Delayed arrival of advanced life support adversely affects the neurological outcome in a multi-tier emergency response system.

AIM: Prehospital management of out-of-hospital cardiac arrest (OHCA) is based on basic life support, with the addition of advanced life support (ALS) if possible. This study aimed to investigate the effect of delayed arrival of ALS on neurological outcomes of patients with OHCA at hospital discharge. METHODS: This was a retrospective study of a registry of patients with OHCA. A multi-tier emergency response system was established in the study area. ALS was initiated when the second-arrival team arrived at the scene. A restricted cubic spline curve was used to investigate the relationship between the response time interval of the second-arrival team and neurological outcomes at hospital discharge. Multivariable logistic regression analysis was performed to assess the independent association between the response time interval of the second-arrival team and neurological outcomes of patients at hospital discharge. RESULTS: A total of 3186 adult OHCA patients who received ALS at the scene were included in the final analysis. A restricted cubic spline curve showed that a long response time interval of the second-arrival team was correlated with a high likelihood of poor neurological outcomes. Meanwhile, multivariable logistic regression analysis showed that a long response time interval of the second-arrival team was independently associated with poor neurological outcomes (odds ratio, 1.10; 95% confidence interval, 1.03-1.17). CONCLUSION: In a multi-tiered prehospital emergency response system, the delayed arrival of ALS was associated with poor neurological outcomes at hospital discharge.

Association between length of stay in the emergency department and outcomes in out-of-hospital cardiac arrest.

OBJECTIVE: Several studies have previously reported that a prolonged emergency department length of stay (EDLOS) is associated with poor outcomes in critically ill patients. This study was performed to investigate the relationship between the EDLOS and the neurologic outcome at 28 days in out-of-hospital cardiac arrest (OHCA) patients. METHODS: We conducted a retrospective analysis of prospectively collected data from OHCA patients who achieved the return of spontaneous circulation (ROSC) in the EDs of three urban tertiary teaching hospitals from December 2013 to October 2020. Patients were divided into four groups according to the EDLOS, according to the quartile distribution: EDLOS <107 min, EDLOS 107-176 min, EDLOS 176-275 min, and EDLOS ≥275 min. Comparisons of outcomes among the groups and multivariable logistic regression analysis were performed. RESULTS: A total of 807 patients were included in the analysis. The proportions of patients with a good neurologic outcome at 28 days in the groups with EDLOS <107 min, EDLOS 107-176 min, EDLOS 176-275 min, and EDLOS ≥275 min were 37.0%, 29.8%, 26.9, and 20.4%, respectively (p < 0.001). In the multivariable analysis, the odds ratios for a poor neurologic outcome at 28 days in the groups with EDLOS 107-176 min, EDLOS 176-275 min, and EDLOS ≥275 min compared with the group with EDLOS <107 min were 1.19 (95% CI, 0.67-2.13), 1.73 (95% CI, 0.95-3.21), and 1.91 (95% CI, 1.03-3.57), respectively. CONCLUSIONS: An EDLOS longer than 275 min after the ROSC was independently associated with a poor neurologic outcome at 28 days.

Association of the duration of on-scene advanced life support with good neurological recovery in out-of-hospital cardiac arrest.

BACKGROUND: As advanced life support (ALS) provided by emergency medical services (EMS) on scene becomes more common, the scene time interval (STI) for which EMS providers stay on scene tends to lengthen. We investigated the relationship between the STI and neurological outcome of patients at hospital discharge when ALS was provided by EMS on scene. METHODS: We conducted a retrospective analysis of prospectively collected out-of-hospital cardiac arrest (OHCA) data between August 2015 and December 2018. A restricted cubic spline curve was used to investigate the relationship between the STI and neurologic outcome, and patients were divided into two groups based on the cut-off value obtained through receiver operating characteristic (ROC) analysis. Comparisons of outcomes between the two groups were performed before and after propensity score matching. RESULTS: 4548 patients were included in the analysis. In ROC analysis, the optimal cut-off value for STI was 19 min. For the group with an STI <19 min, survival admission, survival discharge, and good neurologic outcome at hospital discharge were all higher than for the group with STI ≥19 min before and after propensity score matching. The multivariable model also showed that the STI ≥19 min was significantly associated with poor neurologic outcome at hospital discharge compared with the STI <19 min (adjusted odds ratio, 2.00; 95% CI, 1.40-2.88). CONCLUSIONS: A duration of on-scene ALS more than 19 min was associated with a poor neurologic outcome of patients at hospital discharge in OHCA.

Serum total carbon dioxide as a prognostic factor for 28-day mortality in patients with sepsis.

OBJECTIVE: Metabolic acidosis is commonly associated with the disease severity in patients with sepsis or septic shock. This study was performed to investigate the association between serum total carbon dioxide (TCO2) concentration and 28-day mortality in patients with sepsis. METHODS: This study was a multicenter retrospective cohort study of patients with sepsis or septic shock. The relationships between serum TCO2 and 28-day mortality, bicarbonate, pH, lactate, and anion gap were determined with cubic spline curves. The patients were divided into four groups according to their serum TCO2 concentration: Group I (TCO2 > 20 mmol/l), Group II (15 < TCO2 ≤ 20 mg/dl), Group III (10 < TCO2 ≤ 15 mmol/l), and Group IV (TCO2 ≤ 10 mmol/l). RESULTS: A total of 3168 patients were included in the analysis, and the overall mortality rate was 24.1%. Serum TCO2 concentrations below 20 mmol/l showed an almost linear correlation with mortality as well as with lactate, bicarbonate, and pH. The 28-day mortality rates of Group I, II, III, and IV were 18.3%, 23.6%, 32.6%, and 50.0%, respectively (p < .001). In Multivariable Cox proportional hazard regression analysis, the groups with lower serum TCO2 concentrations had a higher risk of 28-day mortality compared with Group I: Group II (Hazard ratio (HR), 1.35; 95% confidence interval (CI), 1.11-1.64), Group III (HR, 1.74; 95% CI, 1.37-2.21), and Group IV (HR, 2.72; 95% CI, 2.03-3.64). CONCLUSIONS: Serum TCO2 concentrations of 20 mmol/l or less were associated with 28-day mortality in patients with sepsis.

The index of oxygenation to respiratory rate as a prognostic factor for mortality in Sepsis.

OBJECTIVES: An index combining respiratory rate and oxygenation (ROX) has been introduced, and the ROX index is defined as the ratio of oxygen saturation by pulse oximetry/fraction of inspired oxygen to respiratory rate. In sepsis, hypoxemia and tachypnea are commonly observed. We performed this study to investigate the association between the ROX index and 28-day mortality in patients with sepsis or septic shock. METHODS: This retrospective study included 2862 patients. The patients were divided into three groups according to the ROX index: Group I (ROX index >20), Group II (ROX index >10 and ≤ 20), and Group III (ROX index ≤10). RESULTS: The median ROX index was significantly lower in the nonsurvivors than in the survivors (12.8 and 18.2, respectively) (p < 0.001). The 28-day mortality rates in Groups I, II and III were 14.5%, 21.3% and 34.4%, respectively (p < 0.001). In the multivariable Cox regression analysis, Group III had an approximately 40% higher risk of death than Group I during the 28-day period (hazard ratio = 1.41, 95% confidence interval 1.13-1.76). The area under the curve of the ROX index was significantly higher than that of the quick Sequential Organ Failure Assessment score (p < 0.001). CONCLUSIONS: The ROX index was lower in nonsurvivors than in survivors, and a ROX index less than or equal to 10 was an independent prognostic factor for 28-day mortality in patients with sepsis or septic shock. Therefore, the ROX index could be used as a prognostic marker in sepsis.

Antibiotic prescription consistent with guidelines in emergency department is associated with 30-day survival in severe community-acquired pneumonia.

BACKGROUND: The selection of initial empirical antibiotics is an important issue in the treatment of severe community-acquired pneumonia (CAP). This study aimed to investigate whether empirical antibiotic prescription concordant with guidelines in the emergency department (ED) affects 30-day mortality in patients with severe CAP. METHODS: We conducted a retrospective analysis of adult patients with severe CAP who were hospitalized in the ED. Severe CAP was defined according to the criteria of the 2007 Infectious Diseases Society of America/American Thoracic Society guidelines. Patients were divided into two groups according to whether they were prescribed empirical antibiotics concordant with guidelines. Multivariable Cox proportional hazard regression analysis was performed to identify the independent association between the prescription of initial empirical antibiotics concordant with the guidelines and 30-day mortality. Propensity score matching was performed to reduce selection bias between groups and Kaplan-Meier survival analysis was performed to analyze the time-to-event of 30-day survival. RESULTS: In total, 630 patients were hospitalized in the ED for severe CAP, and 179 (28.4%) died within 30 days. Antibiotics consistent with guidelines were prescribed to 359 (57.0%) patients. The 30-day mortality was significantly higher in the guideline-discordant group (p = 0.003) and multivariable Cox proportional hazard regression analysis revealed that the prescription of antibiotics discordant with the guidelines was independently associated with 30-day mortality (hazard ratio 1.43, 95% CI 1.05-1.93). After propensity score matching, there were 255 patients in each group. The 30-day mortality was lower in the group prescribed guideline-concordant antibiotics than in the group prescribed guideline-discordant antibiotics (23.9% vs. 33.3%, p = 0.024). Kaplan-Meier survival analysis showed that antibiotic prescription concordant with the guidelines resulted in higher survival rates at 30 days (p = 0.002). CONCLUSIONS: The prevalence of antibiotic prescription consistent with guidelines for severe CAP seemed to be low in the ED, and this variable was independently associated with 30-day survival.

Developing neural network models for early detection of cardiac arrest in emergency department.

BACKGROUND: Automated surveillance for cardiac arrests would be useful in overcrowded emergency departments. The purpose of this study is to develop and test artificial neural network (ANN) classifiers for early detection of patients at risk of cardiac arrest in emergency departments. METHODS: This is a single-center electronic health record (EHR)-based study. The primary outcome was the development of cardiac arrest within 24 h after prediction. Three ANN models were trained: multilayer perceptron (MLP), long-short-term memory (LSTM), and hybrid. These were compared to other classifiers including the modified early warning score (MEWS), logistic regression, and random forest. We used AUROC, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for the comparison. RESULTS: During the study period, there were a total of 374,605 ED visits and 2,910,321 patient status updates. The ANN models (MLP, LSTM, and hybrid) achieved higher AUROC (AUROC: 0.929, 0.933, and 0.936; 95% confidential interval: 0.926-0.932, 0.930-0.936, and 0.933-0.939, respectively) compared to the non-ANN models, and the hybrid model exhibited the best performance. The ANN classifiers displayed higher performance in most of the test characteristics when the threshold levels of the classifiers were fixed to display the same positive result as those at the three MEWS thresholds (score ≥ 3, ≥4, and ≥5), and when compared with each other. CONCLUSIONS: The ANN improves upon MEWS and conventional machine learning algorithms for the prediction of cardiac arrests in emergency departments. The hybrid ANN model utilizing both baseline and sequence information achieved the best performance.

Moderate to severe hyperphosphataemia as an independent prognostic factor for 28-day mortality in adult patients with sepsis.

BACKGROUND: Ischaemic tissue injury caused by tissue hypoperfusion is one of the major consequences of sepsis. Phosphate concentrations are elevated in ischaemic tissue injury. This study was performed to investigate the association of phosphate concentrations with mortality in patients with sepsis. METHODS: This was a retrospective cohort study of patients with sepsis conducted at an urban, tertiary care emergency department (ED) in Korea. Patients with sepsis arriving between March 2010 and April 2017 were stratified into four groups according to the initial phosphate concentration at presentation to the ED: group I (hypophosphataemia, phosphate <2 mg/dL), group II (normophosphataemia, phosphate 2-4 mg/dL), group III (mild hyperphosphataemia, phosphate 4-6 mg/dL), group IV (moderate to severe hyperphosphataemia, phosphate ≥6 mg/dL). Multivariable Cox proportional hazard regression analyses were performed to evaluate the independent association of initial phosphate concentration with 28-day mortality. RESULTS: Of the 3034 participants in the study, the overall mortality rate was 21.9%. The 28-day mortality rates were group I (hypophosphataemia) 14.6%, group II 17.4% (normophosphataemia), group III (mild hyperphosphataemia) 29.2% and group IV (moderate to severe hyperphosphataemia) 51.4%, respectively (p<0.001). In the multivariable analyses, patients with severe hyperphosphataemia had a significantly higher risk of death than those with normal phosphate levels (HR 1.59; 95% CI 1.23 to 2.05). Mortality in the other groups was not significantly different from mortality in patients with normophosphataemia. CONCLUSIONS: Moderate to severe hyperphosphataemia was associated with 28-day mortality in patients with sepsis. Phosphate level could be used as a prognostic indicator in sepsis.

Prolonged stay in the emergency department is an independent risk factor for hospital-acquired pressure ulcer.

It is not easy to ensure optimal prevention of hospital-acquired pressure ulcer (HAPU) in crowded emergency departments (EDs). We hypothesised that a prolonged ED length of stay (LOS) is associated with an increased risk of HAPU. This is a single-centre observational study. Prospectively collected HAPU surveillance data were analysed. Adult (aged ≥20 years) patients admitted through the ED from April 1, 2013 to December 31, 2016 were included. The primary outcome was the development of HAPU within a month. Covariates included demographics, comorbidities, conditions at triage, initial laboratory results, primary ED diagnosis, critical ED interventions, and ED dispositions. The association between ED LOS and HAPU was modelled using logistic and extended Cox regression. A total of 48 641 admissions were analysed. The crude odds ratio (OR) and hazard ratio (HR) for HAPU were increased to 1.44 (95% CI, 1.20-1.72) and 1.21 (95% CI, 1.02-1.45), respectively, in ED LOS ≥24 hours relative to ED LOS <6 hours. In multivariable logistic regression, ED LOS ≥12 and ≥24 hours were associated with higher risk of HAPU, with ORs of 1.30 (95% CI, 1.05-1.60) and 1.80 (95% CI, 1.45-2.23) relative to ED LOS <6 hours, respectively. The extended Cox regression showed that the risk lasted up to a week, with HRs of 1.42 (95% CI, 1.07-1.88) and 1.92 (95% CI, 1.44-2.57) relative to ED LOS <6 hours, respectively. In conclusion, Prolonged ED LOS is independently associated with HAPU. Shorter ED LOS should be pursued as a goal in a multifaceted solution for HAPU.

Characterization of Fecal Peritonitis-Induced Sepsis in a Porcine Model.

BACKGROUND: Although there are well-established small-animal sepsis models, the longitudinal assessment of hemodynamic variables, laboratory values, and blood culture in a single living sepsis model is limited. Therefore, we aimed to comprehensively characterize fecal peritonitis-induced sepsis in a porcine model. MATERIALS AND METHODS: Autologous feces (1 g/kg) was administered into the peritoneum of 11 male pigs (49 ± 8 kg). The pigs were monitored up to 12 h with full fluid and vasopressor support to maintain the mean arterial pressure at >65 mm Hg. Longitudinal blood culture and laboratory values were obtained at defined time intervals. The cytokine levels in plasma were analyzed. Furthermore, a clinical registry of sepsis patients at a single emergency department was used to compare the Sepsis-related Organ Failure Assessment scores with those of the porcine model. RESULTS: The hyperdynamic phase of increasing cardiac output with decreasing systemic vascular resistance was maintained until 2 h, followed by the reverse (hypodynamic phase). With the escalating requirement for fluid and vasopressor, the lactate level progressively increased while the platelet count, urine output, and serum albumin level consistently decreased. Bacteremia developed 7 h (median) after the administration of feces, and Escherichia coli was the most common pathogen. The pattern of Sepsis-related Organ Failure Assessment scores with prominent cardiovascular failure was comparable to clinical data. CONCLUSIONS: We implemented a porcine fecal peritonitis-induced sepsis model that demonstrates culture-proven bacteremia and multiple organ failure, particularly cardiovascular system failure. This model could facilitate the development of technologies for the early diagnosis of bacterial pathogens in blood.

The Magnitude of Change in Serum Phosphate Concentration Is Associated with Mortality in Patients with Severe Trauma.

PURPOSE: Previous studies have suggested that serum phosphate concentration is a prognostic factor in critically ill patients. However, the association between changes in serum phosphate levels and prognosis of patients with trauma remains unclear. MATERIALS AND METHODS: This study included patients with severe trauma who were treated at the emergency department. Delta phosphate (Δ phosphate) was defined as the difference between serum phosphate concentrations measured at baseline and after 24 hours from the initial measurement. Patients were divided into five groups according to their Δ phosphate levels: group I (Δ phosphate <-2 mg/dL), group II (Δ phosphate -2 to -0.5 mg/dL), group III (Δ phosphate -0.5 to 0.5 mg/dL), group IV (Δ phosphate 0.5 to 2 mg/dL), and group V (Δ phosphate ≥2 mg/dL). RESULTS: Overall, 1905 patients with severe trauma were included in the analysis. The 30-day mortality was the lowest in group III and tended to increase in groups with a larger Δ phosphate in both the positive and negative directions (group I: 13.7%, group II: 6.8%, group III: 4.6%, group IV: 6.6%, and group V: 26.8%). In multivariable analysis with group III as the reference group, the odds ratios (ORs) of mortality were statistically significant in group IV [OR, 1.92; 95% confidence interval (CI), 1.05-3.56] and group V (OR, 5.28; 95% CI, 2.47-11.24). CONCLUSION: An increase in serum phosphate concentrations 24 hours after the initial measurement could be considered as an independent prognostic factor in patients with severe trauma.

Machine learning-based prediction of cerebral oxygen saturation based on multi-modal cerebral oximetry data.

This study develops machine learning-based algorithms that facilitate accurate prediction of cerebral oxygen saturation using waveform data in the near-infrared range from a multi-modal oxygen saturation sensor. Data were obtained from 150,000 observations of a popular cerebral oximeter, Masimo O3™ regional oximetry (Co., United States) and a multi-modal cerebral oximeter, Votem (Inc., Korea). Among these observations, 112,500 (75%) and 37,500 (25%) were used for training and test sets, respectively. The dependent variable was the cerebral oxygen saturation value from the Masimo O3™ (0-100%). The independent variables were the time of measurement (0-300,000 ms) and the 16-bit decimal amplitudes values (infrared and red) from Votem (0-65,535). For the right part of the forehead, the root mean square error of the random forest (0.06) was much smaller than those of linear regression (1.22) and the artificial neural network with one, two or three hidden layers (2.58). The result was similar for the left part of forehead, that is, random forest (0.05) vs logistic regression (1.22) and the artificial neural network with one, two or three hidden layers (2.97). Machine learning aids in accurately predicting of cerebral oxygen saturation, employing the data from a multi-modal cerebral oximeter.

Kidney, ureter, and urinary bladder segmentation based on non-contrast enhanced computed tomography images using modified U-Net.

This study was performed to segment the urinary system as the basis for diagnosing urinary system diseases on non-contrast computed tomography (CT). This study was conducted with images obtained between January 2016 and December 2020. During the study period, non-contrast abdominopelvic CT scans of patients and diagnosed and treated with urinary stones at the emergency departments of two institutions were collected. Region of interest extraction was first performed, and urinary system segmentation was performed using a modified U-Net. Thereafter, fivefold cross-validation was performed to evaluate the robustness of the model performance. In fivefold cross-validation results of the segmentation of the urinary system, the average dice coefficient was 0.8673, and the dice coefficients for each class (kidney, ureter, and urinary bladder) were 0.9651, 0.7172, and 0.9196, respectively. In the test dataset, the average dice coefficient of best performing model in fivefold cross validation for whole urinary system was 0.8623, and the dice coefficients for each class (kidney, ureter, and urinary bladder) were 0.9613, 0.7225, and 0.9032, respectively. The segmentation of the urinary system using the modified U-Net proposed in this study could be the basis for the detection of kidney, ureter, and urinary bladder lesions, such as stones and tumours, through machine learning.

Effect of resuscitative endovascular balloon occlusion of the aorta in nontraumatic out-of-hospital cardiac arrest: a multinational, multicenter, randomized, controlled trial.

BACKGROUND: Out-of-hospital cardiac arrest (OHCA) is a significant public health issue worldwide and is associated with low survival rates and poor neurological outcomes. The generation of optimal coronary perfusion pressure (CPP) via high-quality chest compressions is a key factor in enhancing survival rates. However, it is often challenging to provide adequate CPP in real-world cardiopulmonary resuscitation (CPR) scenarios. Based on animal studies and human trials on improving CPP in patients with nontraumatic OHCA, resuscitative endovascular balloon occlusion of the aorta (REBOA) is a promising technique in these cases. This study aims to investigate the benefits of REBOA adjunct to CPR compared with conventional CPR for the clinical management of nontraumatic OHCA. METHODS: This is a parallel-group, randomized, controlled, multinational trial that will be conducted at two urban academic tertiary hospitals in Korea and Taiwan. Patients aged 20-80 years presenting with witnessed OHCA will be enrolled in this study. Eligible participants must fulfill the inclusion criteria, and written informed consent should be collected from their legal representatives. Patients will be randomly assigned to the intervention (REBOA-CPR) or control (conventional CPR) group. The intervention group will receive REBOA and standard advanced cardiovascular life support (ACLS). Meanwhile, the control group will receive ACLS based on the 2020 American Heart Association guidelines. The primary outcome is the return of spontaneous circulation (ROSC). The secondary outcomes include sustained ROSC, survival to admission, survival to discharge, neurological outcome, and hemodynamic changes. DISCUSSION: Our upcoming trial can provide essential evidence regarding the efficacy of REBOA, a mechanical method for enhancing CPP, in OHCA resuscitation. Our study aims to determine whether REBOA can improve treatment strategies for patients with nontraumatic OHCA based on clinical outcomes, thereby potentially providing valuable insights and guiding further advancements in this critical public health area. TRIAL REGISTRATION: ClinicalTrials.gov NCT06031623. Registered on September 9, 2023.

Composition fluctuation of in and well-width fluctuation in InGaN/GaN multiple quantum wells in light-emitting diode devices.

In this paper, we have observed an atomic-scale structure and compositional variation at the interface of the InGaN/GaN multi-quantum wells (MQW) by both scanning transmission electron microscopy (STEM) using high-angle annular dark-field mode and atom probe tomography (APT). The iso-concentration analysis of APT results revealed that the roughness of InGaN/GaN interface increased as the MQW layers were filled up, and that the upper interface of MQW (GaN/InGaN to the p-GaN side) was much rougher than that of the lower interface (InGaN/GaN tot he n-GaN side). On the basis of experimental results, it is suggested that the formation of interface roughness can affect the quantum efficiency of InGaN-based light-emitting diodes.

MONITORING OF PULMONARY EDEMA USING ULTRASOUND RADIOFREQUENCY SIGNAL.

ABSTRACT: Objectives: Excessive accumulation of extravascular lung water impairs respiratory gas exchange and results in respiratory distress. Real-time radiofrequency signals of ultrasound can continuously and quantitatively monitor excessive lung water. This study aims to evaluate the availability of continuous real-time quantitative pulmonary edema monitoring using ultrasound radiofrequency signals and compare it with Pa o2 (partial pressure of arterial oxygen)/F io2 (fraction of inspired oxygen) (PF) ratio, conventional lung ultrasound, and the Hounsfield unit of chest computed tomography. Methods: Male Yorkshire pigs (40.5 ± 0.5 kg) were anesthetized and mechanically ventilated. A balanced crystalloid was administered to induce hydrostatic pulmonary edema. Three different infusion rates of 2, 4, and 6 mL/kg per minute were tested to determine the infusion rate for the appropriate swine model. The chest computed tomography and ultrasonography with radiofrequency signals were taken every 5 min during the full inspiration. The ultrasonography scans with radiofrequency signals were measured at the intercostal space where the line crossing the two armpits and the right anterior axillary line intersected. Results: The infusion rate of fluid for the pulmonary edema model was determined to be 6 mL/kg per minute, and a total of four pigs were tested at an injection rate of 6 mL/kg. The adjusted R2 values of regression analysis between the radiofrequency signal and computer tomography Hounsfield score were 0.990, 0.993, 0.988, and 0.993 (all P values <0.05). All radiofrequency signal changes preceded changes in PF ratio or lung ultrasound changes. The area under the receiver operating characteristic curve of the radiofrequency signal for predicting PF ratio <300 was 0.88 (95% confidence interval, 0.82-0.93). Conclusion: We evaluated ultrasound radiofrequency signals to assess pulmonary edema in a swine model that can worsen gradually and showed that quantitative ultrasound radiofrequency signal analysis could assess pulmonary edema and its progression before PF ratio or lung ultrasound changes.

Lower limb muscle matters in patients with hypoxic brain injury following out-of-hospital cardiac arrest.

BACKGROUND: There are conflicting results regarding the association between body mass index and the prognosis of cardiac arrest patients. We investigated the association of the composition and distribution of muscle and fat with neurologic outcomes at hospital discharge in successfully resuscitated out-of-hospital cardiac arrest (OHCA) patients. METHODS: This prospective, single-centre, observational study involved adult OHCA patients, conducted between April 2019 and June 2021. The ratio of total skeletal muscle, upper limb muscle, lower limb muscle, and total fat to body weight was measured using InBody S10, a bioimpedance analyser, after achieving the return of spontaneous circulation. Restricted cubic spline curves with four knots were used to examine the relationship between total skeletal muscle, upper limb muscle, and lower limb muscle relative to total body weight and neurologic outcome at discharge. Multivariable logistic regression analysis was performed to assess an independent association. RESULTS: A total of 66 patients were enrolled in the study. The proportion of total muscle and lower limb muscle positively correlated with the possibility of having a good neurologic outcome. The proportion of lower limb muscle showed an independent association in the multivariable analysis (adjusted odds ratio, 2.29; 95% confidence interval, 1.06-13.98), and its optimal cut-off value calculated through receiver operating characteristic curve analysis was 23.1%, which can predict a good neurological outcome. CONCLUSIONS: A higher proportion of lower limb muscle to body weight was independently associated with the probability of having a good neurologic outcome in OHCA patients.

Vagus Nerve Stimulation Improves Mitochondrial Dysfunction in Post-cardiac Arrest Syndrome in the Asphyxial Cardiac Arrest Model in Rats.

Cerebral mitochondrial dysfunction during post-cardiac arrest syndrome (PCAS) remains unclear, resulting in a lack of therapeutic options that protect against cerebral ischemia-reperfusion injury. We aimed to assess mitochondrial dysfunction in the hippocampus after cardiac arrest and whether vagus nerve stimulation (VNS) can improve mitochondrial dysfunction and neurological outcomes. In an asphyxial cardiac arrest model, male Sprague-Dawley rats were assigned to the vagus nerve isolation (CA) or VNS (CA + VNS) group. Cardiopulmonary resuscitation was performed 450 s after pulseless electrical activity. After the return of spontaneous circulation (ROSC), left cervical VNS was performed for 3 h in the CA + VNS group. Mitochondrial respiratory function was evaluated using high-resolution respirometry of the hippocampal tissue. The neurologic deficit score (NDS) and overall performance category (OPC) were assessed at 24, 48, and 72 h after resuscitation. The leak respiration and oxidative phosphorylation capacity of complex I (OXPHOS CI) at 6 h after ROSC were significantly higher in the CA + VNS group than in the CA group (p = 0.0308 and 0.0401, respectively). Compared with the trends of NDS and OPC in the CA group, the trends of those in the CA + VNS group were significantly different, thus suggesting a favorable neurological outcome in the CA + VNS group (p = 0.0087 and 0.0064 between times × groups interaction, respectively). VNS ameliorated mitochondrial dysfunction after ROSC and improved neurological outcomes in an asphyxial cardiac arrest rat model.

Resuscitative endovascular occlusion of the aorta (REBOA) as a mechanical method for increasing the coronary perfusion pressure in non-traumatic out-of-hospital cardiac arrest patients.

AIM OF THE STUDY: Resuscitative endovascular balloon occlusion of the aorta (REBOA), originally designed to block blood flow to the distal part of the aorta by placing a balloon in trauma patients, has recently been shown to increase coronary perfusion in cardiac arrest patients. This study evaluated the effect of REBOA on aortic pressure and coronary perfusion pressure (CPP) in non-traumatic out of-hospital cardiac arrest (OHCA) patients. METHODS: Adult OHCA patients with cerebral performance category 1 or 2 prior to cardiac arrest, and without evidence of aortic disease, were enrolled from January to December 2021. Aortic pressure and right atrial pressure were measured before and after balloon occlusion. The CPP was calculated using the measured aortic and right atrial pressures, and the values before and after the balloon occlusion were compared. RESULTS: Fifteen non-traumatic OHCA patients were enrolled in the study. The median call to balloon time was 46.0 (IQR, 38.0-54.5) min. The median CPP before and after balloon occlusion was 13.5 (IQR, 5.8-25.0) and 25.2 (IQR, 12.0-44.6) mmHg, respectively (P = 0.001). The median increase in the estimated CPP after balloon occlusion was 86.7%. CONCLUSIONS: The results of this study suggest that REBOA may increase the CPP during cardiopulmonary resuscitation in patients with non-traumatic OHCA. Additional studies are needed to investigate the effect on clinical outcomes.