Cardiac Arrest Resuscitation Research Articles

Hyperoxia during extracorporeal cardiopulmonary resuscitation for refractory cardiac arrest is associated with severe circulatory failure and increased mortality

BackgroundHigh levels of arterial oxygen pressures (PaO2) have been associated with increased mortality in extracorporeal cardiopulmonary resuscitation (ECPR), but there is limited information regarding possible mechanisms linking hyperoxia and death in this setting, notably with respect to its hemodynamic consequences. We aimed therefore at evaluating a possible association between PaO2, circulatory failure and death during ECPR.MethodsWe retrospectively analyzed 44 consecutive cardiac arrest (CA) patients treated with ECPR to determine the association between the mean PaO2 over the first 24 h, arterial blood pressure, vasopressor and intravenous fluid therapies, mortality, and cause of deaths.ResultsEleven patients (25%) survived to hospital discharge. The main causes of death were refractory circulatory shock (46%) and neurological damage (24%). Compared to survivors, non survivors had significantly higher mean 24 h PaO2 (306 ± 121 mmHg vs 164 ± 53 mmHg, p < 0.001), lower mean blood pressure and higher requirements in vasopressors and fluids, but displayed similar pulse pressure during the first 24 h (an index of native cardiac recovery). The mean 24 h PaO2 was significantly and positively correlated with the severity of hypotension and the intensity of vasoactive therapies. Patients dying from circulatory failure died after a median of 17 h, compared to a median of 58 h for patients dying from a neurological cause. Patients dying from neurological cause had better preserved blood pressure and lower vasopressor requirements.ConclusionIn conclusion, hyperoxia is associated with increased mortality during ECPR, possibly by promoting circulatory collapse or delayed neurological damage.

Patterns of retinal hemorrhage associated with cardiac arrest and cardiopulmonary resuscitation

Hypoxia and cardiopulmonary resuscitation (CPR) have been proposed as causes of retinal hemorrhage (RH) in children evaluated for abusive head trauma (AHT). We sought to determine the prevalence and characteristics of RH in children who underwent CPR after cardiac arrest. This was a prospective, single-center, consecutive observational study of 38 children (<18 years of age). Indirect ophthalmoscopic examination was completed by an ophthalmologist within 48 hours of CPR. Extensive medical records data were collected to assess for potential confounding factors. Outcomes included the presence and pattern of RH. Of the 38 children, 20 had in-hospital arrest; 18 had out-of-hospital arrest. The median duration of CPR was 10 minutes. Seven children had RH, of whom 6 had an RH pattern consistent with coexistent medical conditions: 4 AHT diagnosable with nonocular findings, including subdural and subarachnoid hemorrhage, rib fractures, abdominal injury (RH pattern: diffuse, numerous, intraretinal and/or multilayered RH); 1 septic shock (RH pattern: 1-2 posterior pole RH); 1 ruptured arteriovenous malformation (RH pattern: 4-8 peripapillary RH). The seventh child had unwitnessed cardiac arrest due to nonfatal drowning and a single superficial intraretinal peripapillary hemorrhage. CPR for cardiac arrest is rarely associated with RH, which, absent coexisting conditions causing retinal hemorrhage, are intraretinal, few in number, and located in the posterior pole. In children who have undergone CPR, when RH are multilayered, or are more than a few in number, or extend outside the posterior pole, another etiology for the RH should be sought.

Impact of lung structure on airway opening index during mechanical versus manual chest compressions in a porcine model of cardiac arrest

ObjectivesThe exhaled CO2 signal provides guidance during cardiopulmonary resuscitation. The Airway opening index (AOI) has been recently used to quantify chest-compression (CC) induced expired CO2 oscillations. We aimed to determine whether levels of intrathoracic pressures developed during CC or parameters related to lung structure may affect AOI. MethodsSecondary analysis of a randomized animal study (n = 12) in a porcine model of cardiac arrest (CA) and cardiopulmonary resuscitation (CPR) during ambulance transport. Animals were randomized to 18-min of manual or mechanical CCs. Changes in AOI and right atrial pressure (ΔRAP) were recorded during CCs in animals undergoing manual (n = 6) or mechanical (n = 6) CCs. Lung CT scan and measurement of the respiratory system compliance (Cpl,rs) were performed immediately after return of spontaneous circulation. ResultsAnimals undergoing mechanical CCs had a lower AOI compared to animals treated with manual CCs (p < 0.001). AOI negatively correlated with the swings of intrathoracic pressure, as measured by the change in ΔRAP (ρ=−0.727, p = 0.007). AOI correlated with the lung density (ρ=−0.818, p = 0.001) and with the Cpl,rs (ρ = 0.676, p = 0.016). Animals with cardiopulmonary resuscitation associated lung edema (CRALE) (i.e. mean CT≥−500 HU) showed lower levels of AOI compared to animals without it (29 ± 12 % versus 50 ± 16 %, p = 0.025). ConclusionsAnimals undergoing mechanical CCs had lower levels of AOI compared to animals undergoing manual CCs. A higher swing of intrathoracic pressure during CC, a denser and a stiffer lung were associated with an impaired CO2 exhalation during CC as observed by a lower AOI.

Transparency in out-of-hospital cardiac arrest resuscitation: decision-making when patients are in the grey area between treatment and futility.

Transparency in out-of-hospital cardiac arrest resuscitation: decision-making when patients are in the grey area between treatment and futility.

Monitoring Mitochondrial Partial Oxygen Pressure During Cardiac Arrest and Extracorporeal Cardiopulmonary Resuscitation. An Experimental Pilot Study in a Pig Model.

Introduction: Ischemia and reperfusion are crucial in determining the outcome after cardiac arrest and can be influenced by extracorporeal cardiopulmonary resuscitation (ECPR). The effect of ECPR on the availability and level of oxygen in mitochondria remains unknown. The aim of this study was to find out if skin mitochondrial partial oxygen pressure (mitoPO2) measurements in cardiac arrest and ECPR are feasible and to investigate its course.Materials and Methods: We performed a feasibility test to determine if skin mitoPO2 measurements in a pig are possible. Next, we aimed to measure skin mitoPO2 in 10 experimental pigs. Measurements were performed using a cellular oxygen metabolism measurement monitor (COMET), at baseline, during cardiac arrest, and during ECPR using the controlled integrated resuscitation device (CIRD).Results: The feasibility test showed continuous mitoPO2 values. Nine experimental pigs could be measured. Measurements in six experimental pigs succeeded. Our results showed a delay until the initial spike of mitoPO2 after ECPR initiation in all six experimental tests. In two experiments (33%) mitoPO2 remained present after the initial spike. A correlation of mitoPO2 with mean arterial pressure (MAP) and arterial partial oxygen pressure measured by CIRD (CIRD-PaO2) seemed not present. One of the experimental pigs survived.Conclusions: This experimental pilot study shows that continuous measurements of skin mitoPO2 in pigs treated with ECPR are feasible. The delay in initial mitoPO2 and discrepancy of mitoPO2 and MAP in our small sample study could point to the possible value of additional measurements besides MAP to monitor the quality of tissue perfusion during cardiac arrest and ECPR.

The Role of Epinephrine in the Resuscitation of Pre-hospital Traumatic Cardiac Arrest

The Role of Epinephrine in the Resuscitation of Pre-hospital Traumatic Cardiac Arrest

The Association Between the Number of Prehospital Providers On-Scene and Out-of-Hospital Cardiac Arrest Outcomes

Objective: The ideal number of emergency medical services (EMS) providers needed on-scene during an out-of-hospital cardiac arrest (OHCA) resuscitation is unknown. Our objective was to evaluate the association between the number of providers on-scene and OHCA outcomes. Methods: This was a secondary analysis of adults (18 years old) with non-traumatic OHCA from a 10-site North American prospective cardiac arrest registry (Resuscitation Outcomes Consortium) including a 2005–2011 cohort and a 2011–2015 cohort. The primary outcome was survival to hospital discharge. We calculated the median number of EMS providers on-scene during the first 10 minutes of the resuscitation and used multivariable logistic regression adjusting for age, sex, witness status, bystander CPR, arrest location, initial rhythm, and dispatch to EMS arrival time. Results: There were 30,613 and 41,946 patients with necessary variables in the 2005–2011 and 2011–2015 cohorts, respectively. Survival to hospital discharge (95% CI) was higher with 9 or more providers on-scene (17.2% [15.8–18.5] and 14.0% [12.6–15.4]) compared to 7–8 (14.1% [13.4–14.8] and 10.5% [9.9–11.1]), 5–6 (10.0% [9.5–10.5] and 8.5% [8.1–8.9]), 3–4 (10.5% [9.3–11.6] and 9.3% [8.5–10.1]), and 1–2 (8.6% [7.2–10.0] and 8.0% [7.1–9.0]) providers for the 2005–2011 and 2011–2015 cohorts, respectively. In multivariable logistic regressions, compared to 5–6 providers, there were no significant differences in survival to hospital discharge for 1–2 or 3–4 providers, while having 7–8 (adjusted odds ratios (aORs) 1.53 [1.39–1.67] and 1.31 [1.20–1.44]) and 9 or more (aORs 1.76 [1.56–1.98] and 1.63 [1.41–1.89]) providers were associated with improved survival in both the 2005–2011 and 2011–2015 cohorts, respectively. Conclusions: The presence of seven or more prehospital providers on-scene was associated with significantly greater adjusted odds of survival to hospital discharge after OHCA compared to fewer on-scene providers.

Mildly Reduced Doses of Adrenaline Do Not Affect Key Hemodynamic Parameters during Cardio-Pulmonary Resuscitation in a Pig Model of Cardiac Arrest.

Adrenaline is recommended for cardiac arrest resuscitation, but its effectiveness has been questioned recently. Achieving return of spontaneous circulation (ROSC) is essential and is obtained by increasing coronary perfusion pressure (CPP) after adrenaline injection. A threshold as high as 35 mmHg of CPP may be necessary to obtain ROSC, but increasing doses of adrenaline might be harmful to the brain. Our study aimed to compare the increase in CPP with reduced doses of adrenaline to the recommended 1 mg dose in a pig model of cardiac arrest. Fifteen domestic pigs were randomized into three groups according to the adrenaline doses: 1 mg, 0.5 mg, or 0.25 mg administered every 5 min. Cardiac arrest was induced by ventricular fibrillation; after 5 min of no-flow, mechanical chest compression was resumed. The Wilcoxon test and Kruskal–Wallis exact test were used for the comparison of groups. Fisher’s exact test was used to compare categorical variables. CPP, EtCO2 level, cerebral, and tissue near-infrared spectroscopy (NIRS) were measured. CPP was significantly lower in the 0.25 mg group 90 s after the first adrenaline injection: 28.9 (21.2; 35.4) vs. 53.8 (37.8; 58.2) in the 1 mg group (p = 0.008), while there was no significant difference with 0.5 mg 39.6 (32.7; 52.5) (p = 0.056). Overall, 0.25 mg did not achieve the threshold of 35 mmHg. EtCO2 levels were higher at T12 and T14 in the 0.5 mg than in the standard group: 32 (23; 35) vs. 19 (16; 26) and 26 (20; 34) vs. 19 (12; 22) (p < 0.05). Cerebral and tissue NIRS did not show a significant difference between the three groups. CPP after 0.5 mg boluses of adrenaline was not significantly different from the recommended 1 mg in our model of cardiac arrest.

REBOA-Assisted Resuscitation in Non-Traumatic Cardiac Arrest due to Massive Pulmonary Embolism: A Case Report with Physiological and Practical Reflections

We present the case of a 36-year-old woman who suffered from and ultimately did not survive a non-traumatic out-of-hospital cardiac arrest (NTCA) likely due to massive pulmonary embolism. The resuscitation attempt included the use of a resuscitative endovascular balloon occlusion of the aorta (REBOA) catheter which resulted in a return of spontaneous circulation and distinct improvements in arterial blood pressure, end-tidal CO2 and cerebral oximetry values. This suggests that the use of REBOA has the physiological basis and potential to improve the rate of both survival and favorable neurologic outcome and warrants further study.

GluN2B S1303 phosphorylation by CaMKII or DAPK1: No indication for involvement in ischemia or LTP

SummaryBinding of two different CaM kinases, CaMKII and DAPK1, to the NMDA-type glutamate receptor (NMDAR) subunit GluN2B near S1303 has been implicated in excitotoxic/ischemic neuronal cell death. The GluN2BΔCaMKII mutation (L1298A, R1300Q) is neuroprotective but abolishes only CaMKII but not DAPK1 binding. However, both kinases can additionally phosphorylate GluN2B S1303. Thus, we here tested S1303 phosphorylation for possible contribution to neuronal cell death. The GluN2BΔCaMKII mutation completely abolished phosphorylation by CaMKII and DAPK1, suggesting that the mutation could mediate neuroprotection by disrupting phosphorylation. However, S1303 phosphorylation was not increased by excitotoxic insults in hippocampal slices or by global cerebral ischemia induced by cardiac arrest and cardiopulmonary resuscitation in vivo. In hippocampal cultures, S1303 phosphorylation was induced by chemical LTD but not LTP stimuli. These results indicate that the additional effect of the GluN2BΔCaMKII mutation on phosphorylation needs to be considered only in LTD but not in LTP or ischemia/excitotoxicity.

4 Outcomes Following Consultation With Online Medical Control During Out-of-Hospital Cardiac Arrest in the Portland Metropolitan Area

Emergency medical services (EMS) frequently seeks advice, often as a local protocol requirement, on further care or termination of resuscitation (TOR) during an out-of-hospital cardiac arrest (OHCA) resuscitation via online medical control (OLMC). Our objective was to characterize the recommendations made by OLMC in OHCA, and to determine the impact of these on EMS transport decisions and patient outcomes.

THE EFFECT OF A CHECKLIST ON VARIABILITY OF CARE AFTER IN HOSPITAL CARDIAC ARREST AT A TERTIARY ACADEMIC MEDICAL CENTER

TOPIC: Critical Care TYPE: Original Investigations PURPOSE: There are approximately 290,000 in hospital cardiac arrests (IHCA) annually in the United States. Recent evidence suggests that post IHCA outcomes may be more related to post return of spontaneous circulation (ROSC) care than intra cardiac arrest resuscitation. The purpose of this study is to assess the effect of a post ROSC checklist on variability care after IHCA with ROSC. METHODS: We performed a retrospective analysis of inpatient adults with an IHCA with ROSC at Harborview Medical Center (HMC) between 1/1/2018-12/31/2019. Included patients had an ICHA on an acute care or intensive care unit (ICU), were over the age of 18, and not placed on extra corporeal membrane oxygenation. IHCA was defined as cardiopulmonary resuscitation delivered by healthcare personnel. Demographics, clinical variables, and process of care metrics were abstracted from the electronic medical record. We then developed a post ROSC checklist utilizing our retrospective data and expert opinion. The checklist was implemented at HMC in January 2020. We conducted a follow up analysis of post-ROSC care since checklist implementation between 1/1/2020-12/31/2020. Pre and post implementation results were compared. RESULTS: 125 IHCA were included in the pre implementation cohort and 47 were included in the post implementation cohort. The mean age of the pre implementation cohort was 55.1 versus 55.9 post implementation. Women comprised 36.8% in the pre implementation cohort and 37.0% in the post implementation cohort. The rate of obtaining an electrocardiogram within one hour of ROSC was 60.8% prior to checklist implementation, and 76.6% after implementation. The rate of obtaining a formal transthoracic echocardiogram within six hours of ROSC was 32.8% prior to checklist implementation, and 34.0% after implementation. The rate of physician documentation occurring within six hours of ROSC was 47.0% prior to checklist implementation, and 85.1% after implementation. The rate of documented notification of family within six hours of ROSC in 67.2% of cases prior to checklist implementation, and 80.8% after implementation. CONCLUSIONS: The introduction of a post ROSC checklist correlated with an increase in obtaining ECGs and completing documentation tasks after IHCA with ROSC at HMC. This study was limited by the small number patients included as well as being a single site study. Confounding circumstances in code blue management related to COVID-19 must be acknowledged. Further research is needed to assess the durability of these findings, and what impact this may have on post IHCA outcomes. CLINICAL IMPLICATIONS: While there will be differences in the management and evaluation of patients who suffer an IHCA, some interventions such as a timely ECG and documentation should be completed with little variance between patients. The use of a checklist decreased the rate of variance, by providing a cognitive aid to guide clinical decisions in a stressful scenario. The use of a post ROSC checklist has the potential to decrease variance in diagnostic and documentation tasks after IHCA. DISCLOSURES: No relevant relationships by David Carlbom, source=Web Response No relevant relationships by Stephen Ferraro, source=Web Response No relevant relationships by Vince Raikhel, source=Web Response No relevant relationships by Vera Schulte, source=Web Response No relevant relationships by James Town, source=Web Response

Rewarming With Closed Thoracic Lavage Following 3-h CPR at 27°C Failed to Reestablish a Perfusing Rhythm.

Introduction: Previously, we showed that the cardiopulmonary resuscitation (CPR) for hypothermic cardiac arrest (HCA) maintained cardiac output (CO) and mean arterial pressure (MAP) to the same reduced level during normothermia (38°C) vs. hypothermia (27°C). In addition, at 27°C, the CPR for 3-h provided global O2 delivery (DO2) to support aerobic metabolism. The present study investigated if rewarming with closed thoracic lavage induces a perfusing rhythm after 3-h continuous CPR at 27°C.Materials and Methods: Eight male pigs were anesthetized, and immersion-cooled. At 27°C, HCA was electrically induced, CPR was started and continued for a 3-h period. Thereafter, the animals were rewarmed by combining closed thoracic lavage and continued CPR. Organ blood flow was measured using microspheres.Results: After cooling with spontaneous circulation to 27°C, MAP and CO were initially reduced by 37 and 58% from baseline, respectively. By 15 min after the onset of CPR, MAP, and CO were further reduced by 58 and 77% from baseline, respectively, which remained unchanged throughout the rest of the 3-h period of CPR. During CPR at 27°C, DO2 and O2 extraction rate (VO2) fell to critically low levels, but the simultaneous small increase in lactate and a modest reduction in pH, indicated the presence of maintained aerobic metabolism. During rewarming with closed thoracic lavage, all animals displayed ventricular fibrillation, but only one animal could be electro-converted to restore a short-lived perfusing rhythm. Rewarming ended in circulatory collapse in all the animals at 38°C.Conclusion: The CPR for 3-h at 27°C managed to sustain lower levels of CO and MAP sufficient to support global DO2. Rewarming accidental hypothermia patients following prolonged CPR for HCA with closed thoracic lavage is not an alternative to rewarming by extra-corporeal life support as these patients are often in need of massive cardio-pulmonary support during as well as after rewarming.

How senior paramedics decide to cease resuscitation in pulseless electrical activity out of hospital cardiac arrest: a mixed methods study

BackgroundEvidenced-based guidelines on when to cease resuscitation for pulseless electrical activity are limited and support for paramedics typically defaults to the senior clinician. Senior clinicians include paramedics employed to work beyond the scope of clinical guidelines as there may be a point at which it is reasonable to cease resuscitation. To support these decisions, one ambulance service has applied a locally derived cessation of resuscitation checklist. This study aimed to describe the patient, clinical and system factors and examine senior clinician experiences when ceasing resuscitation for pulseless electrical activity.Design and methodsAn explanatory sequential mixed method study was conducted in one ambulance service in the South West of England. A consecutive sample of checklist data for adult pulseless electrical activity were retrieved from 1st December 2015 to 31st December 2018. Unexpected results which required exploration were identified and developed into semi-structured interview questions. A purposive sample of senior clinicians who ceased resuscitation and applied the checklist were interviewed. Content framework analysis was applied to the qualitative findings.ResultsSenior clinicians ceased resuscitation for 50 patients in the presence of factors known to optimise survival: Witnessed cardiac arrest (n = 37, 74%), bystander resuscitation (n = 30, 60%), defibrillation (n = 22, 44%), return of spontaneous circulation (n = 8, 16%). Significant association was found between witnessed cardiac arrest and bystander resuscitation (p = .00). Six senior clinicians were interviewed, and analysis resulted in four themes: defining resuscitation futility, the impact of ceasing resuscitation, conflicting views and clinical decision tools. In the local context, senior clinicians applied their clinical judgement to balance survivability. Multiple factors were considered as the decision to cease resuscitation was not always clear. Senior clinicians deviated from the checklist when the patient was perceived as non-survivable.ConclusionSenior clinicians applied clinical judgement to assess patients as non-survivable or when continued resuscitation was considered harmful with no patient benefit. Senior clinicians perceived pre-existing factors with duration of resuscitation and clinical factors known to optimise patient survival. Future practice could look beyond a set criteria in which to cease resuscitation, however, it would be helpful to investigate the value or threshold of factors associated with patient outcome.

Volumetric Capnometry, more than end-tidal carbon dioxide

Monitoring the exhaled caron dioxide pressure, known as end-tidal CO2 (ETCO2) has become the standard of care during anesthesia, intensive care units, and during cardiac arrest resuscitation. However, volumetric capnometry provides much more useful information other than the ETCO2.

High-resolution respirometry for evaluation of mitochondrial function on brain and heart homogenates in a rat model of cardiac arrest and cardiopulmonary resuscitation

The physiology and physiopathology process of mitochondrial function following cardiac arrest remains poorly understood. We aimed to assess mitochondrial respiratory function on the heart and brain homogenates from cardiac arrest rats. The expression level of SIRT1/PGC-1α pathway was measured by immunoblotting. 30 rats were assigned to the CA group and the sham group. Rats of CA were subjected to 6 min of untreated ventricular fibrillation (VF) followed by 8 min of cardiopulmonary resuscitation (CPR). Mitochondrial respiratory function was compromised following CA and I/R injury, as indicated by CIL (451.46 ± 71.48 vs. 909.91 ± 5.51 pmol/min*mg for the heart and 464.14 ± 8.22 vs. 570.53 ± 56.33 pmol/min*mg for the brain), CI (564.04 ± 64.34 vs. 2729.52 ± 347.39 pmol/min*mg for the heart and 726.07 ± 85.78 vs. 1762.82 ± 262.04 pmol/min*mg for the brain), RCR (1.88 ± 0.46 vs. 3.57 ± 0.38 for the heart and 2.05 ± 0.19 vs. 3.49 ± 0.19, for the brain) and OXPHOS coupling efficiency (0.45 ± 0.11 vs. 0.72 ± 0.03 for the heart and 0.52 ± 0.05 vs. 0.71 ± 0.01 for the brain). However, routine respiration was lower in the heart and comparable in the brain after CA. CIV did not change in the heart but was enhanced in the brain. Furthermore, both SIRT1 and PGC-1α were downregulated concurrently in the heart and brain. The mitochondrial respiratory function was compromised following CA and I/R injury, and the major affected respiratory state is complex I-linked respiration. Furthermore, the heart and the brain respond differently to the global I/R injury after CA in mitochondrial respiratory function. Inhibition of the SIRT1/PGC-1α pathway may be a major contributor to the impaired mitochondrial respiratory function.

Collaboration between emergency physicians and citizen responders in out-of-hospital cardiac arrest resuscitation

BackgroundCitizen responder programmes dispatch volunteer citizens to initiate resuscitation in nearby out-of-hospital cardiac arrests (OHCA) before the Emergency Medical Services (EMS) arrival. Little is known about the interaction between citizen responders and EMS personnel during the resuscitation attempt. In the Capital Region of Denmark, emergency physicians are dispatched to all suspected OHCAs. The aim of this study was to evaluate how emergency physicians perceived the collaboration with citizen responders during resuscitation attempts.MethodThis cross-sectional study was conducted through an online questionnaire. It included all 65 emergency physicians at Copenhagen EMS between June 9 and December 13, 2019 (catchment area 1.8 million). The questionnaire examined how emergency physicians perceived the interaction with citizen responders at the scene of OHCA (use of citizen responders before and after EMS arrival, citizen responders’ skills in cardiopulmonary resuscitation (CPR), and challenges in this setting).ResultsThe response rate was 87.7% (57/65). Nearly all emergency physicians (93.0%) had interacted with a citizen responder at least once. Of those 92.5%(n = 49) considered it relevant to activate citizen responders to OHCA resuscitation, and 67.9%(n = 36) reported the collaboration as helpful. When citizen responders arrived before EMS, 75.5%(n = 40) of the physicians continued to use citizen responders to assist with CPR or to carry equipment. Most (84.9%, n = 45) stated that citizen responders had the necessary skills to perform CPR. Challenges in the collaboration were described by 20.7%(n = 11) of the emergency physicians and included citizen responders being mistaken for relatives, time-consuming communication, or crowding problems during resuscitation.ConclusionEmergency physicians perceived the collaboration with citizen responders as valuable, not only for delivery of CPR, but were also considered an extra helpful resource providing non-CPR related tasks such as directing the EMS to the arrest location, carrying equipment and taking care of relatives.

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.

Impact of age on the outcomes of extracorporeal cardiopulmonary resuscitation: analysis using inverse probability of treatment weighting.

Patient selection is crucial to improving the outcomes of extracorporeal cardiopulmonary resuscitation (ECPR). However, ECPR's efficacy with older patients remains unknown. We reviewed patients who underwent extracorporeal membrane oxygenation (ECMO) for refractory cardiac arrest from January 2006 to December 2018. Exclusion criteria were age <18 years, cannulation failure and ECMO applied at another hospital. We divided patients into 2 groups with an age cut-off of 66 years, using the Contal and O'Quigley method for overall survival. We performed inverse probability of treatment weighting (IPTW) between the 2 groups and set the primary outcome as overall survival. We included 318 patients in our study (≤66 years, n = 199; >66 years, n = 119). Before IPTW, we observed that the older group had a higher frequency of diabetes, hypertension, and myocardial infarction. In the young group, more patients had out-of-hospital cardiac arrest as compared with the older group. The hospital mortality rate was 55% (48.7% in the young group, 65.5% in the older group; P = 0.004). In the multivariable analysis after IPTW, the older group showed worse outcomes in overall survival [hazard ratio (HR) = 2.02; 95% confidence interval (CI), 1.50-2.70; P < 0.001] and neurological outcomes at discharge (odds ratio = 2.95; 95% CI, 1.69-5.14; P = <0.001). ECMO insertion during catheterization (HR = 0.57; 95% CI, 0.36-0.90; P = 0.015) and recovery of spontaneous circulation before pump-on (HR = 0.67; 95% CI, 0.50-0.89; P = 0.007) were positive predictors, but initial asystole rhythm, non-cardiac cause (HR = 2.39; 95% CI, 1.59-3.61; P < 0.001), out-of-hospital cardiac arrest (HR = 1.86; 95% CI, 1.24-2.79; P = 0.003) and prolonged cardiopulmonary resuscitation to pump-on time (HR = 1.01; 95% CI, 1.01-1.02; P < 0.001) were negative predictors for overall survival. Older patients who had ECPR had significantly worse survival and neurological outcomes. For patients older than age 66 years, more careful patient selection is critically important for improving the efficacy of ECPR.

Risk of Physical Injury for Dispatched Citizen Responders to Out-of-Hospital Cardiac Arrest.

BackgroundCitizen responder programs are implemented worldwide to dispatch volunteer citizens to participate in out‐of‐hospital cardiac arrest resuscitation. However, the risk of injuries in relation to activation is largely unknown. We aimed to assess the risk of physical injury for dispatched citizen responders.Methods and ResultsSince September 2017, citizen responders have been activated through a smartphone application when located close to a suspected cardiac arrest in the Capital Region of Denmark. A survey was sent to all activated citizen responders, including a specific question about risk of acquiring an injury during activation. We included all surveys from September 1, 2017, to May 15, 2020. From May 15, 2019, to May 15, 2020, we followed up on all survey nonresponders by phone call, e‐mail, or text messages to examine if nonresponders were at higher risk of severe or fatal injuries. In 1665 suspected out‐of‐hospital cardiac arrests, 9574 citizen responders were dispatched and 76.6% (7334) answered the question regarding physical injury. No injury was reported by 99.3% (7281) of the responders. Being at risk of physical injury was reported by 0.3% (24), whereas 0.4% (26) reported an injury (25 minor injuries and 1 severe injury [ankle fracture]). When following up on nonresponders (2472), we reached 99.1% (2449). No one reported acquired injuries, and only 1 reported being at risk of injury.ConclusionsWe found low risk of physical injury reported by volunteer citizen responders dispatched to out‐of‐hospital cardiac arrest. Risk of injury should be considered and monitored as a safety measure in citizen responder programs.