Performance Category Research Articles

The Pediatric Influence of Cooling Duration on Efficacy in Cardiac Arrest Patients (P-ICECAP): Statistical Methods Planned in the Bayesian, Adaptive, Duration Finding Trial.

To determine the optimal cooling duration for children after out-of-hospital cardiac arrest (OHCA) using an adaptive Bayesian trial design. The Pediatric Influence of Cooling duration on Efficacy in Cardiac Arrest Patients (P-ICECAP) trial is a randomized, response-adaptive duration/dose-finding clinical trial with blinded outcome assessment. Participants are randomized to one of several cooling durations (0, 12, 18, 24, 36, 48, 60, 72, 84, or 96 hr). The first 150 participants are randomized 1:1:1 to 24-, 48-, and 72-hour durations. Response-adaptive randomization is used thereafter to allocate participants based on emerging duration-response data. PICUs. Up to 900 pediatric patients 2 days to younger than 18 years old who have survived OHCA and been admitted to an ICU. Duration of targeted temperature management using a surface temperature control device. The primary outcome is the Vineland Adaptive Behavior Scales-Third Edition mortality composite score, assessed at 12 months. Secondary outcomes include changes in the Pediatric Cerebral Performance Category and Pediatric Resuscitation after Cardiac Arrest scores, as well as survival at 12 months. Bayesian modeling is employed to evaluate the duration-response curve and determine the optimal cooling duration. The trial is designed to adaptively update randomization probabilities every 10 weeks, maximizing the allocation of participants to potentially optimal cooling durations. Over 90% power is achieved for the hypothesized scenarios. The P-ICECAP trial aims to identify the shortest cooling duration that provides the maximum treatment effect for pediatric OHCA patients. The adaptive design allows for flexibility and efficiency in handling various clinical scenarios, potentially transforming pediatric cardiac arrest care by optimizing hypothermia treatment protocols.

Electroencephalography (EEG) for Neurological Prognostication in Post-Anoxic Coma Following Cardiac Arrest and Its Relationship to Outcome

Background/Objectives: Cardiac arrest may cause significant hypoxic–ischemic injury leading to coma, seizures, myoclonic jerks, or status epilepticus. Mortality is high, but accurate prognostication is challenging. A multimodal approach is employed, in which electroencephalography (EEG) forms a key part with several recognised patterns of prognostic significance. Methods: In this retrospective study, clinical and qualitative features of the EEG of patients admitted to the Intensive Care Unit (ICU) at Kingston General Hospital following cardiac arrest from 2017 to 2020 were reviewed. The study included 81 adult patients (≥18 years). Outcome was assessed using the Cerebral Performance Category (CPC) as 1–2 (favourable) or 3–5 (unfavourable). EEG patterns were divided into groups within the highly malignant, malignant and benign patterns described in the literature. Results: There were a wide range of causes and 22% had a favourable outcome. Highly malignant, malignant and benign patterns were associated with survival in 0%, 70% and 100%, respectively, and favourable outcomes in 0%, 48% and 100%. All patients with seizures died, and 94% with myoclonus had unfavourable outcomes. In contrast, EEG reactivity and improvement on follow-up EEG were associated with a favourable outcome. Conclusions: Highly malignant EEG, seizures and myoclonus were associated with unfavourable outcomes, while patients with malignant EEG had better outcomes.

A competency framework for simulation facilitation in low-resource settings: a modified Delphi study.

Skilled facilitators are essential to drive effective simulation training in healthcare. Competency-based frameworks support the development of facilitation skills but, to our knowledge, there are no frameworks that specifically address context-sensitive priorities developed with practitioners working in low-resource settings. We aimed to develop a core competency framework for healthcare simulation facilitation in low-resource settings using a modified Delphi process. We drew on the domain expertise of members of the Vital Anaesthesia Simulation Training Community of Practice, with the study guided by a four-member steering group experienced in the conduct of simulation in low-resource settings. In survey round 1, participants (n = 54) were presented with an initial competency set derived from a previous qualitative study and co-created a set of 57 competencies for effective simulation facilitation in low-resource settings. In survey round 2, participants (n = 52) ranked competencies by relevance into three performance categories: techniques; artistry; and values. In survey round 3, participants (n = 50) ranked competencies on their importance. The steering group collated results and presented a draft core competency framework. In survey round 4, participants (n = 50) voted with 98% agreement that this framework represented the most relevant and important competencies for effective facilitation of simulation sessions in low-resource settings. The final 32-item framework encompasses core competencies found in existing standards and includes important new concepts such as demonstration of cultural sensitivity; humility; ability to recognise and respond to potential language barriers; facilitation team collaboration; awareness of logistics; and contingency planning. This competency-based framework highlights specific practices required for effective simulation facilitation in low-resource settings. Further work is required to refine and validate this tool to train simulation facilitators to deliver effective training to improve patient safety.

Plasma phosphorylated tau (p-tau231) and total tau (t-tau) as prognostic markers of neurological outcome after cardiac arrest - a multicentre study

PurposeWe studied the promising Alzheimer biomarker plasma tau phosphorylated at threonine 231 (p-tau231) in a cohort of cardiac arrest patients who survived to intensive care to predict long-term neurological outcomes. We also compared it to total tau (t-tau), which has demonstrated predictive abilities of neurological outcome post-cardiac arrest. MethodsThis observational multicentre cohort study included 425 patients admitted to intensive care after cardiac arrest. Plasma p-tau231 was retrospectively analysed at admission, 12 and 48 h after cardiac arrest. The association of the Cerebral Performance Category (CPC) with p-tau231 was analysed with a one-way analysis of variance (ANOVA). CPC was modelled using multivariate ordinal logistic regression, and the biomarkers’ prognostic performance was assessed by the area under the receiver operating characteristic curve (AUC). ResultsIncreasing p-tau231 levels were significantly associated with worse CPC (p < 0.001). P-tau231 showed moderate prognostic abilities (AUC: 0.69 on admission, 0.72 at 12 h, and 0.71 at 48 h) for all patients but did not improve neurological prognostication after adjusting for clinical covariates. Elevated levels of t-tau were significantly associated with a worse outcome at all time points (p < 0.001). T-tau significantly improved neurological prognosis at 48 h after adjusting for covariates (AUC: 0.95, 95 % CI 0.93–0.98, p < 0.001) compared to the clinical covariate reference model (AUC: 0.88, 95 % CI 0.84–0.93). ConclusionsAlthough p-tau231 showed moderate neurological prognostic ability, t-tau was a stronger predictor, particularly at 48 h, even after adjusting for clinical covariates.

Impact of sedation depth on neurological outcome in post-cardiac arrest patients – A retrospective cohort study

AimsWhether targeted temperature management (TTM) might improve neurologic prognosis in patients after cardiac arrest is currently under debate. Data concerning sedation depth during TTM is rare. This study aimed to compare the impact of different sedation depths on neurological outcomes in post-cardiac arrest patients undergoing TTM . MethodsIn this retrospective, before-and-after registry study, all patients receiving TTM on a medical ICU between 08/2016 and 03/2021 were included. This study evaluated the following sedation targets: RASS-target during TTM −5 until 08/2019 and RASS-target −4 since 09/2019. The primary endpoint was favorable neurological outcome at ICU discharge, defined as a Cerebral Performance Category (CPC) score of 1 or 2. Results403 patients were included (RASS-target −5: N = 285; RASS-target −4: N = 118). Favorable neurological outcome was documented in 54/118 (45.8 %) patients in the group with a RASS-target of −4 compared to 111/285 (38.9 %) in the group with a RASS-target of −5. After adjustment for age, sex, initial shockable rhythm, bystander CPR, duration of CPR and mean arterial pressure 12 h after CPR, favorable neurological outcome was associated with RASS-target −4 (OR 1.82 (95 % CI: 1.02–3.23); p = 0.042). ICU survival was similar in both groups while 30-day survival was associated with RASS-target −4 (OR 1.81 (1.01–3.26); p = 0.047). ConclusionLighter sedation strategies during TTM after cardiac arrest might improve outcome and should be further investigated.

Potassium disorders at intensive care unit admission and functional outcomes after cardiac arrest

BackgroundAbnormal serum potassium levels are commonly found in the intensive care unit (ICU) population. We aimed to determine the prevalence of potassium disorders at ICU admission and its association with functional outcomes in comatose patients resuscitated from cardiac arrest. MethodsWe performed a post hoc analysis of pooled data from four randomised clinical trials involving comatose post-cardiac arrest patients admitted to ICU after return of spontaneous circulation (ROSC). Reference serum potassium levels were defined as between 3.0 and 4.9 mmol/L. An unfavourable functional outcome was defined as a cerebral performance category of 3 to 5 at 180 days. We compared potassium disturbances categorically in a mixed effects logistic regression model including initial rhythm, delay from collapse to return of spontaneous circulation, bystander cardiopulmonary resuscitation, lactate and urea at ICU admission, with normokalaemia set as the reference group. ResultsWe included 1133 patients (557 from the HYPERION, 346 from the TTH48, 120 from the COMACARE, and 110 from the Xe-HYPOTHECA trials) with a median age of 64 years (interquartile range 55–72) and a predominance of males (72 %); a total of 712 (64 %) patients had unfavourable functional outcomes. On admission, 221 patients (19.5 %) experienced hyperkalaemia and 35 (3.1 %) patients experienced hypokalaemia. Fewer patients in the normokalaemia group (513/877, 58.5 %) had an unfavourable functional outcome compared to the hypokalaemia (24/35, 68.6 %) and hyperkalaemia groups (180/221, 81.4 %; p < 0.001). Hyperkalaemia was associated with higher odds for an unfavourable functional outcome (adjusted odds ratio (OR) 1.85, 95 % confidence interval (CI) 1.10–3.12, p = 0.02), while hypokalaemia was not (OR 1.36 95 % CI 0.51–3.60, p = 0.53). The associations were not significant in a subgroup analysis adjusted for the modified cardiac arrest hospital prognosis score in 833 patients (OR 1.74, 95 % CI 0.91–3.34, p = 0.10 for hyperkalaemia and OR 1.48, 95 % CI 0.40–5.44, p = 0.55 for hypokalaemia). ConclusionsOf the comatose patients admitted to ICU after cardiac arrest, one in five experienced a potassium disorder on ICU admission. Hyperkalaemia was associated with unfavourable functional outcomes at 180 days, while hypokalaemia was not.

Combined sonographic optic nerve sheath diameter and cerebral oximeterfor predicting neurological outcome after cardiac arrest.

Cardiac arrest (CA) remains a critical global health issue with high rates of mortality and morbidity. Accurate prediction of neurological outcomes in post-CA patients is essential for optimizing management strategies. Optic nerve sheath diameter (ONSD) and near-infrared spectroscopy (NIRS) are emerging as promising tools for evaluating brain oxygenation and intracranial pressure. However, the potential benefits of combining these methods for improved prognostic accuracy have not been thoroughly explored. This study investigates whether the combined use of ultrasonographic ONSD and NIRS measurements enhances the prediction of neurological outcomes after CA. In this prospective study, ONSD measurements were obtained three times at 24-hour intervals, while regional hemoglobin oxygen saturation (rSO2) using NIRS was recorded twice. Neurological outcomes were assessed using the Full Outline of Unresponsiveness (FOUR) and Cerebral Performance Categories (CPC) scores for both early and late evaluations. Results indicated that 47.5% of patients had poor outcomes and 52.5% had good outcomes based on the FOUR score, while 65% had poor outcomes and 35% had good outcomes according to the CPC score. The combination of ONSD and NIRS measurements showed superior prognostic performance compared to either method alone. While standalone NIRS measurements taken after 24 hours exhibited limited predictive value, combining ONSD and NIRS provided a more reliable approach for neurological assessment in the short term following CA. This integrated method may improve prognostic accuracy and support better clinical decision-making.

Evaluating the late seizures of acute encephalopathy with biphasic seizures and late reduced diffusion via monitoring using continuous electroencephalogram

BackgroundAcute encephalopathy with biphasic seizures and late reduced diffusion (AESD) causes clustered seizures (late seizures; LS) 3–7 days after early seizure (ES); however, few reports provide continuous electroencephalogram (C-EEG) monitoring details. This study aimed to evaluate the initial/last detection date of LS using C-EEG and determine whether LS EEG features correlate with neurological sequelae. Materials and methodsWe analyzed 28 patients diagnosed with AESD who underwent C-EEG monitoring between 2015 and 2020. Multiple pediatric neurologists and epileptologists evaluated the LS detection timing, duration, and severity. Based on the evaluated data, we compared the clinical characteristics and LS-induced neurological sequelae between the ESEEG+LS (initiated C-EEG immediately after ES) and LSEEG+LS (initiated C-EEG after LS confirmation) groups. Additionally, we compared LS clinical characteristics and severity between severe and non-severe groups for 15 patients (baseline Pediatric Cerebral Performance Category Scale score <3). ResultsLS was detected in 17 of 28 patients. The earliest and latest LS detection dates were 2 and 11 days, respectively, and the longest LS duration was 7 days (median, 0.6 days). Regarding neurological sequelae, the LS duration was markedly longer in the severe group than that in the non-severe group during the distant period. However, LS severity was not associated with neurological sequelae. ConclusionThis study highlights the importance of C-EEG as it could aid in the early detection of LS. Neurological sequelae correlated with LS duration but not severity.

Post-intensive-care morbidity among pediatric patients in Thailand: prevalence, risk factors, and the importance of the post-intensive-care clinic.

Long-term survival data for critically ill children discharged to post-intensive care clinics are scarce, especially in Asia. The main objective of this study was to assess the prevalence of post-intensive-care morbidity among pediatric intensive care unit (PICU) survivors at 1 month and 1 year after hospital discharge and to identify the associated risk factors. We conducted a retrospective chart review of all children aged 1 month to 15 years who were admitted to the PICU for >48 hours from July 2019 to July 2022 and visited a post-intensive-care clinic 1 month and 1 year after hospital discharge. Post-intensive care morbidity was defined using the Pediatric Cerebral Performance Category (PCPC). Descriptive statistics, univariate, and multivariate analyses were conducted. A total of 111 children visited the clinic at 1 month, and 100 of these children visited the clinic at 1 year. Only 39 of 111 children (35.2%) had normal PCPC assessments at 1 month, while 54 of 100 (54.0%) were normal at 1 year. Baseline developmental delays were significantly associated with any degree of disability and at least moderate disability at both time points. Mechanical ventilation for >7 days was associated with at least moderate disability at both time points, while PICU stay >7 days was significantly associated with moderate disability at 1 month and any degree of disability at 1 year. A substantial percentage of PICU survivors had persistent disabilities even 1 year after critical illness. A structured multidisciplinary post-intensive-care follow-up plan is warranted to provide optimal care for such children.

Delirium after cardiac arrest: incidence, risk factors, and association with neurologic outcome—insights from the Freiburg Delirium Registry

Abstract Aim Delirium in patients treated in the intensive care unit (ICU) is linked to adverse outcome, according to previous observations. However, data on patients recovering after cardiac arrest are sparse. The aim of this study was to assess incidence, risk factors, and outcome of patients with delirium after cardiac arrest in the Freiburg Delirium Registry (FDR). Methods In this retrospective registry study, all patients after cardiac arrest treated in the Freiburg University Medical Center medical ICU between 08/2016 and 03/2021 were included. Delirium was diagnosed using the Nursing Delirium screening scale (NuDesc), assessed three times daily. Favorable neurological outcome was defined as cerebral performance category (CPC) score at ICU discharge ≤ 2. Results Two hundred seventeen patients were included and among them, delirium was detected in one hundred ninety-nine (91.7%) patients. Age was independently associated with the incidence of delirium (p = 0.003), and inversely associated with the number of delirium-free days (p &lt; 0.001). Favorable neurological outcome was present in 145/199 (72.9%) with, and 17/18 (94.4%) patients without delirium (p = 0.048). While the incidence of delirium was not independently associated with a favorable neurologic outcome, the number of delirium-free days strongly predicted the primary endpoint [OR 2.14 (1.73–2.64), p &gt; 0.001]. Conclusion Delirium complicated the ICU course in almost all patients after cardiac arrest. The number of delirium-free days was associated with favorable outcome while incidence of delirium itself was not. Graphical abstract

Abstract Su907: Post-Cardiac Arrest Potassium Abnormalities Associated With Unfavorable Functional Outcome

Background: Abnormal potassium levels are common findings in the intensive care unit (ICU) population. We aimed to determine the incidence of dyskalemias at ICU admission and their association with functional outcome in comatose patients resuscitated from cardiac arrest. Hypothesis: We hypothesized that both hypokalemia and hyperkalemia are associated with unfavorable functional outcome. Methods: Pooled data from four randomized clinical trials in comatose post-cardiac arrest patients admitted to ICU after return of spontaneous circulation (ROSC). Reference potassium levels were defined as between 3 and 4.9 mmol/L, as proposed in the Simplified Acute Physiology Score II. Favorable functional outcome was defined as a Cerebral Performance Category of 1 or 2 at 180 days. Results: We included 1133 patients (557 from HYPERION, 346 from TTH48, 120 from COMACARE and 110 from Xe-HYPOTHECA) with a median age of 64 (IQR: 55-72) years and a predominance of males (72%). Overall, 421 (36%) patients had favorable functional outcome. On admission, 221 (19.5%) patients experienced hyperkalemia and 35 (3.1%) patients experienced hypokalemia. More patients in the normokalemia group (364/877, 41.5%) had a favorable functional outcome, as compared to the hypokalemia (11/35, 31.4%) and hyperkalemia (41/221, 18.6%) groups p&lt;0.001). In a mixed-effects logistic regression model including initial rhythm, delay from collapse to ROSC, bystander cardiopulmonary resuscitation, lactate, and urea and with normokalemia as reference group, hyperkalemia was associated with higher odds for unfavorable functional outcome (OR 1.85, 95% CI 1.10-3.12, p=0.02) whereas hypokalemia was not (OR 1.36 95% CI 0.51-3.60, p=0.53). Conclusions: One fifth of unconscious cardiac arrest patients experienced dyskalemia on ICU admission. Hyperkalemia was associated with unfavorable functional outcome at 180 days compared to normokalemia, whereas hypokalemia was not an independent predictor of outcome.

Abstract Su701: The Influence of Public Assistance Among Patients Who Received Extracorporeal Cardiopulmonary Resuscitation after Cardiac Arrest in Japan

Background: This study aimed to evaluate the influence of public assistance on patients with out-of-hospital cardiac arrest (OHCA) who received extracorporeal cardiopulmonary resuscitation (ECPR) in Japan. Methods: We conducted a secondary analysis of data from the SAVE-J II study, a retrospective, multicenter registry study involving 36 participating institutions in Japan. Patients with cardiac arrest who received ECPR were divided into two groups depending on whether or not they had received public assistance. The primary outcome was 30-day survival. Secondary outcomes were as follows: 30-day favorable neurological outcomes (cerebral performance category scores 1-2); survival at discharge; favorable neurological outcome at discharge; number of intensive care unit, hospital, ventilator, and extracorporeal membrane oxygenation days; medical expenses; proportion of percutaneous coronary intervention; target temperature management; mechanical circulatory support (MCS) device use; and withdrawal of life-sustaining therapy. Results: Of 2,157 patients registered in the SAVE-J II study, 1,885 patients were enrolled in this study; 99 patients (5.3%) received public assistance and 1,786 patients (94.7%) did not. Multivariable logistic regression analysis did not show a significant difference in 30-day survival (OR 1.22, 95% CI 0.77-1.95, p=0.40). The log-rank test for the Kaplan-Meiercurve on 30-day survival did not demonstrate a significant difference (p=0.46). Except for the use of MCS devices, there were no significant differences in secondary outcomes. Conclusions: The use of public assistance did not influence the prognoses of OHCA patients receiving ECPR. Treatment option during hospitalization may be affected by the use of public assistance.

Abstract 4135335: A randomized trial of expedited intra-arrest transfer versus more extended on-scene resuscitation for refractory out of hospital cardiac arrest: the EVIDENCE Study

Background: Refractory out-of-hospital cardiac arrest (OHCA) has poor outcomes. The benefit of expedited intra-arrest transport with ongoing resuscitation versus more extended on-scene resuscitation for refractory OHCA is not clear. Methods: In this Phase III, multi-center (15 hospitals), randomized, controlled trial conducted in Sydney, Australia, we assigned patients with refractory out-of-hospital cardiac arrest to receive either expedited intra-arrest transport, with mechanical cardiopulmonary resuscitation, to a cardiac catherization-capable hospital for coronary angiography and, where available, extracorporeal membrane oxygenation (ECMO) cardiopulmonary resuscitation (ECPR) or more extended on-scene conventional CPR (advanced cardiac life support). Eligible patients were between 18 and 70 years of age, had received bystander CPR, initial rhythm VT/VF/PEA, and did not have a return of spontaneous circulation after 15 minutes of CPR, or three rounds of resuscitation. The primary outcome was survival with a favorable neurologic outcome, defined as a Cerebral Performance Category score of 1 or 2 at hospital discharge. Analyses were performed on an intention-to-treat basis. Results: One hundred and ninety-seven (197) eligible patients were randomized (median age, 57.0 years; 77 [81%] men), 149 VT/VF (76%). Ninety-five were assigned to receive expedited transfer and 102 to receive conventional CPR. Ten patients in the expedited arms and 6 patients in the conventional arm received ECPR at hospital. At hospital discharge, 15 patients (14.7%) in the expedited transfer group (median on scene time 26 mins) were alive with a favorable neurologic outcome, as compared with 15 patients (15.8%) (median on-scene time 36 minutes). This treatment difference was small and statistically insignificant (risk difference -1.1% [95% CI: -12.2% to 10.0%]), adjusted relative risk 0.95 [p=0.87, 95% CI: 0.50 to 1.8]. Conclusions: Among patients with refractory out-of-hospital cardiac arrest, expedited intra-arrest transport did not significantly improve survival with neurologically favorable outcome at discharge compared with more extended on-scene resuscitation. However, clinically relevant differences could still be consistent with our results.

Abstract Su1202: The utility of post cardiac arrest temperature control protocol according to the severity of hypoxic encephalopathy based on amplitude-integrated electroencephalography findings

Introduction: The TTM2 trial showed that active fever prevention below 37.5°C and hypothermia at 33°C had similar outcomes in out-of-hospital post cardiac arrest patients. However, the patients in the trial had mild hypoxic encephalopathy, and the effects of hypothermia may vary with its severity. We previously reported that amplitude-integrated electroencephalography (aEEG) findings after the return of spontaneous circulation can be used to categorize the severity of hypoxic encephalopathy (Crit Care. 2018;22:226). In September 2022, we adopted a new temperature control protocol wherein the target temperature was set based on aEEG findings. This study examined changes in outcomes before and after implementing this new protocol. Methods: We assessed out-of-hospital cardiac arrest patients who received post cardiac arrest care in our emergency intensive care unit between March 2021 and February 2024. We divided the patients into two groups: before (B) and after (A) the introduction of the new protocol. We classified the patients into categories 1 (C1) to 4 (C4) based on the severity of hypoxic encephalopathy (Figure 1). All patients in group B were treated with hypothermia at 34°C. In group A, patients in C1 were treated with active fever prevention, and those in C2–C4 received hypothermia at 34°C (Figure 2). Primary outcome was favorable neurological outcomes (cerebral performance categories of 1 or 2) at hospital discharge. Secondary outcome was the duration of mechanical ventilation. Results: A total of 160 patients were included. The median age was 62 years and 105 (66%) patients had cardiac etiology. Fifty-five (34%) patients underwent extracorporeal cardiopulmonary resuscitation. The median cardiac arrest time was 29 min. Groups B and A comprised 57 and 103 patients, respectively. C1 category comprised 20 and 28 patients in groups B and A, respectively. The rate of favorable neurological outcomes was 35% in both B and A groups (p=1.00). Regarding C1 patients, the rates were 90% and 86% in B and A groups (p=1.00). Median duration of mechanical ventilation was 5 and 3 days in group B and A, respectively (p=0.11). Conclusion: Neurological outcomes before and after introducing the new protocol were similar. Management of patients with mild hypoxic encephalopathy can be simplified with active fever prevention. A temperature control protocol based on the severity of hypoxic encephalopathy using aEEG findings is feasible for emergency physicians.

Abstract Su804: Use of Machine Learning Models to Predict Neurologically Intact Survival for Advanced Age Adults Following Out-of-hospital Cardiac Arrest

Background: We recently published a multivariable logistic regression model that successfully predicted neurologic outcomes in advanced age adults (≥ 65 years old) who achieve return of spontaneous circulation following out-of-hospital cardiac arrest (OHCA). Prior to externally validating this model, we sought to compare the predictive performance of our logistic regression model against common machine learning (ML) algorithms using the same dataset. Methods: We performed a retrospective observational analysis of the Cardiac Arrest Registry to Enhance Survival database from 2013-2021. All non-traumatic OHCA occurring in adults (≥65 years) who survived to hospital admission were included. The primary outcome measure was neurologically intact survival defined as a cerebral performance category (CPC) score of 1 or 2 at hospital discharge. Our original logistic regression model was compared to Boosted Trees and Decision Tree ML algorithms and assessed using accuracy, Area Under the Receiver Operating Characteristic Curve (AUC-ROC) and Area Under the Precision-Recall Curve (AUC-PR). The model variables included age, gender, race/ethnicity, location, witnessed status, who initiated cardiopulmonary resuscitation, whether an automated external defibrillator was applied prior to emergency medical services arrival, and first monitored rhythm. Results: A total of 83,561 OHCA were included. Median age was 75 years (IQR 69-82), 58.9% were male, 53% were White, 67% experienced an OHCA at home, 52% were witnessed by a bystander, 44% received bystander CPR, and 34% were found in shockable rhythm. Neurologically intact survival (CPC 1 or 2) occurred in 23% of patients. The logistic regression model had an accuracy of 79.6%, AUC-PR 0.542, and AUC-ROC of 0.774. The Boosted Trees model had an accuracy of 79.2%, AUC-PR 0.555, and AUC-ROC of 0.774. The Decision Tree Model had an accuracy of 79.3%, AUC-PR 0.490, and AUC-ROC of 0.717. Conclusion: Boosted Trees and Decision Tree ML models performed comparably to the logistic regression model in predicting favorable versus unfavorable neurological outcomes following successful resuscitation from OHCA in advanced-age adults. Given their similar performance, logistic regression may be preferred for its simplicity and interpretability over alternative ML models. Future efforts to improve and ultimately externally validate the model are warranted.

Abstract Su904: The association between base excess on arrival at the hospital and neurological outcome of adult out-hospital cardiac arrest: observational study

Background: The relationship between base-excess (BE) values, which take into account the time interval from cardiac arrest to blood test, and neurological outcome after out-of-hospital cardiac arrest (OHCA) is not well understood. The purpose of this study was to evaluate the association between BE on arrival at the hospital and neurological outcomes in OHCA patients. Methods: The CRITICAL study, a prospective, multicenter observational study in Osaka, Japan, registered consecutive OHCA patients who were transported to 16 participating critical care centers from 2012 to 2021. We included adult patients aged 18 years with witnessed OHCA whose BE values on hospital arrival was available, and divided patients into quartiles based on BE values of initial blood test on arrival at the hospital: Q1 (BE ≤ −21.1 mmol/L), Q2 (−21.1 &lt; BE ≤ −15.7 mmol/L), Q3 (−15.7 &lt; BE ≤ −10.4 mmol/L), and Q4 (BE &gt; −10.4 mmol/L). The primary outcome was one-month survival with favorable neurological outcome, defined as cerebral performance category scale 1 or 2. Results: A total of 23,854 patients were registered, and 6,066 of them were eligible for analyses. Neurologically favorable outcome was the lowest in the Q1 group (3.2% [49/1,528]), followed by the Q2 (4.7% [70/1,493]), Q3 (9.8% [148/1,515]), and Q4 (23.5% [359/1,530]) group. In the multivariable logistic regression analysis, the adjusted odds ratio of Q1 compared with Q4 for one-month favorable neurological outcome was 0.13 (95% CI 0.090–0.18). The proportion of one-month favorable neurological outcome decreased progressively across decreasing quartiles (p for trend &lt; 0.001). In subgroup analysis, there was an interaction between presence of return of spontaneous circulation (ROSC) before blood test and neurological outcome (p for interaction &lt; 0.001). The neurological outcome worsened as the BE values decreased among those who achieved ROSC before the blood test (p for trend &lt; 0.001), but not in those without ROSC (p for trend = 0.078). There was not a significant interaction between BE values without ROSC before blood test and time from witness to blood test (p for interaction = 0.501). Conclusions: We demonstrated that lower BE values at hospital arrival were associated with worse neurological outcome. The BE values may be one of the effective prognostic indications for neurological outcome, especially in OHCA patients with ROSC before hospital arrival.

Abstract Su1204: Impact of Hypothermia vs. Normothermia Temperature Management Based on Body Temperature at Hospital Arrival on 30-Day Neurological Outcomes in Out-of-Hospital Cardiac Arrest Patients: A Nationwide, Retrospective Study in Japan

Introduction: Temperature management (TM) to prevent fever is crucial to mitigate neurological deterioration post-cardiac arrest. Whether hypothermic TM (h-TM) is superior or equal to normothermic TM (n-TM) after out-of-hospital cardiac arrest (OHCA) is debatable, prompting ongoing effects to identify patients who might benefit more from h-TM. We hypothesized that effect of TM would differ based on body temperature at hospital arrival. Aim: Explore which post-cardiac arrest patient subsets might benefit from h-TM by stratifying them based on body temperature at hospital arrival. Methods: This retrospective, observational study used data from the OHCA registry in Japan. Patients 18 years and older who experienced OHCA due to medical cause and received TM in the intensive care unit were included. Primary outcome measure was 30-day favorable neurological outcomes, defined as a Cerebral Performance Category score of 1 or 2. Patients were stratified into groups based on body temperature at hospital arrival: normothermia (36.0-38.0°C), hypothermia (&lt;36.0°C), and hyperthermia (&gt;38.0°C). Effect of TM post-cardiac arrest (h-TM [32-34°C] or n-TM [35-36°C]) was evaluated in each stratified group. Univariable and multivariable logistic regression analysis was used for comparison. Adjusted odds ratio (OR) for favorable neurological outcome with h-TM was calculated using n-TM as a reference. Hyperthermia was excluded from multivariable analyses due to small sample size. Results: We analyzed 3,044 patients, 1,273 in the normothermia group, 1,747 in the hypothermia group, and 24 in the hyperthermia group. Numbers of patients with favorable neurological outcomes were as follows: 530/1,273 (41.6%) in the normothermia group, 584/1,747 (33.4%) in the hypothermia group, and 4/24 (16.7%) in the hyperthermia group. There were no differences in favorable 30-day neurological outcomes between h-TM and n-TM in any stratified group in the univariable analysis: normothermia (h-TM 323/785 [41.2%] vs. n-TM 207/488 [42.4%], p=0.66); hypothermia (411/1,185 [34.7%] vs. 173/562 [30.8%], p=0.11); hyperthermia (3/13 [23.1%] vs. 1/11 [9.1%], p=0.59). Multivariable analysis also showed no differences: normothermia (OR: 0.96, 95% CI: 0.72-1.26), hypothermia (OR: 1.10, 95% CI: 0.85-1.42). Conclusion: TM (h-TM vs. n-TM) did not significantly affect 30-day neurological outcomes, regardless of initial temperature at hospital arrival.

Abstract Su902: Ability of Composite Magnetic Resonance Brain Imaging Scores to Predict Functional Outcomes in Survivors of Cardiac Arrest

Background: Brain magnetic resonance imaging (MRI) has been examined for neuroprognostication (NP) after out-of-hospital cardiac arrest (OHCA). However, studies have focused on predicting poor outcomes of non-awakening and/or death. Recommendations for utilization of brain MRI in NP remain weak due to its subjective interpretation. Aim: We modified a previously published brain MRI score and examined our quantitated NP scores’ ability to predict good functional outcomes in OHCA survivors. Methods: We screened OHCA cases (2017-2023, Seattle Medic One registry) for patients who survived to hospital discharge and had brain MRIs performed 25 hours-7 days after arrest. Each MRI was reviewed by two adjudicators; a third reviewer served as tie-breaker. Reviewers were blinded to patient outcomes. Diffusion Weighted Imaging and Fluid Attenuated Inversion Recovery sequences were reviewed to score 35 neuroanatomical regions. Graded severity for estimated affected area (0 = zero; 1= &lt; 25%; 2 = 25-50%; 3 = 50-75%; 4 = &gt;75%) and binary (0 = not affected, 1 = affected) scores were tallied. Points were summed for a composite brain MRI score, “ NP score ”, possible range 0-214. Primary outcome was Cerebral Performance Categories (CPC) at hospital discharge (1-2: “independent”, 3: “dependent”, 4: “vegetative state”). Computational modeling employed folded normal distributions and Maximum Likelihood Estimation. Statistical analyses were Pearson’s, Spearman’s, ANOVA, Fisher LSD, t-tests. Results: Forty-two (42) adult patients were included (74% men, 55% Caucasian). Median NP score was 11.5 (IQR 41.5, n=42) overall, 2 (IQR=10, n=21) for independent versus 25.5 (IQR 36.5, n=10) for dependent patients, and 92 (IQR=81, n=11) for those in a vegetative state. NP scores strongly correlated with CPC [ r s (40) = .69, p&lt; .001 ], and were significantly different between CPC groups [F(2,39) = 32.66, p&lt; 0.001 ]. Interrater concordance for NP score was high (Pearson) r = .88 [r = .96; .95; .90; .71]. Conclusions: Our NP score correlated well with good functional outcomes in OHCA survivors, and (1) identified distinct thresholds that well-separate functional outcome groups and (2) had very strong concordance rate among four pairs of adjudicators. NP score-based predictive modeling differentiates functional outcomes beyond good versus poor dichotomy and may help providers and family anticipate recovery potential.

Robust seismic fragility curves for concrete gravity dams incorporating aleatory, epistemic, and fuzzy uncertainties

Concrete gravity dams are critical infrastructure assets, and their failure in seismically active regions poses significant risks. The primary problem addressed in this research is the need for a reliable assessment of the seismic fragility of these dams to ensure safety in such areas. The research aims to develop a comprehensive methodology for seismic fragility analysis that accounts for various uncertainties affecting dam performance, including uncertainties in material properties and seismic characteristics and the fuzziness of damage state thresholds through the Latin Hypercube Sampling method. The methodology involves a three-stage approach: first, a finite element model is created using Abaqus software, incorporating uncertainties in material properties and earthquake characteristics using the Latin Hypercube Sampling method (LHS). Second, incremental dynamic analysis (IDA) defines damage states based on concrete cracking severity and overall stability, utilizing four performance categories of limit states (minor, moderate, extensive, and heavy). Finally, a mathematical model is introduced to characterize the ambiguity in damage state thresholds, recognizing the gradual nature of damage evolution. The primary findings demonstrate that fuzziness substantially influences the probability of exceedance across all damage states, with varying effects on different damage indices because of their differing frequency distributions. This research enhances the reliability and accuracy of seismic fragility assessments, contributing to more robust design guidelines and effective risk mitigation strategies for concrete gravity dams.

Variability of day-to-day pulsatility index change in children with cerebral malaria.

Cerebral malaria (CM) is a devastating disease and better understanding of etiologies of the resulting neurologic injury is needed. The purpose of this study is to describe the day-to-day (DTD) pulsatility index (PI) change measured by transcranial Doppler ultrasound (TCD), a novel measure of cerebral and vascular changes, in children with CM. A retrospective analysis of 122 children in sub-Saharan Africa with CM and 3 or more sequential TCD measurements was performed. Variability of DTD PI change was calculated as a measure of changes in vasculature overtime. Neurologic outcome was determined by the Pediatric Cerebral Performance Category (PCPC) score, a measure of neurologic function. Of the 122 participants, 77.9% had a good neurologic outcome (no neurologic sequelae), and 22.1% had a poor outcome (neurologic sequelae or died). Patients who had a poor neurologic outcome had higher levels of variability of DTD PI change in the right middle cerebral artery (MCA) (0.14 ± 0.21) and left MCA (0.17 ± 0.41) compared to those who had a good neurologic outcome (0.1 ± 0.1 and 0.11 ± 0.19, respectively). A higher variability of both left and right MCA DTD PI change was also associated with higher brain volume assessed through neuroimaging. Variability of DTD PI change may provide early prognostic information regarding PCPC outcomes and brain volume changes seen in CM patients. Expanded research on pathophysiologic contributors to variability of DTD PI changes in children with CM is warranted.