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Background: Rearrest occurs commonly after initial resuscitation following out-of-hospital cardiac arrest (OHCA). We determined (1) the predictors of rearrest during hospitalisation that can be identified in the hours immediately after OHCA, (2) the association between rearrest and favourable long-term outcomes, and (3) the predictors of favourable long-term outcomes in rearrest patients., Methods: Conditional multivariable logistic regression analyses were performed using the Korean Hypothermia Network prospective registry data, which included details of adult OHCA patients treated with targeted temperature management at 22 teaching hospitals in South Korea., Results: Among the 1,233 patients, 260 (21.1%) experienced rearrest. Of the 192 patients resuscitated from first rearrest, 33 (17.2%) achieved 6-month favourable outcomes. Arrhythmia, heart failure, ST-segment elevation, lower initial Glasgow coma scale (GCS) motor score, higher initial lactate level, and antiarrhythmic drug use within 1 h were independently associated with rearrest. Higher lactate level and antiarrhythmic drug use were associated with shockable first rearrest, while arrhythmia, heart failure, ST-segment elevation, and lower GCS motor score were associated with non-shockable first rearrest. Rearrest was independently associated with a lower likelihood of 6-month favourable outcomes (P = 0.003). Initial shockable rhythm after OHCA, absence of diabetes, shorter cumulative time to restoration of spontaneous circulation, coronary angiography, and hypophosphataemia within 7 d were independently associated with 6-month favourable outcomes in the patients resuscitated from first rearrest., Conclusions: Rearrest during hospitalisation after OHCA was inversely associated with 6-month favourable outcomes. We identified several risk factors for rearrest and prognostic factors for patients resuscitated from first rearrest., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Background: Various methods have been used to control body temperature in targeted temperature management (TTM), but few studies have compared specific subtypes of surface cooling systems. The aim of this study was to compare the efficiencies and neurological outcomes between hydrogels pad and water-circulating blanket cooling methods., Methods: We conducted a multicentre, prospective, registry-based study of out-of-hospital cardiac arrest patients treated with TTM between 2015 and 2018. We compared the neurological outcomes, efficacies for cooling, and adverse events between patients who received TTM using a hydrogel pad and water-circulating blanket cooling. Patients were one-to-one matched using propensity scores to adjust for differences in the baseline characteristics of each cooling method. The primary outcome was a favourable neurological outcome at 6 months., Results: We included 1,132 patients in the analysis, 870 of whom underwent hydrogel pad cooling, and the remaining 262 underwent water-circulating blanket cooling. In the unmatched cohort, a greater number of adverse events occurred in the water-circulating blanket group. The favourable neurologic outcome rates at 6 months were similar between the hydrogel pad group and the water circulating blanket group (30.2% vs. 29.8%, p = 0.939). In the propensity-matched cohort, which included 184 pairs, the rates of adverse events between the two groups were similar. The similarity of favourable neurologic outcome rates at 6 months between the two groups persisted (28.8% vs. 29.9%, p = 0.819)., Conclusion: Neurological outcomes and adverse events between the hydrogel pad cooling and water-circulating blanket cooling groups were similar., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Background: Seismocardiography measures the vibrations produced by the beating heart using an accelerometer sensor placed on the chest. We evaluated the ability of smartphone seismocardiography to distinguish between the presence and absence of spontaneous circulation., Methods: Seismocardiography signals were obtained using a smartphone placed on the sternum in a convenience sample of 60 adult patients (30 comatose patients with spontaneous circulation and 30 deceased patients). The maximum, minimum, and standard deviation (SD) of acceleration values for head-to-foot, right-to-left, and dorsoventral axes and the three axis-root mean square (RMS) of the acceleration signals were calculated. Blinded observers (n = 156) were each asked to determine the presence or absence of spontaneous circulation based on seismocardiography video clips for each of the 60 patients., Results: The seismocardiography revealed periodic large positive peaks in the patients with spontaneous circulation, which were absent in the patients without spontaneous circulation. For each of the four output measurements (three independent axes plus the three-axis RMS), the acceleration maxima and SD were significantly higher and the minima significantly lower in the patients with spontaneous circulation than in those without spontaneous circulation (all P < 0.001 except the minimum of three axis-RMS results [P = 0.009]). The observers accurately identified the seismocardiography signals from patients without spontaneous circulation, with a sensitivity of 97.6% (95% confidence interval, 97.0%-98.2%) and a specificity of 98.4% (95% confidence interval, 97.8%-99.0%)., Conclusions: In conclusion, blinded observers accurately distinguished between seismocardiography signals from patients with and without spontaneous circulation., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Background: Early prognostication after cardiac arrest would be useful. We aimed to develop a scoring model for early prognostication in unselected adult cardiac arrest patients., Methods: We retrospectively analysed data of adult non-traumatic cardiac arrest patients treated at a tertiary hospital between 2014 and 2018. The primary outcome was poor outcome at hospital discharge (cerebral performance category, 3-5). Using multivariable logistic regression analysis, independent predictors were identified among known outcome predictors, that were available at intensive care unit admission, in patients admitted in the first 3 years (derivation set, N = 671), and a scoring system was developed with the variables that were retained in the final model. The scoring model was validated in patients admitted in the last 2 years (validation set, N = 311)., Results: The poor outcome rates at hospital discharge were similar between the derivation (66.0%) and validation sets (64.3%). Age <59 years, witnessed collapse, shockable rhythm, adrenaline dose <2 mg, low-flow duration <18 min, reactive pupillary light reflex, Glasgow Coma Scale motor score ≥2, and levels of creatinine <1.21 mg dl -1 , potassium <4.4 mEq l -1 , phosphate <5.8 mg dl -1 , haemoglobin ≥13.2 g dl -1 , and lactate <8 mmol l -1 were retained in the final multivariable model and used to develop the scoring system. Our model demonstrated excellent discrimination in the validation set (area under the curve of 0.942, 95% confidence interval 0.917-0.968)., Conclusions: We developed a scoring model for early prognostication in unselected adult cardiac arrest patients. Further validations in various cohorts are needed., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Aim: To examine the association between heat index (HI) during the induction, maintenance, and rewarming periods of targeted temperature management (TTM) and neurologic outcome in out-of-hospital cardiac arrest (OHCA) survivors., Methods: Adult (≥18 years) comatose OHCA survivors who underwent TTM at 33 °C between 2016 and 2018 were included. We collected data on water temperature (WT) recorded every minute during TTM. We calculated HI during induction as the inverse of the average WT × induction time (h) × 100 and HI of maintenance and rewarming as the inverse of the average WT × 100. The primary outcome was a poor neurologic outcome, based on Cerebral Performance Category 3-5 after 6 months., Results: Of the 118 included patients, 78 (66.1%) had poor outcome. Poor outcome group had lower HI during each of three periods than good outcome group. The areas under the curves for poor outcome of HI during the induction, maintenance, and rewarming periods were 0.819 (95% confidence interval [CI], 0.737-0.883), 0.781 (95% CI, 0.696-0.852), and 0.844 (95% CI, 0.765-0.904), respectively. Induction time (odds ratio [OR], 0.991; 95% CI, 0.983-0.999) and HI during induction (OR, 0.916; 95% CI, 0.854-0.983), maintenance (OR, 0.082; 95% CI, 0.011-0.589), and rewarming (OR, 0.009; 95% CI, 0.000-0.285) were associated with poor outcome., Conclusions: Heat generation was independently associated with neurologic outcome in OHCA survivors who underwent TTM at 33 °C. The performance of HI was higher in the rewarming period than in the induction or maintenance period in association with poor neurologic outcomes., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Background: Lipid profiles are known to be a risk factor for development of cardiovascular disease. However, the relationship between lipid profiles and outcome in out-of-hospital cardiac arrest (OHCA) survivors remains unclear. We aimed to examine the association between lipid profiles and neurologic outcome in OHCA survivors., Methods: This retrospective observational study included adult (≥18 years) OHCA survivors between January 2016 and December 2018. We measured patients' lipid profiles after return of spontaneous circulation (ROSC) including total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and triglyceride. The primary outcome was neurologic outcome at hospital discharge. Good neurologic outcome was defined cerebral performance categories 1 and 2., Results: A total of 182 patients were included. Of them, 57 (31.3%) were discharged with good neurologic outcomes. Median serum levels of total cholesterol (178.0 vs. 123.0 mg/dL), HDL (44.0 vs. 31.0 mg/dL), and LDL (104.0 vs. 75.0 mg/dL) were significantly higher in patients with good neurologic outcome. The area under the curves of total cholesterol, HDL, LDL, and triglyceride were 0.742 (95% confidence interval [CI], 0.672-0.803), 0.729 (95% CI, 0.658-0.792), 0.683 (95% CI, 0.610-0.750), and 0.572 (95% CI, 0.497-0.645), respectively. Total cholesterol (odds ratio [OR], 1.013; 95% CI, 1.000-1.025; p = 0.043) and HDL (OR, 1.071; 95% CI, 1.021-1.123; p = 0.005) levels were associated with good neurologic outcomes., Conclusions: The levels of total cholesterol and HDL after ROSC were associated with good neurologic outcomes in patients with OHCA, without considering the effect of other lipid profiles simultaneously., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: Thrombocytopenia is common and associated with mortality in critically ill patients. However, the time course of platelet counts and its association with the neurologic outcome after out-of-hospital cardiac arrest (OHCA) are not well known. The purpose of this study is to describe the time course of platelet counts in relation to the neurologic outcome in patients undergoing targeted temperature management (TTM) after CA., Methods: Review of consecutive patients receiving TTM after out-of-hospital CA between 2009 and 2016. The blood sample was collected daily until 7 days. The primary outcome was poor neurologic outcome at 6 months after CA defined as Cerebral Performance Category of 3-5 and secondary outcome was mortality at 6 months., Results: A total of 261 consecutive patients treated with TTM after OHCA between 2009 and 2016. One hundred seventy-five patients (67.0%) had poor neurologic outcomes 6 months after CA. The changes in the platelet counts over time between the good and poor outcome groups were statistically significant (p < 0.001). The platelet counts declined during TTM in both groups. The platelet counts recovered to the normal range at the end of the first week in the good neurologic outcome group. However, the platelet counts remained low in the poor outcome group. Low platelet counts on the 7th day were associated with poor neurologic outcomes (aOR 0.975, 95% CI, 0.961-0.989) and mortality at 6 months (aOR 0.986, 95% CI, 0.975-0.997) after adjusting for covariates., Conclusion: The changes in platelet counts in OHCA patients have a biphasic pattern that is significantly different in patients with good neurologic outcomes and those with poor neurologic outcomes at 6 months. A low platelet count 7 days after CA was associated with a poor neurologic outcome and mortality at 6 months., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: Several studies reported that disturbances in cellular ion homeostasis occur following ischaemia, the magnitude of which was proportional to illness severity. The changes in serum electrolyte levels following ischaemia were minor compared with the changes in ion concentrations in the extracellular fluid. To amplify the serum electrolyte changes, we devised a new index (ion shift index), which could be calculated using commonly measured serum electrolyte levels, and explored its prognostic value in adult cardiac arrest patients., Methods: This retrospective observational study included adult cardiac arrest survivors treated at a tertiary university hospital between January 2014 and December 2017. Using the first available serum electrolyte levels, the ion shift index was calculated as follows: ion shift index = (potassium + phosphate + magnesium) / calcium. The primary outcome was poor outcome at hospital discharge (cerebral performance categories 3-5)., Results: The area under the receiver operating characteristic curve (AUC) of ion shift index for predicting poor outcome was 0.878 (95% confidence interval [CI], 0.849-0.907). The AUC of ion shift index was greater than those of individual electrolytes (all p < 0.001). In multivariate analysis, higher ion shift index levels were independently associated with poor outcome (odds ratio, 2.916; 95% CI, 1.798-4.730; p < 0.001). The AUC of multivariate model including ion shift index was greater than that of multivariate model after excluding ion shift index (p =  0.007)., Conclusions: Our results suggest that the ion shift index can be helpful in the early prognostication of adult cardiac arrest patients., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Aim of the Study: Brain swelling after cardiac arrest may affect the ventricles. We aimed to investigate the prognostic performance of ventricular characteristics on brain computed tomography (CT) in cardiac arrest survivors who underwent targeted temperature management (TTM)., Methods: This retrospective cohort study included adult comatose cardiac arrest survivors who underwent brain CT scan within 24 h after resuscitation and underwent TTM from 2014 to 2016. The ventricular areas (lateral, third, and fourth ventricle), distances between the anterior horns of the lateral ventricle (LV) and the posterior horns of the LV, and maximal internal diameter of the skull were measured. Grey-to-white matter ratio (GWR), Evans' index, and relative LV area were calculated. The primary outcome was a 6-month neurologic outcome., Results: Of 258 patients, 176 (68.2%) had an unfavourable neurologic outcome. GWR, LV area, third ventricle area, distance between the anterior horns of the LV, distance between the posterior horns of the LV, Evans' index, and relative LV area were different between neurologic outcome groups. Evans' index (0.683; 95% confidence interval [CI], 0.623-0.739) and relative LV area (0.670; 95% CI, 0.609-0.727) had higher value of area under the curve than the other ventricular characteristics and showed prognostic performance comparable with GWR (0.600; 95% CI, 0.538-0.661). All ventricular characteristics and GWR were not independently associated with neurologic outcome after adjusting for covariates., Conclusion: Ventricular characteristics on brain CT were associated with 6 months neurologic outcome in cardiac arrest survivors. Ventricular characteristics were objective measures that had comparable prognostic performance with GWR., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: Several studies have reported increased levels of phosphate after cardiac arrest. Given the relationship between phosphate level and the severity of ischaemic injury reported in previous studies, higher phosphate levels may be associated with worse outcomes. We investigated the prognostic value of phosphate level after the restoration of spontaneous circulation (ROSC) in adult cardiac arrest patients., Methods: This study was a retrospective observational study including adult cardiac arrest survivors treated at the Chonnam National University Hospital between January 2014 and June 2017. From medical records, data regarding clinical characteristics, outcome at hospital discharge, and laboratory parameters including phosphate levels after ROSC were collected. The primary outcome was poor outcome at hospital discharge, defined as Cerebral Performance Categories 3-5., Results: Of the 674 included patients, 465 had poor outcome at hospital discharge. Serum phosphate level was significantly higher in patients with poor outcome than in those with good outcome (p < 0.001). Phosphate level was correlated with time to ROSC (r = 0.350, p < 0.001). Receiver operating characteristic curve analysis revealed an area under the curve of 0.805 (95% confidence interval [CI], 0.777-0.838) for phosphate level. In multivariate analysis, a higher phosphate level was independently associated with poor outcome at hospital discharge (odds ratio, 1.432; 95% CI, 1.245-1.626; p < 0.001)., Conclusions: A higher phosphate level after ROSC was independently associated with poor outcome at hospital discharge in adult cardiac arrest patients. However, given its modest prognostic performance, phosphate level should be used in combination with other prognostic indicators., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Introduction: Predicting neurologic outcomes after cardiac arrest (CA) is challenging. This study tested the hypothesis that a quantitative analysis of diffusion weighted imaging (DWI) using the FMRIB Software Library (FSL) can predict neurologic outcomes after CA and can clarify the optimal apparent diffusion coefficient (ADC) thresholds for predicting poor neurologic outcomes., Methods: Out-of-hospital CA patients treated with targeted temperature management (TTM) who underwent DWI were included in this study. Voxel-based analysis was performed to calculate the mean ADC value. ADC thresholds (750, 700, 650, 600, 550, 500, 450 and 400) and brain volumes below each threshold were also analyzed for their correlation with outcomes. The patients were divided into early (within 48 h after return of spontaneous circulation (ROSC)) and late group (between 48 h and 7 days after ROSC) according to the DWI scan time. The primary outcome was a poor neurologic outcome at 6 months after CA, defined as a cerebral performance category (CPC) of 3-5., Results: One hundred ten DWIs were analyzed. The mean ADC values were 789.0 (761.5-826.5) × 10 -6  mm 2 /s for the good neurologic outcome group and 715.2 (663.1-778.4) × 10 -6  mm 2 /s for the poor neurologic outcome group (p < 0.001). All the ADC thresholds could differentiate patients with good versus poor outcomes. The ADC threshold of 400 × 10 -6  mm 2 /s had the highest odds ratio (4.648 in the early group and 11.283 in the late group) after adjusting for initial rhythm and anoxic time. To achieve 100% specificity using an ADC threshold of 400 × 10 -6  mm 2 /s, the sensitivity was 64% (cutoff value; >2.5% ADC threshold of 400 × 10 -6  mm 2 /s) in the early group and 79.2% (cutoff value; >1.66% ADC threshold of 400 × 10 -6  mm 2 /s) in the late group., Conclusions: Voxel-based analysis using FSL software can predict neurologic outcomes after CA. The ADC threshold of 400 × 10 -6  mm 2 /s had the highest OR for predicting a poor neurologic outcome., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Aim of the Study: Previous studies on the relationship between age and outcomes after cardiac arrest were performed in settings where the majority of patients died after the withdrawal of life support (WLS). We examined the association between age and outcomes of comatose cardiac arrest survivors in a setting where WLS was not performed., Methods: This single-centre retrospective observational study included adult comatose cardiac arrest survivors treated with targeted temperature management. In Korea, WLS is not permitted unless the patient is pronounced brain-dead. The primary outcome was poor neurologic outcome at hospital discharge, defined as Cerebral Performance Categories scores of 3-5. The secondary outcomes were in-hospital and six-month mortalities., Results: A total of 534 patients were analysed. In multivariate analysis, age was not associated with in-hospital mortality (odds ratio [OR], 1.01; 95% confidence interval [CI], 0.99-1.02), but it was independently associated with neurologic outcome at hospital discharge (OR, 1.03; 95% CI, 1.02-1.05) and six-month mortality (OR, 1.05; 95% CI, 1.03-1.07). When age was categorised into 10-year intervals, age groups less than 61-70 years had significantly lower OR for poor neurologic outcome compared with the reference group (61-70 years), while the OR for poor neurologic outcome in age groups greater than 70 years did not differ from that in the reference group., Conclusion: In a setting where WLS is not performed, we found that age was not associated with in-hospital mortality but was independently associated with neurologic outcome at hospital discharge and six-month mortality., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Aim of the Study: Studies examining associations between time to target temperature and outcomes in cardiac arrest patients who underwent targeted temperature management (TTM) have shown inconsistent results. We examined these associations separately for time from restoration of spontaneous circulation to TTM initiation (pre-induction time) and time from TTM initiation to target temperature (induction time). Furthermore, we examined whether critical time thresholds exist if there is an association., Methods: This was a single-centre retrospective observational study including adult cardiac arrest patients treated with TTM from 2008 to 2015. We tested the associations of pre-induction time and induction time with outcomes at hospital discharge using multivariate logistic regression analysis. We then performed additional multivariate analyses, each with the significant timing variable at different binary cutoffs., Results: A total of 515 patients were analysed. At hospital discharge, 357 patients (69.3%) were alive, of whom 161 (31.3%) had a favourable neurologic outcome. In multivariate analysis, a shorter pre-induction time was independently associated with a favourable neurologic outcome (odds ratio [OR], 1.110; 95% confidence interval [CI], 1.025-1.202), whereas the induction time was not (OR, 0.954; 95% CI, 0.852-1.067). We found two pre-induction time thresholds (120 and 360min) that were associated with neurologic outcome., Conclusion: We found that a shorter pre-induction time was independently associated with a favorable neurologic outcome at hospital discharge, whereas induction time was not. We also found two time thresholds at 120 and 360min, after which initiation of cooling was associated with a worse neurologic outcome., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Aim of Study: The association between long duration of resuscitation efforts in out-of-hospital cardiac arrest (OHCA) and neurologic outcome is unclear and understudied with advancements in post-cardiac arrest care and high-quality cardiopulmonary resuscitation. We investigated how downtime, defined as the interval from collapse-to-return of spontaneous circulation (ROSC), impacts on neurologic outcome in OHCA patients treated with targeted temperature management (TTM)., Methods: A multicenter, registry-based, retrospective cohort study was conducted using cases from 24 hospitals across South Korea. Of the 930 adults (≥18 years) non-traumatic OHCA patients treated with TTM between January 2007 and December 2012 at these hospitals, we included 858 patients who had sufficient data for calculating downtime. Good neurologic outcome was defined as a cerebral performance category score of 1 or 2., Results: Median downtime was 30.0 (22.0-41.0min) and 242 patients (28.2%) had good neurologic outcome. When downtime was divided by 10-min intervals (≤10min, 11-20min, 21-30min, 31-40min, 41-50min, 51-60min, and >60min), their neurologically intact survival rate were 48.2%, 51.6%, 29.2%, 22.1%, 16.1%, 14.8%, and 7.1%, respectively (p=0.01). Although downtime was associated with poor neurologic outcome [odds ratio 1.06 (1.05-1.08), p<0.01], the area under the receiver operating characteristic curve of downtime for outcome was only 0.67, 95% CI (0.63-0.71). Furthermore, even with downtime >20min, 22.2% (150/526) patients still had a good neurologic outcome, and this percentage increased to 50.3% (93/185) in patients with an initial shockable rhythm, and 31.1% (134/431) with age <65 years., Conclusions: We found that neurologically intact survival can occur at prolonged downtimes and were unable to identify a downtime for which survivability was clearly futile. These data suggest that downtime should not be considered as a factor in determining whether to provide aggressive post-arrest care, especially in patients with young patients or those with an initially shockable rhythm., (Copyright © 2016. Published by Elsevier Ireland Ltd.)

Aim of the Study: We evaluated the influence of post-rewarming temperature management (PRTM) on post-rewarming fever development and determined the association between the temperature in the immediate post-targeted temperature management (TTM) period and outcomes., Methods: This retrospective observational study included consecutive adult cardiac arrest survivors treated with TTM from January 2008 to December 2013. Beginning in August 2010, our institution implemented a PRTM protocol involving continued use of temperature management device to maintain normothermia during the first 24h after rewarming. The outcomes were in-hospital mortality and neurologic outcome at discharge. We evaluated the effect on clinical outcomes of post-rewarming fever defined at a temperature over 38 °C within 48 h after rewarming., Results: Of 277 included patients, 55.2% underwent PRTM. The incidence of post-rewarming fever did not differ between the PRTM and no-PRTM groups (odds ratio [OR] 0.963, confidence interval [CI] 0.519, 1.787). Post-rewarming fever was associated with decreased in-hospital mortality (OR 0.243, CI 0.110, 0.534) and decreased rate of unfavorable neurologic outcome (OR 0.312, CI 0.182, 0.534). During 48 h following rewarming, mean temperature was 36.5 °C (36.2-36.8 °C), and peak temperature was 37.5 °C (36.8-38.1 °C). On multivariate analyses, lower mean temperature was associated with increased in-hospital mortality (OR 0.099, CI 0.037, 0.262) and unfavorable neurologic outcome (OR 0.071, CI 0.026, 0.193)., Conclusion: It appeared that PRTM did not prevent post-rewarming fever development. Post-rewarming fever was associated with favorable outcomes while lower body temperature after rewarming was associated with unfavorable outcomes. Our results require further confirmation by larger prospective studies., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Aim of the Study: Previous studies found that the gray matter to white matter ratio (GWR) on brain computed tomography (CT) could be used to predict poor outcomes in cardiac arrest survivors. However, these studies have included cardiac arrests of both cardiac and non-cardiac etiologies. We sought to evaluate if the GWR on brain CT can help to predict poor outcomes after out-of-hospital cardiac arrest (OHCA) of cardiac etiology., Methods: Using a multicenter retrospective registry of adult cardiac arrest survivors treated with therapeutic hypothermia, we identified survivors of OHCA of cardiac etiology who underwent brain CT within 24h after successful resuscitation. Gray and white matter attenuations were measured, and the GWRs were calculated as in previous studies. The prognostic values of the GWRs were analyzed, and a logistic regression analysis was performed to determine the contribution of the GWR in predicting poor outcomes (Cerebral Performance Category 3-5)., Results: of 283 included patients, 140 had good outcomes and 143 had poor outcomes. Although the GWRs could predict poor outcomes with statistical significance, the sensitivities were remarkably low (3.5% to 5.6%) at cutoff values with 100% specificity. No significant difference in predictive performance was found between the primary predictive model, containing independent poor outcome predictors, and the primary predictive model combined with the GWR., Conclusion: In a cohort of comatose adults after OHCA of cardiac etiology, the GWR demonstrated poor predictive performance and was not helpful in predicting poor outcomes., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Aim of the Study: Ischaemic contracture compromises the haemodynamic effectiveness of cardiopulmonary resuscitation and resuscitability. 2,3-Butanedione monoxime (BDM) reduced ischaemic contracture by inhibiting actin-myosin crossbridge formation in an isolated heart model. We investigated the effects of BDM on ischaemic contracture and resuscitation outcomes in a pig model of out-of-hospital cardiac arrest (OHCA)., Methods: After 15min of untreated ventricular fibrillation, followed by 8min of basic life support, 16 pigs were randomised to receive either 2mlkg(-1) of BDM solution (25gl(-1)) or 2mlkg(-1) of saline during advanced cardiac life support (ACLS)., Results: During the ACLS, the control group showed an increase in left ventricular (LV) wall thickness from 10.0mm (10.0-10.8) to 13.0mm (13.0-13.0) and a decrease in LV chamber area from 8.13cm(2) (7.59-9.29) to 7.47cm(2) (5.84-8.43). In contrast, the BDM group showed a decrease in the LV wall thickness from 10mm (9.0-10.8) to 8.5mm (7.0-9.8) and an increase in the LV chamber area from 9.86cm(2) (7.22-12.39) to 12.15 cm(2) (8.02-14.40). Mixed model analyses of the LV wall thickness and LV chamber area revealed significant group effects and group-time interactions. Spontaneous circulation was restored in four (50%) animals in the control group and in eight (100%) animals in the BDM group (p=0.077). All the resuscitated animals survived during an intensive care period of 4h., Conclusion: BDM administered during cardiopulmonary resuscitation reversed ischaemic contracture in a pig model of OHCA., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Aim of the Study: We sought to assess the reliability of the method using the pressure measured at the intraosseous (IO) cannula while squeezing the involved limb (P(squeezing)) in determining the position of the IO needle and to compare its performance with that of the traditional confirmation method., Methods: Eighty limbs of twenty domestic swine were assigned to one of three conditions regarding the position of the IO needle; correct placement (n=40), incorrect placement in which the IO needle was placed into the subcutaneous space without entering the bone (incorrect-subcutaneous placement, n=20), or incorrect placement in which the IO needle passed entirely through the bone (incorrect-penetrating placement, n=20). A blinded investigator randomly identified the position of the needle by the traditional method or test method using P(squeezing). If P(squeezing) was 80 mmHg or higher, the IO cannula was regarded as incorrectly placed., Results: P(squeezing) was higher in incorrect placements (176.0 mmHg (130.0-195.0)) compared with that in correct placements (27.0 mmHg (20.0-34.0)) (p<0.001). The test method correctly identified all 40 placements, but the traditional method was incorrect for one (5%) of 20 correct placements (p=1.000) and 7 (35%) of 20 incorrect placements (p=0.008). In incorrect placements, false positive results occurred mainly in incorrect-penetrating placements., Conclusion: We suggest that the method using the pressure measured at the IO cannula can be used when there is uncertainty about the position of the IO cannula after determination using traditional methods., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

Aim of the Study: We determined whether combining the grey-to-white matter ratio (GWR) on brain computed tomography (CT) and serum neuron specific enolase (NSE) improves the prognostic performance when compared to either alone in cardiac arrest patients treated with therapeutic hypothermia (TH)., Methods: We performed a retrospective study of a cohort of cardiac arrest patients treated with TH. The Hounsfield unit was measured in the caudate nucleus (CN), putamen (P), posterior limb of internal capsule (PIC) and corpus callosum (CC); GWR was calculated as CN/PIC and P/CC. The NSE value was obtained at 0, 24, and 48h after restoration of spontaneous circulation (ROSC). We analysed the prognostic performance of GWR and NSE, singly and in combination, in predicting poor neurologic outcome (cerebral performance category 3-5)., Results: Of the 224 included patients, 82 showed good neurologic outcome at hospital discharge, while 142 showed poor neurologic outcome. The P/CC (area under receiver operating characteristics (AUROC) 0.864, sensitivity/specificity 52.9%/100%) showed better prognostic performance than did the CN/PIC (AUROC 0.721, sensitivity/specificity 19.8%/100%). The NSE value at 48h after ROSC (AUROC 0.895, sensitivity/specificity 60.2%/100%) showed the highest prognostic value among the three NSE time points. Analysis of 119 patients undergoing both brain CT and NSE at 48h indicated that combining P/CC and NSE improved the sensitivity (78.6%) compared to either alone (48.6%, 62.9%)., Conclusion: Combining brain CT and serum NSE improves the prognostic performance when compared to either alone in predicting poor neurologic outcome in cardiac arrest patients treated with TH., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

Aim of the Study: Potassium-based cardioplegia has been the gold standard for cardioprotection during cardiac surgery. We sought to evaluate the feasibility and the effects of potassium-induced cardiac standstill during conventional cardiopulmonary resuscitation (CPR) in a pig model of prolonged ventricular fibrillation (VF)., Methods: VF was induced in 20 pigs, and circulatory arrest was maintained for 14 min. Animals were then resuscitated by standard CPR. Coincident with the start of CPR, 20 ml of saline (control group) or 0.9 mequiv.kg(-1) of potassium chloride diluted to 20 ml (potassium group) was administered into right atrium., Results: Administration of potassium resulted in asystole lasting for 1.0 min (0.2) in the potassium group animals. VF reappeared in all but one animal, in which wide QRS complex bradycardia followed. Restoration of spontaneous circulation (ROSC) was attained in two animals (20%) in the control group and in seven animals (70%) in the potassium group (p=0.070). Resuscitated animals in the potassium group required fewer countershocks (3, 4 vs. 2 (1-2)), smaller doses of adrenaline (1.84, 1.84 vs. 0.94 (0.90-1.00)mg), and shorter duration of CPR (8, 10 vs. 4.0 (4.0-4.0)min) than did the control group. Potassium concentrations normalised rapidly after ROSC in both groups, and the potassium concentrations at 5 min (5.5, 6.6 vs. 6.8 (6.5-7.8)mequiv.l(-1)) and 4h (4.9, 5.4 vs. 5.9 (5.1-6.4)mequiv.l(-1)) after ROSC were similar in the both groups., Conclusion: In a pig model of untreated VF cardiac arrest for 14 min, resuscitation with potassium-induced cardiac standstill during conventional CPR was found to be feasible., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

Aim of the Study: Adjustment of adrenaline (epinephrine) dosage according to cardiac arrest (CA) duration, rather than administering the same dose, may theoretically improve resuscitation outcomes. We evaluated variable effects of high-dose adrenaline (HDA) relative to standard-dose adrenaline (SDA) on resuscitation outcomes according to CA duration., Methods: Twenty-eight male domestic pigs were randomised to the following 4 groups according to the dosage of adrenaline (SDA 0.02 mg/kg vs. HDA 0.2mg/kg) and duration of CA before beginning cardiopulmonary resuscitation (CPR): 6 min SDA, 6 min HDA, 13 min SDA, or 13 min HDA. After the predetermined duration of untreated ventricular fibrillation, CPR was provided., Results: All animals in the 6 min SDA, 6 min HDA, and 13 min HDA groups were successfully resuscitated, while only 4 of 7 pigs in the 13 min SDA group were successfully resuscitated (p=0.043). HDA groups showed higher right atrial pressure, more frequent ventricular ectopic beats, higher blood glucose, higher troponin-I, and more severe metabolic acidosis than SDA groups. Animals of 13 min groups showed more severe metabolic acidosis and higher troponin-I than animals of 6 min groups. All successfully resuscitated animals, except two animals in the 13 min HDA group, survived for 7 days (p=0.121). Neurologic deficit score was not affected by the dose of adrenaline., Conclusion: HDA showed benefit in achieving restoration of spontaneous circulation in 13 min CA, when compared with 6 min CA. However, this benefit did not translate into improved long-term survival or neurologic outcome., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Aim of the Study: The available data suggest that automated external defibrillators (AED) can be safely used in vibration-like moving conditions such as rigid inflatable boats and aircraft environments. However, little literature exists examining their performance in a moving ambulance. The present study was undertaken to determine whether an AED is able to analyse the heart rhythm correctly during ambulance transport., Methods: An ambulance was driven on paved (20-100 km/h) and unpaved (10 km/h) roads. The performance of two AED devices (CU ER 2, CU Medical Systems Inc., Korea, and Heartstart MRx, Phillips, USA) was determined in a moving ambulance using manikins. Vibration intensity was measured simultaneously with a digital vibrometer. AED performance was then evaluated again on manikins and on a swine model under simulated vibration intensities (0.5-5m/s(2)) measured by the vibrometer in the previous phase of the investigation., Results: The vibration intensity increased with increasing speeds on paved roads (1.98+/-0.44 m/s(2) at 100 km/h). While driving on unpaved roads, it increased to 6.40+/-1.06 m/s(2). Both AED algorithms analysed the heart rhythm correctly under resting state. When tested on pigs, both algorithms showed substantially degraded performances, even at low vibration intensities of 0.5-1m/s(2), which corresponded to vibration intensities while driving on paved roads at 20-60 km/h. This study also showed that electrocardiograms generated on manikins were more resistant to motion artifacts than were the pig electrocardiograms., Conclusion: Ambulance personnel should consider the possibility of misinterpretation by an AED when this device is used while transporting a patient., (Copyright (c) 2010 Elsevier Ireland Ltd. All rights reserved.)

Purpose: The present study was undertaken to determine whether flushing the carotid artery with normal saline at 4 degrees C (hypothermic carotid arterial flush, HCAF) during cardiac arrest can achieve selective cerebral hypothermia rapidly during cardiac arrest and improve cerebral outcome., Methods: Ventricular fibrillation (VF) was induced in fourteen dogs and circulatory arrest was maintained for 9 min. Dogs were then resuscitated by cardiopulmonary resuscitation. The dogs were divided into two groups; a control group (n=7), which underwent precisely the same procedure as the experimental group but not HCAF, and an experimental group (HCAF group; n=7), which received HCAF from 8 min after the onset of VF., Results: Two dogs in the control group and in the HCAF group died within 72 h after the recovery of spontaneous circulation (ROSC) due to extracerebral complications. The remaining 10 dogs survived to final evaluation at 72 h post-ROSC. In the HCAF group, tympanic temperature decreased from 37.7 degrees C (37.5-37.8) to 34 degrees C in 1 min (1-1.5) from the start of HCAF and was maintained below 34 degrees C until 6.5 min (3-12) after the start of HCAF, whereas oesophageal and rectal temperatures were maintained above 35 degrees C. Neurological deficit scores (0-100%) at 72 h post-ROSC were 42.4% (27.0-80.6) in the control group and 18.4% (14.0-36.0) in the HCAF group (p<0.05)., Conclusion: HCAF induced selective cerebral hypothermia rapidly during cardiac arrest and improved neurological deficit scores after 9 min of no blood flow in the described canine cardiac arrest model.