Impact of cooling method on the outcome of initial shockable or non-shockable out of hospital cardiac arrest patients receiving target temperature management: a nationwide multicentre cohort study

Background Little is known about the effectiveness of surface cooling (SC) and endovascular cooling (EC) on the outcome of out-of-hospital cardiac arrest (OHCA) patients receiving target temperature management (TTM) according to their initial rhythm. Methods We retrospectively analysed data from the Japanese Association for Acute Medicine Out‐of‐Hospital Cardiac Arrest registry, a multicentre, prospective nationwide database in Japan. For our analysis, OHCA patients aged ≥ 18 years who were treated with TTM between June 2014 and December 2017 were included. The primary outcome was 30-day survival with favourable neurological outcome defined as a Glasgow–Pittsburgh cerebral performance category score of 1 or 2. Cooling methods were divided into the following groups: SC (ice packs, fans, air blankets, and surface gel pads) and EC (endovascular catheters and any dialysis technique). We investigated the efficacy of the two categories of cooling methods in two different patient groups divided according to their initially documented rhythm at the scene (shockable or non-shockable) using multivariable logistic regression analysis and propensity score analysis with inverse probability weighting (IPW). Results In the final analysis, 1082 patients were included. Of these, 513 (47.4%) had an initial shockable rhythm and 569 (52.6%) had an initial non-shockable rhythm. The proportion of patients with favourable neurological outcomes in SC and EC was 59.9% vs. 58.3% (264/441 vs. 42/72), and 11.8% (58/490) vs. 21.5% (17/79) in the initial shockable patients and the initial non-shockable patients, respectively. In the multivariable logistic regression analysis, differences between the two cooling methods were not observed among the initial shockable patients (adjusted odd ratio [AOR] 1.51, 95% CI 0.76–3.03), while EC was associated with better neurological outcome among the initial non-shockable patients (AOR 2.21, 95% CI 1.19–4.11). This association was constant in propensity score analysis with IPW (OR 1.40, 95% CI 0.83–2.36; OR 1.87, 95% CI 1.01–3.47 among the initial shockable and non-shockable patients, respectively). Conclusion We suggested that the use of EC was associated with better neurological outcomes in OHCA patients with initial non-shockable rhythm, but not in those with initial shockable rhythm. A TTM implementation strategy based on initial rhythm may be important.

Abstract 8894: Post-Resuscitation Diastolic Blood Pressure is a Better Predictive Factor for Outcomes of Cardiac Arrest Patients

Introduction: Post-resuscitation hemodynamic level was associated with outcomes. Our study hypothesized that post-resuscitation diastolic blood pressure (DBP) was a better predictive factor for outcomes. Methods: Starting from TaIwan Network of Targeted Temperature ManagEment for CARDiac Arrest (TIMECARD) registry, we recruited 540 adult patients who received target temperature management (TTM) during January 2014 and September 2019. After excluding 37 patients with pre-arrest cerebral performance categories scale (CPC) 3-4 and 55 patients with extracorporeal membrane oxygenation support, 448 patients were analyzed. Patient’s characteristics, comorbidities, resuscitation factors, arrest etiologies, systolic blood pressure (SBP) and DBP after resuscitation were included for analysis. Primary outcomes were survival of discharge (SOD) and discharge with favorable neurologic outcomes (CPC 1-2). Univariate and multivariate analysis were performed to identify favorable predictors. Predictive values of SBP and DBP for both outcomes were compared by calculating area under receiver operating characteristic (AUC). Results: Among 448 patients, 182 (40.7%) patients had SOD and 89 (19.9%) patients had CPC 1-2. DBP was significantly higher in patients with SOD (p<0.001) and CPC 1-2 (p=0.003). In multivariate analysis, DBP was also an independent factor for SOD (p=0.004) and CPC 1-2 (p =0.048). When comparing SBP and DBP, DBP was a better predictor for CPC 1-2 (SBP AUC: 0.58 vs DBP AUC: 0.64, p=0.003). In subgroup analysis, DBP > 80 served as a favorable predictor for both SOD and CPC 1-2. When comparing patients with DBP <80 and SBP >80, patients with higher DBP values had significantly higher percentage of cardiac etiologies arrest and relative higher percentage of initial shockable rhythm. Conclusion: DBP is a better hemodynamic parameter than SBP for predicting outcomes. In multivariate model, DBP > 80 was an independent predictor for better survival and favorable neurologic outcomes.

Abstract 10739: Simulation Based Assessment of Trainee’s Performance in Post-Cardiac Arrest Resuscitation

Up to 22% of patients survive to hospital admission following out-of-hospital cardiac arrest (OHCA). Post cardiac arrest is complex and requires a multidisciplinary approach. Our aim is to assess trainee’s performance in managing post-cardiac arrest care using a high-fidelity manikin-based simulation. We also sought to obtain evidence regarding the validity of our findings. Methods: In this prospective, observational, simulation based study, participants ranging from sub interns to attending physicians evaluated and managed a post cardiac arrest patient, complicated by refractory status epilepticus. Critical actions were developed by a modified Delphi approach based on relevant American Heart Association guidelines and the Neurocritical Care Society’s Emergency Neurological Life Support protocols. The primary outcome measure was the critical action item sum score. We sought validity evidence to support our findings by comparing trainees’ performance across four levels of training. Results: Forty-nine participants completed the simulation. The mean sum of critical actions completed by participants was 10/21(49%). Eleven(22%) participants verbalized a differential diagnosis for the arrest. Thirty-two(65%) recognized the abnormal electrocardiography, and consulted cardiology. Forty trainees(81%) independently decided to start target temperature management (TTM), but only 20(41%) insisted on TTM when asked to reconsider. There was an effect of level of training on critical action checklist sum scores (novice mean score [standard deviation (SD)] = 4.8 (1.8) vs. intermediate mean score (SD) = 10.4 (2.1) vs. advanced mean score (SD) = 11.6 (3.0) vs. expert mean score (SD) = 14.7 (2.2) Conclusions: High-fidelity manikin-based simulation holds promise as an assessment tool in the performance of post-cardiac arrest care. Areas for further educational initiatives to improve performance include diagnostic work-up of OHCA and implementation of TTM.

Differences in the gray-to-white matter ratio according to different computed tomography scanners for outcome prediction in post-cardiac arrest patients receiving target temperature management

The gray-to-white matter ratio (GWR) has been used to identify brain damage in comatose patients after cardiac arrest. However, Hounsfield units (HUs), the measurement of brain density on computed tomography (CT) images, may vary depending on the machine type or parameter. Therefore, differences in CT scanners may affect the GWR in post-cardiac arrest patients. We performed a retrospective study on comatose post-cardiac arrest patients who visited the hospital from 2007 to 2017. Two CT, Lightspeed and SOMATOM, scanners were used. Two observers independently measured the HUs of the caudate nucleus, putamen, posterior internal capsule, and corpus callosum using regions of interest. We compared the GWR calculated from the HUs measured at different CT scanners. The analysis of different scanners showed statistically significant differences in the measured HUs and GWR. The HUs and GWR of Lightspeed were measured lower than SOMATOM. The difference between the two CT scanners was also evident in groups divided by neurological prognosis. The area under the curve of the receiver operating characteristic curve to predict poor outcomes of Lightspeed was 0.798, and the cut-off value for 100% specificity was 1.172. The SOMATOM was 0.855, and the cut-off value was 1.269. The difference in scanners affects measurements and performance characteristics of the GWR in post-cardiac arrest patients. Therefore, when applying the results of the GWR study to clinical practice, reference values for each device should be presented, and an integrated plan should be prepared.

Reliability of prognostic biomarkers after prehospital extracorporeal cardiopulmonary resuscitation with target temperature management

Background Extracorporeal cardiopulmonary resuscitation (ECPR) performed at the emergency scene in out-of-hospital cardiac arrest (OHCA) can minimize low-flow time. Target temperature management (TTM) after cardiac arrest can improve neurological outcome. A combination of ECPR and TTM, both implemented as soon as possible on scene, appears to have promising results in OHCA. To date, it is still unknown whether the implementation of TTM and ECPR on scene affects the time course and value of neurological biomarkers. Methods 69 ECPR patients were examined in this study. Blood samples were collected between 1 and 72 h after ECPR and analyzed for S100, neuron-specific enolase (NSE), lactate, D-dimers and interleukin 6 (IL6). Cerebral performance category (CPC) scores were used to assess neurological outcome after ECPR upon hospital discharge. Resuscitation data were extracted from the Regensburg extracorporeal membrane oxygenation database and all data were analyzed by a statistician. The data were analyzed using non-parametric methods. Diagnostic accuracy of biomarkers was determined by area under the curve (AUC) analysis. Results were compared to the relevant literature. Results Non-hypoxic origin of cardiac arrest, manual chest compression until ECPR, a short low-flow time until ECPR initiation, low body mass index (BMI) and only a minimal need of extra-corporeal membrane oxygenation support were associated with a good neurological outcome after ECPR. Survivors with good neurological outcome had significantly lower lactate, IL6, D-dimer, and NSE values and demonstrated a rapid decrease in the initial S100 value compared to non-survivors. Conclusions A short low-flow time until ECPR initiation is important for a good neurological outcome. Hypoxia-induced cardiac arrest has a high mortality rate even when ECPR and TTM are performed at the emergency scene. ECPR patients with a higher BMI had a worse neurological outcome than patients with a normal BMI. The prognostic biomarkers S100, NSE, lactate, D-dimers and IL6 were reliable indicators of neurological outcome when ECPR and TTM were performed at the emergency scene.

Targeted Temperature Management after Cardiac Arrest: A Systematic Review and Meta-Analysis with Trial Sequential Analysis

Target temperature management (TTM) in cardiac arrest (CA) survivors is recommended after hospital admission for its possible beneficial effects on survival and neurological outcome. Whether a lower target temperature (i.e., 32–34 °C) improves outcomes is unclear. We conducted a systematic review and meta-analysis on Pubmed and EMBASE to evaluate the effects on mortality and neurologic outcome of TTM at 32–34 °C as compared to controls (patients cared with “actively controlled” or “uncontrolled” normothermia). Results were analyzed via risk ratios (RR) and 95% confidence intervals (CI). Eight randomized controlled trials (RCTs) were included. TTM at 32–34 °C was compared to “actively controlled” normothermia in three RCTs and to “uncontrolled” normothermia in five RCTs. TTM at 32–34 °C does not improve survival as compared to normothermia (RR:1.06 (95%CI 0.94, 1.20), p = 0.36; I2 = 39%). In the subgroup analyses, TTM at 32–34 °C is associated with better survival when compared to “uncontrolled” normothermia (RR: 1.31 (95%CI 1.07, 1.59), p = 0.008) but shows no beneficial effects when compared to “actively controlled” normothermia (RR: 0.97 (95%CI 0.90, 1.04), p = 0.41). TTM at 32–34 °C does not improve neurological outcome as compared to normothermia (RR: 1.17 (95%CI 0.97, 1.41), p = 0.10; I2 = 60%). TTM at 32–34 °C increases the risk of arrhythmias (RR: 1.35 (95%CI 1.16, 1.57), p = 0.0001, I2 = 0%). TTM at 32–34 °C does not improve survival nor neurological outcome after CA and increases the risk of arrhythmias.

Impact of Cooling Method on the Outcome of Initial Shockable or Non-Shockable Out of Hospital Cardiac Arrest Patients Receiving Target Temperature Management: A Nationwide Multicentre Prospective Cohort Study

Background: Little is known about the effectiveness of surface cooling (SC) and endovascular cooling (EC) on the outcome of out-of-hospital cardiac arrest (OHCA) patients receiving target temperature management (TTM) according to their initial rhythm.Methods: We retrospectively analysed data from the Japanese Association for Acute Medicine Out‐of‐Hospital Cardiac Arrest registry, a multicentre, prospective nationwide database in Japan. For our analysis, OHCA patients aged ≥ 18 years who were treated with TTM between June 2014 and December 2017 were included. The primary outcome was 30-day survival with favourable neurological outcome defined as a Glasgow-Pittsburgh cerebral performance category score of 1 or 2. Cooling methods were divided into the following groups: SC (ice packs, fans, air blankets, and surface gel pads) and EC (endovascular catheters and any dialysis technique). We investigated the efficacy of the two categories of cooling methods in two different patient groups divided according to their initially documented rhythm at the scene (shockable or non-shockable) using multivariable logistic regression analysis and propensity score analysis with inverse probability weighting (IPW).Results: In the final analysis, 1082 patients were included. Of these, 513 (47.4%) had an initial shockable rhythm and 569 (52.6%) had an initial non-shockable rhythm. The proportion of patients with favourable neurological outcomes in SC and EC was 59.9% vs. 58.3% (264/441 vs. 42/72), 11.8% and (58/490) vs. 21.5% (17/79) in the initial shockable patients and the initial non-shockable patients, respectively. In the multivariable logistic regression analysis, differences between the two cooling methods were not observed among the initial shockable patients (adjusted odd ratio [AOR] 1.45, 95% CI 0.81–2.60), while EC was associated with better neurological outcome among the initial non-shockable patients (AOR 2.13, 95% CI 1.10–4.13). This association was constant in propensity score analysis with IPW (OR 1.40, 95% CI 0.83–2.36; OR 1.87, 95% CI 1.01–3.47 among the initial shockable and non-shockable patients, respectively).Conclusion: We demonstrated that the use of EC was associated with better neurological outcomes in OHCA patients with initial non-shockable rhythm, but not in those with initial shockable rhythm. A TTM implementation strategy based on initial rhythm may be important.Trial registration: None

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

Background Target temperature management (TTM) is suggested to reduce brain damage in the presence of global or local ischemia. Prompt TTM application may help to improve outcomes, but it is often hindered by technical problems, mainly related to the portability of cooling devices and temperature monitoring systems. Tympanic temperature (TTy) measurement may represent a practical, non-invasive approach for core temperature monitoring in emergency settings, but its accuracy under different TTM protocols is poorly characterized. The present scoping review aimed to collect the available evidence about TTy monitoring in TTM to describe the technique diffusion in various TTM contexts and its accuracy in comparison with other body sites under different cooling protocols and clinical conditions. Methods The scoping review was conducted following the guidelines of the Preferred Reporting Items for Systematic Review and Meta-Analysis extension for scoping reviews (PRISMA-ScR). PubMed, Scopus, and Web of Science electronic databases were systematically searched to identify studies conducted in the last 20 years, where TTy was measured in TTM context with specific focus on pre-hospital or in-hospital emergency settings. Results The systematic search identified 35 studies, 12 performing TTy measurements during TTM in healthy subjects, 17 in patients with acute cardiovascular events, and 6 in patients with acute neurological diseases. The studies showed that TTy was able to track temperature changes induced by either local or whole-body cooling approaches in both pre-hospital and in-hospital settings. Direct comparisons to other core temperature measurements from other body sites were available in 22 studies, which showed a faster and larger change of TTy upon TTM compared to other core temperature measurements. Direct brain temperature measurements were available only in 3 studies and showed a good correlation between TTy and brain temperature, although TTy displayed a tendency to overestimate cooling effects compared to brain temperature. Conclusions TTy was capable to track temperature changes under a variety of TTM protocols and clinical conditions in both pre-hospital and in-hospital settings. Due to the heterogeneity and paucity of comparative temperature data, future studies are needed to fully elucidate the advantages of TTy in emergency settings and its capability to track brain temperature.