria: OHCA of presumed cardiac cause, persistent unconsciousness, age ≥ 18 years. Intervention: 80 patients will be randomized in a 1:1 ratio to a single 1-h intravenous infusion of either tocilizumab or placebo (NaCl). During the study period, patients will receive standard of care, including sedation and targeted temperature management of 36 ° for at least 24 h, vasopressors and/or inotropes as/if needed, prophylactic antibiotics, and any additional treatment at the discretion of the treating physician. Blood samples are drawn for measurements of biomarkers included in the primary and secondary endpoints during the initial 72 h. Primary endpoint: reduction in C-reactive protein (CRP). Secondary endpoints (abbreviated): cytokine levels, markers of brain, cardiac, kidney and liver damage, hemodynamic and hemostatic function, adverse events, and follow-up assessment of cerebral function and mortality.

Discussion

We hypothesize that reducing the effect of circulating IL-6 by administering an IL-6 receptor antibody will mitigate the systemic inflammatory response and thereby modify the severity of PCAS, in turn leading to lessened vasopressor use, more normal hemodynamics, and better organ function. This will be assessed by primarily focusing on hemodynamics and biomarkers of organ damage during the initial 72 h.

In addition, pro-inflammatory and anti-inflammatory cytokines will be measured to assess if cytokine patterns are modulated by IL-6 receptor blockage.

Trial registration

ClinicalTrials.gov Identifier: NCT03863015; submitted February 22, 2019, first posted March 5, 2019.

EudraCT: 2018-002686-19; date study was authorized to proceed: November 7, 2018.

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.

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.).

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.

Demographics of Pediatric OHCA Survivors With Postdischarge Diseases: A National Population-Based Follow-Up Study

Background: Postdischarge diseases (PDDs) have been reported for adult survivors of out-of-hospital cardiac arrest (OHCA). However, the detailed demographics of pediatric OHCA survivors with PDDs are not well-documented, and information regarding functional survivors is particularly limited. We aimed to report detailed information on the PDDs of survivors of traumatic and non-traumatic pediatric OHCA using a national healthcare database. Methods: We retrospectively obtained data from the Taiwan government healthcare database (2011-2015). Information on the demographics of traumatic and non-traumatic pediatric OHCA survivors (<20 years) was obtained and reported. The patients who survived to discharge (survivors) and those classified as functional survivors were followed up for 1 year for the analysis of newly diagnosed PDDs. The time from discharge to PDD diagnosis was also reported. Results: A total of 2,178 non-traumatic and 288 traumatic OHCA pediatric cases were included. Among the non-traumatic OHCA survivors (n = 374, survival rate = 17.2%), respiratory tract (n = 270, 72.2%), gastrointestinal (n = 187, 50.0%), and neurological diseases (n = 167, 49.1%) were the three most common PDD categories, and in these three categories, the majority of PDDs were atypical/influenza pneumonia, non-infective acute gastroenteritis, and generalized/status epilepsy, respectively. Among the traumatic OHCA survivors (n = 21, survival rate = 7.3%), respiratory tract diseases (n = 17, 81.0%) were the most common, followed by skin or soft tissue (n = 14, 66.7%) diseases. Most functional survivors still suffered from neurological and respiratory tract diseases. Most PDDs, except for skin or soft tissue diseases, were newly diagnosed within the first 3 months after discharge. Conclusions: Respiratory tract (pneumonia), neurological (epilepsy), and skin or soft tissue (dermatitis) diseases were very common among both non-traumatic and traumatic OHCA survivors. More importantly, most PDDs, except for skin or soft tissue diseases, were newly diagnosed within the first 3 months after discharge.

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.

Early Changes in Circulatory T Helper Type 1, 2, and 17 Cells of Patients with Out-of-Hospital Cardiac Arrest after Successful Cardiopulmonary Resuscitation

Background

Immune disorder is an important feature of patients with out-of-hospital cardiac arrest (OHCA) after the return of spontaneous circulation (ROSC). We investigated the expression of circulatory T helper type (Th) 1, Th2, and Th17 cells to explore the early immune alteration in OHCA patients after ROSC.

Methods

During July-September 2016 and March-September 2017, 65 consecutive OHCA patients with ROSC >12 h and 30 healthy individuals were enrolled in this study. Clinical and 28-day survival data were collected. Peripheral blood samples were analyzed to evaluate the expression of Th1/Th2/Th17 cells by flow cytometry from OHCA patients after ROSC on days 1 and 3 and from healthy individuals.

Results

Compared with healthy individuals, T lymphocyte counts and Th1 cell counts decreased on days 1 and 3 after ROSC (1464 [1198, 2152] vs. 779 [481, 1140] vs. 581 [324, 1118]/μl, χ² = 30.342, P < 0.001; 154 [90, 246] vs. 39 [19, 78] vs. 24 [12, 53]/μl, χ² = 42.880, P < 0.001), and Th2 and Th17 cell counts decreased on day 3 (17.0 [10.8, 24.0] vs. 9.0 [3.0, 15.5]/μl, Z = -3.228, P = 0.001; 4.7 [2.7, 9.1] vs. 2.7 [1.0, 6.5]/μl, Z = -2.294, P = 0.022). No change in CD4+/CD3+ lymphocyte ratio was seen on day 1 or day 3 (57.9 [49.4, 63.0] vs. 55.4 [46.5, 66.5] vs. 55.4 [50.2, 67.0]%, χ² = 0.171, P = 0.918). Th1/CD4+ lymphocyte ratio decreased on days 1 and 3 (19.0 [14.0, 24.9] vs. 9.3 [4.6, 13.9] vs. 9.5 [4.9, 13.6]%, χ² = 25.754, P < 0.001), and Th2/CD4+ lymphocyte ratio increased on day 1 and decreased on day 3 (1.9 [1.2, 2.5] vs. 2.5 [1.6, 4.0] vs. 1.9 [1.6, 3.8]%, χ² = 6.913, P = 0.032). Th1/Th2 cell ratio also decreased on both days (9.4 [7.3, 13.5] vs. 3.1 [1.9, 5.6] vs. 4.2 [2.8, 5.9], χ² = 44.262, P < 0.001). Despite an upward trend in the median of Th17/CD4+ lymphocyte ratio in OHCA patients, there was no significant difference compared with healthy individuals (0.9 [0.4, 1.2] vs. 0.7 [0.4, 1.2] vs. 0.6 [0.3, 1.0]%, χ² = 2.620, P = 0.270). The dynamic expression of Th1/Th2/Th17 cells on days 1 and 3 were simultaneously analyzed in 28/53 OHCA patients who survived >3 days; patients were divided into survivors (n = 10) and nonsurvivors (n = 18) based on 28-day survival. No significant differences in Th1/Th2/Th17 cell counts, ratios in CD4+ lymphocytes, and Th1/Th2 cell ratio were seen between survivors and nonsurvivors on both days (all P > 0.05). There was no difference over time in both survivors and nonsurvivors (all P > 0.05).

Conclusion

Downregulated T lymphocyte counts, including Th1/Th2/Th17 subsets and Th1/Th2 cell ratio imbalance, occur in the early period after ROSC, that may be involved in immune dysfunction in OHCA patients.

Ventilator Management and Respiratory Care After Cardiac Arrest: Oxygenation, Ventilation, Infection, and Injury

Return of spontaneous circulation after cardiac arrest results in a systemic inflammatory state called the post-cardiac arrest syndrome, which is characterized by oxidative stress, coagulopathy, neuronal injury, and organ dysfunction. Perturbations in oxygenation and ventilation may exacerbate secondary injury after cardiac arrest and have been shown to be associated with poor outcome. Further, patients who experience cardiac arrest are at risk for a number of other pulmonary complications. Up to 70% of patients experience early infection after cardiac arrest, and the respiratory tract is the most common source. Vigilance for early-onset pneumonia, as well as aggressive diagnosis and early antimicrobial agent administration are important components of critical care in this population. Patients who experience cardiac arrest are at risk for the development of ARDS. Risk factors include aspiration, pulmonary contusions (from chest compressions), systemic inflammation, and reperfusion injury. Early evidence suggests that they may benefit from ventilation with low tidal volumes. Meticulous attention to mechanical ventilation, early assessment and optimization of respiratory gas exchange, and therapies targeted at potential pulmonary complications may improve outcomes after cardiac arrest.

Endotoxemia induces lung-brain coupling and multi-organ injury following cerebral ischemia-reperfusion

Post-ischemic neurodegeneration remains the principal cause of mortality following cardiac resuscitation. Recent studies have implicated gastrointestinal ischemia in the sepsis-like response associated with the post-cardiac arrest syndrome (PCAS). However, the extent to which the resulting low-grade endotoxemia present in up to 86% of resuscitated patients affects cerebral ischemia-reperfusion injury has not been investigated. Here we report that a single injection of low-dose lipopolysaccharide (50μg/kg, IP) delivered after global cerebral ischemia (GCI) induces blood-brain barrier permeability, microglial activation, cortical injury, and functional decline in vivo, compared to ischemia alone. And while GCI was sufficient to induce neutrophil (PMN) activation and recruitment to the post-ischemic CNS, minimal endotoxemia exhibited synergistic effects on markers of systemic inflammation including PMN priming, lung damage, and PMN burden within the lung and other non-ischemic organs including the kidney and liver. Our findings predict that acute interventions geared towards blocking the effects of serologically occult endotoxemia in survivors of cardiac arrest will limit delayed neurodegeneration, multi-organ dysfunction and potentially other features of PCAS. This work also introduces lung-brain coupling as a novel therapeutic target with broad effects on innate immune priming and post-ischemic neurodegeneration following cardiac arrest and related cerebrovascular conditions.

Demographics and Clinical Features of Postresuscitation Comorbidities in Long-Term Survivors of Out-of-Hospital Cardiac Arrest: A National Follow-Up Study

The outcome of patients suffering from out-of-hospital cardiac arrest (OHCA) is very poor, and postresuscitation comorbidities increase long-term mortality. This study aims to analyze new-onset postresuscitation comorbidities in patients who survived from OHCA for over one year. The Taiwan National Health Insurance (NHI) Database was used in this study. Study and comparison groups were created to analyze the risk of suffering from new-onset postresuscitation comorbidities from 2011 to 2012 (until December 31, 2013). The study group included 1,346 long-term OHCA survivors; the comparison group consisted of 4,038 matched non-OHCA patients. Demographics, patient characteristics, and risk of suffering comorbidities (using Cox proportional hazards models) were analyzed. We found that urinary tract infections (n = 225, 16.72%), pneumonia (n = 206, 15.30%), septicemia (n = 184, 13.67%), heart failure (n = 111, 8.25%) gastrointestinal hemorrhage (n = 108, 8.02%), epilepsy or recurrent seizures (n = 98, 7.28%), and chronic kidney disease (n = 62, 4.61%) were the most common comorbidities. Furthermore, OHCA survivors were at much higher risk (than comparison patients) of experiencing epilepsy or recurrent seizures (HR = 20.83; 95% CI: 12.24-35.43), septicemia (HR = 8.98; 95% CI: 6.84-11.79), pneumonia (HR = 5.82; 95% CI: 4.66-7.26), and heart failure (HR = 4.88; 95% CI: 3.65-6.53). Most importantly, most comorbidities occurred within the first half year after OHCA.

Early antibiotics administration during targeted temperature management after out-of-hospital cardiac arrest: a nationwide database study

Background

Patients resuscitated after cardiac arrest are reportedly at high risk for infection and sepsis, especially those treated with targeted temperature management (TTM). There is, however, limited evidence suggesting that early antibiotic use improves patient outcomes. We examined the hypothesis that early treatment with antibiotics reduces mortality in patients with cardiac arrest receiving TTM.

Methods

We identified 2803 patients with cardiogenic out-of-hospital cardiac arrest (OHCA) that were treated with TTM and were admitted to 371 hospitals that contribute to the Japanese Diagnosis Procedure Combination inpatient database between July 2007 and March 2013. Of these, 1272 received antibiotics within the first 2 days (antibiotics) and 1531 did not (control). We generated 802 propensity score-matched pairs.

Results

There was no significant difference in 30-day mortality between the groups (control vs. antibiotics; 33.0 % vs. 29.9 %; difference, 3.1 %; 95 % confidence interval [CI], −1.4 to 7.7 %, p = 0.18). Analysis using the hospital antibiotics prescribing rate as an instrumental variable showed that antibiotic use was not significantly associated with a reduction in 30-day mortality (6.6 %, CI 95 %, −0.5 to 13.7 %, p = 0.28). A subgroup analysis of patients who required extracorporeal membrane oxygenation (ECMO) indicated a significant difference in 30-day mortality between the 2 groups (62.9 % vs. 43.5 %; difference 19.3 %, CI 95 %, 5.9 to 32.7 %, p = 0.005). In the instrumental variable model, the estimated reduction in 30-day mortality associated with antibiotics was 18.2 % (CI 95 %, 21.3 to 34.4 %, p = 0.03) in ECMO patients.

Conclusions

Although there was no significant association between the use of antibiotics and mortality after overall cardiogenic OHCA treated with TTM, antibiotics may be beneficial in patients who require ECMO.