Successful Return Of Spontaneous Circulation Research Articles

Time-Dependent Association Between Agonal Respirations and Cardiopulmonary Resuscitation Hemodynamics in a Porcine Model of Cardiac Arrest

Objective: Agonal respirations (AR) are common in patients with cardiac arrest (CA) and are associated with a higher likelihood of successful return of spontaneous circulation (ROSC). Prior preclinical studies suggest that the favorable effects of AR may be mediated by improved coronary perfusion pressure (CPP) during subsequent cardiopulmonary resuscitation (CPR) efforts, but whether this relationship is influenced by the duration of CA has yet to be studied. Accordingly, we measured CPR hemodynamics in swine following 7 minutes or 10 minutes of untreated ventricular fibrillation (VF) to determine if the frequency of AR is associated with CPP after prolonged CA. Methods: Swine (n=71) were subjected to either 7 minutes (n=50) or 10 minutes (n=21) of electrically-induced VF CA, during which the frequency of AR was recorded before the initiation of CPR with chest compressions (100/minute) and mechanical ventilation (16-20 breaths/minute). CPP was assessed during CPR by calculating the difference between aortic pressure and right atrial pressure during decompression. Animals were retrospectively stratified into two groups (high and low frequency of AR) based on the median number of AR in each cohort (7-minute CA median = 6 AR; 10-minute CA median = 9 AR).>Results: In the 7-minute CA cohort, the high AR group (9.7±2.9 AR; n=28) had a significantly longer time from first to last AR (102±6 vs. 34±6 seconds; p<0.001), shorter time from final AR to CPR initiation (208±8 vs. 280±15 seconds; p<0.001), and higher CPP during CPR (14.4±1.0 vs. 9.3±0.6 mmHg; p<0.001) than the low AR group (2.9±0.4 AR; n=22). In contrast, following 10 minutes of CA, the high AR group (12.0±0.4 AR; n=11) did not have a significantly different CPP during CPR (8.7±1.8 vs. 10.4±1.5 mmHg; p=0.48) when compared to the low AR group (6.2±0.5 AR; n=10). A greater number of defibrillation attempts were required to terminate VF after 10 minutes of CA (3.0±0.6) vs. 7 minutes of CA (1.2±0.1; p<0.001), but this was not impacted by the frequency of AR in either cohort. Conclusion: Consistent with prior studies in swine subjected to 5 minutes of untreated CA, a high frequency of AR during a 7-minute episode of CA was associated with higher CPP upon initiation of CPR. However, the favorable effects of AR frequency on CPP during CPR were no longer apparent when the duration of untreated CA was extended to 10 minutes. These results demonstrate that the beneficial effects of AR on CPR hemodynamics are time-dependent and highlight the importance of early initiation of CPR following CA. Supported by funding from the NIH and US Department of Veteran's Affairs. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Exploring the Role of Bispectral Index in Interrupting CPR for ROSC Diagnosis: A Call for Further Research

The current approach in cardiopulmonary resuscitation (CPR) involves interrupting the chest compressions to assess the pulse and diagnose Return of Spontaneous Circulation (ROSC). This critical step is essential for determining the effectiveness of resuscitation efforts. However, the interruption of CPR poses a challenge, prompting researchers to explore alternative methods for diagnosing ROSC without compromising the ongoing resuscitation process.
 One potential solution proposed in the literature is the use of the Bispectral Index (BIS). BIS is a numerical value derived from processed electroencephalogram data, providing a measure of the depth of anesthesia or sedation. Some studies have reported an increase in BIS values following successful ROSC during CPR. This observation suggests that monitoring BIS levels could offer real-time information about cerebral perfusion and neurological status, eliminating the need for pulse checks that require CPR interruption.
 Despite these promising indications, it is crucial to acknowledge the limited existing literature on the subject. The evidence supporting the use of BIS in diagnosing ROSC during CPR is not yet robust, and further research is warranted. Researchers are encouraged to delve into this unexplored area, conducting comprehensive studies to assess the reliability and effectiveness of BIS as a tool for continuous monitoring during resuscitation efforts.
 In conclusion, while the concept of using BIS to diagnose ROSC during CPR holds potential, it remains an area that requires substantial research attention. The limited existing literature underscores the need for more extensive investigations to determine the feasibility and reliability of integrating BIS into the CPR protocol. As technology advances, exploring innovative approaches for continuous assessment during resuscitation becomes imperative for improving outcomes in cardiac arrest scenarios

Abstract 158: Exploring the Potential for Kidney Donation in Out-of-Hospital Cardiac Arrest Cases With No Chance of Survival

Introduction: The global kidney shortage can potentially be addressed through the implementation of the uncontrolled donation after circulatory death (uDCD) pathway. However, the current Termination-of-Resuscitation (TOR) rules, although effective in identifying futile resuscitation, do not consider the potential benefits of organ donation. Objective: This study aims to assess the potential pool of uDCD kidney donors among patients with resuscitation attempts by Emergency Medical Services (EMS) who meet TOR criteria. Methods: Retrospective analysis was conducted using data from the Paris Sudden Death Expertise Center (SDEC) registry spanning from 2011 to 2020. TOR criteria evaluation and identification of potential organ donors were performed using established selection criteria from previous protocols on TOR rules and uDCD. Incidence rates (per patient-years) were calculated using data from the National Institute of Statistics and Economic Studies. Results: Out of 19,976 cases of Out-of-Hospital-Cardiac Arrest (OHCA) with resuscitation attempts by EMS, 12,890 (64.5%) did not achieve sustained Return of Spontaneous Circulation (ROSC). Among patients with no successful ROSC, the annual number and incidence of patients with no chance of survival varied across different TOR rules, ranging from 626 to 1081 cases and from 8.14 to 10.04 per 100,000 patient-years. The proportion of OHCA patients meeting both TOR criteria and extended kidney criteria ranged from 67.8% to 73.6% of total cases of OHCA who did not achieve sustained ROSC. Conclusion: Our findings demonstrate that the implementation of a uDCD program, in cases where TOR rules indicate no chance of survival, has the potential to significantly increase the pool of potential organ donors.

Survival to discharge and outcome of a dog following out‐of‐hospital cardiac arrest due to asphyxiation

AbstractA 7‐month‐old dog presented with a 10‐minute history of upper respiratory tract obstruction and secondary loss of consciousness in the minute before its arrival to the hospital. The dog was found to be dead on arrival. Cardiopulmonary resuscitation was initiated, which led to successful return of spontaneous circulation 20 minutes later, with subsequent regain of consciousness. Symptomatic therapy and supportive care were provided for 3.5 weeks before discharging the dog into the care of its owners. Despite having made an initial improvement, it was subsequently euthanised 4 weeks later due to persistent severe neurological deficits. Although the neurological improvement was not deemed sufficient for the dog to have a good quality of life, this case report highlights that return of spontaneous circulation after out‐of‐hospital cardiac arrest and a prolonged period of cardiopulmonary resuscitation is feasible, and neurological improvement thereafter is possible.

Unexpected carboxyhemoglobin half-life during cardiopulmonary resuscitation: a case report

BackgroundCardiac arrest (CA) following CO poisoning (CO-induced CA) exposes patients to an extremely high risk of mortality and remains challenging to treat effectively. Terminal carboxyhemoglobin elimination half-life (COHbt1/2) is critically affected by ventilation, oxygen therapy, and cardiac output, which are severely affected conditions in cases of CA.Case presentationAsystole occurred in an 18-year-old woman after unintentional exposure to CO in her bathroom. Cardiopulmonary resuscitation (CPR) was started immediately, including mechanical ventilation with a fraction of inspired oxygen (FiO2) of 1.0 and external chest compressions with a LUCAS® device. CPR was stopped after 101 min, as it was unsuccessful. During this period, we calculated a COHbt1/2 of 40.3 min using a single compartmental model.ConclusionsThis result suggests that prolongation of CPR time needed to back COHb at 10%, a level more compatible with successful return of spontaneous circulation (ROSC), could be compatible with a realistic CPR time. Calculating COHbt1/2 during CPR may help with decision-making regarding the optimal duration of resuscitation efforts and further with HBO2 or ECLS. Further evidence-based data are needed to confirm this result.

Total arch and descending thoracic aortic replacement for massive hemoptysis requiring CPR caused by intrapulmonary penetration of chronic dissecting aortic aneurysm: a case report

BackgroundIntrapulmonary penetration of the thoracic aorta is a rare, life-threatening complication of a chronic dissecting aortic aneurysm. It causes massive hemoptysis requiring prompt intervention to prevent fatal airway bleeding. A surgical approach that enables diverse surgical maneuvers and intraoperative organ protection is crucial.Case presentationA 62-year-old man, who underwent graft replacement of the ascending aorta for an acute type A aortic dissection 20 months before, developed massive hemoptysis and cardiac arrest. The hemoptysis was secondary to an aortopulmonary fistula from a rapidly expanding dissecting aortic aneurysm. However, a successful return of spontaneous circulation was achieved with cardiopulmonary resuscitation, including establishment of veno-arterial extracorporeal membrane oxygenation. The patient successfully underwent a total arch and descending thoracic aortic replacement. This was achieved by a median sternotomy combined with a left thoracotomy using a straight incision with a rib-cross (SIRC) approach. The patient was uneventfully discharged and remained well for the following 2 years.ConclusionsWhen performing a surgical graft replacement for an aortopulmonary fistula with a thoracic aortic aneurysm, the surgical approach chosen is critical. A surgical procedure using a median sternotomy combined with a left thoracotomy and a SIRC approach can be an effective therapeutic option.

199 Heart Rate Entropy Predicts Impending Rearrest Due to Ventricular Tachycardia/Fibrillation but Not Pulseless Electrical Activity

Cardiac rearrest after successful return of spontaneous circulation (ROSC) is a significant barrier to successful resuscitation, making it a high priority for emergency care research. Rearrest is commonly due to ventricular tachycardia/fibrillation (VT/VF) or pulseless electrical activity (PEA), each with different, yet poorly understood mechanisms. In general, heart rate variability (HRV) has been associated with long-term risk of primary VT/VF, related to altered autonomic tone; however, its association with rearrest due to VT/VF or PEA after ROSC is not clear.

Resuscitative Endovascular Balloon Occlusion of the Aorta for Traumatic Cardiopulmonary Arrest in the Emergency Department: The First Case With Successful Return of Spontaneous Circulation in Taiwan.

Exsanguinating torso hemorrhage is a leading cause of death in trauma patients. Bleeding leads to hypothermia, acidosis, and coagulopathy, the so-called "lethal triad," and creates a vicious cycle. Therefore, bleeding control tops the priority list in the management of trauma patients. Placement of resuscitative endovascular balloon occlusion of the aorta (REBOA) in patients with traumatic non-compressible torso hemorrhage is a developing technique in the emergency departments (EDs) in Taiwan, and it is a possible solution for abdominal and pelvic trauma patients with hemodynamic instability. It not only temporarily controls bleeding below the inflation site but also increases cerebral and coronary circulation. It can create a bridge for definitive care such as an operation or an embolization, possibly preventing death. Compared to thoracotomy followed by an aortic cross clamp, REBOA is a less invasive and possibly, a more efficient way to control the hemorrhage and may lead to better overall survival. The use of REBOA has been proven to be associated with improved survival-to-discharge in severely injured trauma patients. We report a case of out-of-hospital cardiac arrest caused by penetrating injury wherein return of spontaneous circulation was successfully achieved after 39-minute cardiopulmonary resuscitation and REBOA placement in the ED. The REBOA balloon was deflated after bleeding was stopped during the laparotomy operation. The patient was then transferred to the intensive care unit for postoperative care. Unfortunately, the patient passed away approximately 12 hours after the surgery.

A randomised preclinical trial of adrenaline use during cardiac arrest in mice

BackgroundAdrenaline is routinely administered during cardiac arrest resuscitation. Using a novel murine model of cardiac arrest, this study evaluates the effects of adrenaline use on survival and end-organ injury. MethodsA total of 58 mice, including cardiac arrest (CA) and sham (SHAM) groups received intravenous potassium chloride either as a bolus (CA) or slow infusion (SHAM), inducing ECG-confirmed asystole (in CA only) for 4-minutes prior to intravenous adrenaline (+ADR;250 ul,32 ug/ml) or saline (-ADR;250 ul) and manual chest compressions (300 BPM) for 4-minutes. Mice with return of spontaneous circulation (ROSC) were assessed at 24- or 72-h timepoints. ResultsAmong animals that underwent CA, rates of ROSC (n = 21 (95 %) vs n = 14 (82 %), P = 0.18) and survival to the planned endpoint (n = 11 (50 %) vs n = 12 (71 %), P = 0.19) were similar when comparing those treated with (CA+ADR) and without (CA-ADR) adrenaline. However, in CA animals that initially achieved ROSC, subsequent mortality was approximately 3-fold greater with adrenaline treatment (48 % vs 14 %, P = 0.042). Among SHAM animals, adrenaline use had no impact on survival rates or other endpoints. Greater myocardial injury occurred in CA+ADR vs CA-ADR, with increased Hs-Troponin levels measured at 24- (26.0 ± 0.9 vs 9.4 ± 5.3 ng/mL, P = 0.015) and 72-h (20.9 ± 8.3 vs 5.0 ± 2.4 ng/mL, P = 0.012), associated with increased expression of pro-inflammatory and fibrotic genes within cardiac and renal tissue. ConclusionAdrenaline did not improve ROSC or overall survival but following successful ROSC, its use resulted in 3-fold greater mortality rates. Adrenaline was also associated with increased myocardial injury, end-organ inflammation, and fibrosis. These findings underscore the need for further preclinical evaluation of alternate pharmacologic adjuncts for cardiopulmonary resuscitation that improve survival and limit end-organ injury.

Whole Blood Selective Aortic Arch Perfusion for Exsanguination Cardiac Arrest: Assessing Myocardial Tolerance to the Duration of Cardiac Arrest.

Selective aortic arch perfusion (SAAP) is an endovascular technique that consists of aortic occlusion with perfusion of the coronary and cerebral circulation. It been shown to facilitate return of spontaneous circulation (ROSC) after exanguination cardiac arrest (ECA), but it is not known how long arrest may last before the myocardium can no longer be durably recovered. The aim of this study is to assess the myocardial tolerance to exsanguination cardiac arrest before successful ROSC with SAAP. Male adult swine (n = 24) were anesthetized, instrumented, and hemorrhaged to arrest. Animals were randomized into three groups: 5, 10, and 15 min of cardiac arrest before resuscitation with SAAP. Following ROSC, animals were observed for 60 min in a critical care environment. Primary outcomes were ROSC, and survival at 1-h post-ROSC. Shorter cardiac arrest time was associated with higher ROSC rate and better 1-h survival. ROSC was obtained for 100% (8/8) of the 5-min ECA group, 75% (6/8) of the 10-min group, 43% (3/7) of the 15-min group (P = 0.04). One-hour post-ROSC survival was 75%, 50%, and 14% in 5-, 10-, and 15-min groups, respectively (P = 0.02). One-hour survivors in the 5-min group required less norepinephrine (1.31 mg ± 0.83 mg) compared with 10-SAAP (0.76 mg ± 0.24 mg), P = 0.008. Whole blood SAAP can accomplish ROSC at high rates even after 10 min of unsupported cardiac arrest secondary to hemorrhage, with some viability beyond to 15 min. This is promising as a tool for ECA, but requires additional optimization and clinical trials.Animal Use Protocol, IACUC: 0919015.

Abstract 9114: Impact of the Number of Prehospital Defibrillation Attempts on Neurologically Intact Survival in Patients With Out-of-Hospital Cardiac Arrest and Shockable Rhythm

Background: Early return of spontaneous circulation (ROSC) leads to survival with a favorable neurologic outcome in patients with out-of-hospital cardiac arrest (OHCA). For the early ROSC, defibrillation plays a crucial role for OHCA with shockable rhythm. However, little is known about the relation between the number of prehospital defibrillation attempts or etiology of OHCA and neurologically intact survival. Methods: Using a nationwide OHCA registry database from 2005 to 2017 in Japan, a cohort of 1,527,447 patients with OHCA were retrospectively analyzed. We included the patients of witnessed OHCAs with initial shockable rhythm. The relation between early ROSC, defined as prehospital ROSC achieved with defibrillation ≤3 times without adrenaline, and a neurologically intact survival rate (cerebral performance category score of 1 or 2 at 1 month) was evaluated. We also analyzed factors related to the successful early ROSC, including etiology of OHCA. Results: A total of 75,342 patients were included. Among patients with OHCA and prehospital ROSC, neurologically intact survival rates were better in patients who achieved early ROSC than their counterpart (62% vs. 36%, p<0.001). Success in early ROSC was an independent predictor of neurologically intact survival after adjustment of multiple cofounders (Table). Multivariate analysis showed cerebral vascular disease as an etiology of OHCA was a predictor of early ROSC (odds ratio 1.15, 95% confidence interval 1.03-1.29, p=0.02), but was significantly associated with a poor neurologic outcome at 1 month (Table). Conclusions: Success in early ROSC was associated with neurologically intact survival in patients with OHCA and initial shockable rhythm. Patients with OHCA due to cerebral vascular disease were likely to be resuscitated from cardiac arrest by defibrillations but had a poor neurologic outcome.

O10 Myocardial tolerance to exsanguination and retrieval using whole blood-selective aortic arch perfusion

Abstract Introduction Exsanguination cardiac arrest is the leading preventable cause of death in trauma. Treatment modalities are limited, and prognosis remains dismal. Selective aortic arch perfusion (SAAP) is an emerging endovascular resuscitation technique consisting of aortic occlusion and perfusion of coronary and cerebral circulation with oxygenated resuscitation fluid. Translational research has demonstrated promising outcomes; however, little is known about the duration of cardiac arrest beyond which the myocardium cannot be resuscitated. The aims of this study are to assess the myocardial tolerance to exsanguination cardiac arrest before successful return of spontaneous circulation (ROSC) following resuscitation with SAAP, and 1-hour survival. Method 23 male adult swine were anaesthetised and instrumented. Controlled hemorrhage was performed until cardiac arrest defined by MAP <20 mmHg. Animals were randomized into 3 groups: 5, 10 and 15 minutes of cardiac arrest before resuscitation with SAAP. Following ROSC animals were observed for 60 minutes. Result Baseline characteristics were similar between groups (P > 0.05). ROSC was 100% (8/8) in the 5 min group, 75% (6/8) and 43% (3/7) in 10- and 15-min groups respectively (P = 0.042). 60 min survival was 75%, 50% and 14% in 5-, 10- and 15-min groups respectively (P = 0.015). 1-hour survivors in the 5 min group required less noradrenaline 23.6 (±7.4) compared to other animals 40.9 (±25.8), (P = 0.008). Conclusion Selective aortic arch perfusion is an effective resuscitative tool in eliciting ROSC in a swine model of exsanguination cardiac arrest lasting >5 min. Sustainable resuscitability using SAAP declines after 10 min of exsanguination cardiac arrest. Take-home Message SAAP is an emerging resuscitation technique with promising outcomes in exsanguination cardiac arrest and may be a segway to Extracorporeal life support. The time limit for resuscitability of the myocardium lies somewhere between 10 and 15 min after the start of exsanguination cardiac arrest.

Prognostic Effects of Vasomotor Reactivity during Targeted Temperature Management in Post-Cardiac Arrest Patients: A Retrospective Observational Study.

Early and precise neurological prognostication without self-fulfilling prophecy is challenging in post-cardiac arrest syndrome (PCAS), particularly during the targeted temperature management (TTM) period. This study aimed to investigate the feasibility of vasomotor reactivity (VMR) using transcranial Doppler (TCD) to determine whether final outcomes of patients with comatose PCAS are predicted. This study included patients who had out-of-hospital cardiac arrest in a tertiary referral hospital over 4 years. The eligible criteria included age ≥18 years, successful return of spontaneous circulation, TTM application, and bedside TCD examination within 72 h. Baseline demographics and multimodal prognostic parameters, including imaging findings, electrophysiological studies, and TCD-VMR parameters, were assessed. The final outcome parameter was cerebral performance category scale (CPC) at 1 month. Potential determinants were compared between good (CPC 1–2) and poor (CPC 3–5) outcome groups. The good outcome group (n = 41) (vs. poor (n = 117)) showed a higher VMR value (54.4% ± 33.0% vs. 25.1% ± 35.8%, p < 0.001). The addition of VMR to conventional prognostic parameters significantly improved the prediction power of good outcomes. This study suggests that TCD-VMR is a useful tool at the bedside to evaluate outcomes of patients with comatose PCAS during the TTM.

B-PO02-201 ELECTRICAL CARDIOVERSION: KEEP AN EYE ON THE T!

Torsades de pointes (TdP) often seen in the setting of QT prolongation is an uncommon arrhythmia after synchronized electrical cardioversion (CV). Report a case of unexpected TdP after successful electrical CV. NA A 78-year-old man with coronary artery disease and prior CABG, ischemic cardiomyopathy with prior LVEF 50-55% was admitted with acute decompensated heart failure with newly depressed LVEF 20-25% and new-onset atrial flutter (AF) with 2:1 AV conduction (Fig. A). Due to persistent rapid ventricular rates despite digoxin and metoprolol, he underwent synchronized CV with successful restoration of sinus rhythm (Fig. B, QTc 478 ms). He experienced an episode of TdP 33 hours after CV, initiated by a short-long-short sequence, preceded by giant T-U waves (Fig. C). He underwent CPR / defibrillation with successful return of spontaneous circulation within 5 minutes. Post-arrest ECG showed sinus rhythm with prolonged QTc (500-620 ms) and macroscopic T-wave alternans (Fig. D); another showed junctional rhythm with giant T-U waves preceding frequent ventricular ectopic beats (Fig. E). Electrolytes were normal. He was treated with isoproterenol; digoxin and metoprolol were discontinued. Coronary angiogram showed no new stenoses. He underwent implantation of secondary prevention dual-chamber ICD with backup pacing rate set at 70 bpm, with no TdP recurrence at 2 months. CV is a common, effective procedure for termination of AF. There is increased risk of TdP due to repolarization abnormalities post CV. Macroscopic T-wave alternans and giant T-U waves are ominous ECG signs of impending ventricular arrhythmias.

Association between previous health condition and outcome after cardiac arrest

IntroductionOverall survival of patients with out-of-hospital cardiac arrest (OHCA) remains low, even in those with return of spontaneous circulation (ROSC). In addition to usual prognostic characteristics, patients’ medical history may also influence their outcome. This study aimed to investigate the role of pre-arrest comorbidities on hospital survival, neurological outcome and mode of death in OHCA patients with successful ROSC. MethodsFrom Jan 2012 to Sep 2017, all consecutive non-traumatic OHCA adults, admitted with a stable ROSC were included. Utstein characteristics, circumstances of arrest and interventions were prospectively recorded. Prior comorbidities were measured using the Charlson Comorbidity Index (CCI), and the population was divided into 3 groups (CCI 0, CCI 1–3 and CCI ≥ 4). The association of CCI with early and long-term mortality was assessed using logistic regression and association with withdrawal-of-life sustaining treatments (WLST) or another cause of death using multinomial regression. ResultsDuring the study period, 777 patients were analyzed and 483 (62%) died before hospital discharge, with death rate of 49%, 60% and 70% in CCI 0, CCI 1–3 and CCI ≥ 4 respectively. After adjustment, an increase CCI was significantly associated with in-hospital mortality (OR = 2.47 [1.35–4.52], p = 0.001 for CCI 1–3; OR = 2.82 [1.49–5.33], p = 0.003 for CCI ≥ 4; ref = CCI 0). Other independent predictors were non-shockable rhythm (OR = 3.23 [2.08–5]), lack of bystander CPR (OR = 1.96 [1.22–3.13]), epinephrine dose ≥ 2 mg (OR = 5.56 [3.70–8.33]), CA to CPR ≥ 5 min (OR = 1.96 [1.28–3.03]) and CPR to ROSC ≥ 20 min (OR = 2.13 [1.39–3.23]).Using multinomial regression, an increase in CCI was associated with all modes of in-hospital death, particularly with WLST-related death (RRadj = 2.48 [1.26–4.90], p = 0.01 for CCI = 1–3 and 3.75 [1.85−8.7.58], p < 0.001 for CCI ≥ 4, reference CCI = 0). ConclusionAlteration of chronic health status, as assessed by an elevated CCI, was associated with a higher mortality and a worse neurological outcome in OHCA patients. Presence and burden of comorbidities should be considered in the evaluation of the prognosis in patients admitted in hospital after cardiac arrest.

The interplay between bystander cardiopulmonary resuscitation and ambient temperature on neurological outcome after cardiac arrest: A nationwide observational cohort study

BackgroundAt lower ambient temperature, patients with out-of-hospital cardiac arrest (OHCA) easily experience hypothermia. Hypothermia has shown to improve the rate of successful return of spontaneous circulation (ROSC) in animal models. We hypothesized that lower temperature affects the impact of bystander cardiopulmonary resuscitation (CPR) on the increased odds of a favorable neurological outcome post-OHCA. MethodsThis study used information collected by the prospective, nationwide, Utstein registry to examine data from 352,689 adult patients who experienced OHCA from 2012 to 2016 in Japan. The primary outcome was a 1-month favorable neurological outcomes. Multivariable logistic regression analyses were conducted to test the impact of bystander CPR according to the temperature on the favorable outcome. ResultsA total of 201,111 patients with OHCA were included in the complete case analysis. The lower temperature group had lower proportions of receiving bystander CPR (46.5 vs. 47.9%) and having favorable outcome (2.1 vs 2.8%) than those in the higher group. Multivariable analysis revealed that bystander CPR at lower temperatures was significantly associated with favorable outcomes (adjusted odds ratio, 1.22; 95% CI, 1.09–1.37), whereas bystander CPR at higher temperatures was not associated with favorable outcomes (1.02; 0.92–1.13). The nonlinear relationship using a spline curve in the multivariable model revealed that odds ratio of favorable neurological outcomes associated with bystander CPR increased as the temperature decreased. ConclusionBystander CPR was associated with favorable neurological outcomes at lower temperatures. The odds of a favorable outcome associated with bystander CPR increased as the temperature decreased.

Shoulder strap fixation of LUCAS-2 to facilitate continuous CPR during non-supine (stair) stretcher transport of OHCAs patients

Early recognition and rapid initiation of high-quality cardiopulmonary resuscitation (CPR) are key to maximising chances of achieving successful return of spontaneous circulation in patients with out-of-hospital cardiac arrests (OHCAs), as well as improving patient outcomes both inside and outside hospital. Mechanical chest compression devices such as the LUCAS-2 have been developed to assist rescuers in providing consistent, high-quality compressions, even during transportation. However, providing uninterrupted and effective compressions with LUCAS-2 during transportation down stairwells and in tight spaces in a non-supine position is relatively impossible. In this study, we proposed adaptations to the LUCAS-2 to allow its use during transportation down stairwells and examined its effectiveness in providing high-quality CPR to simulated OHCA patients. 20 volunteer emergency medical technicians were randomised into 10 pairs, each undergoing 2 simulation runs per experimental arm (LUCAS-2 versus control) with a loaded Resusci Anne First Aid full body manikin weighing 60 kg. Quality of CPR compressions performed was measured using the CPRmeter placed on the sternum of the manikin. The respective times taken for each phase of the simulation protocol were recorded. Fisher’s exact tests were used to analyse categorical variables and median test to analyse continuous variables. The LUCAS-2 group required a longer time (~ 35 s) to prepare the patient prior to transport (p < 0.0001) and arrive at the ambulance (p < 0.0001) compared to the control group. The CPR quality in terms of depth and rate for the overall resuscitation period did not differ significantly between the LUCAS-2 group and control group, though there was a reduction in both parameters when evaluating the device’s automated compressions during transport. Nevertheless, the application of the LUCAS-2 device yielded a significantly higher chest compression fraction of 0.76 (p < 0.0001). Our novel adaptations to the LUCAS-2 device allow for uninterrupted compressions in patients being transported down stairwells, thus yielding better chest compression fractions for the overall resuscitation period. Whether potentially improved post-OHCA survival rates may be achieved requires confirmation in a real-world scenario study.

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

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

Successful prolonged cardiopulmonary resuscitation in a Siamese cat: A case of post‐cardiac arrest concerns

AbstractA 4.5‐year‐old male neutered Siamese cat was admitted to referral hospital for medical work‐up of chronic anorexia and emesis. No severe abnormalities were detected on routine blood work; however thickened gastric wall and small intestines were noted on abdominal ultrasonography. The cat was premedicated with buprenorphine followed by a diazepam‐propofol co‐induction. Endotracheal intubation was performed, and anaesthesia was maintained using isoflurane in oxygen for endoscopic investigation of the thickened gastric wall and biopsies retrieval. During the anaesthetic recovery, the animal went into cardiopulmonary arrest. Successful ROSC (return of spontaneous circulation) was achieved at approximate 40 minutes (prolonged) post‐arrest, and the animal had a survived event (ROSC &gt; 20 minutes). However, failure to identify the inciting cause of the CPA and laxity in the post‐cardiac arrest care resulted in rearrest of the cat, 77 hours after the initial ROSC with no success of a second ROSC.

Incidence of unexpected cardiac arrest among intensive care unit patients in national guard hospitals in Jeddah, Riyadh, and Al Ahsa

Background: Cardiac arrest (CA) is a sudden collapse of cardiac mechanical function as evidenced by the absence of detectable pulse and the absence or gasping of breath, which all combined with a loss of consciousness. Although researches on resuscitation efforts have been increasing significantly recently, little investigations have been done on the incidence of unexpected CA among intensive care unit (ICU) patients, in particular, in Saudi Arabia. Aim: The main goal of this research is to explore the rate and patient characteristics of unexpected CA among in ICU patients in the National Guard Health Affairs hospitals in Jeddah, Riyadh, and Al Ahsa. Materials and Methods: This study was a retrospective analysis of ICU patients who experienced unexpected CA. Settings: The study was conducted at the ICUs of three National Guard hospitals in Saudi Arabia. Results: Findings showed that only 11% of the ICU patients who received cardiopulmonary resuscitation (CPR) had a successful return of spontaneous circulation and the overall mortality rate was 89%. The most common cause of unexpected CA is sepsis, found in 348 out of 1233 patients (28%). The most common medical history accompanied by the ICU patients' medical history is a multi-organ dysfunction, found in 184 out of 1233 (14.9%) patients. We found a weak negative relationship between patients' gender and the causes of unexpected CA (relative risk = −0.069 and P < 0.05). Conclusion: The findings are in line with prior studies confirming that mortality increases when unexpected CA occurs on patients with sepsis. There was no significant relationship seen between patients' age and CPR outcomes.