Prediction of cerebral perfusion pressure during CPR using electroencephalogram in a swine model of ventricular fibrillation.

BACKGROUND: Measuring the quality of cardiopulmonary resuscitation (CPR) is important for improving outcomes in cardiac arrest. Cerebral perfusion pressure (CePP) could represent cerebral circulation during CPR, but it is difficult to measure non-invasively. In this study, we developed the electroencephalogram (EEG) based brain index (EBRI) derived from EEG signals by machine learning techniques, which could estimate CePP accurately in a porcine cardiac arrest model. METHODS: We conducted a randomised crossover study using nine female pigs. After 1 min of untreated ventricular fibrillation, we performed CPR with 12 different 2-min tilting angle sessions, including two different head-up tilt (HUT) angles (30°, 15°) twice, horizontal angle (0°) four times and two different head-down tilt (HDT) angles (-15°, -30°) twice with the random order. We collected EEG signals using a single channel EEG electrode in real-time during CPR. We derived the EBRI models to predict the CePP classified by the 5 or 10 groups using three different machine learning algorithms, including the support vector machine (SVM), k-nearest neighbour (KNN) and random forest classification (RFC) method. We assessed the accuracy, sensitivity and specificity of each model. RESULTS: The accuracy of the EBRI model using an SVM algorithm in the 5-group CePP classification was 0.935 with a standard deviation (SD) from 0.923 to 0.946. The accuracy in the 10-group classification was 0.904 (SD: 0.896, 0.913). The accuracy of the EBRI using the KNN method in the 5-group classification was 0.927 (SD: 0.920, 0933) and in the 10-group was 0.894 (SD: 0.880, 0.907). The accuracy of the RFC algorithm was 0.947 (SD: 0.931, 0.963) in the 5-group classification and 0.920 (SD: 0.911, 0.929) in the 10-group classification. CONCLUSION: We developed the EBRI model using non-invasive acquisition of EEG signals to predict CePP during CPR. The accuracy the EBRI model was 0.935, 0.927 and 0.947 for each machine learning algorithm, and the EBRI could be used as a surrogate indicator for measuring cerebral perfusion during CPR.

Case Report of Efficacy of Skin Perfusion After Hyperbaric Oxygen Therapy Following Peripheral Tissue Injury due to Usage of Inotropes and Vasopressors.

Hyperbaric Oxygen Therapy (HBOT) has garnered significant attention as a therapeutic principle with potential benefits across a variety spectrum of medical conditions, ranging from wound healing and ischemic conditions to neurologic disorders and radiation-induced tissue damage. HBOT involves the administration of 100% oxygen at higher atmospheric pressures, leading to increased oxygen dissolved in bodily fluids and tissues. The elevated oxygen levels are proposed to facilitate tissue repair, reduce inflammation, and promote angiogenesis. This case report presents a compelling instance of the usefulness of HBOT in promoting skin perfusion and healing following peripheral tissue injury resulting from the administration of inotropic and vasopressor agents in septic shock patients.

The effect of regional distribution of isolation rooms in emergency departments on ambulance travel time during the COVID-19 pandemic.

OBJECTIVE: The number and distribution of isolation rooms in Korea differ by region. The distribution of isolation beds in emergency departments may have affected ambulance travel time and burden on emergency medical service (EMS) during the COVID-19 pandemic. METHODS: This retrospective observational study analyzed EMS records in four regions of the Gyeonggi Province, Korea, from January 01, 2019 to December 31, 2020. The main exposure was the number of emergency department isolation rooms in each region. The primary outcome was call-to-return time for the EMS. The interaction effect of the number of regional isolation rooms on the call-to-return time during the COVID-19 pandemic was analyzed using a generalized linear model (GLM) and logistic regression. RESULTS: A total of 781,246 cases was included in the analyses. During the COVID-19 pandemic, the call-to-scene time (before 8 minutes vs. after 9 minutes, P<0.05) and call-to-return time (before 46 minutes vs. after 52 minutes, P<0.05) for emergency patients increased significantly compared to before the pandemic. As the number of regional isolation rooms increased, the effect of COVID-19 on the call-to-return time decreased significantly in the multivariable GLM with an interaction term (with 10.14 isolation rooms per million population: adjusted exponential ß coefficient [exp(ß)], 1.33; with 12.24 isolation rooms per million population: adjusted exp(ß), 1.18). As the number of regional isolation rooms increased, the effect of COVID-19 on the call-to-scene time decreased significantly in the multivariable GLM with an interaction term (with 10.14 isolation rooms per million population: adjusted exp(ß), 1.20; with 12.24 isolation rooms per million population: adjusted exp(ß), 1.09). CONCLUSION: During the pandemic, the increases in call-to-return time and call-to-scene time were smaller in regions with more isolation rooms per population.

Effect of topography and weather on delivery of automatic electrical defibrillator by drone for out-of-hospital cardiac arrest.

Delivery of automatic electrical defibrillator (AED) by unmanned aerial vehicle (UAV) was suggested for out-of-hospital cardiac arrest (OHCA). The goal of this study is to assess the effect of topographic and weather conditions on call to AED attach time by UAV-AED. We included OHCA patients from 2013 to 2016 in Seoul, South Korea. We developed a UAV-AED flight simulator using topographic information of Seoul for Euclidean and topographic flight pathway including vertical flight to overcome high-rise structures. We used 4 kinds of UAV flight scenarios according to weather conditions or visibility. Primary outcome was emergency medical service (EMS) call to AED attach time. Secondary outcome was pre-arrival rate of UAV-AED before current EMS based AED delivery. Call to AED attach time in topographic pathway was 7.0 min in flight and control advanced UAV and 8.0 min in basic UAV model. Pre-arrival rate in Euclidean pathway was 38.0% and 16.3% for flight and control advanced UAV and basic UAV. Pre-arrival rate in the topographic pathway was 27.0% and 11.7%, respectively. UAV-AED topographic flight took longer call to AED attach time than Euclidean pathway. Pre-arrival rate of flight and control advanced UAV was decreased in topographic flight pathway compared to Euclidean pathway.

Relationship between serum potassium level and survival outcome in out-of-hospital cardiac arrest using CAPTURES database of Korea: Does hypokalemia have good neurological outcomes in out-of-hospital cardiac arrest?

BACKGROUND: Sudden cardiac arrest is a major cause of death worldwide. Serum potassium level is an initial laboratory test that serves as part of an electrolyte panel easily obtainable by most emergency departments (EDs). OBJECTIVES: To evaluate the relationship between serum potassium level and the survival outcome for out-of-hospital cardiac arrest (OHCA) patients. MATERIAL AND METHODS: We used the Cardiac Arrest Pursuit Trial with Unique Registration and Epidemiological Surveillance (CAPTURES) database, which made up the OHCA cohort of 27 EDs in Korea from January to December 2014. The inclusion criteria were all OHCA patients in the cohort who had received cardiopulmonary resuscitation (CPR) in the hospital. The patients were excluded if they were transferred from another hospital, had a pre-hospital return of spontaneous circulation (ROSC), or if the potassium level and clinical outcome data were missing or not captured. The main parameter was serum potassium level on ED arrival. According to the serum potassium level, the patients were divided into a hypokalemia group (K+ < 3.5 mEq/L), a normokalemia group (K+ = 3.5-5.4 mEq/L) and a hyperkalemia group (K+ ≥ 5.5 mEq/L). The primary outcome was neurologically favorable survival discharge. RESULTS: Among the 1,616 patients in the CAPTURES cohort, 913 patients were included in the analysis, of whom 46 patients (5.9%) were assigned to the hypokalemia group, 370 patients (40.5%) were assigned to the normokalemia group and 497 patients (54.4%) were assigned to the hyperkalemia group. The hypokalemia group has a significantly higher percentage of good neurological outcomes (26.1%). There was a significant positive correlation with neurologically favorable survival (odds ratio (OR) = 4.45; 95% confidence interval (95% CI) = 1.67-11.91) and a significant positive correlation with survival discharge (OR = 2.25; 95% CI = 1.05-4.82). CONCLUSIONS: In OHCA patients, serum potassium level measured in the hospital showed a significant association with survival outcome. Hypokalemia had a significant association with good neurological outcome and survival discharge.

Effect of endotracheal intubation and supraglottic airway device placement during cardiopulmonary resuscitation on carotid blood flow over resuscitation time: An experimental porcine cardiac arrest study.

BACKGROUND: Supraglottic airway devices (SGDs) are widely used during the resuscitation of out-of-hospital cardiac arrest (OHCA). The effect of SGDs on carotid blood flow (CBF) as resuscitation time passes is controversial. We assessed the effects of endotracheal intubation (ETI) and 3 types of SGD placement on CBF over time in prolonged resuscitation through an experimental porcine cardiac arrest study. METHODS: We conducted a randomized crossover study using 12 female pigs. After 4 min of untreated ventricular fibrillation, 3 pairs of ETI for 3 min and each type of SGD placement, including Combitube, I-gel, and laryngeal mask airway, for 3 min were conducted. The order of the 3 pairs of ETI and SGD were randomly assigned for each pig. We measured physiological parameters including CBF and mean arterial pressure (MAP). We compared CBF and MAP between the last 1 min of the insertion period for each of the 3 types of SGD and the preceding ETI period. Trends of CBF and MAP according to ETI and SGD transition were also plotted during the prolonged resuscitation duration. RESULTS: CBF decreased after inserting I-gel and Combitube compared to ETI (mean difference (95% CI): -685 ml (-1052 to -318) for Combitube, -369 ml (-623 to -114) for I-gel). MAP subsequently decreased after transitioning airway devices as resuscitation was prolonged, regardless of the device type. The mean CBF during the transition from ETI to SGD decreased by -480 ml (95% CI: -675 to -286), but the decrease in CBF during the transition from SGD to ETI was only -4 ml (95% CI: -182 to 175). CONCLUSION: SGD placement was associated with decreased carotid blood flow during cardiopulmonary resuscitation in an experimental porcine model. As time passed during prolonged resuscitation, reduction in CBF was aggravated after the transition to SGD placement compared to the reduction after the transition to ETI. This study was approved by the study institution IACUC 16-0140-S1A0.

Extracorporeal life support and survival after out-of-hospital cardiac arrest in a nationwide registry: A propensity score-matched analysis.

BACKGROUND: The benefit of extracorporeal life support (ECLS) in highly selective patients with out-of-hospital cardiac arrest (OHCA) is supported by previous studies; however, it is unclear whether the effects of ECLS are observed at a population level. This study aimed to determine whether ECLS is associated with improved survival outcomes compared to conventional CPR (cardiopulmonary resuscitation) at a national level. METHODS: We used a Korean national OHCA cohort database from 2009 to 2013. The inclusion criteria were OHCA adults with presumed cardiac aetiology and resuscitation by emergency medical services (EMS). Patients were excluded if their information on prehospital time intervals or clinical outcomes at hospital discharge was incomplete or not captured. The primary outcome was neurologically favourable survival to discharge. We compared the primary outcomes between the ECLS and non-ECLS groups using a multivariable logistic regression and a propensity score matching analysis. RESULTS: Of the 119,077 patients with OHCA, 36,547 were included in the analysis. There were 320 patients who received ECLS. There was no significant difference in neurologically favourable survival to discharge between the ECLS group and the non-ECLS group after adjusting for covariates (adjusted OR, 0.65; 95% CI, 0.41-1.04). In the propensity score-matched cohort, there was also no significant difference between the two groups (adjusted OR, 0.94; 95% CI, 0.41-2.14). CONCLUSIONS: In this propensity score-matched cohort using a nationwide OHCA database, OHCA victims who received ECLS did not show better survival outcomes than those who did not receive ECLS.