Chun Song Youn

Diffusion-weighted magnetic resonance imaging for predicting the clinical outcome of comatose survivors after cardiac arrest: a cohort study

IntroductionThe aim of this study was to examine whether the patterns of diffusion-weighted imaging (DWI) abnormalities and quantitative regional apparent diffusion coefficient (ADC) values can predict the clinical outcome of comatose patients following cardiac arrest.MethodsThirty-nine patients resuscitated from out-of-hospital cardiac arrest were prospectively investigated. Within five days of resuscitation, axial DWIs were obtained and ADC maps were generated using two 1.5-T magnetic resonance scanners. The neurological outcomes of the patients were assessed using the Glasgow Outcome Scale (GOS) score at three months after the cardiac arrest. The brain injuries were categorised into four patterns: normal, isolated cortical injury, isolated deep grey nuclei injury, and mixed injuries (cortex and deep grey nuclei). Twenty-three subjects with normal DWIs served as controls. The ADC and percent ADC values (the ADC percentage as compared to the control data from the corresponding region) were obtained in various regions of the brains. We analysed the differences between the favourable (GOS score 4 to 5) and unfavourable (GOS score 1 to 3) groups with regard to clinical data, the DWI abnormalities, and the ADC and percent ADC values.ResultsThe restricted diffusion abnormalities in the cerebral cortex, caudate nucleus, putamen and thalamus were significantly different between the favourable (n = 13) and unfavourable (n = 26) outcome groups. The cortical pattern of injury was seen in one patient (3%), the deep grey nuclei pattern in three patients (8%), the cortex and deep grey nuclei pattern in 21 patients (54%), and normal DWI findings in 14 patients (36%). The cortex and deep grey nuclei pattern was significantly associated with the unfavourable outcome (20 patients with unfavourable vs. 1 patient with favourable outcomes, P < 0.001). In the 22 patients with quantitative ADC analyses, severely reduced ADCs were noted in the unfavourable outcome group. The optimal cutoffs for the mean ADC and the percent ADC values determined by receiver operating characteristic (ROC) curve analysis in the cortex, caudate nucleus, putamen, and thalamus predicted the unfavourable outcome with sensitivities of 67 to 93% and a specificity of 100%.ConclusionsThe patterns of brain injury in early diffusion-weighted imaging (DWI) (less than or equal to five days after resuscitation) and the quantitative measurement of regional ADC may be useful for predicting the clinical outcome of comatose patients after cardiac arrest.

Early brain computed tomography findings are associated with outcome in patients treated with therapeutic hypothermia after out-of-hospital cardiac arrest

BackgroundThis study evaluated the association between the results of immediate brain computed tomography (CT) scans and outcome in patients who were treated with therapeutic hypothermia after cardiac arrest. The evaluation was based on the changes in the ratio of gray matter to white matter.MethodsA total of 167 patients who were successfully resuscitated after cardiac arrest from March 2009 to December 2011 were included in this study. We selected 51 patients who received a brain CT scan within 1 hour after the return of spontaneous circulation (ROSC) and who had been treated with therapeutic hypothermia. Circular regions of measurement (10 mm2) were placed over regions of interest (ROIs), and the average attenuations in gray matter (GM) and white matter (WM) were recorded in the basal ganglia, at the level of the centrum semiovale and in the high convexity area. Three GM-to-WM ratios (GWRs) were calculated: one for the basal ganglia, one for the cerebrum and the average of the two. The neurological outcomes were assessed using the Cerebral Performance Category (CPC) scale at the time of hospital discharge, and a good neurological outcome was defined as a CPC score of 1 or 2.ResultsThe average GWR was the strongest predictor of poor neurological outcome as determined using receiver operating characteristic curves (basal ganglia area under the curve (AUC) = 0.716; cerebrum AUC = 0.685; average AUC = 0.747). An average GWR < 1.14 predicted a poor neurological outcome with a sensitivity of 13.3% (95% confidence interval (CI) 3.8-30.7), a specificity of 100% (95% CI 83.9-100), a positive predictive value of 100% (95% CI 2.5-100), and a negative predictive value of 44.7% (CI 28.9-58.9).ConclusionsOur study demonstrated that low GWRs in the immediate brain CT scans of patients treated with therapeutic hypothermia after ROSC were associated with poor neurological outcomes. Immediate brain CT scans could help predict outcome after cardiac arrest.

The prognostic value of continuous amplitude-integrated electroencephalogram applied immediately after return of spontaneous circulation in therapeutic hypothermia-treated cardiac arrest patients

INTRODUCTION The purpose of this study was to examine the prognostic value of continuous amplitude-integrated electroencephalogram (aEEG) applied immediately after return of spontaneous circulation (ROSC) in therapeutic hypothermia (TH)-treated cardiac arrest patients. METHODS From September 2010 to August 2011, we prospectively studied comatose patients treated with TH after cardiac arrest who were monitored with aEEG. Monitoring at the forehead was applied as soon as possible after ROSC in the emergency department and continued until recovery of consciousness, death, or 72 h after ROSC. Neurological outcome was assessed with the Cerebral Performance Category (CPC) scale at hospital discharge, and good neurological outcome was defined as a CPC score of 1 or 2. RESULTS A total of 55 TH-treated patients were included. Monitoring started at a median of 96 min after ROSC (interquartile range, 49-174). At discharge, 28 patients had a CPC of 1-2, and 27 patients had a CPC of 3-5. Seventeen patients had a continuous normal voltage (CNV) trace at the start of monitoring, and this voltage was strongly associated with a good outcome (16/17 [94.1%]; sensitivity and specificity of 57.1 and 96.3%, respectively). No development of a CNV trace within the recorded period accurately predicted a poor outcome (21/21 [100%]; sensitivity and specificity of 77.8 and 100%, respectively). CONCLUSIONS An initial CNV trace in aEEG applied to forehead immediately after ROSC is a good early predictor of a good outcome in TH-treated cardiac arrest patients. Conversely, no development of a CNV trace within 72h is an accurate and reliable predictor of a poor outcome with a false-positive rate of 0%.

Continuous Amplitude-Integrated Electroencephalographic Monitoring is a Useful Prognostic Tool for Hypothermia-Treated Cardiac Arrest Patients

Background— Modern treatments have improved the survival rate following cardiac arrest, but prognostication remains a challenge. We examined the prognostic value of continuous electroencephalography according to time by performing amplitude-integrated electroencephalography on patients with cardiac arrest receiving therapeutic hypothermia. Methods and Results— We prospectively studied 130 comatose patients treated with hypothermia from September 2010 to April 2013. We evaluated the time to normal trace (TTNT) as a neurological outcome predictor and determined the prognostic value of burst suppression and status epilepticus, with a particular focus on their time of occurrence. Fifty-five patients exhibited a cerebral performance category score of 1 to 2. The area under the curve for TTNT was 0.97 (95% confidence interval, 0.92–0.99), and the sensitivity and specificity of TTNT<24 hours after resuscitation as a threshold for predicting good neurological outcome were 94.6% (95% confidence interval, 84.9%–98.9%) and 90.7% (95% confidence interval, 81.7%–96.2%), respectively. The threshold displaying 100% specificity for predicting poor neurological outcome was TTNT>36 hours. Burst suppression and status epilepticus predicted poor neurological outcome (positive predictive value of 98.3% and 96.4%, respectively). The combination of these factors predicted a negative outcome at a median of 6.2 hours after resuscitation (sensitivity and specificity of 92.0% and 96.4%, respectively). Conclusions— A TTNT<24 hours was associated with good neurological outcome. The lack of normal trace development within 36 hours, status epilepticus, and burst suppression were predictors of poor outcome. The combination of these negative predictors may improve their prognostic performance at an earlier stage.

Serum highly selective C-reactive protein concentration is associated with the volume of ischemic tissue in acute ischemic stroke.

BACKGROUND There is growing evidence that inflammation plays an important role in atherogenesis. Previous studies have shown that the concentration of peripheral inflammatory markers, particularly C-reactive protein (CRP), strongly correlates with stroke severity and independently predicts mortality and recurrent vascular events in patients with acute ischemic stroke. The aim of this study was to clarify the relationship between inflammatory markers and stroke severity by means of volumetric measurement of infarct size. METHODS From March 1, 2008, to February 28, 2009, 96 patients who had laboratory investigations and magnetic resonance imaging scans were included retrospectively in this study. Diffusion-weighted imaging (DWI) lesions were outlined using a semiautomatic threshold technique. Diffusion-weighted imaging lesion volumes were measured with MIPAV software (Medical Image Processing, Analysis and Visualization, version 4.1.1; National Institutes of Health, Bethesda, MD). The relationship between highly selective CRP (hs-CRP) levels and DWI infarct volume quartiles was examined. RESULTS The mean age of patients was 66.9 years, and 50 patients (51.2%) were male. There was a significant correlation between hs-CRP and DWI volumes (Spearman ρ = 0.239, P = .010). The median hs-CRP values for successive volumes of DWI lesion quartiles (lowest to highest quartile) were as follows: 1.17, 1.14, 1.63, and 3.76 (P = .029). CONCLUSIONS Higher hs-CRP levels were associated with larger infarct volumes in patients with acute ischemic stroke. These results suggest that elevated hs-CRP levels, reflecting a large volume of infarct, may serve as a helpful serologic marker in the evaluation of severity of acute ischemic stroke.

Association of blood glucose at admission with outcomes in patients treated with therapeutic hypothermia after cardiac arrest

BACKGROUND It is well known that hyperglycemia is associated with poor outcomes in critically ill patients. We investigated the association between blood glucose level at admission and the outcomes of patients treated with therapeutic hypothermia (TH) after cardiac arrest. METHODS A total of 883 cardiac arrest patients who were treated with TH were analyzed from the Korean Hypothermia Network retrospective registry. We examined the association of blood glucose at admission with survival and neurologic outcomes at hospital discharge. Favorable neurologic outcomes were defined as Cerebral Performance Category scores of 1 and 2. RESULTS The mean age of the sample was 56.7 ± 16.2 years, 69.5% of subjects were male, and the mean blood glucose at admission was 14.1 ± 7.0 mmol/L. After adjustment for sex, age, history of diabetes mellitus, hypertension, renal disease and stroke, time from arrest to return of spontaneous circulation, initial rhythm, witness status, bystander cardiopulmonary resuscitation, cause of arrest, and cumulative dose of adrenaline, the associations between glucose and outcomes were as follows: for favorable neurologic outcomes, an odds ratio of 0.955 (95% confidence interval, 0.918-0.994); and for survival, an odds ratio of 0.974 (95% confidence interval, 0.952-0.996). CONCLUSION These results show that blood glucose level at admission is associated with survival and favorable neurologic outcomes at hospital discharge in patients treated with TH after cardiac arrest. Blood glucose level at admission could be a surrogate marker of ischemic insult severity during cardiac arrest. However, randomized, controlled evidence is needed to address the significance of tight glucose control during TH after cardiac arrest.

The validity of the Canadian Triage and Acuity Scale in predicting resource utilization and the need for immediate life-saving interventions in elderly emergency department patients.

BackgroundWe evaluated the validity of the Canadian Triage and Acuity Scale (CTAS) in elderly emergency department (ED) patients. In particular, we examined the sensitivity and specificity of the CTAS for identifying elderly patients who received an immediate life-saving intervention in the ED.MethodsWe reviewed the medical records of consecutive patients who were 65 years of age or older and presented to a single academic ED within a three-month period. The CTAS triage scores were compared to actual patient course, including disposition, discharge outcome and resource utilization. We calculated the sensitivity and specificity of the CTAS triage for identifying patients who received an immediate intervention.ResultsOf the 1903 consecutive patients who were ≥ 65 years of age, 113 (5.9%) had a CTAS level of 1, 174 (9.1%) had a CTAS level of 2, 1154 (60.6%) had a CTAS level of 3, 347 (18.2%) had a CTAS level of 4, and 115 (6.0%) had a CTAS level of 5. As a patients triage score increased, the severity (such as mortality and intensive care unit admission) and resource utilization increased significantly. Ninety-four of the patients received a life-saving intervention within an hour following their arrival to the ED. The CTAS scores for these patients were 1, 2 and 3 for 46, 46 and 2 patients, respectively. The sensitivity and specificity of a CTAS score of ≤ 2 for identifying patients for receiving an immediate intervention were 97.9% and 89.2%, respectively.ConclusionsThe CTAS is a triage tool with high validity for elderly patients, and it is an especially useful tool for categorizing severity and for recognizing elderly patients who require immediate life-saving intervention.

Outcome analysis of cardiac arrest due to hanging injury

OBJECTIVE The aim of this study was to review patient characteristics and analyze the outcomes in patients who have had cardiac arrest from hanging injuries. METHODS A retrospective review was performed that examined the victims of out-of-hospital cardiac arrest (OHCA) due to hanging who presented to a tertiary general hospital from January 2000 to December 2009. Utstein style variables were evaluated, and patient outcomes were assessed at the time of hospital discharge using the cerebral performance category (CPC) scale. RESULTS Fifty-two patients with OHCA due to hanging were enrolled in this study from the aforementioned 10-year inclusion period. Resuscitation attempts were performed in 31 patients (60%), and 21 patients were pronounced dead. In all cases, the first monitored cardiac rhythms were either asystole or pulseless electrical activity (PEA) and were therefore nonshockable rhythms. Of the patients for whom resuscitation was attempted, 13 (42%) experienced a return of spontaneous circulation and 1 revealed cervical spine fracture. Of the 13 return-of-spontaneous-circulation patients, 5 survived to be discharged. The mean age of these 5 surviving patients was 36 years. All 5 patients were graded as cerebral performance category 4 at discharge. CONCLUSION The first monitored cardiac rhythms of patients presenting with OHCA due to hanging were nonshockable rhythms wherein the survival rate of these patients was 9.6%. All of the survivors were relatively young and demonstrated poor neurologic outcomes at discharge. Physicians must consider cervical spine fracture in patients who had cardiac arrest from hanging.

Combination of initial neurologic examination and continuous EEG to predict survival after cardiac arrest.

BACKGROUND Prognosticating outcome following cardiac arrest requires a multimodal approach. We tested whether the combination of initial neurologic examination combined with continuous EEG was superior to either test alone for predicting survival after cardiac arrest. METHODS Review of consecutive patients receiving continuous EEG monitoring between April 2010 and June 2013. Initial neurologic examination was evaluated using the Full Outline of UnResponsiveness (FOUR) score and organ system dysfunction determined using the SOFA score. We defined four categories of initial post-cardiac arrest illness severity (PCAC): (I) awake, (II) coma (not following commands but intact brainstem responses) + mild cardiopulmonary dysfunction (SOFA cardiac + respiratory score < 4), (III) coma + moderate-severe cardiopulmonary dysfunction (SOFA cardiac + respiratory score ≥ 4), and (IV) coma without brainstem reflexes. A second analysis focusing on neurologic injury divided subjects into three groups according to initial FOUR_B score; FOUR_B = 0-1, FOUR_B = 2 and FOUR_B = 4. A blinded rater dichotomized continuous EEG patterns during the first 48h into malignant patterns (non-convulsive status epilepticus, convulsive status epilepticus, myoclonic status epilepticus and generalized periodic epileptiform discharges). The primary outcome was survival to hospital discharge. RESULTS Of 331 subjects, mean age was 58 (SD 17) years and 206 (62.2%) subjects were male. Ventricular fibrillation or tachycardia (VF/VT) was the initial rhythm for 93 (28.1%) subjects. Among subjects with malignant cEEG, survival to hospital discharge rate was 0% for FOUR_B 0-1, 8.1% for FOUR_B 2 and 12.5% for FOUR_B 4, respectively. In one multivariate analysis, survival was independently associated with VF/VT, FOUR_B of 2, FOUR_B of 4, and non-malignant cEEG. In a separate model, survival was associated with VF/VT, PCAC < 4 and non-malignant cEEG. The AUCs of FOUR_B, cEEG and the combination of FOUR_B and cEEG are 0.740 (95% C.I. 0.684-0.797), 0.674 (95% C.I. 0.615-0.732) and 0.820 (95% C.I. 0.773-0.868) respectively. The AUCs of PCAC, cEEG and the combination of PCAC and cEEG are 0.779 (95% C.I. 0.721-0.838), 0.672 (95% C.I. 0.612-0.7321) and 0.846 (95% C.I. 0.798-0.894) respectively. CONCLUSION Combining the initial neurologic examination using either FOUR_B or PCAC, with cEEG was superior to any individual test for predicting survival after cardiac arrest. We caution against using these findings to speed prognostication until they are externally validated.

Repeated diffusion weighted imaging in comatose cardiac arrest patients with therapeutic hypothermia.

BACKGROUND The aim of this study was to evaluate the changing pattern and prognostic values of diffusion-weighted imaging (DWI) at two time points in cardiac arrest patients treated with therapeutic hypothermia. METHODS Twenty two patients with cardiac arrest who underwent two DWI studies were enrolled in the retrospective study. The first DWI was performed after the induction of therapeutic hypothermia (median 6.0h) and was repeated between 48h and 168h (second DWI, median 74h). Apparent diffusion coefficient (ADC) values were measured in the predefined brain regions, and qualitative analysis was also performed. Good neurologic outcomes were defined as Cerebral Performance Category (CPC) scores of 1 and 2. RESULTS The ADC value tended to increase over time except the cortical regions of the poor outcome group (N=10). In the comparisons of receiver operating characteristic (ROC) curve to predict poor outcome using ADC value, postcentral cortex in the second DWI has a better association with neurological outcome (p=0.001, area under the curve (AUC)=0.996 for second DWI, AUC=0.571 for first DWI). In the same analysis using qualitative score, precentral cortex, postcentral cortex, parietal lobe, occipital lobe, caudate and putamen in the second DWI have a better association with neurological outcome. CONCLUSIONS The changing pattern of ADC values after cardiac arrest is different according to anatomic region and neurologic status. The DWI after 48h has a better association with neurological outcome of cardiac arrest patients in both quantitative and qualitative analysis.