Part 9: Post–Cardiac Arrest Care

Timing of coronary angiography in patients following out-of-hospital cardiac arrest without ST-segment elevation: A systematic review and Meta-analysis of randomized trials

INTRODUCTION

Out-of-hospital cardiac arrest (OHCA) has a poor prognosis. The timing and role of early coronary angiography (CAG) in OHCA patients without ST elevation remains unclear.

OBJECTIVE

We performed a meta-analysis of randomized controlled trials (RCTs) that compared early CAG to delayed CAG in OHCA patients without ST elevation.

METHODS

We searched PubMed, Cochrane, and ClinicalTrials.gov databases (from inception to September 2021) for studies comparing early CAG to delayed CAG in OHCA patients without ST elevation. We used a random-effect model to calculate relative ratio (RR) with 95% confidence interval (CI). The primary outcome was all-cause mortality at 30 days. Secondary outcomes included neurological status with cerebral performance category ≤2 (CPC) and the rate of percutaneous coronary intervention (PCI) following CAG.

RESULTS

A total of 6 RCTs including 1822 patients, of whom 895 underwent early CAG, and 927 underwent delayed CAG, were included in this meta-analysis. There was no statistically significant difference between the 2 groups in terms of 30-day all-cause mortality (Relative risk [RR] 1.06; 95%CI 0.94-1.20; P = 0.32; I² = 13%), neurological status (CPC ≤2) (RR 1.01; 95%CI 0.90-1.13; P = 0.85, I² = 37%), and rates of PCI following CAG (RR 1.08; 95%CI 0.84-1.39; P = 0.56; I² = 49%).

CONCLUSION

In patients suffering OHCA without ST-elevation, early CAG is not associated with reduced 30-day mortality when compared to patients who underwent delayed CAG. Given our meta-analysis results including multiple trials that have not shown a benefit, it is likely that updated guidelines will not support early angiography in patients suffering OHCA without ST-elevation.

Hemoperitoneum identified by focused assessment with sonography for trauma following cardiopulmonary resuscitation

It is generally recognized that lives are saved by administering high-quality cardiopulmonary resuscitation (CPR) to patients in cardiac arrest. A focused assessment with sonography for trauma (FAST) examination is an effective and non-invasive method for detecting rare complications of CPR, such as hemorrhage from abdominal visceral injury. We report the case of a 56-year-old female suffering from intra-abdominal hemorrhage caused by a liver laceration following CPR. The hemoperitoneum was diagnosed by a FAST examination. Although severe complications of CPR are rare, they can be easily detected with the use of a FAST examination. A FAST examination should be considered as a post-resuscitation approach to assess for life-threatening complications in all patients following cardiopulmonary resuscitation.

Physiological Impact of Hypothermia: The Good, the Bad and the Ugly

Hypothermia is defined as a core body temperature of < 35°C, and as body temperature is reduced the impact on physiological processes can be beneficial or detrimental. The beneficial effect of hypothermia enables circulation of cooled experimental animals to be interrupted for 1-2 h without creating harmful effects, while tolerance of circulation arrest in normothermia is between 4 and 5 min. This striking difference has attracted so many investigators, experimental as well as clinical, to this field, and this discovery was fundamental for introducing therapeutic hypothermia in modern clinical medicine in the 1950's. Together with the introduction of cardiopulmonary bypass, therapeutic hypothermia has been the cornerstone in the development of modern cardiac surgery. Therapeutic hypothermia also has an undisputed role as a protective agent in organ transplantation and as a therapeutic adjuvant for cerebral protection in neonatal encephalopathy. However, the introduction of therapeutic hypothermia for organ protection during neurosurgical procedures or as a scavenger after brain and spinal trauma has been less successful. In general, the best neuroprotection seems to be obtained by avoiding hyperthermia in injured patients. Accidental hypothermia occurs when endogenous temperature control mechanisms are incapable of maintaining core body temperature within physiologic limits and core temperature becomes dependent on ambient temperature. During hypothermia spontaneous circulation is considerably reduced and with deep and/or prolonged cooling, circulatory failure may occur, which may limit safe survival of the cooled patient. Challenges that limit safe rewarming of accidental hypothermia patients include cardiac arrhythmias, uncontrolled bleeding, and "rewarming shock".

The effect of fluid bolus administration on cerebral tissue oxygenation in post-cardiac arrest patients

PURPOSE

Fluid boluses (FB) are often used in post-cardiac arrest (CA) patients with haemodynamic instability. Although FB may improve cardiac output (CO) and mean arterial pressure (MAP), FB may also increase central venous pressure (CVP), reduce arterial PaO₂, dilute haemoglobin and cause interstitial oedema. The aim of the present study was to investigate the net effect of FB administration on cerebral tissue oxygenation saturation (SctO₂) in post-CA patients.

METHODS

Pre-planned sub-study of the Neuroprotect post-CA trial (NCT02541591). Patients with anticipated fluid responsiveness based on stroke volume variation (SVV) or passive leg raising test were administered a FB of 500 ml plasma-lyte A (Baxter Healthcare) and underwent pre- and post-FB assessments of stroke volume, CO, MAP, CVP, haemoglobin, PaO₂ and SctO₂.

RESULTS

52 patients (mean age 64 ± 12 years, 75% male) received a total of 115 FB. Although administration of a FB resulted in a significant increase of stroke volume (63 ± 22 vs 67 ± 23 mL, p = 0.001), CO (4,2 ± 1,6 vs 4,4 ± 1,7 L/min, p = 0.001) and MAP (74,8 ± 13,2 vs 79,2 ± 12,9 mmHg, p = 0.004), it did not improve SctO₂ (68.54 ± 6.99 vs 68.70 ± 6.80%, p = 0.49). Fluid bolus administration also resulted in a significant increase of CVP (10,0 ± 4,5 vs 10,7 ± 4,9 mmHg, p = 0.02), but did not affect PaO₂ (99 ± 31 vs 94 ± 31 mmHg, p = 0.15) or haemoglobin concentrations (12,9 ± 2,1 vs 12,8 ± 2,2 g/dL, p = 0.10). In a multivariate model, FB-induced changes in CO (beta 0,77; p = 0.004) and in CVP (beta -0,23; p = 0.02) but not in MAP (beta 0,02; p = 0.18) predicted post-FB ΔSctO₂.

CONCLUSIONS

Despite improvements in CO and MAP, FB administration did not improve SctO₂ in post-cardiac arrest patients.

Updates on the Management of Neurologic Complications of Post-Cardiac Arrest Resuscitation

Sudden cardiac arrest (SCA) is one of the leading causes of mortality and morbidity in the United States, and survivors are frequently left with severe disability. Of the 10% successfully resuscitated from SCA, only around 10% of these live with a favorable neurologic outcome. Survivors of SCA commonly develop post-cardiac arrest syndrome (PCAS). PCAS is composed of neurologic, myocardial, and systemic injury related to inadequate perfusion and ischemia-reperfusion injury with free radical formation and an inflammatory cascade. While targeted temperature management is the cornerstone of therapy, other intensive care unit-based management strategies include monitoring and treatment of seizures, cerebral edema, and increased intracranial pressure, as well as prevention of further neurologic injury. In this review, we discuss the scientific evidence, recent updates, future prospects, and knowledge gaps in the treatment of post-cardiac arrest patients.

Complications and survival after subcutaneous ureteral bypass device placement in 24 cats: a retrospective study (2016-2019)

OBJECTIVES

The aim of this study was to document survival, complications and risk factors for the development of complications and mortality prior to discharge after placement of a subcutaneous ureteral bypass (SUB) device in cats.

METHODS

The medical records of cats with SUB placement between January 2016 and August 2019 were retrospectively analysed. The development of complications (overall, intraoperative, perioperative, short- and long-term complications) and risk factors for mortality prior to discharge were statistically assessed with univariate binary logistic regression. All variables with a P value ⩽0.10 in the univariate analysis were assessed in a multivariate model. Variables were significant if P <0.05.

RESULTS

Twenty-four cats were included; 12 (50.0%) received a unilateral SUB, 11 (45.8%) a bilateral nephrostomy tube with single cystostomy catheter and the remaining cat (4.2%) two unilateral SUBs. Nearly 80% of the cats developed complications, ranging from mild to fatal, including (partial) SUB obstruction (33.3% of complications), lower urinary tract infection (20.8%), pyelonephritis (20.8%) and sterile cystitis (12.5%). Five cats (20.8%) died prior to discharge. Six cats (25.0%) underwent revision surgery. The overall median survival time (MST) was 274 days (range 1-311 days). Complications were most common in the long-term period (14/16 cats), followed by the short-term (9/18 cats), perioperative (10/23 cats) and intraoperative (4/24 cats) periods. Older cats had an increased risk for developing perioperative complications (P = 0.045) and were less likely to survive to discharge (P = 0.033). An increased haematocrit at presentation was a risk factor for the occurrence of short-term complications (P = 0.03).

CONCLUSIONS AND RELEVANCE

Although complications similar to those previously described were observed, the complication rate was higher and the MST shorter than previously reported in cats undergoing SUB placement. Despite good short-term survival, the development of complications may necessitate regular and intensive control visits. Owners that consider SUB placement should be informed that follow-up can be strenuous and expensive.

Combination of neuron-specific enolase measurement and initial neurological examination for the prediction of neurological outcomes after cardiac arrest

This study aimed to investigate the efficacy of the combination of neuron-specific enolase (NSE) measurement and initial neurological examination in predicting the neurological outcomes of patients with cardiac arrest (CA) by retrospectively analyzing data from the Korean Hypothermia Network prospective registry. NSE levels were recorded at 48 and 72 h after CA. The initial Full Outline of UnResponsiveness (FOUR) and Glasgow Coma Scale (GCS) scores were recorded. These variables were categorized using the scorecard method. The primary endpoint was poor neurological outcomes at 6 months. Of the 475 patients, 171 (36%) had good neurological outcomes at 6 months. The areas under the curve (AUCs) of the categorized NSE levels at 72 h, GCS score, and FOUR score were 0.889, 0.722, and 0.779, respectively. The AUCs of the combinations of categorized NSE levels at 72 h with categorized GCS scores and FOUR score were 0.910 and 0.912, respectively. Each combination was significantly higher than the AUC value of the categorized NSE level at 72 h alone (with GCS: p = 0.015; with FOUR: p = 0.026). Combining NSE measurement and initial neurological examination improved the prediction of neurological outcomes.

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.

The utility of computed tomography to evaluate thoracic complications after cardiopulmonary resuscitation

Background

Cardiopulmonary resuscitation (CPR) in adults following non-traumatic out of hospital cardiac arrest (OHCA) can cause thoracic complications including rib fractures, sternal fractures, and pneumothorax. Post-CPR complication rates are poorly studied and the optimum imaging modality to detect these complications post-resuscitation has not been established.

Methods

We performed a retrospective review of adult patients transported to a single, urban, academic hospital following atraumatic OHCA between September 2015 and January 2020. Patients who achieved sustained return of spontaneous circulation (ROSC) and who underwent computed tomography (CT) imaging of the chest following radiographic chest x-ray were included in the analyses. Patient demographics and prehospital data were collected. Descriptive statistics and multivariate logistic regression analysis were performed. Sensitivity and specificity of chest x-ray for the detection of thoracic injury in this population were estimated.

Results

786 non-traumatic OHCA patients were transported to the ED, 417 of whom obtained sustained ROSC and were admitted to the hospital (53%). 137 (32.9%) admitted patients underwent CT imaging of the chest in the ED. Of these imaged patients median age was 62 years old (IQR 53–70) with 54.0% female and 38.0% of patients having received bystander CPR. 40/137 (29.2%) patients had skeletal fractures noted on CT imaging and 12/137 (8.8%) had pneumothorax present on CT imaging. X-ray yielded a sensitivity of 7.5% for rib fracture and 50% for pneumothorax with a specificity of 100% for both. Logistic regression analysis revealed no significant association between age, sex, bystander CPR, or resuscitation length with thoracic fractures or pneumothorax.

Conclusions

Complications from OHCA CPR were high with 29.2% of CT imaged patients having rib fractures and 8.8% having pneumothoraces. X-ray had poor sensitivity for these post-resuscitation complications. Post-CPR CT imaging of the chest should be considered for detecting post-CPR complications.

Resuscitation in Community Healthcare Facilities in Israel

Background: Out-of-hospital cardiac-arrest (OHCA) is a major public health challenge. Community health care providers (CHP) may play an important role through early identification, basic life support and defibrillation. Few studies have evaluated the incidence and characteristics of OHCAs initially cared for by CHP, most finding improved survival. This study combined CHP treated OHCA case analysis, with assessment of provider resuscitation preparedness. Methods: An analysis of all CHP initiated resuscitations in a large Health Maintenance Organization (HMO) reported over 42 months, coupled with an online survey assessing CHP resuscitation knowledge, experience, training and self-confidence. Results: 22 resuscitations met inclusion criteria. In 21 CHP initiated chest-compressions but in only 8 cases they utilized the clinic’s automated external defibrillator (AED) prior to emergency medical services (EMS) arrival. There were 275 providers surveyed. Of the surveyed providers, 89.4% reported previous basic life support (BLS)/advanced cardiovascular life support (ALS) training, 67.9% within the last three years. Previous resuscitation experience was reported by 72.7%. The lowest scoring knowledge question was on indications for AED application −56.3%. Additionally, 44.4% reported low confidence in their resuscitation skills. CHP with previous cardiopulmonary resuscitation (CPR) experience reported higher confidence. Longer time since last CPR training lowered self-confidence. Conclusions: Early AED application is crucial for patients with OHCA. All clinics in our study were equipped with AED’s and most CHP received training in their use, but remained insecure regarding their use, often failing to do so.

Insight into the use of tympanic temperature during target temperature management in emergency and critical care: a scoping review

BACKGROUND

Target temperature management (TTM) is suggested to reduce brain damage in the presence of global or local ischemia. Prompt TTM application may help to improve outcomes, but it is often hindered by technical problems, mainly related to the portability of cooling devices and temperature monitoring systems. Tympanic temperature (T_Ty) measurement may represent a practical, non-invasive approach for core temperature monitoring in emergency settings, but its accuracy under different TTM protocols is poorly characterized. The present scoping review aimed to collect the available evidence about T_Ty monitoring in TTM to describe the technique diffusion in various TTM contexts and its accuracy in comparison with other body sites under different cooling protocols and clinical conditions.

METHODS

The scoping review was conducted following the guidelines of the Preferred Reporting Items for Systematic Review and Meta-Analysis extension for scoping reviews (PRISMA-ScR). PubMed, Scopus, and Web of Science electronic databases were systematically searched to identify studies conducted in the last 20 years, where T_Ty was measured in TTM context with specific focus on pre-hospital or in-hospital emergency settings.

RESULTS

The systematic search identified 35 studies, 12 performing T_Ty measurements during TTM in healthy subjects, 17 in patients with acute cardiovascular events, and 6 in patients with acute neurological diseases. The studies showed that T_Ty was able to track temperature changes induced by either local or whole-body cooling approaches in both pre-hospital and in-hospital settings. Direct comparisons to other core temperature measurements from other body sites were available in 22 studies, which showed a faster and larger change of T_Ty upon TTM compared to other core temperature measurements. Direct brain temperature measurements were available only in 3 studies and showed a good correlation between T_Ty and brain temperature, although T_Ty displayed a tendency to overestimate cooling effects compared to brain temperature.

CONCLUSIONS

T_Ty was capable to track temperature changes under a variety of TTM protocols and clinical conditions in both pre-hospital and in-hospital settings. Due to the heterogeneity and paucity of comparative temperature data, future studies are needed to fully elucidate the advantages of T_Ty in emergency settings and its capability to track brain temperature.

Association between length of stay in the emergency department and outcomes in out-of-hospital cardiac arrest

OBJECTIVE

Several studies have previously reported that a prolonged emergency department length of stay (EDLOS) is associated with poor outcomes in critically ill patients. This study was performed to investigate the relationship between the EDLOS and the neurologic outcome at 28 days in out-of-hospital cardiac arrest (OHCA) patients.

METHODS

We conducted a retrospective analysis of prospectively collected data from OHCA patients who achieved the return of spontaneous circulation (ROSC) in the EDs of three urban tertiary teaching hospitals from December 2013 to October 2020. Patients were divided into four groups according to the EDLOS, according to the quartile distribution: EDLOS <107 min, EDLOS 107-176 min, EDLOS 176-275 min, and EDLOS ≥275 min. Comparisons of outcomes among the groups and multivariable logistic regression analysis were performed.

RESULTS

A total of 807 patients were included in the analysis. The proportions of patients with a good neurologic outcome at 28 days in the groups with EDLOS <107 min, EDLOS 107-176 min, EDLOS 176-275 min, and EDLOS ≥275 min were 37.0%, 29.8%, 26.9, and 20.4%, respectively (p < 0.001). In the multivariable analysis, the odds ratios for a poor neurologic outcome at 28 days in the groups with EDLOS 107-176 min, EDLOS 176-275 min, and EDLOS ≥275 min compared with the group with EDLOS <107 min were 1.19 (95% CI, 0.67-2.13), 1.73 (95% CI, 0.95-3.21), and 1.91 (95% CI, 1.03-3.57), respectively.

CONCLUSIONS

An EDLOS longer than 275 min after the ROSC was independently associated with a poor neurologic outcome at 28 days.

EEG-Based Prediction of the Recovery of Carotid Blood Flow during Cardiopulmonary Resuscitation in a Swine Model

The recovery of cerebral circulation during cardiopulmonary resuscitation (CPR) is important to improve the neurologic outcomes of cardiac arrest patients. To evaluate the feasibility of an electroencephalogram (EEG)-based prediction model as a CPR feedback indicator of high- or low-CBF carotid blood flow (CBF), the frontal EEG and hemodynamic data including CBF were measured during animal experiments with a ventricular fibrillation (VF) swine model. The most significant 10 EEG parameters in the time, frequency and entropy domains were determined by neighborhood component analysis and Student’s t-test for discriminating high- or low-CBF recovery with a division criterion of 30%. As a binary CBF classifier, the performances of logistic regression, support vector machine (SVM), k-nearest neighbor, random forest and multilayer perceptron algorithms were compared with eight-fold cross-validation. The three-order polynomial kernel-based SVM model showed the best accuracy of 0.853. The sensitivity, specificity, F1 score and area under the curve of the SVM model were 0.807, 0.906, 0.853 and 0.909, respectively. An automated CBF classifier derived from non-invasive EEG is feasible as a potential indicator of the CBF recovery during CPR in a VF swine model.

Mild therapeutic hypothermia improves neurological outcomes in a rat model of cardiac arrest

Cardiac arrest (CA) is the leading cause of death in humans. Research has shown that mild therapeutic hypothermia (MTH) can reduce neurological sequelae and mortality after CA. Nevertheless, the mechanism remains unclear. This study aimed to determine whether MTH promotes neurogenesis, attenuates neuronal damage, and inhibits apoptosis of neurons in rats after CA. Sprague-Dawley rats were divided into the normothermia and mild hypothermia groups. The rats in the normothermia and hypothermia groups were exposed to 2 h of normothermia (36-37℃) and hypothermia (32-33℃), respectively, immediately after resuscitation from 5 min of asphyxial CA. Corresponding control groups not subjected to CA were included. On days 1-6, 5-bromodeoxyuridine (BrdU) 100 mg/kg/day was administered intraperitoneally. The animals were euthanized 1 week after CA. Compared with the normothermia group, the hypothermia group showed a significant increase in the number of doublecortin (DCX) immune-positive cells in the subgranular zone of the hippocampus 1 week after CA. Neurogenesis was assessed using double immunofluorescent labeling of BrdU with neuronal-specific nuclear protein (NeuN)/DCX. There was no marked change in the number of newborn mature (BrdU+-NeuN+) neurons, though there was a significant increase in the number of newborn immature (BrdU+-DCX+) neurons in the hypothermia than in the normothermia group 1 week after CA. Neuronal injury and apoptosis in the CA1 region of the hippocampus, assessed using NeuN immunofluorescence and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assays, were significantly reduced in the hypothermia group 1 week after CA. Moreover, mild hypothermia increased the expression of cold-shock protein RNA-binding motif protein 3 (RBM3) in the early stage (24 h/48 h) after CA. These results suggested that mild hypothermia promotes generation of neuronal cells, reduces neuronal injury, and inhibits apoptosis of neurons, which may be related to RBM3 expression.

Association between body mass index and clinical outcomes in out-of-hospital cardiac arrest survivors treated with targeted temperature management

BACKGROUND

To determine the impact of body mass index (BMI) on clinical outcomes in out-of-hospital cardiac arrest (OHCA) survivors treated with targeted temperature management (TTM).

METHODS

We conducted a retrospective cohort study of 261 adult OHCA survivors who received complete TTM between January 2011 and December 2018 using data from the Research Patient Database Registry of Partners HealthCare system in Boston. Patients were categorized as underweight (BMI < 18.5 kg/m2), normal weight (BMI = 18.5-24.9 kg/m2), overweight (BMI = 25-29.9 kg/m2), and obese (BMI ≥ 30 kg/m2), according to the World Health Organization classification.

RESULTS

The average BMI was 28.9 ± 7.1 kg/m2. Patients with a higher BMI had higher rates of hypertension and diabetes mellitus, and were more likely to be witnessed on collapse. Patients with lower BMI levels had higher sequential organ failure assessment (SOFA) scores, blood urea nitrogen values, and mild thrombocytopenia rates (platelet count <150 K/μL) after the TTM treatment. The survival to discharge and favorable neurological outcome at discharge were reported in 117 (44.8%) and 76 (29.1%) patients, respectively. The survival at discharge, favorable neurologic outcomes at discharge, length of hospital admission, and the occurrence of acute kidney injury did not significantly differ between the BMI subgroups. In logistic regression model, BMI was not an independent predictor for survival at discharge (adjusted odds ratio 0.945, 95% CI 0.883-1.012, p = 0.108) nor for the favorable neurologic outcome at discharge (adjusted odds ratio 1.022, 95% CI 0.955-1.093, p = 0.528).

CONCLUSION

In OHCA patients treated with TTM, there was no significant difference across BMI subgroups for survival or favorable neurologic outcome at discharge.

Feline cardiopulmonary resuscitation: Getting the most out of all nine lives

PRACTICAL RELEVANCE

Cardiopulmonary arrest (CPA) can occur in any veterinary or animal care setting and is a particular risk in scenarios involving ill, injured or anesthetized patients. Education of all staff on the prevention and recognition of CPA, as well as the performance of cardiopulmonary resuscitation (CPR), is vital to influencing outcome.

EVIDENCE BASE

While there is a plethora of information regarding CPA and CPR in human medicine, there are comparably few studies in the veterinary literature. Many of the current veterinary guidelines are extrapolated from human medicine or studies based on animal models. Ongoing work is needed to tailor guidelines and recommendations to our domestic feline (and canine) patients in a clinical setting.

AIM

The aim of this article, which is intended for veterinarians in all areas of small animal practice, is to provide an evidence-based review of CPA and CPR in feline patients. The authors have drawn heavily on detailed recommendations published by the Reassessment Campaign on Veterinary Resuscitation (RECOVER) initiative - one of the few resources specific to the veterinary clinical setting - as well as reviewing the available peer-reviewed literature studies, in constructing this article. Among the topics discussed are recognizing and preventing CPA, staff training and clinic preparedness, basic life support and advanced life support interventions, and appropriate post-cardiac arrest care.

Gender differences and survival after an out-of-hospital cardiac arrest: a systematic review and meta-analysis

Patients who experience out-of-hospital cardiac arrest (OHCA) have unacceptably high mortality rates. It remains unclear whether gender has an association with survival in this regard. Hence, we aimed to investigate the association between gender and survival by conducting a systematic review and meta-analysis. The databases of PubMed, Embase, and Cochrane Database of Systematic Reviews were searched from inception to 17 March, 2020. Studies assessing the association between gender and survival to discharge or 30-day survival after OHCA were included. Two reviewers independently assessed the eligibility of the identified studies. The random-effects model was used to pool data, and the outcome was reported as odds ratios (ORs) and 95% confidence intervals, as the relative measure of association. Twenty-three eligible studies enrolling 897,805 patients were included in this systematic review. Overall, women were older and less likely to experience arrest in public places. When arrest occurred, women had less initial shockable rhythm, were less likely to be witnessed by bystanders, and were less likely provided with CPR compared with men. After admission, women underwent less coronary angiography, percutaneous coronary angiography, and targeted temperature management therapy. Eleven studies with ORs were pooled, showing a significant survival benefit in women (OR = 1.08, p < 0.05, I² = 52.3%). In the subgroup analysis, both premenopausal women (< 50 years) (OR = 1.42, p < 0.001, I² = 0%) and postmenopausal women (≥ 50 years) (OR = 1.07, p < 0.05, I² = 16.4%) had higher odds of survival compared with age-matched men. Despite the unfavorable factors, the pooled results showed a significant survival benefit in women after OHCA, especially in premenopausal women.

Efficacy of Targeted Temperature Management after Pediatric Cardiac Arrest: A Meta-Analysis of 2002 Patients

Cardiac arrest (CA) is associated with high mortality and poor life quality. Targeted temperature management (TTM) or therapeutic hypothermia is a therapy increasing the survival of adult patients after CA. The study aim was to assess the feasibility of therapeutic hypothermia after pediatric CA. We performed a systematic review and meta-analysis of randomized controlled trials and observational studies evaluating the use of TTM after pediatric CA. The primary outcome was survival to hospital discharge or 30-day survival. Secondary outcomes included a one-year survival rate, survival with a Vineland adaptive behavior scale (VABS-II) score ≥ 70, and occurrence of adverse events. Ten articles (n = 2002 patients) were included, comparing TTM patients (n = 638) with controls (n = 1364). In a fixed-effects meta-analysis, survival to hospital discharge in the TTM group was 49.7%, which was higher than in the non-TTM group (43.5%; odds ratio, OR = 1.22; 95% confidence interval, CI: 1.00, 1.50; p = 0.06). There were no differences in the one-year survival rate or the occurrence of adverse events between the TTM and non-TTM groups. Altogether, the use of TTM was associated with a higher survival to hospital discharge; however, it did not significantly increase the annual survival. Additional high-quality prospective studies are necessary to confer additional TTM benefits.

The Potential Risk Factors for Mortality in Patients After In-Hospital Cardiac Arrest: A Multicenter Study

Background and Purpose: In-hospital cardiac arrest (IHCA) has high mortality rate, which needs more research. This multi-center study aims to evaluate potential risk factors for mortality in patients after IHCA.

Methods: Data for this study retrospectively enrolled IHCA patients from 14 regional hospitals, two district hospitals, and five medical centers between 2013 June and 2018 December. The study enrolled 5,306 patients and there were 2,871 patients in subgroup of intensive care unit (ICU) and emergency room (ER), and 1,894 patients in subgroup of general wards.

Results: As for overall IHCA patients, odds ratio (OR) for mortality was higher in older patients (OR = 1.69; 95% CI:1.33–2.14), those treated with ventilator (OR = 1.79; 95% CI:1.36–2.38) and vasoactive agents (OR = 1.88; 95% CI:1.45–2.46). Whereas, better survival was reported in IHCA patients with initial rhythm as ventricular tachycardia (OR = 0.32; 95% CI: 0.21–0.50) and ventricular fibrillation (OR = 0.26; 95% CI: 0.16–0.42). With regard to ICU and ER subgroup, there was no mortality difference among different nursing shifts, whereas for patients in general wards, overnight shift (OR = 1.83; 95% CI: 1.07–3.11) leads to poor outcome.

Conclusion: For IHCA patients, old age, receiving ventilator support and vasoactive agents reported poor survival. Overnight shift had poor survival for IHCA patients in general wards, despite no significance in overall and ICU/ER subgroups.

Post-cardiac arrest syndrome in adult hospitalized patients

Adult In-hospital Cardiac Arrest (IHCA) is defined as the loss of circulation of an in-patient. Following high-quality cardiopulmonary resuscitation (CPR), if the return of spontaneous circulation (ROSC) is achieved, the post-cardiac arrest syndrome develops (PCAS). This review is intended to discuss the current diagnosis and treatment of PCAS. To approach this topic, a bibliography search was conducted through direct digital access to the scientific literature published in English and Spanish between 2014 and 2020, in MedLine, SciELO, Embase and Cochrane. This search resulted in 248 articles from which original articles, systematic reviews, meta-analyses and clinical practice guidelines were selected for a total of 56 documents. The etiologies may be divided into 56% of in-hospital cardiac, and 44% of non-cardiac arrests. The incidence of this physiological collapse is up to 1.6 cases/1,000 patients admitted, and its frequency is higher in the intensive care units (ICU), with an overall survival rate of 13% at one year. The primary components of PCAS are brain injury, myocardial dysfunction and the persistence of the precipitating pathology. The mainstays for managing PCAS are the prevention of cardiac arrest, ventilation support, control of peri-cardiac arrest arrythmias, and interventions to optimize neurologic recovery. A knowledgeable healthcare staff in PCAS results in improved patient survival and future quality of life. Finally, there is clear need to do further research in the Latin American Population.

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.

Feasibility and beneficial effects of an early goal directed therapy after cardiac arrest: evaluation by conductance method

Although beneficial effects of an early goal directed therapy (EGDT) after cardiac arrest and successful return of spontaneous circulation (ROSC) have been described, clinical implementation in this period seems rather difficult. The aim of the present study was to investigate the feasibility and the impact of EGDT on myocardial damage and function after cardiac resuscitation. A translational pig model which has been carefully adapted to the clinical setting was employed. After 8 min of cardiac arrest and successful ROSC, pigs were randomized to receive either EGDT (EGDT group) or therapy by random computer-controlled hemodynamic thresholds (noEGDT group). Therapeutic algorithms included blood gas analysis, conductance catheter method, thermodilution cardiac output and transesophageal echocardiography. Twenty-one animals achieved successful ROSC of which 13 pigs survived the whole experimental period and could be included into final analysis. cTnT and LDH concentrations were lower in the EGDT group without reaching statistical significance. Comparison of lactate concentrations between 1 and 8 h after ROSC exhibited a decrease to nearly baseline levels within the EGDT group (1 h vs 8 h: 7.9 vs. 1.7 mmol/l, P < 0.01), while in the noEGDT group lactate concentrations did not significantly decrease. The EGDT group revealed a higher initial need for fluids (P < 0.05) and less epinephrine administration (P < 0.05) post ROSC. Conductance method determined significant higher values for preload recruitable stroke work, ejection fraction and maximum rate of pressure change in the ventricle for the EGDT group. EGDT after cardiac arrest is associated with a significant decrease of lactate levels to nearly baseline and is able to improve systolic myocardial function. Although the results of our study suggest that implementation of an EGDT algorithm for post cardiac arrest care seems feasible, the impact and implementation of EGDT algorithms after cardiac arrest need to be further investigated.

Repetitive anodal transcranial direct current stimulation improves neurological recovery by preserving the neuroplasticity in an asphyxial rat model of cardiac arrest

BACKGROUND

Non-shockable rhythms present an increasing proportion of out-of-hospital cardiac arrest (CA) patients, but are associated with poor prognosis and received limited therapeutic effect of targeted temperature management (TTM). Previous study showed repetitive anodal transcranial direct current stimulation (tDCS) improved neurological outcomes in animals with ventricular fibrillation. Here, we examine the effectiveness of tDCS on neurological recovery and the potential mechanisms in a rat model of asphyxial CA.

METHOD

Cardiopulmonary resuscitation was initiated after 5 min of untreated asphyxial CA. Animals were randomized to three experimental groups immediately after successful resuscitation (n = 12/group, 6 males): no-treatment control (NTC) group, TTM group, and tDCS group. Post resuscitation hemodynamics, quantitative electroencephalogram (EEG), neurological deficit score, and 96-h survival were evaluated. Brain tissues of additional animals undergoing same experimental procedure was harvested for enzyme-linked immunoassay-based quantification assays of neuroplasticity-related biomarkers and compared with the sham-operated rats (n = 6/group).

RESULTS

We observed that after resuscitation tDCS-treated animals exhibited significantly higher mean arterial pressure and left ventricular ejection fraction than NTC group and showed greatly improved EEG characteristics including weighted-permutation entropy and gamma band power, and neurologic deficit scores and 96-h survival rates compared to NTC and TTM groups. Furthermore, neuroplastic biomarkers including microtubule-associated protein 2, growth-associated protein 43, postsynaptic density protein 95 and synaptophysin, were significantly higher in tDCS group when compared with NTC and TTM groups.

CONCLUSION

In this rat model of asphyxial CA, repetitive anodal tDCS commenced after resuscitation improved neurological recovery, and it may exert a neuroprotective effect by preserving the neuroplasticity.

A descriptive analysis of cross-sectional imaging findings in patients after non-traumatic sudden cardiac arrest

Introduction

Cross-sectional imaging is frequently obtained after sudden cardiac arrest (SCA) to determine the aetiology. Although imaging studies may reveal acute and/or chronic findings that may impact downstream medical management, lack of standardized guidelines results in significant practice variability. We aimed to perform a descriptive analysis and to report on radiographic findings after SCA.

Methods

This was a retrospective observational descriptive study that included all adult SCA patients who presented to our emergency department (ED) over a 6-year period, achieved sustained return of spontaneous circulation, and subsequently received cross-sectional imaging while in the ED. Each imaging study was reviewed and graded based on a predefined scale, and significant radiographic findings were tabulated.

Results

1573 patients were identified, and 452 patients remained after applying predefined exclusion criteria. A total of 298, 184, and 113 computed tomography (CT) studies were performed of the head, chest, and abdomen, respectively. For head, chest, and abdominal imaging, 13 (4.4%), 23 (12.5%), and 6 (5.3%) studies had radiographic findings that likely contributed to SCA, respectively. Altogether, 42 (7.1%) radiographic studies had findings that likely contributed to SCA. Eighty (13.4%) studies (head [n = 38, 12.8%], chest [n = 26, 14.1%], abdomen [n = 16, 14.2%]) resulted in a change of clinical care (e.g. specialty consultation or procedures).

Conclusion

Given the clinical uncertainty and relative instability during the post-SCA phase, cross-sectional imaging frequently reveals important acute and chronic diagnostic findings.

Effect of Out-of-Hospital Sodium Nitrite on Survival to Hospital Admission After Cardiac Arrest: A Randomized Clinical Trial

IMPORTANCE

Therapeutic delivery of sodium nitrite during resuscitation improved survival in animal models of cardiac arrest, but efficacy has not been evaluated in clinical trials in humans.

OBJECTIVE

To determine whether parenteral administration of sodium nitrite given by paramedics during resuscitation for out-of-hospital cardiac arrest improved survival to hospital admission.

DESIGN, SETTING, AND PARTICIPANTS

Double-blind, placebo-controlled, phase 2 randomized clinical trial including 1502 adults in King County, Washington, with out-of-hospital cardiac arrest from ventricular fibrillation or nonventricular fibrillation. Patients underwent resuscitation by paramedics and were enrolled between February 8, 2018, and August 19, 2019; follow-up and data abstraction were completed by December 31, 2019.

INTERVENTIONS

Eligible patients with out-of-hospital cardiac arrest were randomized (1:1:1) to receive 45 mg of sodium nitrite (n = 500), 60 mg of sodium nitrite (n = 498), or placebo (n = 499), which was given via bolus injection by the paramedics as soon as possible during active resuscitation.

MAIN OUTCOMES AND MEASURES

The primary outcome was survival to hospital admission and was evaluated with 1-sided hypothesis testing. The secondary outcomes included out-of-hospital variables (rate of return of spontaneous circulation, rate of rearrest, and use of norepinephrine to support blood pressure) and in-hospital variables (survival to hospital discharge; neurological outcomes at hospital discharge; cumulative survival to 24 hours, 48 hours, and 72 hours; and number of days in the intensive care unit).

RESULTS

Among 1502 patients with out-of-hospital cardiac arrest who were randomized (mean age, 64 years [SD, 17 years]; 34% were women), 99% completed the trial. Overall, 205 patients (41%) in the 45 mg of sodium nitrite group and 212 patients (43%) in the 60 mg of sodium nitrite group compared with 218 patients (44%) in the placebo group survived to hospital admission; the mean difference for the 45-mg dose vs placebo was -2.9% (1-sided 95% CI, -8.0% to ∞; P = .82) and the mean difference for the 60-mg dose vs placebo was -1.3% (1-sided 95% CI, -6.5% to ∞; P = .66). None of the 7 prespecified secondary outcomes were significantly different, including survival to hospital discharge for 66 patients (13.2%) in the 45 mg of sodium nitrite group and 72 patients (14.5%) in the 60 mg of sodium nitrite group compared with 74 patients (14.9%) in the placebo group; the mean difference for the 45-mg dose vs placebo was -1.7% (2-sided 95% CI, -6.0% to 2.6%; P = .44) and the mean difference for the 60-mg dose vs placebo was -0.4% (2-sided 95% CI, -4.9% to 4.0%; P = .85).

CONCLUSIONS AND RELEVANCE

Among patients with out-of-hospital cardiac arrest, administration of sodium nitrite, compared with placebo, did not significantly improve survival to hospital admission. These findings do not support the use of sodium nitrite during resuscitation from out-of-hospital cardiac arrest.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03452917.

Association of Timing of Electrocardiogram Acquisition After Return of Spontaneous Circulation With Coronary Angiography Findings in Patients With Out-of-Hospital Cardiac Arrest

IMPORTANCE

Electrocardiography (ECG) is an important tool to triage patients with out-of-hospital cardiac arrest (OHCA) after return of spontaneous circulation (ROSC). An immediate coronary angiography after ROSC is recommended only in patients with an ECG that is diagnostic of ST-segment elevation myocardial infarction (STEMI). To date, the benefit of this approach has not been demonstrated in patients with a post-ROSC ECG that is not diagnostic of STEMI.

OBJECTIVE

To assess whether the time from ROSC to ECG acquisition is associated with the diagnostic accuracy of ECG for STEMI.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective, multicenter cohort study (the Post-ROSC Electrocardiogram After Cardiac Arrest study) analyzed consecutive patients older than 18 years who were resuscitated from OHCA between January 1, 2015, and December 31, 2018, and were admitted to 1 of the 3 participating centers in Europe (Pavia, Italy; Lugano, Switzerland; and Vienna, Austria).

EXPOSURE

Only patients who underwent coronary angiography during hospitalization and who acquired a post-ROSC ECG before the angiography were enrolled. Patients with a nonmedical cause of OHCAs were excluded.

MAIN OUTCOMES AND MEASURES

The primary end point was false-positive ECG findings, defined as the percentage of patients with post-ROSC ECG findings that met STEMI criteria but who did not show obstructive coronary artery disease on angiography that was worthy of percutaneous coronary angioplasty.

RESULTS

Of 586 consecutive patients who were admitted to the 3 participating centers, 370 were included in the analysis (287 men [77.6%]; median age, 62 years [interquartile range, 53-70 years]); 121 (32.7%) were enrolled in the participating center in Pavia, Italy; 38 (10.3%) in Lugano, Switzerland; and 211 (57.0%) in Vienna, Austria. The percentage of false-positive ECG findings in the first tertile of ROSC to ECG time (≤7 minutes) was significantly higher than that in the second (8-33 minutes) and third (>33 minutes) tertiles: 18.5% in the first tertile vs 7.2% in the second (odds ratio [OR], 0.34; 95% CI, 0.13-0.87; P = .02) and 5.8% in the third (OR, 0.27; 95% CI, 0.15-0.47; P < .001). These differences remained significant when adjusting for sex (≤7 minutes: reference; 8-33 minutes: OR, 0.32; 95% CI, 0.12-0.85; P = .02; >33 minutes: OR, 0.26; 95% CI, 0.14-0.47; P < .001), age (≤7 minutes: reference; 8-33 minutes: OR, 0.34; 95% CI, 0.13-0.89; P = .03; >33 minutes: OR, 0.27; 95% CI, 0.15-0.46; P < .001), number of segments with ST-elevation (≤7 minutes: reference; 8-33 minutes: OR, 0.35; 95% CI, 0.15-0.81; P = .01; >33 minutes: OR, 0.28; 95% CI, 0.15-0.52; P < .001), QRS duration (≤7 minutes: reference; 8-33 minutes: OR, 0.35; 95% CI, 0.14-0.87; P = .02; >33 minutes: OR, 0.27; 95% CI, 0.15-0.48; P < .001), heart rate (≤7 minutes: reference; 8-33 minutes: OR, 0.35; 95% CI, 0.13-0.93; P = .04; >33 minutes: OR, 0.29; 95% CI, 0.15-0.55; P < .001), epinephrine administered (≤7 minutes: reference; 8-33 minutes: OR, 0.35; 95% CI, 0.13-0.98; P = .045; >33 minutes: OR, 0.27; 95% CI, 0.16-0.48; P < .001), shockable initial rhythm (≤7 minutes: reference; 8-33 minutes: OR, 0.35; 95% CI, 0.13-0.96; P = .04; >33 minutes: OR, 0.26; 95% CI, 0.15-0.46; P < .001), and 3 or more shocks administered (≤7 minutes: reference; 8-33 minutes: OR, 0.36; 95% CI, 0.13-1.00; P = .05; >33 minutes: OR, 0.27; 95% CI, 0.16-0.48; P < .001) in bivariable analyses.

CONCLUSIONS AND RELEVANCE

This study suggests that early ECG acquisition after ROSC in patients with OHCA is associated with a higher percentage of false-positive ECG findings for STEMI. It may be reasonable to delay post-ROSC ECG by at least 8 minutes after ROSC or repeat the acquisition if the first ECG is diagnostic of STEMI and is acquired early after ROSC.

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.

Outcome and status of postcardiac arrest care in Korea: results from the Korean Hypothermia Network prospective registry

Objective

High-quality intensive care, including targeted temperature management (TTM) for patients with postcardiac arrest syndrome, is a key element for improving outcomes after out-of-hospital cardiac arrest (OHCA). We aimed to assess the status of postcardiac arrest syndrome care, including TTM and 6-month survival with neurologically favorable outcomes, after adult OHCA patients were treated with TTM, using data from the Korean Hypothermia Network prospective registry.

Methods

We used the Korean Hypothermia Network prospective registry, a web-based multicenter registry that includes data from 22 participating hospitals throughout the Republic of Korea. Adult comatose OHCA survivors treated with TTM between October 2015 and December 2018 were included. The primary outcome was neurological outcome at 6 months.

Results

Of the 1,354 registered OHCA survivors treated with TTM, 550 (40.6%) survived 6 months, and 413 (30.5%) had good neurological outcomes. We identified 839 (62.0%) patients with preClinsumed cardiac etiology. A total of 937 (69.2%) collapses were witnessed, shockable rhythms were demonstrated in 482 (35.6%) patients, and 421 (31.1%) patients arrived at the emergency department with prehospital return of spontaneous circulation. The most common target temperature was 33°C, and the most common target duration was 24 hours.

Conclusion

The survival and good neurologic outcome rates of this prospective registry show great improvements compared with those of an earlier registry. While the optimal target temperature and duration are still unknown, the most common target temperature was 33°C, and the most common target duration was 24 hours.

Veno-arterial CO2 difference and respiratory quotient after cardiac arrest: An observational cohort study

PURPOSE

To characterize venous-arterial CO₂ difference (ΔpCO₂) and the respiratory quotient (RQ) in post cardiac arrest patients and evaluate the association between these parameters and patient outcome.

MATERIALS AND METHODS

Data were obtained retrospectively from post cardiac arrest patients admitted between 2007 and 2016 to a medical intensive care unit. Comatose, adult patients in whom arterial and venous blood gas analyses were concomitantly performed in the first 24 h were included. Patients were grouped according to the time-point of sampling; 0-6, 6-12 and 12-24 h after admission.

RESULTS

308 patients were included; 174 (56%) died before ICU discharge and 212 (69%) had an unfavorable neurologic outcome. RQ was associated with ICU mortality (OR:1.09 (95%CI: 1.04-1.14; p < 0.01)), although not with neurological outcome. ΔpCO₂ was negatively associated with both ICU mortality (OR: 0.92 (95%CI: 0.86-0.99; p = 0.02)) and poor neurologic outcome (adjusted OR: 0.93 (95%CI: 0.87-0.99; p = 0.02)). ΔpCO₂ predicted an elevated RQ; a ΔpCO₂ above 8.5 mmHg identified a high RQ with reasonable sensitivity and specificity.

CONCLUSIONS

RQ was associated with ICU mortality and ΔpCO₂ identified elevated RQ in the early phase after cardiac arrest. However, ΔpCO₂ were negatively associated with both ICU mortality and neurologic outcome.

Intra-arterial Cold Saline Infusion in Stroke: Historical Evolution and Future Prospects

Acute ischemic stroke (AIS) is a perpetual threat to life and functionality due to its high morbidity and mortality. In the past several decades, therapeutic hypothermia has garnered interest as an effective neuroprotective method in the setting of AIS. However, traditional hypothermic methods have been criticized for their low cooling efficiency and side effects. Intra-arterial cold saline infusion (IA-CSI), as a novel hypothermic method, not only minimizes these side effects, but is also perfectly integrated with widely accepted recanalization modalities in AIS, thereby serving as a promising prospect for clinical translation. In this article, we review the historical development of IA-CSI, summarize major studies of IA-CSI in rodents, large animals, and humans to date, and suggest insight into future development prospects in the field of AIS. We hope that this article will provide inspiration for the future application of hypothermia in AIS patients.

A pilot protocol and review of triple neuroprotection with targeted hypothermia, controlled induced hypertension, and barbiturate infusion during emergency carotid endarterectomy for acute stroke after failed tPA or beyond 24-hour window of opportunity

An alternative to tissue plasminogen activator (tPA) failure has been a daunting challenge in ischemic stroke management. As tPA is time-dependent, delays can occur in definitive treatment while passively waiting to observe a clinical response to intravenous thrombolysis. Until today, uncertainty exists in the management strategy of wake-up stroke patients or those presenting beyond the therapeutic tPA window. Clinical dilemmas in these situations can prolong the transitional period of inertia, resulting in an adverse neurological outcome. We propose and review an innovative approach called triple neuro-protection (TNP), which encompasses three technical domains-targeted hypothermia, systemic induced hypertension, and barbiturates infusion, to protect the brain during carotid endarterectomy after failed tPA and/or beyond the 24-hour therapeutic mechanical thrombectomy window. This proposal assimilates discussion on the clinical evidence of the individual domains of TNP with our own clinical experience with TNP. Our first TNP was successfully employed in a 55-year-old man in 2015 while performing emergency carotid endarterectomy after he was referred to us 72 hours post tPA failure. The patient had a successful clinical outcome despite being in therapeutic inertia with 90–99% ipsilateral carotid stenosis and contralateral occlusion on presentation. In the last five years, we have safely used TNP in 25 selected cases with favourable clinical outcomes.

Emerging Trends and Hot Topics in Cardiopulmonary Resuscitation Research: A Bibliometric Analysis from 2010 to 2019

Background

Cardiopulmonary resuscitation (CPR) is a topic of great scientific and clinical interest that has received much attention in the past decade. Our study aimed to predict the trends in CPR research activities and evaluate hot topics via bibliometric means, quantitatively and qualitatively.

Material/Methods

All data were collected from a search of the Web of Science Core Collection on May 12, 2020. Retrieved information was investigated with bibliometric analysis by CiteSpace and VOSviewer software and the Online Analysis Platform of Literature Metrology to analyze and predict the trends and hotspots in this field.

Results

Our search returned a total of 9563 articles and reviews on CPR published from 2010 through 2019. The number of original research studies on CPR has been increasing annually. The journal Resuscitation published the greatest number of manuscripts involved CPR, and the leading country and institution with regard to contributions on CPR were the United States and the University of Pennsylvania. Keyword co-occurrence/co-citation-cluster analysis showed that the most popular terms associated with CPR occurred in the manner of cluster labels, such as therapeutic hypothermia and treatment recommendation, among others. In addition, palliative care, sepsis, extracorporeal membrane oxygenation, and brain injury were identified as new foci through burst detection analysis.

Conclusions

Our study showed that the scientific research focus on CPR is switching from traditional therapeutic treatments to a public health practice, with in-depth understanding and development of CPR-related techniques expanding over the past decade. These results demonstrate trends in the CPR research and detected the possible neo-foci for ensuing research.

Moderate Hypothermia Effectively Alleviates Acetaminophen-Induced Liver Injury With Prolonged Action Beyond Cooling

Acetaminophen (APAP) overdose accounts for the highest incidence of acute liver failure, despite the availability of an antidote i.e. N-acetylcysteine. This calls for alternative strategies to manage APAP-induced liver injury (AILI). Therapeutic hypothermia has been explored in past studies for hepatoprotection, but these phenomenal reports lack clarification of its optimal window for application, and mechanistic effects in specific AILI. Hence, we conducted an in vitro study with transforming growth factor-α transgenic mouse hepatocytes cell line, TAMH, and human liver hepatocytes cell line, L-02, where cells were conditioned with deep (25°C) or moderate (32°C) hypothermia before, during or after APAP toxicity. Cell viability was evaluated as a hallmark of cytoprotection, along with cell death. Simultaneously, cold shock proteins (CSPs) and heat shock proteins expressions were monitored; key liver functions including drug-metabolizing ability and hepatic clearance were also investigated. Herein, we demonstrated significant hepatoprotection with 24-hour moderate hypothermic conditioning during AILI and this effect sustained for at least 24 hours of rewarming. Such liver preservation was associated with a CSP—RNA-binding motif protein 3 (RBM3) as its knockdown promptly abolished the cytoprotective effects of hypothermia. With mild and reversible liver perturbations, hypothermic therapy appears promising and its RBM3 involvement deserves future exploration.

Meta-Analysis of the Usefulness of Therapeutic Hypothermia After Cardiac Arrest

Despite current guidelines recommending therapeutic hypothermia (TH) for post cardiac arrest comatose patient, its use remains limited. Randomized controlled trials (RCTs) have also reported conflicting results on the efficacy of TH. Therefore, we conducted an updated meta-analysis to evaluate the effect of TH in post cardiac arrest patients. We searched electronic databases for RCTs comparing TH (32°C to 34°C) with controls (normothermia or temperature ≥36°C) in comatose patients who sustained cardiac arrest. Mortality and neurological outcomes were the outcomes of interest. We used random effect meta-analysis to estimate risk ratio (RR) with 95% confidence interval (CI). Eight RCTs with a total of 2,026 patients (TH n = 1,025 and control n = 1,001) were included. Irrespective of initial rhythm, TH was associated with significant reduction in poor neurological outcomes (RR 0.87, 95% CI 0.77 to 0.98; p = 0.02) without any difference in mortality (RR 0.94, 95% CI 0.85 to 1.03; p = 0.17). In patients with initial shockable rhythm compared with control, TH reduced mortality (RR 0.85, 95% CI 0.73 to 0.99; p = 0.04) and poor neurological outcomes (RR 0.81, 95% CI 0.67 to 0.99; p = 0.04). Whereas, in patients with initial nonshockable rhythm, TH was associated with decreased poor neurological outcomes after excluding one trial (RR 0.95 95% CI 0.91 to 1.00; p = 0.05). In conclusion, TH is associated with improved neurological outcomes in all patients sustaining cardiac arrest and with decreased mortality in patients with initial shockable rhythm.

Targeted Temperature Management for Treatment of Cardiac Arrest

Purpose of review

Cardiac arrest is a common condition associated with high mortality and a substantial risk of neurological injury among survivors. Targeted temperature management (TTM) is the only strategy shown to reduce the risk of neurologic disability cardiac arrest patients. In this article, we provide a comprehensive review of TTM with an emphasis on recent trials.

Recent findings

After early studies demonstrating the benefit of TTM in out-of-hospital cardiac arrest due to a shockable rhythm, newer studies have extended the benefit of TTM to patients with a nonshockable rhythm and in-hospital cardiac arrest. A target temperature of 33 °C was not superior to 36 °C, suggesting that a lenient targeted temperature may be appropriate especially for patients unable to tolerate lower temperatures. Although early initiation of TTM appears to be beneficial, the benefit of prehospital cooling has not been shown and use of intravenous cold saline in the prehospital setting may be harmful.

Summary

There is substantial risk of neurological injury in cardiac arrest survivors who remain comatose. TTM is an effective treatment that can lower the risk of neurological disability in such patients and ideally delivered as part of a comprehensive, goal-directed post-resuscitation management by a multidisciplinary team in a tertiary medical center.

In Hospitals With More Nurses Who Have Baccalaureate Degrees, Better Outcomes For Patients After Cardiac Arrest

In 2010, prompted by compelling evidence that demonstrated better patient outcomes in hospitals with higher percentages of nurses with a bachelor of science in nursing (BSN), the Institute of Medicine recommended that 80 percent of the nurse workforce be qualified at that level or higher by 2020. Using data from the American Heart Association's Get With the Guidelines-Resuscitation registry (for 2013-18), RN4CAST-US hospital nurse surveys (2015-16), and the American Hospital Association (2015), we found that each 10-percentage-point increase in the hospital share of nurses with a BSN was associated with 24 percent greater odds of surviving to discharge with good cerebral performance among patients who experienced in-hospital cardiac arrest. Lower patient-to-nurse ratios on general medical and surgical units were also associated with significantly greater odds of surviving with good cerebral performance. These findings contribute to the growing body of evidence that supports policies to increase access to baccalaureate-level education and improve hospital nurse staffing.

Therapeutic hypothermia and cardiac intervention after cardiac arrest in pregnancy with underlying maternal arrhythmia: A case report

There are few case reports of utilization of therapeutic hypothermia during pregnancy, and most report successful maternal and fetal outcomes. There is no available evidence that supports withholding therapeutic hypothermia in these patients. There are no long-term data on neonatal outcomes. We report the case of a 28-year-old pregnant patient with long QT syndrome who experienced multiple cardiac arrests during the second trimester and underwent therapeutic hypothermia, cardiac ablation, transvenous pacemaker placement, and placement of an implantable cardioverter defibrillator (ICD). She subsequently delivered a viable infant at term. The evidence seems to support the use of hypothermia during pregnancy, but patients should be counseled about the unknown maternal and fetal risks and long-term neonatal outcomes. Decisions to utilize therapeutic hypothermia should be made on an individual basis.

Near-Infrared Spectroscopy to Assess Cerebral Autoregulation and Optimal Mean Arterial Pressure in Patients With Hypoxic-Ischemic Brain Injury: A Prospective Multicenter Feasibility Study

Supplemental Digital Content is available in the text.

We provide preliminary multicenter data to suggest that recruitment and collection of physiologic data necessary to quantify cerebral autoregulation and individualized blood pressure targets are feasible in postcardiac arrest patients. We evaluated the feasibility of a multicenter protocol to enroll patients across centers, as well as collect continuous recording (≥ 80% of monitoring time) of regional cerebral oxygenation and mean arterial pressure, which is required to quantify cerebral autoregulation, using the cerebral oximetry index, and individualized optimal mean arterial pressure thresholds. Additionally, we conducted an exploratory analysis to assess if an increased percentage of monitoring time where mean arterial pressure was greater than or equal to 5 mm Hg below optimal mean arterial pressure, percentage of monitoring time with dysfunctional cerebral autoregulation (i.e., cerebral oximetry index ≥ 0.3), and time to return of spontaneous circulation were associated with an unfavorable neurologic outcome (i.e., 6-mo Cerebral Performance Category score ≥ 3).

Assessment of the Clinical Pulmonary Infection Scores for prediction of ventilator associated pneumonia in patients with out of hospital cardiac arrest

BACKGROUND

Patients suffering out-of-hospital cardiac arrest (OHCA) are at an increased risk of aspiration pneumonitis and development of subsequent aspiration pneumonia. The diagnostic uncertainty in this context can lead to a large proportion receiving broad spectrum antibiotics.

METHODS

This was a three-year, retrospective cohort study of consecutive patients admitted with OHCA. Data were collected in an Australian tertiary centre intensive care unit (ICU) between December 2016-December 2019. We assessed the incidence of Ventilator associated pneumonia (VAP), admission Clinical Pulmonary Infection Scores (CPIS) in patients with OHCA and its' association with VAP at day 3 [1]. We also assessed antibiotics prescribing (timing of initiation and drug choice) and intensive care mortality relative to the day 1 CPIS.

RESULTS

Over the three years, 100 patients were admitted with OHCA. The incidence of VAP was 6%. The CPIS on admission was not associated with development of VAP at day 3 (p = 0.75) and no significant association was found between choice of antibiotic regimens and VAP incidence. Timing of initiation of antibiotics was associated with VAP (12hrs vs 48hrs, p = 0.035) but not the choice of antibiotic (penicillin and cephalosporins vs antipseudomonal antibiotics). CPIS score at day 1 was not associated with ICU mortality in a multivariate analysis.

CONCLUSION

We demonstrated a very low incidence of VAP in OHCA patients in comparison to published studies. In this context, there was no evidence for an association between CPIS score and VAP at day 3. The CPIS may have utility as a decision support tool for targeted antibiotic prescribing in this cohort.

Continuous Neuromuscular Blockade Following Successful Resuscitation From Cardiac Arrest: A Randomized Trial

Background

Neuromuscular blockade (NMB) agents are often administered to control shivering during targeted temperature management following cardiac arrest. In this study, we hypothesized that early, continuous NMB would result in a greater reduction in serum lactate levels among comatose patients after cardiac arrest.

Methods and Results

Randomized trial of continuous NMB for 24 hours versus usual care following cardiac arrest conducted at 5 urban centers in the United States. Adult patients who achieved return of spontaneous circulation, remained unresponsive, and underwent targeted temperature management after cardiac arrest were included. The primary outcome was change in lactate over 24 hours. A total of 83 patients were randomized, and 80 were analyzed (37 and 43 in the NMB and usual care arms, respectively). There was no significant interaction between time and treatment group with respect to change in lactate over 24 hours (median lactate change from 4.2 to 2.0 mmol/L [−2.2 mmol/L] in the NMB arm versus 4.0 to 1.7 mmol/L [−2.3 mmol/L] in the usual care arm; geometric mean difference, 1.3 [95% CI, 1.0–1.8]; P=0.07 for the interaction term). There was no difference in hospital survival (38% [NMB] versus 33% [usual care]; P=0.63) or survival with good functional outcome (30% [NMB] versus 21% [usual care]; P=0.35). There were no adverse events in either arm attributed to study interventions.

Conclusions

Continuous NMB compared with usual care did not reduce lactate over the first 24 hours after enrollment compared with usual care. There was no difference in overall hospital survival, hospital survival with good neurologic outcome, or adverse events.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02260258.

Glycemic homeostasis and hepatic metabolism are modified in rats with global cerebral ischemia

Cerebral ischemia-induced hyperglycemia has been reported to accentuate neurological damage following focal or global cerebral ischemia. Hyperglycemia found in rats following focal brain ischemia occurs in the first 24 h and has been claimed to be caused by increased liver gluconeogenesis and insulin resistance. However, liver gluconeogenesis and the mechanisms leading to hyperglycemia after global cerebral ischemia remain uncertain. This study investigated the glycemic homeostasis and hepatic metabolism in rats after transient four-vessel occlusion (4-VO)-induced global cerebral ischemia, an event that mimics to a certain degree the situation during cardiac arrest. Several metabolic fluxes were measured in perfused livers. Activities and mRNA expressions of hepatic glycolysis and glyconeogenesis rate-limiting enzymes were assessed as well as respiratory activity of hepatic isolated mitochondria. Global cerebral ischemia was associated with hyperglycemia and hyperinsulinemia 24 h after ischemia. Insulin resistance developed later and was prominent after the 5th day. Hepatic anabolism and catabolism were both modified in a complex and time-dependent way. Gluconeogenesis, β-oxidation, ketogenesis and glycolysis were diminished at 24 h after ischemia. At 5 days after ischemia glycolysis had normalized, but gluconeogenesis, ketogenesis and β-oxidation were accelerated. The overall metabolic modifications suggest that a condition of depressed metabolism was established in response to the new conditions generated by the cerebral global ischemia. Whether the modifications in the liver metabolism found in rats after the ischemic insult can be translated to individuals following global brain ischemia remains uncertain, but the results of this study are hoped to encourage further investigations.

RNA-seq analysis of the key long noncoding RNAs and mRNAs related to cognitive impairment after cardiac arrest and cardiopulmonary resuscitation

Cardiac arrest (CA) is the leading cause of death around the world. Survivors after CA and cardiopulmonary resuscitation (CPR) develop moderate to severe cognitive impairment up to 60% at 3 months. Accumulating evidence demonstrated that long non-coding RNAs (lncRNAs) played a pivotal role in ischemic brain injury. This study aimed to identify potential key lncRNAs associated with early cognitive deficits after CA/CPR. LncRNA and mRNA expression profiles of the hippocampus in CA/CPR or sham group were analyzed via high-throughput RNA sequencing, which exhibited 1920 lncRNAs and 1162 mRNAs were differentially expressed. These differentially expressed genes were confirmed to be primarily associated with inflammatory or apoptotic signaling pathways through GO and KEGG pathway enrichment analysis and coding-noncoding co-expression network analysis. Among which, five key pairs of lncRNA-mRNA were further analyzed by qRT-PCR and western blot. We found that the lncRNANONMMUT113601.1 and mRNA Shc1, an inflammation and apoptosis-associated gene, exhibited the most significant changes in hippocampus of CA/CPR mice. Furthermore, we found that the correlations between this lncRNA and mRNA mainly happened in neurons of hippocampus by in situ hybridization. These results suggested that the critical pairs of lncRNA-mRNA may act as essential regulators in early cognitive deficits after resuscitation.

Inter-Hospital Transfer after Return of Spontaneous Circulation Shows no Correlation with Neurological Outcomes in Cardiac Arrest Patients Undergoing Targeted Temperature Management in Cardiac Arrest Centers

This study evaluated whether inter-hospital transfer (IHT) after the return of spontaneous circulation (ROSC) was associated with poor neurological outcomes after 6 months in post-cardiac-arrest patients treated with targeted temperature management (TTM). We used data from the Korean Hypothermia Network prospective registry from November 2015 to December 2018. These out-of-hospital cardiac arrest (OHCA) patients had either received post-cardiac arrest syndrome (PCAS) care at the same hospital or had been transferred from another hospital after ROSC. The primary endpoint was the neurological outcome 6 months after cardiac arrest. Subgroup analyses were performed to determine differences in the time from ROSC to TTM induction according to the electrocardiography results after ROSC. We enrolled 1326 patients. There were no significant differences in neurological outcomes between the direct visit and IHT groups. In patients without ST elevation, the mean time to TTM was significantly shorter in the direct visit group than in the IHT group. IHT after achieving ROSC was not associated with neurologic outcomes after 6 months in post-OHCA patients treated with TTM, even though TTM induction was delayed in transferred patients.

A Population-Based Retrospective Analysis of Post-In-Hospital Cardiac Arrest Survival after Modification of the Chain of Survival

BACKGROUND

In 2010, the American Heart Association recommended that postcardiac arrest care should be included in the chain of survival to reduce permanent neurological damage, improve quality of life, and reduce health care expenses of postcardiac arrest care.

OBJECTIVES

To investigate post-in-hospital cardiac arrest (IHCA) survival prior to and after modification of the chain of survival in 2010, with subgroup analyses per age and concomitant coronary heart disease (CHD).

METHODS

We retrospectively searched the National Health Insurance Research Database for the 2007-2015 period to collect case data coded as "427.41" or "427.5" per International Classification of Disease Clinical Modification, Ninth revision codes and analyzed the data with SPSS v22.0.

RESULTS

The 1-day survival rate in the 2011-2015 period was 2% higher than that in the 2007-2010 period (odds ratio [OR] 1.02, 95% confidence interval [CI] 1.01-1.04). Moreover, in the 2011-2015 period, the survival-to-discharge rate was increased by 1% in patients under 65 years (OR 1.01, 95% CI 1.00-1.02) and 1% in CHD patients (OR 1.01, 95% CI 1.01-1.02) compared with that in the 2007-2010 period.

CONCLUSION

For patients with IHCA, the overall short-term survival improved significantly after modification of the chain of survival. Younger patients and patients with CHD had better long-term survival.

Determining Optimal Mean Arterial Pressure After Cardiac Arrest: A Systematic Review

The use of cerebral autoregulation monitoring to identify patient-specific optimal mean arterial pressure (MAP_OPT) has emerged as a technique to augment cerebral oxygen delivery in post-cardiac arrest patients. Our systematic review aims to determine (a) the average MAP_OPT in these patients, (b) the feasibility of identifying MAP_OPT, (c) the brain tissue oxygenation levels when MAP is within proximity to the MAP_OPT and (d) the relationship between neurological outcome and MAP_OPT-targeted resuscitation strategies. We carried out this review in accordance with the PRISMA guidelines. We included all studies that used cerebral autoregulation to determine MAP_OPT in adult patients (> 16 years old) who achieved return of spontaneous circulation (ROSC) following cardiac arrest. All studies had to include our primary outcome of MAP_OPT. We excluded studies where the patients had any history of traumatic brain injury, ischemic stroke or intracranial hemorrhage. We identified six studies with 181 patients. There was wide variability in cerebral autoregulation monitoring methods, length of monitoring, calculation and reporting of MAP_OPT. Amongst all studies, the median or mean MAP_OPT was consistently above 65 mmHg (range 70-114 mmHg). Definitions of feasibility varied among studies and were difficult to summarize. Only one study noted that brain tissue oxygenation increased as patients' MAP approached MAP_OPT. There was no consistent association between targeting MAP_OPT and improved neurological outcome. There is considerable heterogeneity in MAP_OPT due to differences in monitoring methods of autoregulation. Further research is needed to assess the clinical utility of MAP_OPT-guided strategies on decreasing secondary injury and improving neurological outcomes after ROSC.