Part 9: Post–Cardiac Arrest Care

Initial Rhythm and Resuscitation Outcomes for Patients Developing Cardiac Arrest in Hospital: Data From Low-Middle Income Country

BACKGROUND

Health care resource allocation remains challenging in lower middle income countries such as Kenya with meager resources being allocated to resuscitation and critical care. The causes and outcomes for in-hospital cardiac arrest and resuscitation have not been studied.

OBJECTIVES

This study sought to determine the initial rhythm and the survival for patients developing in-hospital cardiac arrest.

METHODS

This was a prospective study for in-hospital cardiac arrest in 6 Kenyan hospitals from July 2014 to April 2016. Resuscitation teams were utilized to collect data during resuscitation using a standardized protocol. Patients with do-not-resuscitate orders, trauma, postsurgical, and pregnancy-related complications were excluded. The Modified Early Warning Score (MEWS)- systolic blood pressure, heart rate, respiration rate, temperature, and responsiveness-was determined based on worst parameters at least 4 hours prior to the arrest.

RESULTS

A total of 353 patients with cardiac arrest were included over 19 months. The mean age was 61 years, 53.5% were male, and admission diagnoses included cardiovascular disease (15%), pneumonia 18.13%, and cancer 9%. The mean MEWS was 4.48 and low, intermediate, and high MEWS were found in 25.8%, 29.5%, and 44.8%, respectively. The mean time to cardiopulmonary resuscitation was 0.84 min. The initial rhythm was asystole in 47.6%, pulseless electrical activity in 38.2%, ventricular tachycardia/ventricular fibrillation in 5.4%, and unknown in 8.8%. Return of spontaneous circulation (ROSC) occurred in 29.2% of patients with the mean time to ROSC being 5.3 min. ROSC occurred in 17.3% of patients with asystole, 40.7% in pulseless electrical activity, 57.9% in ventricular tachycardia/ventricular fibrillation, and 25.8% in patients with an unknown rhythm. Of all patients, 16 (4.2%) were discharged alive.

CONCLUSIONS

Nonshockable rhythms account for the majority of the cardiac arrests in hospitals in a lower middle income country and are associated with unfavorable outcomes. Future work should be directed to training health care personnel in recognizing early warning signs and implementing appropriate measures in a resource-scarce environment.

Association between sedation-analgesia and neurodevelopment outcomes in neonatal hypoxic-ischemic encephalopathy

OBJECTIVE

To evaluate the association between sedation-analgesia (SA) during initial 72 h and death/disability at 18 months of age in neonatal hypoxic-ischemic encephalopathy (HIE).

DESIGN

This was a secondary analysis of the NICHD therapeutic hypothermia (TH) randomized controlled trial in moderate or severe HIE. Receipt of SA and anticonvulsant medications at five time points were considered: prior to and at baseline, 24, 48, and 72 h of TH or normothermia. Disability was defined as mental developmental index <85, cerebral palsy, blindness, hearing impairment, or Gross Motor Function Classification System 2-5.

RESULTS

Of the 208 RCT participants, 38 (18%) infants had no exposure to SA or anticonvulsants at any of the five time points, 20 (10%) received SA agents only, 81 (39%) received anticonvulsants only, and 69 (33%) received both SA and anticonvulsants. SA category drugs were not administered in 57% of infants while 18% received SA at ≥3 time points; 72% infants received anticonvulsants during 72 h of intervention. At 18 months of age, disability among survivors and death/disability was more frequent in the groups receiving anticonvulsants, with (48 and 65%) or without (37 and 58%) SA, compared to groups with no exposure (14 and 34%) or SA (13 and 32%) alone. Severe HIE (aOR 3.60; 1.59-8.13), anticonvulsant receipt (aOR 2.48; 1.05-5.88), and mechanical ventilation (aOR 7.36; 3.15-17.20) were independently associated with 18-month death/disability, whereas TH (aOR 0.28; 0.13-0.60) was protective. SA exposure showed no association with outcome.

CONCLUSIONS

The risk benefits of SA in HIE need further investigation.

Severe ischaemic cardiogenic shock with cardiac arrest and prolonged asystole: a case report

Background

Extracorporeal life support (ECLS) by veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is a valuable treatment option during severe cardiogenic shock and during cardiac arrest unresponsive to conventional management. It is applied to bridge the first critical days until the patient recovers or a destination therapy is established.¹ Prolonged episodes without cardiac electrical activity during VA-ECMO are a major problem, as they may cause pulmonary oedema and severe left ventricular (LV) thrombosis.² Here, we report a case of a 50-year-old man who presented with a 30-h episode of complete absence of electromechanical activity during ECLS and finally recovered with favourable neurological outcome.

Case summary

A 50-year-old man with out-of-hospital cardiac arrest was transferred to a peripheral hospital after initial successful cardiopulmonary resuscitation (CPR). In the emergency room, he presented with ST-segment elevation myocardial infarction and cardiogenic shock with third-degree atrioventricular block. After immediate insertion of a temporary pacemaker, he received percutaneous coronary intervention of the left anterior descending artery and the circumflex artery. Due to worsening cardiogenic shock, ECLS with VA-ECMO and an Impella^® pump was established. Cumulative time of CPR (out of hospital and in hospital) was 41 min. After transfer to our institution’s intensive care unit, both the heart’s mechanical and electrical activity ceased for more than 24 h and recovered slowly thereafter. After showing promising neurological outcome, epicardial pacemaker leads, an implantable cardioverter-defibrillator, and finally, a LV assist device were implanted. He was dismissed into rehabilitation with only minor neurological residua 6 weeks later.

Discussion

Impella^® implantation on top of VA-ECMO may be considered beneficial in the therapy of prolonged cardiac arrest.³ While VA-ECMO ensures oxygenation and organ perfusion, Impella^® vents the left ventricle and enhances coronary perfusion. In the presented case, a favourable outcome was reached despite an ‘untreated’ prolonged absence of cardiac electromechanical activity. Under specific circumstances during ECLS with extracorporeal membrane oxygenation and Impella^®, waiving of temporary pacing may be considered in absent cardiac electromechanical activity to avoid further complications.

Sex-related disparities in obstructive coronary artery disease, percutaneous coronary intervention, and mortality in adults with cardiac arrest

OBJECTIVES

Despite numerous advances in the delivery of resuscitative care, cardiac arrest (CA) continues to be associated with high morbidity and mortality. We sought to examine the association between sex and presence of obstructive coronary artery disease (CAD), percutaneous coronary intervention (PCI), and mortality in adults with CA.

METHODS

The study population included 208 consecutive patients hospitalized with CA who underwent resuscitation and subsequent coronary angiogram at an academic tertiary medical center. The primary outcome of interest was presence of obstructive CAD, defined as >1 coronary artery with >70% stenosis or >1 coronary bypass graft with >70% stenosis.

RESULTS

Of the study population, 150 patients (72%) were men and 58 (28%) were women. Women had a trend toward lower rates of obstructive CAD (69% vs 80%, p = 0.09) and lower rates of multivessel CAD compared to their male counterparts, but no significant difference in rates of PCI (62% vs 53%, p = 0.26). While rates of therapeutic hypothermia and vasopressor requirement were similar in men and women, women were less likely to require percutaneous left ventricular support. In-hospital mortality rates were similar in men and women (23% vs 21%, p = 0.68). In multivariate analysis, sex was not independently associated with obstructive CAD or mortality.

CONCLUSIONS

In this observational contemporary study of adults with CA undergoing coronary angiogram, although women had a trend toward lower rates of obstructive CAD, no significant difference in rates of PCI and in-hospital mortality were noted between men and women.

Amiodarone does not affect brain injury in a rat model of transient forebrain ischemia

OBJECTIVES

Although amiodarone may cause neurotoxicity that can affect patient outcomes when used during cardiopulmonary resuscitation (CPR), it has been commonly prescribed during CPR. This study investigated the possible neurotoxic effects of amiodarone in a rat model of transient forebrain ischemia.

DESIGN

A prospective laboratory animal study was carried out.

SETTING

Animal laboratory.

MATERIALS

Male Sprague-Dawley rats.

INTERVENTION

Eight minutes of forebrain ischemia was induced in rats by bilateral carotid occlusion and hypotension (mean arterial pressure=35mmHg) under isoflurane (1.5%) anesthesia. Amiodarone (0, 50, 100 and 150mg/kg) with saline was injected intraperitoneally 10min after ischemia. Rats given 0mg/kg of amiodarone were used as saline-treated controls. Sham operated rats received no treatment.

VARIABLES OF INTEREST

Animals were evaluated neurologically on postoperative days 4-7, and histologically after a one-week recovery period.

RESULTS

The greatest improvement in water maze test performance corresponded to the sham operated group (p=0.015 vs. saline-treated controls). No differences in performance were seen in amiodarone-treated rats compared with saline-treated controls. In the control group, 45% of the CA1 hippocampal neurons survived, compared with 78% in the sham operated group (p=0.009). Neuron survival after ischemia in the amiodarone treatment groups (50, 100 and 150mg/kg) (58%, 40% and 36%, respectively) and in the control rats did not differ significantly.

CONCLUSIONS

The administration of amiodarone immediately after transient forebrain ischemia did not worsen spatial cognitive function or neuronal survival in the hippocampal CA1 region in rats. The current results must be applied with caution in humans. However, they indicate that the potential neurotoxicity induced by amiodarone during resuscitation after cardiac arrest may be negligible.

Emergency Neurological Life Support: Airway, Ventilation, and Sedation

Airway management and ventilation are central to the resuscitation of the neurologically ill. These patients often have evolving processes that threaten the airway and adequate ventilation. Furthermore, intubation, ventilation, and sedative choices directly affect brain perfusion. Therefore, Airway, Ventilation, and Sedation was chosen as an Emergency Neurological Life Support protocol. Topics include airway management, when and how to intubate with special attention to hemodynamics and preservation of cerebral blood flow, mechanical ventilation settings and the use of sedative agents based on the patient's neurological status.

Emergency Neurological Life Support: Resuscitation Following Cardiac Arrest

Cardiac arrest is the most common cause of death in North America. An organized bundle of neurocritical care interventions can improve chances of survival and neurological recovery in patients who are successfully resuscitated from cardiac arrest. Therefore, resuscitation following cardiac arrest was chosen as an Emergency Neurological Life Support protocol. Key aspects of successful early post-arrest management include: prevention of secondary brain injury; identification of treatable causes of arrest in need of emergent intervention; and, delayed neurological prognostication. Secondary brain injury can be attenuated through targeted temperature management (TTM), avoidance of hypoxia and hypotension, avoidance of hyperoxia, hyperventilation or hypoventilation, and treatment of seizures. Most patients remaining comatose after resuscitation from cardiac arrest should undergo TTM. Treatable precipitants of arrest that require emergent intervention include, but are not limited to, acute coronary syndrome, intracranial hemorrhage, pulmonary embolism and major trauma. Accurate neurological prognostication is generally not appropriate for several days after cardiac arrest, so early aggressive care should never be limited based on perceived poor neurological prognosis.

Predictors of Obstructive Coronary Disease and Mortality in Adults Having Cardiac Arrest

Coronary angiography is a key component of systematic, multi-disciplinary post-cardiac arrest (CA) care, however, coronary angiogram is not routinely performed in the setting of CA. We sought to identify the predictors of obstructive coronary artery disease (CAD) and mortality in adults with CA undergoing coronary angiogram. The study population included 208 consecutive patients hospitalized with CA who underwent resuscitation and subsequent coronary angiogram at an academic tertiary medical center. The primary outcome of interest was presence of obstructive CAD, defined as >1 coronary artery with >70% stenosis or >1 coronary bypass graft with >70% stenosis. The secondary outcome of interest was in-hospital mortality. Of the 208 patients studied, 160 (76.9%) had obstructive CAD while 48 (23.1%) did not. In-hospital mortality occurred in 47 patients (22.6%). In multivariate analysis, ST-elevation myocardial infarction (STEMI) (OR 7.69, 95% CI 2.89 to 20.51), defibrillation (OR 4.90, 95% CI 1.19 to 20.17), vasopressors (OR 3.53, 95% CI 1.15 to 10.81), and absence of therapeutic hypothermia (OR 0.38, 95% CI 0.15 to 0.98) were independently associated with presence of obstructive CAD while STEMI (OR 3.21, 95% CI 1.01 to 10.24), vasopressors (OR 4.92, 95% CI 1.78 to 13.62), therapeutic hypothermia (OR 3.89, 95% CI 1.47 to 10.31), and admission blood urea nitrogen (OR 1.06, 95% CI 1.00 to 1.11) were independently associated with higher rates of in-hospital mortality. In this observational contemporary study, predictors of obstructive CAD and mortality exist in adults with CA undergoing coronary angiogram. Such risk models may aid in identification of CA patients who will benefit from early angiography and percutaneous coronary intervention.

Dissociated Oxygen Consumption and Carbon Dioxide Production in the Post-Cardiac Arrest Rat: A Novel Metabolic Phenotype

BACKGROUND

The concept that resuscitation from cardiac arrest (CA) results in a metabolic injury is broadly accepted, yet patients never receive this diagnosis. We sought to find evidence of metabolic injuries after CA by measuring O2 consumption and CO2 production (VCO2) in a rodent model. In addition, we tested the effect of inspired 100% O2 on the metabolism.

METHODS AND RESULTS

Rats were anesthetized and randomized into 3 groups: resuscitation from 10-minute asphyxia with inhaled 100% O2 (CA-fraction of inspired O2 [FIO2] 1.0), with 30% O2 (CA-FIO2 0.3), and sham with 30% O2 (sham-FIO2 0.3). Animals were resuscitated with manual cardiopulmonary resuscitation. The volume of extracted O2 (VO2) and VCO2 were measured for a 2-hour period after resuscitation. The respiratory quotient (RQ) was RQ=VCO2/VO2. VCO2 was elevated in CA-FIO2 1.0 and CA-FIO2 0.3 when compared with sham-FIO2 0.3 in minutes 5 to 40 after resuscitation (CA-FIO2 1.0: 16.7±2.2, P<0.01; CA-FIO2 0.3: 17.4±1.4, P<0.01; versus sham-FIO2 0.3: 13.6±1.1 mL/kg per minute), and then returned to normal. VO2 in CA-FIO2 1.0 and CA-FIO2 0.3 increased gradually and was significantly higher than sham-FIO2 0.3 2 hours after resuscitation (CA-FIO2 1.0: 28.7±6.7, P<0.01; CA-FIO2 0.3: 24.4±2.3, P<0.01; versus sham-FIO2 0.3: 15.8±2.4 mL/kg per minute). The RQ of CA animals persistently decreased (CA-FIO2 1.0: 0.54±0.12 versus CA-FIO2 0.3: 0.68±0.05 versus sham-FIO2 0.3: 0.93±0.11, P<0.01 overall).

CONCLUSIONS

CA altered cellular metabolism resulting in increased VO2 with normal VCO2. Normal VCO2 suggests that the postresuscitation Krebs cycle is operating at a presumably healthy rate. Increased VO2 in the face of normal VCO2 suggests a significant alteration in O2 utilization in postresuscitation. Several RQ values fell well outside the normally cited range of 0.7 to 1.0. Higher FIO2 may increase VO2, leading to even lower RQ values.

The past, present, and future of ventilation during cardiopulmonary resuscitation

PURPOSE OF REVIEW

To evaluate the past and present literature on ventilation during out of hospital cardiac arrest, highlighting research that has informed current guidelines.

RECENT FINDINGS

Previous studies have studied what are optimal compression-to-ventilation ratios, ventilation rates, and methods of ventilation. Continuous chest compression cardiopulmonary resuscitation (CPR) has not shown to provide a significant survival benefit over the traditional 30 : 2 CPR. The optimal ventilation rate is recommended at 8 to 10 breaths per minute. Methods such as capnography and thoracic impedance are being used to evaluate ventilation in research studies.

SUMMARY

Future out of hospital cardiac arrest studies are still exploring how to optimize the delivery of ventilation during the initial stages of resuscitation. More prospective studies focusing on ventilation are needed to inform guidelines.

Out-of-Hospital Cardiac Arrest Resuscitation Systems of Care: A Scientific Statement From the American Heart Association

The American Heart Association previously recommended implementation of cardiac resuscitation systems of care that consist of interconnected community, emergency medical services, and hospital efforts to measure and improve the process of care and outcome for patients with cardiac arrest. In addition, the American Heart Association proposed a national process to develop and implement evidence-based guidelines for cardiac resuscitation systems of care. Significant experience has been gained with implementing these systems, and new evidence has accumulated. This update describes recent advances in the science of cardiac resuscitation systems and evidence of their effectiveness, as well as recent progress in dissemination and implementation throughout the United States. Emphasis is placed on evidence published since the original recommendations (ie, including and since 2010).

Targeted Temperature Management for Improved Outcomes: Are We There Yet?

Therapeutic hypothermia, also referred to as targeted temperature management, has been a component of the postcardiac arrest treatment guidelines since 2010. Although almost a decade has passed since its inclusion in the postarrest guidelines, many unanswered questions remain regarding selection of the appropriate patient population, optimal target temperature, ideal window of time in which to initiate therapy after arrest, most efficient, safe, and accurate equipment choice for inducing and maintaining hypothermia, most effective duration of treatment, and rate of cooling or rewarming. On a national and international level, critical care nurses are in a unique position to participate in research that will define targeted temperature management protocols and practices. Nurses are also ideal for standardizing the targeted temperature management policy and protocol locally and nationally based on current available evidence. This review aims to serve 2 purposes: first, to provide a broad update on the current clarifications and limitations per research findings on target temperature management therapy; second, to explain how critical care nurses can use this updated information to improve outcomes for their patients with cardiac arrest.

Age and benefit of early coronary angiography after out-of-hospital cardiac arrest in patients presenting with shockable rhythm: Insights from the Sudden Death Expertise Center registry

BACKGROUND

Little is known about the association between provision of post-resuscitation care and prognosis of out-of-hospital cardiac arrest (OHCA) in elderly patients. Previous studies have suggested futility after 65 years of age.

OBJECTIVES

We aimed to evaluate the association of early coronary angiogram (CAG) followed if necessary by percutaneous coronary intervention (PCI), with favorable outcome after OHCA among elderly patients, compared to younger patients.

METHODS

Using a large French registry, we included all OHCA patients with an initial shockable rhythm, transported to hospital from 2011 to 2015. Favorable outcome was defined as hospital discharge with Cerebral Performance Category (CPC) 1 or 2. and were evaluated by multivariate logistic regression. Subgroup analyses were performed according to age groups: <65, 65-75 and >75 years.

RESULTS

Among 1502 included patients, 31% were older than 65 and 12% older than 75 years. An early CAG was performed in 79%, 88% and 76% of patients below 65, between 65 and 75 and above 75, respectively (P = 0.002). The rate of patients discharged with CPC1 or 2 was 42% below 65, 38% between 65 and 75 and 24% above 75 (P < 0.001). Among the whole population, early CAG (OR = 6.4, 95% CI = 3.9-10.5, P < 0.001) was associated with favorable outcome. In subgroups analysis, CAG was associated with favorable outcome among patients <65 and 65-75. In patients >75, there was a trend towards a favorable outcome (OR2.9, 95CI = 0.9-9.1).

CONCLUSIONS

In a large registry of OHCA survivors, the early CAG use was associated with a better prognosis. This benefit was persistent up to 75 years of age, suggesting that age alone should not guide the decision for early invasive strategy.

Acute brain lesions on magnetic resonance imaging in relation to neurological outcome after cardiac arrest

BACKGROUND

Magnetic resonance imaging (MRI) of the brain including diffusion-weighted imaging (DWI) is reported to have high prognostic accuracy in unconscious post-cardiac arrest (CA) patients. We documented acute MRI findings in the brain in both conscious and unconscious post-CA patients treated with target temperature management (TTM) at 32-34°C for 24 h as well as the relation to patients' neurological outcome after 6 months.

METHODS

A prospective observational study with MRI was performed regardless of the level of consciousness in post-CA patients treated with TTM. Neurological outcome was assessed using the Cerebral Performance Categories scale and dichotomized into good and poor outcome.

RESULTS

Forty-six patients underwent MRI at 3-5 days post-CA. Patients with good outcome had minor, mainly frontal and parietal, lesions. Acute hypoxic/ischemic lesions on MRI including DWI were more common in patients with poor outcome (P = 0.007). These lesions affected mostly gray matter (deep or cortical), with or without involvement of the underlying white matter. Lesions in the occipital and temporal lobes, deep gray matter and cerebellum showed strongest associations with poor outcome. Decreased apparent diffusion coefficient, was more common in patients with poor outcome.

CONCLUSIONS

Extensive acute hypoxic/ischemic MRI lesions in the cortical regions, deep gray matter and cerebellum detected by visual analysis as well as low apparent diffusion coefficient values from quantitative measurements were associated with poor outcome. Patients with good outcome had minor hypoxic/ischemic changes, mainly in the frontal and parietal lobes.

Advanced Cardiac Life Support: 2016 Singapore Guidelines

The main areas of emphasis in the Advanced Cardiac Life Support (ACLS) guidelines are: early recognition of cardiac arrest and call for help; good-quality chest compressions; early defibrillation when applicable; early administration of drugs; appropriate airway management ensuring normoventilation; and delivery of appropriate post-resuscitation care to enhance survival. Of note, it is important to monitor the quality of the various care procedures. The resuscitation team needs to reduce unnecessary interruptions to chest compressions in order to maintain adequate coronary perfusion pressure during the ACLS drill. In addition, the team needs to continually look out for reversible causes of the cardiac arrest.

Effects of inhaled nitric oxide on outcome after prolonged cardiac arrest in mild therapeutic hypothermia treated rats

Guidelines endorse targeted temperature management to reduce neurological sequelae and mortality after cardiac arrest (CA). Additional therapeutic approaches are lacking. Inhaled nitric oxide (iNO) given post systemic ischemia/reperfusion injury improves outcomes. Attenuated inflammation by iNO might be crucial in brain protection. iNO augmented mild therapeutic hypothermia (MTH) may improve outcome after CA exceeding the effect of MTH alone. Following ten minutes of CA and three minutes of cardiopulmonary resuscitation, 20 male Sprague-Dawley rats were randomized to receive MTH at 33 °C for 6hrs or MTH + 20ppm iNO for 5hrs; one group served as normothermic control. During the experiment blood was taken for biochemical evaluation. A neurological deficit score was calculated daily for seven days post CA. On day seven, brains and hearts were harvested for histological evaluation. Treatment groups showed a significant decrease in lactate levels six hours post resuscitation in comparison to controls. TNF-α release was significantly lower in MTH + iNO treated animals only at four hours post ROSC. While only the combination of MTH and iNO improved neurological function in a statistically significant manner in comparison to controls on days 4–7 after CA, there was no significant difference between groups treated with MTH and MTH + iNO.

Administration of placenta-derived mesenchymal stem cells counteracts a delayed anergic state following a transient induction of endogenous neurogenesis activity after global cerebral ischemia

BACKGROUND

Global cerebral ischemia (GCI) is a major obstacle for cardiac arrest survival. Recent studies have suggested the possibility of mesenchymal stem cell (MSC) as a novel therapeutic option for GCI, but these results were limited to the neuroprotective effects of MSCs. Therefore, we aimed to investigate specific characteristics of neurogenesis after transient GCI, and to assess the effect of MSC on these characteristics.

METHODS

Adult male Sprague-Dawley rats were subjected to 7 min of transient GCI and randomized into 7 groups: baseline, MSC, and control administered groups, to be analyzed at 2, 3, and 4 weeks after GCI, respectively. The same interventions were repeated for sham operated animals. Rats were euthanized at the designated time after GCI.

RESULTS

A comparison of GCI and sham groups without MSC treatment, showed that the counts of bromodeoxyuridine (BrdU)- and doublecortin (DCX)-positive cells were significantly increased in the GCI group at 1 week after insult, but the trend was reversed at 3 weeks after insult. The counts of BrdU-, Ki67- and DCX-positive cells and the intensity of zinc translocator 3 (ZnT3) were all significantly higher in the MSC-treated group than those in the control group at 3 weeks after GCI. The count of NeuN-positive cells in the hippocampus was significantly increased in the MSC group at 4 weeks after GCI.

CONCLUSIONS

GCI induces transient neurogenesis, followed by an anergic state. MSC may counteract this anergy of neurogenesis and result in an increase in intact neurons in later stages.

Association of plasma neutrophil gelatinase-associated lipocalin with acute kidney injury and clinical outcome in cardiac arrest survivors depends on the time of measurement

PURPOSE

The optimal timing for measurement of neutrophil gelatinase-associated lipocalin (NGAL) level to predict acute kidney injury (AKI) and prognosis in cardiac arrest (CA) survivors has not been elucidated. We aimed to compare the diagnostic and prognostic performance of NGAL levels after return of spontaneous circulation (ROSC) and at 48 h after CA.

METHODS

We included 231 adult cardiac arrest survivors who underwent targeted temperature management between May 2013 and December 2016. The primary outcome was stage 2 and 3 AKI (high stage AKI), and the secondary outcomes were in-hospital mortality and neurologic outcome. Sixty-one (26.4%) developed high stage AKI, 50 (21.6%) died, and 152 (65.8%) had a poor neurologic outcome.

RESULTS

NGAL level at 48 h (0.876; 95% confidence interval [CI], 0.826-0.916) had a higher area under receiver operating characteristic curve than NGAL level after ROSC (0.694; 95% CI, 0.631-0.753). Both NGAL levels were independently associated with high stage AKI. NGAL level at 48 h (1.001; 95% CI, 1.000-1.002) remained a significant predictor for in-hospital mortality, while neither of the NGAL levels were independently associated with neurologic outcome.

CONCLUSIONS

NGAL at 48 h after CA seems to be a robust predictor for high stage AKI and in-hospital mortality.

Decreased cAMP Level and Decreased Downregulation of β1-Adrenoceptor Expression in Therapeutic Hypothermia-Resuscitated Myocardium Are Associated With Improved Post-Resuscitation Myocardial Function

Background

Epinephrine administered during cardiopulmonary resuscitation (CPR) is associated with severe post‐resuscitation myocardial dysfunction. We previously demonstrated that therapeutic hypothermia reduced the severity of post‐resuscitation myocardial dysfunction caused by epinephrine; however, the relationship between myocardial adrenoceptor expression and myocardial protective effects by hypothermia remains unclear.

Methods and Results

Rats weighing between 450 and 550 g were randomized into 5 groups: (1) normothermic placebo, (2) normothermic epinephrine, (3) hypothermic placebo, (4) hypothermic epinephrine, and (5) sham (not subject to cardiac arrest and resuscitation). Ventricular fibrillation was induced and untreated for 8 minutes for all other groups. Hypothermia was initiated coincident with the start of CPR and maintained at 33±0.2°C for 4 hours. Placebo or epinephrine was administered 5 minutes after the start of CPR and 3 minutes before defibrillation. Post‐resuscitation ejection fraction was measured hourly for 4 hours then hearts were harvested. Epinephrine increased coronary perfusion pressure during CPR (27±6 mm Hg versus 21±2 mm Hg P<0.05). Post‐resuscitation myocardial function was impaired in the normothermic epinephrine group compared with other groups. The concentration of myocardial cAMP doubled in the normothermic epinephrine group (655.06±447.63 μmol/L) compared with the hypothermic epinephrine group (302.51±97.98 μmol/L; P<0.05). Myocardial β₁‐adrenoceptor expression decreased with normothermia cardiac arrest but not with hypothermia regardless of epinephrine.

Conclusions

Epinephrine, administered during normothermic CPR, increased the severity of post‐resuscitation myocardial dysfunction. This adverse effect was inhibited by intra‐arrest hypothermia resuscitation. Declined cAMP with more preserved β₁‐adrenoceptors in hypothermia‐resuscitated myocardium is associated with improved post‐resuscitated myocardial function in vivo.

The prognostic value of bispectral index and suppression ratio monitoring after out-of-hospital cardiac arrest: a prospective observational study

Background

We investigated the ability of bispectral index (BIS) monitoring to predict poor neurological outcome in out-of-hospital cardiac arrest (OHCA) patients fully treated according to guidelines.

Results

In this prospective, observational study, 77 successfully resuscitated OHCA patients were enrolled in whom BIS, suppression ratio (SR) and electromyographic (EMG) values were continuously monitored during the first 36 h after the initiation of targeted temperature management at 33 °C. The Cerebral Performance Category (CPC) scale was used to define patients’ outcome at 180 days after OHCA (CPC 1–2: good–CPC 3–5: poor neurological outcome). Using mean BIS and SR values calculated per hour, receiver operator characteristics curves were constructed to determine the optimal time point and threshold to predict poor neurological outcome. At 180 days post-cardiac arrest, 39 patients (51%) had a poor neurological outcome. A mean BIS value ≤ 25 at hour 12 predicted poor neurological outcome with a sensitivity of 49% (95% CI 30–65%), a specificity of 97% (95% CI 85–100%) and false positive rate (FPR) of 6% (95% CI 0–29%) [AUC: 0.722 (0.570–0.875); p = 0.006]. A mean SR value ≥ 3 at hour 23 predicted poor neurological with a sensitivity of 74% (95% CI 56–87%), a specificity of 92% (95% CI 78–98%) and FPR of 11% (95% CI 3–29%) [AUC: 0.836 (0.717–0.955); p < 0.001]. No relationship was found between mean EMG and BIS < 25 (R² = 0.004; p = 0.209).

Conclusion

This study found that mean BIS ≤ 25 at hour 12 and mean SR ≥ 3 at hour 23 might be used to predict poor neurological outcome in an OHCA population with a presumed cardiac cause. Since no correlation was observed between EMG and BIS < 25, our calculated BIS threshold might assist with poor outcome prognostication following OHCA.

Hemodynamic Resuscitation Characteristics Associated with Improved Survival and Shock Resolution After Cardiac Arrest

PURPOSE

To determine which strategy of early post-cardiac arrest hemodynamic resuscitation was associated with best clinical outcomes. We hypothesized that higher mean arterial pressure (MAP) achieved using IV fluids over vasopressors would yield better outcomes.

METHODS

Retrospective cohort study of post-cardiac arrest patients between March 2011 and June 2012. Patients successfully resuscitated from cardiac arrest, admitted to an intensive care unit and surviving at least 24 h, were included. Patients missing data for >2 h after return of spontaneous circulation were excluded. The institutional standard for post-resuscitation MAP was ≥65 mm Hg with no guidelines on how MAP was supported. We examined the association between early (6 h) average MAP, vasopressor use summarized as cumulative vasopressor index and fluid intake with outcomes including survival to discharge, favorable neurologic outcome based on Cerebral Performance Category 1 or 2, and the surrogate outcome measure of lactate clearance using Pearson correlation and multivariable regression.

RESULTS

Of 118 patients, 55 (46%) survived to hospital discharge, 21 (18%) with favorable neurologic outcome. Higher 6-h mean cumulative vasopressor index was independently associated with worsened survival (OR 0.67; 95% CI 0.53, 0.85; P = 0.001). Resuscitation subgroups receiving higher than median vasopressors had worsened survival to hospital discharge regardless of fluid intake. In addition, higher MAP-6h correlated with increased lactate clearance (r = 0.29; P = 0.011).

CONCLUSIONS

Early post-return of spontaneous circulation hemodynamic resuscitation achieving higher MAP using fluid preferentially over vasopressors is associated with improved survival to hospital discharge as well as better lactate clearance.

Effect of target temperature management at 32-34 °C in cardiac arrest patients considering assessment by regional cerebral oxygen saturation: A multicenter retrospective cohort study

AIM

Target temperature management (TTM) is used in comatose post-cardiac arrest patients, but the recommended temperature range is wide. This study aimed to assess the effectiveness of TTM at 32-34 °C while considering the degree of cerebral injury and cerebral circulation, as assessed by regional cerebral oxygen saturation (rSO₂).

METHODS

This is a secondary analysis of prospectively collected registry data from comatose patients who were transferred to 15 hospitals in Japan after out-of-hospital cardiac arrest (OHCA) from 2011 to 2013. The primary outcome was all-cause mortality at 90 days after OHCA, and the secondary outcome was favorable neurological outcomes as evaluated according to the Cerebral Performance Category. We monitored rSO₂ noninvasively with near-infrared spectroscopy, which could assess cerebral perfusion and the balance of oxygen delivery and uptake.

RESULTS

We stratified 431 study patients into three groups according to rSO₂ on hospital arrival: rSO₂ ≤40% (n = 296), rSO₂ 41-60% (n = 67), and rSO₂ ≥61% (n = 68). Propensity score analysis revealed that TTM at 32-34 °C decreased all-cause mortality in patients with rSO₂ 41-60% (average treatment effect on treated [ATT] by propensity score matching [PSM] -0.51, 95%CI -0.70 to -0.33; ATT by inverse probability of treatment weighting [IPW] -0.52, 95%CI -0.71 to -0.34), and increased favorable neurological outcomes in patients with rSO₂ 41-60% (ATT by PSM 0.50, 95%CI 0.32-0.68; ATT by IPW 0.52, 95%CI 0.35-0.69).

CONCLUSION

TTM at 32-34 °C effectively decreased all-cause mortality in comatose OHCA patients with rSO₂ 41-60% on hospital arrival in Japan.

Survival factors of hospitalized out-of-hospital cardiac arrest patients in Taiwan: A retrospective study

The chain of survival has been shown to improve the chances of survival for victims of cardiac arrest. Post-cardiac arrest care has been demonstrated to significantly impact the survival of out-of-hospital cardiac arrest (OHCA). How post-cardiac arrest care influences the survival of OHCA patients has been a main concern in recent years. The objective of this study was to assess the survival outcome of hospitalized OHCA patients and determine the factors associated with improved survival in terms of survival to discharge. We conducted a retrospective observational study by analyzing records from the National Health Insurance Research Database of Taiwan from 2007 to 2013. We collected cases with an International Classification of Disease Clinical Modification, 9^threvision primary diagnosis codes of 427.41 (ventricular fibrillation, VF) or 427.5 (cardiac arrest) and excluded patients less than 18 years old, as well as cases with an unknown outcome or a combination of traumatic comorbidities. We then calculated the proportion of survival to discharge among hospitalized OHCA patients. Factors associated with the dependent variable were examined by logistic regression. Statistical analysis was conducted using SPSS 22 (IBM, Armonk, NY). Of the 11,000 cases, 2,499 patients (22.7%) survived to hospital discharge. The mean age of subjects who survived to hospital discharge and those who did not was 66.7±16.7 and 71.7±15.2 years, respectively. After adjusting for covariates, neurological failure, cardiac comorbidities, hospital level, intensive care unit beds, transfer to another hospital, and length of hospital stay were independent predictors of improved survival. Cardiac rhythm on admission was a strong factor associated with survival to discharge (VF vs. non-VF: adjusted odds ratio: 3.51; 95% confidence interval: 3.06–4.01). In conclusion, cardiac comorbidities, hospital volume, cardiac rhythm on admission, transfer to another hospital and length of hospital stay had a significant positive association with survival to discharge in hospitalized OHCA patients in Taiwan.

Use of Neuromuscular Blockers During Therapeutic Hypothermia After Cardiac Arrest: A Nursing Protocol

BACKGROUND

Neuromuscular blockers used to prevent shivering during therapeutic hypothermia in comatose patients after out-of-hospital cardiac arrest are associated with adverse events.

OBJECTIVE

To assess the influence of a nurse-implemented protocol on use of neuromuscular blockers in patients treated with 24-hour therapeutic hypothermia after out-of-hospital cardiac arrest.

METHODS

A before and after study was done in a 24-bed cardiac arrest center. During the before period, paralysis was maintained by continuous infusion of vecuronium during therapeutic hypothermia. During the after period, a nurse-implemented protocol was used to strictly control use of neuromuscular blockers. The primary outcome measure was duration of infusion of neuromuscular blockers; secondary end points included rates of ventilator-associated pneumonia and intensive care unit mortality.

RESULTS

Among the 22 patients in the before group and the 23 patients in the after group, most were men (78%) with a median age of 66 years. Baseline characteristics were similar between the 2 groups. Median duration of sedation was 36 hours, shorter in the after group (34 hours) than in the before group (38 hours; P = .02). Median duration of infusion of neuromuscular blockers was significantly shorter in the after group (6 hours) than in the before group (33 hours; P < .001). Ventilator-associated pneumonia occurred more frequently in the before group (45%) than in the after group (13%; P = .02). Overall intensive care unit mortality rate was 58%, similar in both groups (P = .44).

CONCLUSION

Use of a nurse-implemented protocol to reduce use of neuromuscular blockers is feasible.

Improving Temporal Trends in Survival and Neurological Outcomes After Out-of-Hospital Cardiac Arrest

BACKGROUND

Considerable effort has gone into improving outcomes from out-of-hospital cardiac arrest (OHCA). Studies suggest that survival is improving; however, prior studies had insufficient data to pursue the relationship between markers of guideline compliance and temporal trends. The objective of the study was to evaluate trends in OHCA survival over an 8-year period that included the implementation of the 2005 and 2010 international cardiopulmonary resuscitation (CPR) guidelines.

METHODS AND RESULTS

This was a population-based cohort study of all consecutive treated OHCA patients of presumed cardiac cause between 2006 and 2013 in the City of Toronto, Canada, and surrounding regions. Temporal changes were measured by χ2 trend test. The association between year of the OHCA and survival was evaluated using logistic regression and joinpoint analysis. A total of 23 619 patients with OHCA met study inclusion criteria. During the study period, survival to hospital discharge doubled (4.8% in 2006 to 9.4% in 2013; P<0.0001), and survival with good neurological outcome increased (6.2% in 2010 to 8.5% in 2013; P=0.005). Improvements occurred in the rates of bystander CPR and automated external defibrillator application, high-quality CPR metrics, and in-hospital targeted temperature management. After adjusting for the Utstein variables, survival to hospital discharge (odds ratio, 1.12; 95% confidence interval, 1.09-1.15) and survival with good neurological outcome (odds ratio, 1.13; 95% confidence interval, 1.05-1.22) increased with each year of study.

CONCLUSIONS

Survival after OHCA has improved over time. This trend was associated with improved rates of bystander CPR, automated external defibrillator use, high-quality CPR metrics, and in-hospital targeted temperature management. The results suggest that multiple factors, each improving over time, may have contributed to the observed increase in survival.

Neurological Prognostications for the Therapeutic Hypothermia among Comatose Survivors of Cardiac Arrest

Background

Currently, there are limited data of prognostic clues for neurological recovery in comatose survivors undergoing therapeutic hypothermia (TH). We aimed to evaluate clinical signs and findings that could predict neurological outcomes, and determine the optimal time for the prognostication.

Materials and Methods

We retrospectively reviewed database of postarrest survivors treated with TH in our hospital from 2006 to 2014. Cerebral performance category (CPC), neurological signs and findings in electroencephalography (EEG) and brain computed tomography (CT) were evaluated. In addition, the optimal time to evaluate neurological status was analyzed.

Results

TH was performed in 51 postarrest patients. Approximately 53% of TH patients survived at discharge and 33% of the hospital survivors had favorable outcome (CPC1-2). The prognostic clues for unfavorable outcome (CPC3-5) at discharge were lack of pupillary light response (PLR) and/or gag reflex after rewarming, and the absence of at least one of the brainstem reflexes, no eye-opening, or abnormal motor response on the 7^th day. Myoclonus and seizure could not be used to indicate poor prognosis. In addition, prognostic values of EEG and CT findings were inconclusive.

Conclusions

Our study showed the simple neurological signs helped predict short-term neurological prognosis. The most reliable sign determining unfavorable outcome was the lack of PLR. The optimal time to assess prognosis was either at 48-72 h or 7 days after return of spontaneous circulation.

Admission levels of high-density lipoprotein and apolipoprotein A-1 are associated with the neurologic outcome in patients with out-of-hospital cardiac arrest

Objective

To investigate whether serum levels of high-density lipoprotein (HDL) and apolipoprotein A-1 (ApoA1), after the return of spontaneous circulation, can predict the neurologic outcome in patients with out-of-hospital cardiac arrest (OHCA).

Methods

This was a retrospective observational study conducted in a single tertiary hospital intensive care unit. All adult OHCA survivors with admission lipid profiles were enrolled from March 2013 to December 2015. Good neurologic outcome was defined as discharge cerebral performance categories 1 and 2.

Results

Among 59 patients enrolled, 13 (22.0%) had a good neurologic outcome. Serum levels of HDL (56.7 vs. 40 mg/dL) and ApoA1 (117 vs. 91.6 mg/dL) were significantly higher in patients with a good outcome. Areas under the HDL and ApoA1 receiver operating curves to predict good outcomes were 0.799 and 0.759, respectively. The proportion of good outcome was significantly higher in patients in higher tertiles of HDL and ApoA1 (test for trend, both P=0.003). HDL (P=0.018) was an independent predictor in the multivariate logistic regression model.

Conclusion

Admission levels of HDL and ApoA1 are associated with neurologic outcome in patients with OHCA. Prognostic and potential therapeutic values of HDL and ApoA1 merit further evaluation in the post-cardiac arrest state, as in other systemic inflammatory conditions such as sepsis.

Is Esophageal Temperature Better to Estimate Brain Temperature during Target Temperature Management in a Porcine Model of Cardiopulmonary Resuscitation?

Brain temperature monitoring is important in target temperature management for comatose survivors after cardiac arrest. Since acquisition of brain temperature is invasive and unrealistic in scene of resuscitation, we tried to sought out surrogate sites of temperature measurements that can precisely reflect cerebral temperature. Therefore, we designed this controlled, randomized animal study to investigate whether esophageal temperature can better predict brain temperature in two different hypothermia protocols. The results indicated that esophageal temperature had a stronger correlation with brain temperature in the early phase of hypothermia in both whole and regional body cooling protocols. It means that esophageal temperature was considered as priority method for early monitoring once hypothermia is initiated. This clinical significance of this study is as follows. Since resuscitated patients have unstable hemodynamics, collecting temperature data from esophagus probe is cost-efficient and easier than the catheter in central vein. Moreover, it can prevent the risk of iatrogenic infection comparing with deep vein catheterization, especially in survivors with transient immunoexpressing in hypothermia protocol.

Clinical Experience of Therapeutic Hypothermia in Cases of Near-Hanging and Recovered from Cardiac Arrest Due to Hanging

Objective

There is no specific treatment for comatose patients after near-hanging or in those who recover from cardiac arrest (CA) caused by hanging. Since 2009, we have used therapeutic hypothermia (TH) to treat all comatose survivors of near-hanging and in patients who recovered from CA caused by hanging. The purpose of this study was to describe the outcomes in comatose patients after near-hanging.

Design

Case series.

Setting

Emergency departments of two regional hospitals.

Methods

We collected patient data from the Samsung Medical Center hypothermia database between November 2009 and November 2011. We included all patients presented with near-hanging or CA caused by hanging; who remained comatose and received TH after resuscitation for analysis. Clinical characteristics and outcome of patients were presented. Results During the study period, 26 patients were admitted to the emergency department after near-hanging or CA caused by hanging; 21 patients were enrolled in this study. Twelve patients with CA and 9 comatose patients without CA were treated with TH. Only 1 patient with CA had a good neurological outcome. By contrast, all near-hanging patients without CA had a good neurological outcome.

Conclusions

TH can be an effective therapeutic modality in cases of near-hanging without CA. However, the effectiveness of TH is questionable in patients who survive from CA caused by hanging. (Hong Kong j.emerg.med. 2014;21:316-321)

Predictors of Outcome in Out-Of-Hospital Cardiac Arrest Survived to Hospital Admission

Objective

To identify the independent predictors of survival to hospital discharge in the group of patients admitted to hospital with out-of-hospital cardiac arrest.

Design

Prospective cohort study.

Setting

Two public hospitals in a cluster in Hong Kong.

Methods

Data were reported to local Cardiac Arrest Registry using Utstein style template from 1st August 2010 to 31st October 2012. The post cardiac arrest care and outcome, premorbid mobility, activities of daily living (ADL) and medical illnesses were traced from medical records. Independent predictors were calculated using logistic regression model.

Results

A total of 323 patients were recruited in this study. Patients' age (Odds raio [OR]=0.966; 95% confidence interval [CI]=0.937-0.996), total down time (OR=0.897; 95% CI=0.858-0.938), pre-hospital defibrillation (OR=5.649; 95% CI=1.673-19.07), post-cardiac arrest intensive care (OR=3.674; 95% CI=1.001-13.951) were independent predictors of survival to hospital discharge.

Conclusions

Younger age, shorter down time, prehospital defibrillation for shockable rhythm, post-cardiac arrest intensive care are independent predictors of survival to discharge for patients admitted to hospital after out-of-hospital cardiac arrest. Premorbid health conditions, ADL and mobility are not predictors to patient's survival. (Hong Kong j.emerg.med. 2014;21:131-139)

Temperature management for out-of-hospital cardiac arrest

More than 300,000 Americans suffer a cardiac arrest outside of the hospital each year and even among those who are successfully resuscitated and survive to hospital admission, outcomes remain poor. Temperature management (previously known as therapeutic hypothermia) is the only intervention that has been reproducibly demonstrated to ameliorate the neurologic injury that follows cardiac arrest. The results of a recent large randomized controlled trial have highlighted the uncertainty about temperature management strategies following cardiac arrest. This article reviews the issues and recommendations.

The Influence of Sedation Level Guided by Bispectral Index on Therapeutic Effects for Patients with Severe Traumatic Brain Injury

BACKGROUND

Sedation therapy is vital for treating severe traumatic brain injury (TBI). Yet, types of sedation assessment tools and sedation levels that are suitable for sedation treatment have not been investigated.

OBJECTIVE

To investigate the influence of different sedation levels guided by the Bispectral Index (BIS) on the therapeutic effects for severe TBI.

METHODS

According to inclusion, exclusion, and rejection criteria, 35 patients were prospectively included and divided into Richmond Agitation Sedation Scale (RASS), BIS(I), and BIS(II) groups. The RASS group was controlled the level of sedation to within -2 or -3, and the BIS(I) and (II) groups within the range of 40-50 and 50-60, respectively. In addition to clinical data, RASS, BIS, and intracranial pressure (ICP) values were collected. RASS and ICP variability were introduced to investigate the different of sedative control effect with or without BIS monitor, and the control effect of ICP between different sedation levels. Statistical analysis was performed to estimate the effectiveness of different sedation levels guided by BIS in sedation treatment within 72 hours.

RESULTS

There were no significant differences in demographics among the 3 groups. RASS variability of the BIS(I) and (II) groups was significantly lower than that of the RASS group (P < 0.05), and in the BIS(I) group it was insignificantly lower than in the BIS(II) group. The ICP of the BIS(I) and (II) groups declined to <13.5 mm Hg significantly earlier than that of the RASS group (P < 0.05), and the difference between BIS(I) and (II) was insignificant. ICP variability of RASS group was higher than those of the BIS(I) and (II) groups (P < 0.05), and ICP variability of the BIS(I) group was significantly lower than that of the BIS(II) group (P < 0.05). Differences in days in the neurosurgery intensive care unit and outcomes among the 3 groups were insignificant.

CONCLUSIONS

BIS is more reliable than RASS for maintaining a stable sedation status and ICP. Deeper sedation levels (BIS 40-50) cause ICP to decrease more quickly, with lower ICP variability.

Hemodynamic effects of IV sodium nitrite in hospitalized comatose survivors of out of hospital cardiac arrest

BACKGROUND

Patients resuscitated from cardiac arrest have brain and cardiac injury. Recent animal studies suggest that the administration of sodium nitrite after resuscitation from 12min of asystole limits acute cardiac dysfunction and improves survival and neurologic outcomes. It has been hypothesized that low doses of IV sodium nitrite given during resuscitation of out of hospital cardiac arrest (OHCA) will improve survival. Low doses of sodium nitrite (e.g., 9.6mg of sodium nitrite) are safe in healthy individuals, however the effect of nitrite on blood pressure in resuscitated cardiac arrest patients is unknown.

METHODS

We performed a single-center, pilot trial of low dose sodium nitrite (1 or 9.6mg dose) vs. placebo in hospitalized out-of-hospital cardiac arrest patient to determine whether nitrite administration reduced blood pressure and whether whole blood nitrite levels increased in response to nitrite administration.

RESULTS

This is the first reported study of sodium nitrite in cardiac arrest patients. Infusion of low doses of sodium nitrite in comatose survivors of OHCA (n=7) compared to placebo (n=4) had no significant effects on heart rate within 30min after infusion (70±20 vs. 78±3 beats per minute, p=0.18), systolic blood pressure (103±20 vs 108±15mmHg, p=0.3), or methemoglobin levels (0.92±0.33 vs. 0.70±0.26, p=0.45). Serum nitrite levels of 2-4μM were achieved within 15min of a 9.6mg nitrite infusion.

CONCLUSIONS

Low dose sodium nitrite does not cause significant hemodynamic effect in patients with OHCA, which suggests that nitrite can be delivered safely in this critically ill patient population. Higher doses of sodium nitrite are necessary in order to achieve target serum level of 10μM.

Changes in cardiac arrest patients' temperature management after the publication of 2015 AHA guidelines for resuscitation in China

A survey was performed to assess the current management of targeted temperature management (TTM) in patients following cardiac arrest (CA) and whether healthcare providers will change target temperature after publication of 2015 American Heart Association guidelines for resuscitation in China. 52 hospitals were selected from whole of China between August to November 2016. All healthcare providers in EMs and/or ICUs of selected hospitals participated in the study. 1952 respondents fulfilled the survey (86.8%). TTM in CA patients was declared by 14.5% of physicians and 6.7% of the nurses. Only 4 of 64 departments, 7.8% of physicians and 5.7% of the nurses had implemented TH for CA patients. Since the publication of 2015 AHA guidelines, 33.6% of respondents declared no modification of target temperature, whereas 51.5% declared a target temperature's change in future practice. Respondents were more likely to choose 35∼36 °C-TTM (54.7%) after guidelines publication, as compared to that before guidelines publication they preferred 32∼34 °C-TTM (54.0%). TTM for CA patients was still in the early stage in China. Publication of 2015 resuscitation guidelines did have impact on choice of target temperature among healthcare providers. They preferred 35∼36 °C-TTM after guidelines publication.

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.

Plasma Neutrophil Gelatinase-Associated Lipocalin Measured Immediately After Restoration of Spontaneous Circulation Predicts Acute Kidney Injury in Cardiac Arrest Survivors Who Underwent Therapeutic Hypothermia

Early diagnosis of acute kidney injury (AKI) after cardiac arrest (CA) is challenging. We aimed to identify the diagnostic and prognostic performance of neutrophil gelatinase-associated lipocalin (NGAL) for AKI and its clinical outcomes. A retrospective observational study, involving adult comatose CA survivors treated with therapeutic hypothermia between May 2013 and December 2016, was conducted. AKI was classified according to the guidelines of Kidney Disease Improving Global Outcomes. NGAL levels were measured after return of spontaneous circulation (ROSC). The primary outcome was development of AKI within 7 days after CA, and the secondary outcome was inhospital mortality. The study included 279 patients, of which 111 (39.8%) developed AKI and 61 (21.9%) died. Thirty-seven (33.3%) of patients in the AKI group had stage 3 AKI, and 45 (40.5%) patients received renal replacement therapy. The area under the curve of NGAL levels for diagnosing AKI was 0.725 (95% confidence interval [CI] 0.668-0.776), and NGAL levels were independently associated with the development of AKI (odds ratio [OR] 1.004; 95% CI 1.002-1.006). Nonsurvivors had significantly higher NGAL levels (221.0 ng/mL [154.0-355.5] vs. 148.5 ng/mL [97.0-232.9]; p < 0.001). The development of AKI was independently associated with mortality (OR 4.926; 95% CI 2.353-10.311); however, NGAL level was not associated with mortality (OR 1.000; 95% CI 0.999-1.001). Plasma NGAL level measured after ROSC can be an early predictor for the development of AKI after CA. The presence of AKI was associated with increased inhospital mortality.

An experimental study and finite element modeling of head and neck cooling for brain hypothermia

Reducing brain temperature by head and neck cooling is likely to be the protective treatment for humans when subjects to sudden cardiac arrest. This study develops the experimental validation model and finite element modeling (FEM) to study the head and neck cooling separately, which can induce therapeutic hypothermia focused on the brain. Anatomically accurate geometries based on CT images of the skull and carotid artery are utilized to find the 3D geometry for FEM to analyze the temperature distributions and 3D-printing to build the physical model for experiment. The results show that FEM predicted and experimentally measured temperatures have good agreement, which can be used to predict the temporal and spatial temperature distributions of the tissue and blood during the head and neck cooling process. Effects of boundary condition, perfusion, blood flow rate, and size of cooling area are studied. For head cooling, the cooling penetration depth is greatly depending on the blood perfusion in the brain. In the normal blood flow condition, the neck internal carotid artery temperature is decreased only by about 0.13°C after 60min of hypothermia. In an ischemic (low blood flow rate) condition, such temperature can be decreased by about 1.0°C. In conclusion, decreasing the blood perfusion and metabolic reduction factor could be more beneficial to cool the core zone. The results also suggest that more SBC researches should be explored, such as the optimization of simulation and experimental models, and to perform the experiment on human subjects.

Immediate coronary angiography in survivors of out-of-hospital cardiac arrest without obvious extracardiac cause: Who benefits?

BACKGROUND

Immediate coronary angiography (iCA) and primary percutaneous coronary angioplasty (pPCI) in patients successfully resuscitated after out-of-hospital cardiac arrest (OHCA) of suspected cardiac cause is controversial. Our aims were to assess the results of iCA, the prognostic impact of pPCI after OHCA, and to identify subgroups most likely to benefit from this strategy.

METHODS

In this single-centre retrospective study, patients aged ≥18 years with sustained return of spontaneous circulation after OHCA and no evidence of a non-cardiac cause underwent routine iCA at admission, with pPCI if indicated. Results of iCA, and factors associated with in-hospital survival were analysed.

RESULTS

Between 2006 and 2013, 160 survivors from OHCA presumed of cardiac origin were included (median age, 60 years; 85% males). iCA showed significant coronary-artery lesions in 75% of patients, and acute occlusion or unstable lesion in only 41%. pPCI was performed in 34% of patients and was not associated with survival by univariate or multivariate analysis (P=0.67). ST-segment elevation predicted acute coronary occlusion in 40%. An initial shockable rhythm was associated with higher in-hospital survival (52% vs. 19%; P<0.001). After initial defibrillation, the first rhythm recorded by 12-lead electrocardiography was highly associated with prognosis: secondary asystole had a very low survival rate (5%, 1/21) despite PCI in 43% of patients, compared to sustained ventricular tachycardia/fibrillation (42%, 15/36) and supraventricular rhythm (71%, 50/70) (P<0.001).

CONCLUSIONS

In our experience, the prevalence of acute coronary occlusion or unstable lesion immediately after OHCA of likely cardiac cause is only 41%. Immediate CA in OHCA survivors, with pPCI if indicated, should be restricted to highly selected patients.

Does Antiarrhythmic Drug During Cardiopulmonary Resuscitation Improve the One-month Survival: The SOS-KANTO 2012 Study

BACKGROUND

Antiarrhythmic drugs (AAD) are often used for fatal ventricular arrhythmias during cardiopulmonary resuscitation (CPR). However, the efficacy of initial AAD administration during CPR in improving long-term prognosis remains unknown. This study retrospectively evaluated the effect of AAD administration during CPR on 1-month prognosis in the SOS-KANTO 2012 study population.

METHODS AND RESULTS

Of the 16,164 out-of-hospital cardiac arrest cases, 1350 shock-refractory patients were included: 747 patients not administered AAD and 603 patients administered AAD. Statistical adjustment for potential selection bias was performed using propensity score matching, yielding 1162 patients of whom 792 patients were matched (396 pairs). The primary outcome was 1-month survival. The secondary outcome was the proportion of patients with favorable neurological outcome at 1 month. Logistic regression with propensity scoring demonstrated an odds ratio (OR) for 1-month survival in the AAD group of 1.92 (P < 0.01), whereas the OR for favorable neurological outcome at 1 month was 1.44 (P = 0.26).

CONCLUSIONS

Significantly greater 1-month survival was observed in the AAD group compared with the non-AAD group. However, the effect of ADD on the likelihood of a favorable neurological outcome remains unclear. The findings of the present study may indicate a requirement for future randomized controlled trials evaluating the effect of ADD administration during CPR on long-term prognosis.

Severe burns in a patient after out-of-hospital CPR

We present a case of a patient after prolonged cardio-pulmonary resuscitation on hot asphalt, who suffered from first and second degree burns which worsened during hospitalization. The patient was treated with therapeutic hypothermia. Possible effect of therapeutic hypothermia on the course of burns is discussed.