Cardiac Arrest Resuscitation Research Articles

Abstract 244: Preliminary Results on Angiotensin II as a Novel Vasopressor in Modeled Out-of-Hospital Cardiac Arrest and Cardiopulmonary Resuscitation

Introduction: The PARAMEDIC2-trial reported a higher survival rate comparing standard epinephrine treatment with placebo, but severe neurologic impairment was found more often in patients who received epinephrine. Angiotensin II (AT2) has been recently authorized by FDA and EMA to treat distributive shock in adults. It is not approved as a vasopressor in the treatment of cardiac arrest (CA) and has not been studied in a standardized model of out-of hospital cardiac arrest with subsequent guideline-based cardiopulmonary resuscitation (CPR) before. Hypothesis: AT2 administration during CPR will 1. result in higher rates for return of spontaneous circulation (ROSC) after modeled out-of-hospital CA and 2. will achieve a greater increase in mean arterial blood pressure (MAP) compared to standard epinephrine bolus regimen. Methods: After legal approval (81-02.04.2019A072) and in conformance with the AHA position statement (Circulation 1985; 71:849A), we conducted a prospective, randomized trial in 25 swine weighing 32 to 43.5 kilogram bodyweight (kgBW) under general anesthesia. In 22 swine randomized to intervention groups i) EPI or ii) AT2, ventricular fibrillation was induced electrically and mechanical ventilation was discontinued. After 10 minutes (min) of untreated CA, ventilation was resumed and CPR was performed adapted to current guidelines for up to 56 min. After the third unsuccessful defibrillation (6 min CPR), swine received either i) boluses of epinephrine 0.01 mg/kgBW every 4 min or ii) an initial bolus of AT2 (25 μg/kgBW) followed by continuous infusion at 1 μg/kgBW/min. Three animals served as sham controls and received identical treatment but neither CA nor CPR. Results: ROSC was achieved in 7/22 swine and in 5/20 requiring vasopressors (EPI 1/10 vs. AT2 4/10, n. s.). The initial vasopressor bolus increased MAP significantly more in AT2 compared to EPI (p = 0.03). However, this could not be maintained under continuous infusion of AT2. Conclusions: For the first time, we have demonstrated the feasibility of successful guideline-based CPR using AT2 as sole vasopressor. But still, questions such as the optimal dosage remain. We strongly encourage larger trials to investigate this newly available drug also for the treatment of CA.

Abstract 364: Continuous Electrocardiogram Classification During Resuscitation Using Transfer Learning

Introduction: Cardiac arrest resuscitation requires CPR interruption for ECG rhythm analysis, but pausing CPR is adversely associated with survival. Ideally, automated rhythm analysis would occur agnostic of CPR state throughout resuscitation and discriminate non-shockable from shockable rhythms. Transfer learning of pre-trained deep convolutional neural networks (CNNs) may enable accurate ECG analysis when applied to time-frequency representations of the ECG. We designed and evaluated a transfer learning algorithm to identify ventricular fibrillation (VF), asystole (AS), and organized (OR) rhythms agnostic of CPR. Methods: In this observational study of out-of-hospital cardiac arrest, rhythms were manually diagnosed in continuous defibrillator ECG recordings. Non-overlapping adjacent 2-s ECG segments were extracted from the first 30 min of each case regardless of CPR during VF, AS, and OR. Each segment was represented by an intrafrequency-normalized Morlet wavelet transform from 4-40 Hz. Using a 2/3 subset of patients for training, a series of two ResNet-101 CNNs were retrained to perform a shock decision (VF vs. non-shockable) followed by a specific non-shockable prediction (AS, OR, or Indeterminate). Performance was evaluated in a 1/3 validation subset of patients using a range of probability decision thresholds to predict the class of each segment. Results: In total, 275100 segments were collected from 461 patients. Of 90962 segments from 152 validation patients, using a 0.7 probability threshold for class prediction, 21% (18930/90962) were indeterminate, shock vs. no-shock sensitivity and specificity were 90% (19702/21930) and 97% (48421/50102), and specificities among non-shockable rhythms for AS vs. OR were 84% (5032/5998) and 86% (37760/44104), respectively (Fig 1). Conclusion: Transfer learning may enable shock/no-shock and rhythm-specific ECG classification continuously throughout resuscitation regardless of CPR.

Abstract 202: Video Laryngoscopy for Out of Hospital Cardiac Arrest

Introduction: Intubation is an essential component of cardiac arrest resuscitation. While prior studies have evaluated video laryngoscopy (VL) to assist intubation for in hospital cardiac arrest, there is a paucity of research evaluating VL for out of hospital cardiac arrest (OHCA). We sought to evaluate the association of video laryngoscopy with first pass success and ROSC. Hypothesis: Video laryngoscopy improves first pass success rate and improves the rate of ROSC Methods: We analyzed the 2018 data from ESO Inc. (Austin, TX), a national prehospital electronic health record used by 1289 EMS agencies in the US. We included all adult (age >18 years), non-traumatic cardiac arrests that were intubated with an endotracheal device. We applied a chi2 test to evaluate the first pass success rate for VL vs direct laryngoscopy (DL). We then created a mixed model, fitting agency as a random intercept and adjusting for age, gender, race, location of arrest, witnessed arrest, initial shockable rhythm, and bystander CPR. We applied the mixed model to analyze the association between VL and first pass success rate, ROSC, and sustained ROSC (survival to ED or ROSC for greater than 20 minutes). Results: We included 22,097 patients cared for by 914 agencies. 5,674 (25.7%) patients were intubated with video laryngoscopy. The median age was 66 (IQR 55-77). 61.9% of patients were male and 73.0% were white. 71.9% of cardiac arrest happened at home, 56.8% of were witnessed, 37.4% had bystander CPR, and 20.6% had a shockable rhythm. Compared to DL, VL had a lower rate of bystander CPR (41.4% v 36.1%, p<.001), but other characteristics were similar between the groups. We found that VL had a higher first pass success rate than DL (75.1% v 69.5%, p<.001). Using a mixed model analysis, VL was associated with a higher rate of first pass success (OR 1.5, CI 1.3-1.6), but VL was not associated with improvement in ROSC (OR 1.1, CI 0.97-1.2) or sustained ROSC (OR 1.1, CI 0.9-1.2). Conclusion: VL had a higher first pass success rate than DL, and on adjusted, mixed-model analysis, VL use was associated with increased rate of first pass success. However, VL was not associated with increased rate of ROSC

Abstract 285: Resuscitation Practices of Cardiac Arrest in Children with Cardiac Disease in Cardiac Intensive Care Units Compared to Pediatric Intensive Care Units

Introduction: Hospitalized children with critical cardiac disease experience cardiac arrest more than any other disease type. Varying models are devoted to caring for this population, including pediatric intensive care units (PICU) and dedicated cardiac intensive care units (CICU). The process of CPR delivery has not been evaluated in CICUs in comparison to PICUs. Hypothesis: There will be no difference in cardiac arrest resuscitation practices between unit types. Methods: We analyzed patients <18 years from the American Heart Association Get with the Guidelines-Resuscitation database (GWTG-R) with an illness category of medical or surgical cardiac disease who received CPR in a CICU or PICU from 2014 to 2018. Events were assessed for compliance with GWTG-R achievement measures of time to first chest compressions ≤ 1 minute, time to IV/IO epinephrine ≤ 5 minutes, time to first shock ≤ 2 minutes for VF/pulseless VT first documented rhythm, and confirmation of endotracheal tube (ETT) placement in trachea. Results: CPR practices were evaluated on 866 patients, 687 CICU and 179 PICU (55% male and 65% neonatal). Surgical cardiac disease was present in 56%. Cardiac malformations were present in 81% (45% cyanotic 29% acyanotic). Pulseless arrest was the initial event in 41% with a shockable rhythm in 14%. Return of spontaneous circulation occurred in 86% and survival to hospital discharge in 58%. Univariate analysis comparing resuscitation practice is shown in Table 1. ECPR use was the only variable noted to be significantly different between units (CICU 22% vs PICU 6%, P<0.01). On multivariate analysis, there were no differences in GWTG-R achievement measures between ICU types for ETT placement confirmation, time to IV/IO epinephrine dose, time to first chest compression to first shock (P>0.05). Conclusion: Despite differences in infrastructure, process, and provider expertise, there were no differences in cardiac arrest resuscitation practice between CICUs and PICUs.

Metformin ameliorates brain damage caused by cardiopulmonary resuscitation via targeting endoplasmic reticulum stress-related proteins GRP78 and XBP1

Cerebral damage after cardiac arrest (CA) and cardiopulmonary resuscitation (CPR) is a primary cause of death. Endoplasmic reticulum stress (ERS) is very important during these situations. This study aimed to explore the role of metformin in protecting brain endoplasmic reticulum post CA/CPR. Male SD rats (n = 132) were treated with 6-min CA-posted asphyxia and sham surgery. Before CA/CPR, metformin (200 mg/kg/day) or a vehicle (0.9% saline) were administered randomly for two weeks. The neurological deficit scores were assessed 24 h, 48 h, 72 h, and 7 days after CA/CPR, and the rat brains were analyzed by Western blotting and qRT-PCR. Apoptosis was detected by the TUNEL assay according to the mitochondrial membrane potential (MMP). Oxidative stress and ERS-related protein expression were also investigated. The Western blotting and qRT-PCR results revealed that the resuscitated animals had time-dependent elevated GRP78 and XBP1 levels compared with the sham operative rats. Moreover, our results showed that the rats treated with metformin had increased neurological deficit scores (NDS), an improved seven-day survival rate, decreased cell apoptosis within the hippocampus CA1 area, and less oxidative stress compared with the CA/CPR group. Furthermore, metformin inhibited the mRNA and protein expressions of glucose-regulated protein 78 (GRP78) and X-box binding protein 1 (XBP1) in the CA/CPR rat model. We confirmed that CA/CPR can induce ERS-related apoptosis and oxidative stress in the brain; moreover, inhibiting ERS-related proteins GRP78 and XBP1 with metformin might attenuate cerebral injury post CA/CPR.

Changes over time in 30-day survival and the incidence of shockable rhythms after in-hospital cardiac arrest - A population-based registry study of nearly 24,000 cases

ObjectiveTo determine changes over time in 30-day survival and the incidence of shockable rhythms after in-hospital cardiac arrest, from a countrywide perspective. MethodsPatient information from the Swedish Registry for Cardiopulmonary Resuscitation was analysed in relation to monitoring level of ward and initial rhythm. The primary outcome was defined as survival at 30 days. Changes in survival and incidence of shockable rhythms were reported per year from 2008 to 2018. Also, epidemiological data were compared between two time periods, 2008–2013 and 2014–2018. ResultsIn all, 23,186 unique patients (38.6% female) were included in the study. The mean age was 72.6 (SD 13.2) years. Adjusted trends indicated an overall increase in 30-day survival from 24.7% in 2008 to 32.5% in 2018, (on monitoring wards from 32.5% to 43.1% and on non-monitoring wards from 17.6% to 23.1%). The proportion of patients found in shockable rhythms decreased overall from 31.6% in 2008 to 23.6% in 2018, (on monitoring wards from 42.5% to 35.8 % and on non-monitoring wards from 20.1% to 12.9%). Among the patients found in shockable rhythms, the proportion of patients defibrillated before the arrival of cardiac arrest team increased from 71.0% to 80.9%. ConclusionsIn an 11-year perspective, resuscitation in in-hospital cardiac arrest in Sweden was characterised by an overall increase in the adjusted 30-day survival, despite a decrease in shockable rhythms. An increased proportion, among the patients found in a shockable rhythm, who were defibrillated before the arrival of a cardiac arrest team may have contributed to the finding.

After a century, Epinephrine's role in cardiac arrest resuscitation remains controversial.

Epinephrine is recommended in contemporary educational efforts by the American Heart Association (AHA) as central to adult Advanced Cardiac Life Support (ACLS). However, the International Liaison Committee on Resuscitation (ILCOR) 2019 recommendations update describes large evidentiary gaps for epinephrine use in cardiopulmonary resuscitation, highlighting that clinical and experimental evidence do not support the current AHA recommendations. This controversies article was written as a response to updated AHA and ILCOR adult ACLS recommendations in late 2019. This report summarizes and evaluates the evidence surrounding epinephrine for cardiac arrest with a focus on the historical perspective of epinephrine research. According to the 2019 AHA ACLS guidelines, epinephrine is an integral component of adult out-of-hospital cardiac arrest resuscitation. Epinephrine improves rates of return of spontaneous circulation and might provide benefit at different doses or in select resuscitation scenarios, such asystole as an initial rhythm at onset of resuscitation efforts. However, evidence indicates potential harms with routine use of standard dose epinephrine (1mg/10mL), with no improvement in neurologic or long-term outcomes. Despite years of use and inclusion in resuscitation guidelines, epinephrine is not associated with improved neurologic outcomes. The AHA Emergency Cardiovascular Care committee should revise ACLS guidelines reflecting evidence that standard-dose epinephrine offers little benefit to successful patient recovery including neurologic outcomes. Future resuscitation guidelines should reflect this important consideration.

The effect of emergency manuals on team performance during two different simulated perioperative crises: A prospective, randomized controlled trial

Study objectiveWhether having an emergency manual (EM) available for use during perioperative crises enhances or detracts from team performance, especially for multi-factorial diagnostic situations that do not explicitly match a chapter of the EM. DesignA simulation-based, prospective randomized trial based upon two perioperative crises, one involving a patient with a transfusion reaction for which the EM contains a specific chapter, and the other involving a patient with refractory hypotension progressing into septic shock for which the EM does not have a specific chapter. Setting52 regularly scheduled 6-h courses at the Center for Medical Simulation in Boston, Massachusetts, USA. Study group304 US-trained practicing anesthesiologists. InterventionsThe absence or presence of the EM during the simulation case. MeasurementsTeams were rated in the following categories: primary underlying diagnosis, fluid resuscitation, treatment of primary diagnosis, cardiac arrest management, overall crisis management, and (if applicable) EM usage. Also, raters recorded free-text ‘field notes’ about the usage-patterns and perceived utility of the EM. Using these ‘field notes’ and a two-stage, inductively revised procedure, two independent reviewers examined a subset of case videos for action analysis. Main resultsPerformance ratings for a total of 51 teams and 95 simulations were included in the final analysis. No effect on performance was demonstrated with providing the EM in either the refractory hypotension/septic shock case or the transfusion reaction case, with the exception of the PEA arrest category. In the subset of simulations in which resuscitation from PEA arrest performance could be evaluated, EM availability was associated with an adjusted mean 1.3 point (99% confidence interval [CI]: 0.2, 2.4) improvement in performance in the transfusion reaction case (p = 0.004), but only an adjusted mean 0.2 point (99% CI, −0.7, 1.1) improvement in the refractory hypotension/septic shock case (p = 0.530) (p for interaction = 0.069). Analysis of actions found that when available, the EM was usually used, but often not until after cardiac arrest had occurred. In some cases, teams persisted with incorrect diagnoses and treatments irrespective of the presence or absence of an EM. ConclusionsProviding an EM did not affect team performance in areas like diagnosis, treatment, fluid resuscitation, communication, and teamwork in management of perioperative crises such as transfusion reaction where an explicit chapter in the EM exists and refractory hypotension / septic shock where an explicit chapter does not exist. A suggestion of improved cardiac arrest resuscitation with the availability of an EM was found, but should be interpreted with caution given a limited sample size. Observed actions using the EM demonstrated that only about half of the teams used the EM to any substantive degree and most used it relatively late in the crisis. By observation, the EM appeared to be helpful in about half of the cases and did not, by itself, deter from appropriate management.

Ventilation in Simulated Out-of-Hospital Cardiac Arrest Resuscitation Rarely Meets Guidelines

Objective The American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care recommend ventilation rates of eight to ten breaths per minute or two ventilations every 30 compressions, and tidal volumes between 500–600 ml. However, compliance with these guidelines is mainly unknown. The objective of this study is to estimate the proportion of simulated adult OHCA cases that meet guideline-based ventilation targets. Methods We conducted a blinded prospective observational study of standardized simulated cases of EMS-witnessed adult OHCA. During scheduled training sessions, resuscitations were performed by high-quality CPR trained EMS teams composed of four on-duty, full-time EMT/Paramedics from a large urban fire-based EMS agency. A high-fidelity simulation center allowed complete audio and video monitoring from a control room. Rescuers were unaware of the study, or that ventilation practices were being observed. All interventions, including airway and ventilation strategies, were at the discretion of the clinical team. A calibrated Laerdal SimMan 3 G manikin and associated Laerdal Debrief Viewer software recorded ventilation rate, tidal volume, and minute ventilation. Simulations achieving median ventilation rate 7–10 breaths/min, tidal volume 500–600 ml, and minute ventilation 3.5–6 liters/min were considered meeting guideline-based targets. Results A total of 106 EMS teams were included in the study. Only 3/106 [2.8% (95% CI: 0.6–8.0)] of the EMS teams demonstrated ventilation characteristics meeting all guideline-based targets. The median ventilation rate was 5.8 breaths/min (IQR 4.4–7.7 breaths/min) with 26/106 [24.5% (95% CI: 17.2–33.7)] between 7–10 breaths/min. The median tidal volume was 413.5 ml (IQR 280.5–555.4 ml), with 18/106 [17.0% (95% CI: 10.9–25.5)] between 500–600 ml. The median minute ventilation was 2.4 L/min (IQR 1.2–3.6 L/min) with 16/106 [15.1% (95% CI: 9.4–23.3)] between 3.5–6.0 L/min. Conclusion During simulated adult OHCA resuscitation attempts, ventilation practices rarely met guideline-based targets, despite being performed by well-trained EMS providers. Methods should be developed to monitor and ensure high-quality ventilation during actual OHCA resuscitation attempts.

Relationship between knowledge and skill for basic life support in personnel of emergency medical services, Islamic Republic of Iran.

Pre-hospital resuscitation in cardiac arrest is crucial to survival of patients, so emergency medical services personnel must have up-to-date knowledge and good skills. This study aimed to determine the association between knowledge and skills of emergency medical services personnel of basic life support in north-west Khuzestan province, Islamic Republic of Iran. This cross-sectional study included all personnel of emergency medical services (75 participants) in two emergency centres. Data were collected on characteristics of the participants (age, time since last retraining, academic degree, and length of experience), and their knowledge of basic life support. Skills were assessed by observing the personnel carry out basic life support and use of an automated external defibrillator on a mannequin. Poor knowledge was found in 31% of the personnel (mean score: 19.35 (SD 3.9); range: 0-34) and 42.7% had poor skills (mean score: 5.40 (SD 2.39); range: 0-9). Most of the staff (71%) did not use the automated external defibrillator correctly. No statistically significant relationship was found between staff knowledge and skills (P = 0.298). Staff knowledge and skills were significantly associated with correct use of the defibrillator (P = 0.039). Knowledge score was significantly associated with length of time since doing resuscitation training (P = 0.006) and academic qualification (P = 0.046). The skills score was significantly associated with time since doing training (P = 0.004). Strategies to maintain and improve the life support knowledge and skills of personnel in emergency medical services are recommended.

277 Age Is the Only Factor That Affects Survival to Hospital Admission in Video-Reviewed Out-of-Hospital Cardiac Arrest Resuscitations

Out-of-hospital cardiac arrest (OHCA) affects more than 350,000 people in the United States each year with a survival rate of approximately 12%. Many factors have been implicated for their role in determining survival. For example, the American Heart Association recommends limiting pulse check time to <10 seconds and maintaining chest compression fraction (CCF) >80%. We utilized data from video-reviewed OHCA resuscitations at an urban academic emergency department (ED) to investigate factors associated with survival to hospital admission. Data was gathered on 96 OHCA resuscitations between July 2, 2017 and December 9, 2019. Each resuscitation was recorded in real-time in critical care bays within the ED. Videos were reviewed independently by two emergency medicine residents. The data compiled represents that from video review and retrospective review of the patients’ charts. Descriptive statistics (T-/Wilcoxon-Mann-Whitney and Chi-squared/Fishers exact tests) and logistic regression were used to identify the factors associated with the survival to hospital admission. Overall rate of survival to hospital admission was 29%. Out-of-hospital variables including witnessed arrest, bystander CPR and defibrillator use, and length of out-of-hospital code had no significant effect on survival to hospital admission (all p>0.05). Notably, in-hospital variables including length of code, time to monitor placement, time to definitive airway placement, length of pulse checks, and CCF were also not associated with a significant effect on survival (all p>0.05). Of the factors investigated, only age was statistically significant (p=0.035) with the data suggesting that as age increases, rate of survival to hospital admission decreases (p=-0.041). In our population, variables that have previously been reported to affect outcomes (bystander CPR and defibrillation, length of code, CCF etc.) along with variables unique to video-review cases (time to monitor, time to IV access, length of pulse checks, etc.) had no significant effect on survival to hospital admission.

Practice parameters of extracorporeal cardio-pulmonary resuscitation for refractory cardiac arrest in Germany. A nation-wide survey by the eCPR/ECMO working group of the German resuscitation council

Aim: Extracorporeal cardiopulmonary resuscitation, eCPR is increasingly becoming available as a therapy option in refractory in- or out-of-hospital cardiac arrest (IHCA or OHCA), respectively. To further assess the current state and practices of eCPR in Germany, we conducted a survey among 99 institutions by the eCPR/ECMO working group of the German Resuscitation Council.

Impact of Out-of-Hospital Organ Donor Cardiac Arrest and Cardiopulmonary Resuscitation on Donor Kidney Histology and Function

Impact of Out-of-Hospital Organ Donor Cardiac Arrest and Cardiopulmonary Resuscitation on Donor Kidney Histology and Function

Journal-related Activities and Other Special Activities at the 2020 American Society of Anesthesiologists Meeting.

Journal-related Activities and Other Special Activities at the 2020 American Society of Anesthesiologists Meeting.

398 Racial Disparities in Cardiac Arrest Resuscitation Efforts: A Cross-Sectional Study of Out-of-Hospital and Emergency Department Code Duration

398 Racial Disparities in Cardiac Arrest Resuscitation Efforts: A Cross-Sectional Study of Out-of-Hospital and Emergency Department Code Duration

The adaptive immune response in cardiac arrest resuscitation induced ischemia reperfusion renal injury

BackgroundThe present study aims to investigate, immunohistochemically, the role of the adaptive immune response in cardiac arrest/resuscitation-induced ischemia–reperfusion renal injury (IRI), namely to assess the presence of lymphocytes in renal tissue samples and the connection between the extent of the damage and the concentration of the lymphocytes by comparing the kidneys of non resuscitated swine with the kidneys of resuscitated swine.MethodsTwenty four swine underwent cardiac arrest (CA) via a pacemaker wire. After 7 min, without any intervention, Cardiopulmonary Resuscitation, CPR, was commenced. Five min after CPR was commenced advanced life-support, ALS. Animals were divided into resuscitated animals and non resuscitated animals. Tissue samples obtained from the two groups for immunohistological study aiming to detect T-cells, B-cells and plasma cells using CD3 + , CD20 + , and CD138 + antibodies.ResultsThere seems to be a strong concentration of T lymphocytes in the kidney tissues after ischemia of both non-resuscitated and resuscitated swine. B lymphocytes, also, appear to have infiltrated the ischemic kidneys of both animal groups; nevertheless, the contribution of T lymphocytes to the induction of injury remains greater. There is no strong evidence of correlation between the plasma cells and the damage.ConclusionThe adaptive immune response seems to have a strong association with kidney injury and acute tubular necrosis after cardiac arrest/ resuscitation-induced ischemia–reperfusion. However, the extent to which the adaptive immune cells are involved in the induction of renal injury remains uncertain and there are many questions about the mechanism of function of these cells, the answers of which require further studies.

CODE BLUE-19: Proposal to Mitigate COVID-19 Transmission in the Emergency Department for Out-of-hospital Cardiac Arrest.

Resuscitation of cardiac arrest in coronavirus disease 2019 (COVID-19) patients places the healthcare staff at higher risk of exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Unfortunately, COVID-19 status is unknown in most patients presenting to the emergency department (ED), and therefore special attention must be given to protect the healthcare staff along with the other patients. This is particularly true for out-of-hospital cardiac arrest patients who are transported to the ED. Based on the current data available on transmissibility of SARS-CoV-2, we have proposed a protocolized approach to out-of-hospital cardiac arrests to limit risk of transmission.

The Spinal Cord Damage in a Rat Asphyxial Cardiac Arrest/Resuscitation Model.

After cardiac arrest/resuscitation (CA/R), animals often had massive functional restrictions including spastic paralysis of hind legs, disturbed balance and reflex abnormalities. Patients who have survived CA also develop movement restrictions/disorders. A successful therapy requires detailed knowledge of the intrinsic damage pattern and the respective mechanisms. Beside neurodegenerations in the cerebellum and cortex, neuronal loss in the spinal cord could be a further origin of such movement artifacts. Thus, we aimed to evaluate the CA/R-induced degeneration pattern of the lumbar medulla spinalis by immunocytochemical expression of SMI 311 (marker of neuronal perikarya and dendrites), IBA1 (microglia marker), GFAP (marker of astroglia), calbindin D28k (marker of the cellular neuroprotective calcium-buffering system), MnSOD (neuroprotective antioxidant), the transcription factor PPARγ and the mitochondrial marker protein PDH after survival times of 7 and 21days. The CA/R specimens were compared with those from sham-operated and completely naïve rats. RESULTS& CONCLUSION: The main ACA/R-mediated results were: (1) degeneration of lumbar spinal cord motor neurons, characterized by neuronal pyknotization and peri-neuronal tissue artifacts; (2) attendant activation of microglia in the short-term group; (3) attendant activation of astroglia in the long-term group; (4) degenerative pattern in the intermediate gray matter; (5) activation of the endogenous anti-oxidative defense systems calbindin D28k and MnSOD; (6) activation of the transcription factor PPARγ, especially in glial cells of the gray matter penumbra; and (7) activation of mitochondria. Moreover, marginal signs of anesthesia-induced cell stress were already evident in sham animals when compared with completely naïve spinal cords. A correlation between the NDS and the motor neuronal loss could not be verified. Thus, the NDS appears to be unsuitable as prognostic tool.

Hyperoxygenation With Cardiopulmonary Resuscitation and Targeted Temperature Management Improves Post-Cardiac Arrest Outcomes in Rats.

BackgroundOxygen plays a pivotal role in cardiopulmonary resuscitation (CPR) and postresuscitation intervention for cardiac arrest. However, the optimal method to reoxygenate patients has not been determined. This study investigated the effect of timing of hyperoxygenation on neurological outcomes in cardiac arrest/CPR rats treated with targeted temperature management.Methods and ResultsAfter induction of ventricular fibrillation, male Sprague‐Dawley rats were randomized into 4 groups (n=16/group): (1) normoxic control; (2) O2_CPR, ventilated with 100% O2 during CPR; (3) O2_CPR+postresuscitation, ventilated with 100% O2 during CPR and the first 3 hours of postresuscitation; and (4) O2_postresuscitation, ventilated with 100% O2 during the first 3 hours of postresuscitation. Targeted temperature management was induced immediately after resuscitation and maintained for 3 hours in all animals. Postresuscitation hemodynamics, neurological recovery, and pathological analysis were assessed. Brain tissues of additional rats undergoing the same experimental procedure were harvested for ELISA‐based quantification assays of oxidative stress–related biomarkers and compared with the sham‐operated rats (n=6/group). We found that postresuscitation mean arterial pressure and quantitative electroencephalogram activity were significantly increased, whereas astroglial protein S100B, degenerated neurons, oxidative stress–related biomarkers, and neurologic deficit scores were significantly reduced in the O2_CPR+postresuscitation group compared with the normoxic control group. In addition, 96‐hour survival rates were significantly improved in all of the hyperoxygenation groups.ConclusionsIn this cardiac arrest/CPR rat model, hyperoxygenation coupled with targeted temperature management attenuates ischemia/reperfusion‐induced injuries and improves survival rates. The beneficial effects of high‐concentration oxygen are timing and duration dependent. Hyperoxygenation commenced with CPR, which improves outcomes when administered during hypothermia.

Closed-loop communication during out-of-hospital resuscitation

Training for effective communication in high-stakes environments actively promotes targeted communicative strategies. One oft-recommended strategy is closed-loop communication (CLC), which emphasises three components to signal understanding: call-out, checkback and closing of the loop. Using CLC is suggested to improve clinical outcomes, but research indicates that medical practitioners do not always apply CLC in team communication. Our paper analyses a context in which speakers’ linguistic choices are guided by explicit recommendations during training, namely out-of-hospital cardiac arrest (OHCA) resuscitation. We examined 20 real-life OHCA resuscitations to determine whether paramedics adopt CLC in the critical first five minutes after the arrival of the designated team leader (a paramedic specially trained in handling OHCA resuscitation), and what other related communication strategies may be used. The findings revealed that the standard form of CLC was not consistently present in any of the resuscitations despite opportunities to use it. Instead, we found evidence of non-standard forms of CLC and closed-ended communication (containing the first two components of standard CLC). These findings may be representative of what happens when medical practitioners communicate in time-critical, real-life contexts where responses to directives can be immediately observed, and suggest that CLC may not always be necessary for effective communication in these contexts.