Mechanism of delayed encephalopathy after acute carbon monoxide poisoning

Serum glucose/potassium ratio as an indicator of early and delayed outcomes of acute carbon monoxide poisoning

BACKGROUND

Carbon monoxide (CO) poisoning is a major health problem associated with a high rate of severe morbidity and mortality.

AIMS

This study aimed to evaluate the validity of the serum glucose/potassium (Glu/K) ratio as a quick predictor of both early and delayed unfavorable outcomes following acute CO poisoning.

PATIENTS AND METHODS

This prospective cohort study included 136 patients with acute CO poisoning admitted at Tanta Poison Control Center, Egypt, between January 2023 and June 2024. The serum Glu/K ratio was calculated for all patients. The primary outcome was a prediction of mortality. Secondary outcomes were the prediction of delayed neurological sequelae (DNS) within six months after CO exposure, the need for mechanical ventilation, and the need for hyperbaric oxygen. A receiver operating curve analysis was applied to test the performance of the Glu/K ratio in predicting acute CO poisoning outcomes.

RESULTS

The mortality rate was 12.5% of patients with acute CO poisoning. Meanwhile, 14.7% of patients developed DNS. Furthermore, mechanical ventilation was required in 16.9% of patients. An elevated Glu/K ratio was significantly associated with the severity of acute CO poisoning. At a cut-off value of >31.62, the Glu/K ratio demonstrated an AUC of 0.649 for predicting mortality. The Glu/K ratio was employed to predict DNS at a cut-off value of 33.10, with a sensitivity of 60.0%, a specificity of 82.76%, and an AUC of 0.692.

CONCLUSIONS

Early Glu/K ratio may be an effective, reliable, and convenient laboratory predictor of mortality, DNS, and the need for mechanical ventilation in patients with acute CO poisoning.

Edaravone combined with hyperbaric oxygen therapy in delayed encephalopathy after acute carbon monoxide poisoning: A meta-analysis

BACKGROUND

The use of both edaravone (EDA) and hyperbaric oxygen therapy (HBOT) is increasingly prevalent in the treatment of delayed encephalopathy after carbon monoxide poisoning (DEACMP). This meta-analysis aims to evaluate the efficacy of using EDA and HBOT in combination with HBOT alone in the treatment of DEACMP.

METHODS

We searched and included all randomized controlled trials (RCTs) published before November 6, 2023, from 12 Chinese and English databases and clinical trial centers in China and the United States. The main outcome indicator was the total effective rate. The secondary outcome indicators included the Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), National Institutes of Health Stroke Scale (NIHSS), Barthel Index (BI), Hasegawa Dementia Scale (HDS), Fugl-Meyer Assessment (FMA), Superoxide Dismutase (SOD), and Malondialdehyde (MDA). Statistical measures utilized include risk ratios (RR), weighted mean difference (WMD), and 95 % confidence intervals (95 % CI).

RESULTS

Thirty studies involving a combined total of 2075 participants were ultimately incorporated. It was observed that the combination of EDA with HBOT for the treatment of DEACMP demonstrated an improvement in the total effective rate (RR: 1.25; 95 % CI: 1.20-1.31; P < 0.01), MMSE (WMD: 3.67; 95 % CI: 2.59-4.76; P < 0.01), MoCA (WMD: 4.38; 95 % CI: 4.00-4.76; P < 0.01), BI (WMD: 10.94; 95 % CI: 5.23-16.66; P < 0.01), HDS (WMD: 6.80; 95 % CI: 4.05-9.55; P < 0.01), FMA (WMD: 8.91; 95 % CI: 7.22-10.60; P < 0.01), SOD (WMD: 18.45; 95 % CI: 16.93-19.98; P < 0.01); and a reduction in NIHSS (WMD: -4.12; 95 % CI: -4.93 to -3.30; P < 0.01) and MDA (WMD: -3.05; 95 % CI: -3.43 to -2.68; P < 0.01).

CONCLUSION

Low-quality evidence suggests that for DEACMP, compared to using HBOT alone, the combined use of EDA and HBOT may be associated with better cognition and activity of daily living. In the future, conducting more meticulously designed multicenter and large-sample RCTs to substantiate our conclusions is essential.

Analysis of factors associated with the development of delayed encephalopathy following acute carbon monoxide poisoning

In this study, we analyzed the factors influencing the development of delayed encephalopathy in patients with acute carbon monoxide poisoning (ACOP) (DEACMP) following conventional treatment such as hyperbaric oxygen therapy (HBOT). Between January 2012 and January 2022, we retrospectively analyzed 775 patients with ACOP, who were admitted to the Second Department of Rehabilitation Medicine and received HBOT in the Second Hospital of Hebei Medical University. These patients were divided into the non-DEACMP and DEACMP groups based on their follow-up; we then compared the general data, clinical characteristics, admission examination, and treatment between the two groups to identify risk factors for the development of DEACMP. The DEACMP group comprised of 168 cases, while the non-DEACMP group consisted of 607 cases. Univariate analysis showed that there were 20 possible prognostic factors in the non-DEACMP and DEACMP groups. The results of multivariable regression analyses suggested that the occurrence of DEACMP was significantly correlated with advanced age, the combination of multiple medical histories, the duration of CO exposure, the duration of coma, poisoning degree, the Interval between ACOP and the first HBOT, the total number of HBOTs, and the combination with rehabilitation treatment. DEACMP patients who are older, have more comorbidities, prolonged CO exposure, prolonged coma, severe intoxication, long intervals between ACOP and the first HBOT, fewer HBOT treatments, and who are not treated with a combination of rehabilitative therapies have a poor prognosis.

Delayed encephalopathy after acute carbon monoxide poisoning: a case study

Delayed encephalopathy after acute carbon monoxide poisoning (DEACMP) is a relatively rare inflammatory-associated neurometabolic complication. In this article, we present a case report of a 50-year-old male patient with a history of carbon monoxide poisoning. This acute poisoning, although successfully controlled during a stay in the intensive care unit of a local hospital, later led to persistent neurological symptoms. The patient was then treated in the inpatient unit of the rehabilitation clinic, where cognitive deterioration began to develop 20 days after admission. Subsequent examination using EEG and magnetic resonance imaging confirmed severe encephalopathy later complicated by SARS-CoV-2 infection with fatal consequences due to bronchopneumonia. Because currently there are no approved guidelines for the management of DEACMP, we briefly discuss the existing challenges for future studies, especially the application of rational immunosuppressive therapy already in the acute treatment phase of CO poisoning, which could prevent the development of a severe form of DEACMP.

Sodium butyrate exerts a neuroprotective effect in rats with acute carbon monoxide poisoning by activating autophagy through the mTOR signaling pathway

Acute carbon monoxide (CO) poisoning is a prevalent type of poisoning that causes significant harm globally. Delayed encephalopathy after acute carbon monoxide poisoning (DEACMP) is a severe complication that occurs after acute CO poisoning; however, the exact underlying pathological cause of DEACMP remains unclear. Accumulating evidence indicates that abnormal inflammation and immune-mediated brain damage, cellular apoptosis and autophagy, and direct neuronal toxicity are involved in the development of delayed neurologic sequelae. Sodium butyrate, a histone deacetylase inhibitor, has gained increasing attention for its numerous beneficial effects on various diseases, such as obesity, diabetes, inflammatory diseases, and cerebral damage. In this study, an acute carbon monoxide poisoning (ACOP) model is established in rats to investigate the mechanism of CO poisoning and the therapeutic potential of sodium butyrate. The results suggested that the ACOP rats had impaired spatial memory, and cell apoptosis was observed in the hippocampi with activated autophagy. Sodium butyrate treatment further increased the activation of autophagy in the hippocampi of CO-exposed rats, inhibited apoptosis, and consolidated spatial memory. These findings indicated that sodium butyrate may improve memory and cognitive function in ACMP rats by promoting autophagy and inhibiting apoptosis.

Targeting Ferroptosis Promotes Functional Recovery by Mitigating White Matter Injury Following Acute Carbon Monoxide Poisoning

Survivors experiencing acute carbon monoxide poisoning (ACMP) tend to develop white matter injury (WMI). The mechanism of ACMP-induced WMI remains unclear. Considering the role of ferroptosis in initiating oligodendrocyte damage to deteriorate WMI, exploring therapeutic options to attenuate ferroptosis is a feasible approach to alleviating WMI. Our results indicated that ACMP induced accumulation of iron and reactive oxygen species (ROS) eventually leading to WMI and motor impairment after ACMP. Furthermore, ferrostatin-1 reduced iron and ROS deposition to alleviate ferroptosis, thereafter reducing WMI to promote the recovery of motor function. The nuclear factor erythroid-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathway was found to be involved in alleviating ferroptosis as seen with the administration of ferrostatin-1. The present study rationalizes that targeting ferroptosis to alleviate WMI is a feasible therapeutic strategy for managing ACMP.

Serum neurofilament light chain for predicting delayed neurological sequelae after acute carbon monoxide poisoning

INTRODUCTION

Acute carbon monoxide (CO) poisoning survivors may experience persistent delayed neurological sequelae (DNS). No studies have investigated the serum neurofilament light chain (NFL) as a prognostic biomarker in acute CO poisoning. This study aimed to determine the serum NFL levels to predict the DNS after acute CO poisoning.

METHODS

Patients with acute CO poisoning who were consecutively admitted from October 2020 to September 2022 were included. The predictive performance of NFLs for the DNS was assessed through the analyses of the correlation, the logistic regression, and the receiver operating characteristic (ROC) curve.

RESULTS

Overall, 9.7% (15/155) of the patients had DNS. The serum NFLs in patients with DNS was 113.7 pg/mL, which is significantly higher than that in the non-DNS group (25.8 pg/mL; P < 0.001). Correlation analysis shows that the serum NFLs are positively correlated with DNS (r = 0.567, P < 0.001). After multiple adjustments, the serum NFLs are independently correlated with DNS [adjusted odds ratio 1.032; 95% confidence interval (CI) 1.001, 1.064; p = 0.043]. The ROC curve indicates an area under the curve (AUC) of 0.923 (95% CI 0.869, 0.960), with a sensitivity of 100% and a specificity of 84.3% at the best cutoff value of 73.4 pg/mL. Pairwise comparison shows that the AUC of the NFL is significantly higher than that of the neuron specific enolase (AUC = 0.779) using the Hanley and McNeil test (Z = 2.283, p = 0.022).

CONCLUSION

Serum NFL could be a biomarker of the DNS after acute CO poisoning.

A patient with toxic encephalopathy associated with acute carbon monoxide poisoning–A clinical case

Carbon monoxide (CO) is a colorless, odorless, and lacking in irritative properties gas. It has a higher affinity towards hemoglobin than oxygen and thus the complex carboxyhemoglobin develops. Acute CO poisoning leads to poly-organic insufficiency and the organs that suffer the most are the ones with higher oxygen needs- the brain, the heart and the kidneys. We present a clinical case of 49-year-old woman with a sudden appearance of complaints of dizziness, stiffness throughout the entire body, inability to move. Subsequently she was found by her relatives with disorientated and “foaming around her mouth”. Earlier she had been using a gasoline generator because of a power outage. Her laboratory results came out with higher carboxyhemoglobin (40%), nitrogen waste products and mixed type acidosis. From the conducted brain MRI there were changes, correlating to toxic encephalopathy after acute CO poisoning.

Early gray matter atrophy and neurological deficits in patients with carbon monoxide poisoning

PURPOSE

To investigate early neurological deficits-related change patterns in gray matter (GM) volume in patients with carbon monoxide poisoning (COP) and GM volume differences between patients with and without delayed neurological sequelae (DNS) and those with and without T2 hyperintense lesions after COP.

METHODS

Forty-one COP patients (24 patients with DNS) and 36 sex- and age-matched healthy controls (HC) were enrolled in this study. The neurological assessments were administered within 24 h after MRI scans. Voxel-based morphometry analysis was used to detect regional GM volume change.

RESULTS

The COP group had statistically significant GM atrophy in the bilateral prefrontal and temporal lobes, anterior cingulate (ACC), thalamus, posterior cerebellum, and right hippocampus compared to the HC group. Atrophy in the left medial orbital superior frontal gyrus (SFG), bilateral ACC, and bilateral thalamus were related to lower Mini-Mental State Examination (MMSE) scores and higher Unified Parkinson's Disease Rating Scale subsection III and neuro-psychiatric inventory scores. Atrophy in the hippocampus and posterior cerebellum were also related to decrease MMSE scores. The DNS subgroup had greater GM atrophy in the limbic system than the non-DNS subgroup. Compared to the subgroup without T2 hyperintense lesions, greater GM atrophy in the limbic system, motor and visual cortex, and default network was observed in the subgroup with T2 hyperintense lesions.

CONCLUSION

GM atrophy in the medial orbital SFG, ACC, thalamus, hippocampus, and posterior cerebellum is associated with early neurological deficits in patients with COP. Greater atrophy occurred in patients with DNS and those with T2 hyperintense lesions.

LncRNA CRNDE binds hnRNPA1 to facilitate carbon monoxide poisoning-induced delayed encephalopathy via inhibiting UCHL5-mediated SMO deubiquitination

Delayed encephalopathy after acute carbon monoxide poisoning (DEACMP) is one of the most common complications following carbon monoxide intoxication. Long noncoding RNAs (lncRNAs) exert critical functions in numerous neurological disorders. We intended to investigate the role of CRNDE in DEACMP. The DEACMP model in rats and the oxygen-glucose deprivation/reoxygenation (OGD/R) model in PC-12 cells were established. Brain and cell injuries were assessed with H&E staining, Nissl staining, TUNEL and CCK8 assays, respectively. Related proteins and RNAs were quantified with western blot and qRT-PCR. The N6-methyladenosine (m6A) level was determined using MeRIP-qPCR and immunofluorescence. Loss and gain function studies were performed to investigate the biological function of CRNDE. The potential mechanisms between each factor were explored using RNA immunoprecipitation, RNA-pull down and co-immunoprecipitation. CRNDE was increased in the hippocampal tissues of DEACMP rats and in OGD/R-treated PC-12 cells, which was positively correlated to m6A modification. Knockdown of CRNDE reduced cell damage and elevated UCHL5 and SMO expressions in OGD/R-treated PC-12 cells. hnRNPA1 was upregulated in DEACMP. In addition, inhibiting hnRNPA1 prevented apoptosis in PC-12 cells subjected to OGD/R. hnRNPA1 bound to CRNDE and remained in the nucleus, which inhibited UCHL5 expression through the formation of CRNDE-hnRNPA1-mRNA complex. UCHL5 could inhibit SMO ubiquitination and suppress PC-12 cell apoptosis during OGD/R. CRNDE silencing blocked brain injury in DEACMP, while knocking down UCHL5 reversed these effects. CRNDE interacted with hnRNPA1 to facilitate DEACMP via inhibition of UCHL5-mediated SMO deubiquitination. CRNDE might be a latent therapeutic target for treating DEACMP.

Investigation of the relationship between MBP gene polymorphisms and delayed encephalopathy after acute carbon monoxide poisoning

Increasing evidence reveals that delayed encephalopathy after acute carbon monoxide poisoning (DEACMP) results from the combined effects of environmental and genetic factors. The main pathological feature of DEACMP was generalized demyelination of cerebral white matter. Myelin basic protein (MBP) levels in cerebrospinal fluid (CSF) and serum samples from DEACMP patients were elevated. This study investigated the association of MBP single nucleotide polymorphisms(SNPs) (rs470555, rs470724, rs4890785, rs595997, rs76452994, and rs921336) with DEACMP. We genotyped 416 DEACMP patients and 785 age, educational level, and sex-matched ACMP patients for rs470555, rs470724, rs4890785, rs595997, rs76452994, and rs921336 SNPs using the Agena MassArray. There were no significant differences in the allele frequency distribution, four genetic models, and genotype distributions between the DEACMP and ACMP groups for rs470555, rs470724, rs4890785, and rs595997. However, significant differences were observed for rs76452994 and rs921336. This study revealed that the MBP polymorphisms, rs470555, rs470724, rs4890785, and rs595997, were not associated with DEACMP. Based on the codominant, dominant, and overdominant genetic inheritability patterns, the MBP rs76452994 and rs921366 polymorphisms were associated with DEACMP. Furthermore, the G allele of rs76452994 and T allele of rs921336 could lead to higher DEACMP risk.

Correlation Between Rats Hippocampal ATP Content and Delayed Encephalopathy After Acute Carbon Monoxide Poisoning

OBJECTIVE

To study the correlation between the adenosine triphosphate (ATP) content in the hippocampus of rats and delayed encephalopathy after acute carbon monoxide (CO) poisoning.

METHODS

A total of 40 male Wistar rats weighing 180-230g, in accordance with the random number table, were selected and divided into the delayed encephalopathy after acute carbon monoxide poisoning (DEACMP: Rats with cognitive impairment after carbon monoxide poisoning) group (n = 32) and the control group (n = 8). A DEACMP rat model was generated by inhalation of CO. The Morris water maze evaluated the ability to learn and memorize in rats. The changes in neurons in the hippocampus of the rats were observed by hematoxylin-eosin (HE) staining. Lastly, the ATP content in the hippocampus of the rats was measured by high-performance liquid chromatography (HPLC).

RESULTS

The ATP content of the experimental group was significantly higher than that of the control group in the hippocampus of the rat model, so the difference was statistically significant (P < 0.05); the intra-group comparison was made for the ATP content in the experimental group, and the difference was statistically significant as group 21d > group 14d > group 7d (P < 0.05); and no significant difference was found between group 21d and group 28d (P > 0.05).

CONCLUSION

The changes in the ATP content in the hippocampus of the rats are correlated with the occurrence of delayed encephalopathy after acute carbon monoxide poisoning; it may take part in the pathogenesis of DEACMP. This offers some elicitation to the prevention and treatment of the disease.

Prognostic factors of hyperbaric oxygen therapy for patients with delayed encephalopathy after acute carbon monoxide poisoning

Delayed encephalopathy after acute carbon monoxide poisoning (DEACMP) is a disease with an incomplete pathological mechanism, long treatment time, and uncertain factors affecting the therapeutic effect. This study explored prognostic factors for DEACMP patients treated with hyperbaric oxygen therapy (HBOT) in 15 hospitals in China. The findings might provide a theoretical basis for further improving the prognosis of DEACMP patients. In this study, data from 330 patients with DEACMP who were admitted to HBOT centers of 15 hospitals in Hunan Province (China) from June 2015 to June 2020 were retrospectively analyzed, and their medical records related to disease prognosis were collected and followed up by telephone. Univariate and multivariate analyses were used to identify independent risk factors for the prognosis of DEACMP patients after HBOT. Univariate analysis revealed 11 possible prognostic factors. Consistent with univariate analysis, multivariate analysis found that underlying diseases (Odds radio(OR) = 2.886, P = 0.048), hypermyotonia (OR = 5.2558, P = 0.008), and HBOT pressure no less Than 2.3 atm absolute (ATA) ((OR = 7.812, P = 0.004) were identified as independent prognostic factors among 20 variables for poor prognosis of DEACMP patients treated with HBOT in the study. This multicenter retrospective analysis revealed that the adverse prognostic markers for DEACMP patients treated with HBOT might be underlying diseases, hypermyotonia, and an HBOT pressure of 2.3 ATA or higher.

Methemoglobinemia and Delayed Encephalopathy After 5-Bromo-2-Nitropyridine Poisoning: A Rare Case Report

5-bromo-2-nitropyridine, an intermediate in the synthesis of pharmaceutical and pesticide products, is toxic to the human body. However, 5-bromo-2-nitropyridine poisoning has not been previously reported. Here, we report the case of a 40-year-old man who suffered skin and respiratory tract exposure to leaked 5-Bromo-2-nitropyridine at work. After exposure, the patient rapidly developed dizziness, fatigue, nausea, vomiting, chest distress, diffuse cyanosis, and coma. Methemoglobinemia, hemolytic anemia, rhabdomyolysis, and acute renal failure were observed after admission. He improved markedly after treatment, but delayed encephalopathy was confirmed 82 days after the exposure. This case highlights that 5-bromo-2-nitropyridine can be absorbed through the skin and respiratory tract, resulting in methemoglobinemia and delayed encephalopathy.

Carbon Monoxide Poisoning was Associated With Lifetime Suicidal Ideation: Evidence From A Population-Based Cross-Sectional Study in Hebei Province, China

Objectives: We want to test the association between carbon monoxide poisoning (CMP) experiencing and lifetime suicidal ideation/suicide plan among community residents.

Methods: This is a population-based cross-sectional study conducted among community residents in Hebei province, China. We analyzed a total of 21,376 valid questionnaires. CMP experience and lifetime suicidal ideation/suicide plan were assessed in this study. Logistic regression and false discovery rate correction were conducted to analyze the associations and correct the p values.

Results: We found that CMP (OR = 2.56, p &lt; 0.001, corrected-p = 0.001) was associated with lifetime suicidal ideation, and the other risk factors were female (OR = 0.53, p &lt; 0.001, corrected-p = 0.001). The association between CMP and suicide plan was not supported after false discovery rate correction (OR = 2.15, p = 0.035, corrected-p = 0.385). For the CMP patients, experiencing ≥2 times CMP (OR = 2.76, p = 0.001, corrected-p = 0.011) was also in higher risk of lifetime suicidal ideation. The association between CMP times and lifetime suicidal plan was not supported after false discovery rate correction (OR = 4.95, p = 0.021, corrected-p = 0.231).

Conclusion: CMP patients are in higher risk of lifetime suicidal ideation. For CMP patients, some strategies are needed to control their suicidal ideation.

Therapeutic effect and molecular mechanism of Salvia Miltiorrhiza on rats with acute brain injury after carbon monoxide poisoning based on the strategy of internet pharmacology

The pathogenesis of brain injury caused by carbon monoxide poisoning (COP) is very complex, and there is no exact and reliable treatment in clinic. In the present study, we screened the therapeutic target and related signal pathway of Salvia Miltiorrhiza for acute COP brain injury, and clarified the pharmacological mechanism of multicomponent, multitarget, and multisignal pathway in Salvia Miltiorrhiza by network pharmacology. To further verify the therapeutic effect of Salvia Miltiorrhiza on acute brain injury based on the results of network analysis, a total of 216 male healthy Sprague Dawley rats were collected in the present study and randomly assigned to a normal control group, a COP group and a Tanshinone IIA sulfonate treatment group (72 rats in each group). The rat model of acute severe COP was established by the secondary inhalation in a hyperbaric oxygen chamber. We found that Salvia Miltiorrhiza had multiple active components, and played a role in treating acute brain injury induced by COP through multiple targets and multiple pathways, among them, MAPK/ERK1/2 signaling pathway was one of the most important. COP can start apoptosis process, activate the MAPK/ERK1/2 signaling pathway, and promote the expression of VEGF-A protein and the formation of brain edema. Tanshinone IIA can effectively inhibit apoptosis, up-regulate the expressions of VEGF-A, P-MEK1/2 and P-ERK1/2 proteins, thereby protect endothelial cells, promote angiogenesis and microcirculation, and finally alleviate brain edema.

Construction and imaging of a neurovascular unit model

In 2001, the concept of the neurovascular unit was introduced at the Stroke Progress Review Group meeting. The neurovascular unit is an important element of the health and disease status of blood vessels and nerves in the central nervous system. Since then, the neurovascular unit has attracted increasing interest from research teams, who have contributed greatly to the prevention, treatment, and prognosis of stroke and neurodegenerative diseases. However, additional research is needed to establish an efficient, low-cost, and low-energy in vitro model of the neurovascular unit, as well as enable noninvasive observation of neurovascular units in vivo and in vitro. In this review, we first summarize the composition of neurovascular units, then investigate the efficacy of different types of stem cells and cell culture methods in the construction of neurovascular unit models, and finally assess the progress of imaging methods used to observe neurovascular units in recent years and their positive role in the monitoring and investigation of the mechanisms of a variety of central nervous system diseases.

Inhibition of ROCK2 kinase activity improved behavioral deficits and reduced neuron damage in a DEACMP rat model

The main pathological changes that occur in delayed encephalopathy after acute carbon monoxide poisoning (DEACMP) are extensive demyelination of brain white matter and neuron damage. Previous studies suggested that demyelination and neuron injury are related to activating the Rho/ROCK signaling pathway. Inhibition of the Rho/ROCK signaling pathway can alleviate neuron injury and promote myelin repair. This study utilized a DEACMP model in which rats were prepared by space injection of CO gas intraperitoneally (CO group), and the association between the Rho/ROCK signaling pathway and DEACMP was investigated. The ROCK2 kinase inhibitor Y-27632 was used to prevent the effects of the DEACMP model to elucidate its protective mechanism. The results demonstrated that the cognitive and motor functions were significantly impaired, and the GFAP, NSE, RhoA, and ROCK2 protein levels were significantly increased in the CO group within three weeks after the model was established. After Y-27632 intervention, the cognitive and motor functions of the CO+Y-27632 group were significantly improved within three weeks after the model was established. In the CO+Y-27632 group, the RhoA, ROCK2, GFAP, and NSE (indicating neuron injury) protein levels decreased significantly, and the MBP protein levels (indicating myelin repair) increased significantly within three weeks after the model was established. These results suggested that the pathogenesis of DEACMP was associated with activation of the Rho/ROCK pathway and that Y-27632 inhibited ROCK2 kinase activity in the CO exposed rats, resulting in improved behavioral deficits, reduced neuron damage, and promotion of myelin repair. Therefore, Y-27632 might be a potentially effective drug for the treatment of DEACMP-induced brain damage.

Carbon monoxide poisoning-induced encephalopathy in a carbon dioxide arc welder: a case report

Background

It is widely known that carbon dioxide (CO₂) arc welding generates carbon monoxide (CO). However, to the best of our knowledge, no case reports have been published regarding CO poisoning in CO₂ arc welders. Therefore, we aimed to report a case of CO poisoning-induced encephalopathy in a CO₂ arc welder in the Republic of Korea to inform about the dangers of CO exposure among CO₂arc welders.

Case presentation

A 40-year-old man working as a CO₂ arc welder for 15 years visited a local hospital with a tremor, involuntary urination, and speaking gibberish, on April 9, 2019. He stated that he had intermittent headache and forgetting symptoms for the last 5 years, and had been lost on the way to work several times. On April 9, 2019, he was diagnosed with CO poisoning-induced encephalopathy through brain magnetic resonance imaging. He received hyperbaric oxygen therapy, and some of his symptoms improved. According to the exposure assessment of his work environment, he was continuously exposed to high concentrations of CO for 15 years while operating CO₂ arc welding machines.

Conclusions

After evaluating the patient's work environment and evaluating his medical history, we concluded that his encephalopathy was caused by CO exposure during CO₂ arc welding. Thus CO₂ arc welders must be aware of the risk of CO poisoning and strive to avoid CO exposure.

The Effect of Adding Transcranial Direct Current Stimulation to Hyperbaric Oxygen Therapy in Patients With Delayed Encephalopathy After Carbon Monoxide Poisoning: A Randomised Controlled Trial

Objective: To investigate the effect of transcranial direct current stimulation (tDCS) combined with hyperbaric oxygen therapy (HBOT) in patients with delayed encephalopathy after carbon monoxide poisoning (DEACMP).

Design: A parallel-group, open-label randomised controlled study.

Setting: Hyperbaric Oxygen Therapy Room of the Second Hospital of Hebei Medical University.

Subjects: A total of 40 patients were recruited for the current study. Patients were randomly divided into a treatment group and a control group (20 cases/group).

Interventions: Control group: conventional, individualised rehabilitation therapy. Treatment group: conventional, individualised rehabilitation therapy and tDCS.

Main Measures: cognitive function of patients, the Barthel Index (BI).

Results: After treatment, significantly higher MMSE and BI scores, as well as a greater reduction in P300 latency and an increase in P300 amplitude, were observed in the treatment group compared to the control group (MMSE: 13 ± 7 vs. 9 ± 5; P300 latency: 342 ± 29 vs. 363 ± 17 ms; P300 amplitude: 7.0 ± 3.3 vs. 5.1 ± 2.7 μV; all P < 0.05). In both groups, however, MMSE and BI scores, in addition to P300 amplitude, were significantly improved; in contrast, there was a decrease in P300 latency in both groups after treatment compared to before treatment (all P < 0.05).

Conclusion: Combined with HBOT, tDCS can help improve cognitive function and ADL in patients with DEACMP. This combination therapy might be a helpful method to enhance the recovery of patients with DEACMP.

The efficacy of Rhodiola Rosea based on DTI image Segmentation Algorithm for patients with delayed Encephalopathy caused by CO poisoning

Objectives

By using DTI image segmentation algorithm investigate the effect of large plants Rhodiola injection on myocardial injury in patients with acute severe CO poisoning (ACOP), and to explore the clinical and CT delayed encephalopathy after ACOP.

Methods

Seventy-two ACOP patients were randomly divided into control and observation group, 36 cases in each group from December 2015 - December 2017. The control group received hyperbaric oxygen, mannitol, dexamethasone, citicoline injection, gangliosides, dracone; observation group were large strain Rhodiola injection treatment group based on the once daily for two weeks of continuous treatment. The head CT, head MRI results were analyzed retrospectively.

Results

(1) hsCRP and ET-1 in the observation group were significantly lower than those in the control group, and VEGF was significantly higher than that in the control group (P<0.01). No, NOS, and iNOS were significantly lower than those of the control group (P<0.01); (2) CT images of 16 cases showed bilateral symmetrical fusion lesions with blurred edges, low density, and oval center around the ventricle; (3) MRI showed that the lesion was located in the cerebral cortex, white matter lateral ventricle and/or basal ganglia in 12 cases.

Conclusion

Rhodiola can reduce myocardial vascular endothelial cell injury, improve cardiac function, and protect the damaged myocardium. Meanwhile, after acute CO poisoning delayed encephalopathy early for CT and MRI examination facilitate analysis and prognosis of the disease.

Alterations in cerebral and cardiac mitochondrial function in a porcine model of acute carbon monoxide poisoning

OBJECTIVES

The purpose of this study is the development of a porcine model of carbon monoxide (CO) poisoning to investigate alterations in brain and heart mitochondrial function.

DESIGN

Two group large animal model of CO poisoning.

SETTING

Laboratory.

SUBJECTS

Ten swine were divided into two groups: Control (n = 4) and CO (n = 6).

INTERVENTIONS

Administration of a low dose of CO at 200 ppm to the CO group over 90 min followed by 30 min of re-oxygenation at room air. The Control group received room air for 120 min.

MEASUREMENTS

Non-invasive optical monitoring was used to measure cerebral blood flow and oxygenation. Cerebral microdialysis was performed to obtain semi real time measurements of cerebral metabolic status. At the end of the exposure, both fresh brain (cortical and hippocampal tissue) and heart (apical tissue) were immediately harvested to measure mitochondrial respiration and reactive oxygen species (ROS) generation and blood was collected to assess plasma cytokine concentrations.

MAIN RESULTS

Animals in the CO group showed significantly decreased Complex IV-linked mitochondrial respiration in hippocampal and apical heart tissue but not cortical tissue. There also was a significant increase in mitochondrial ROS generation across all measured tissue types. The CO group showed a significantly higher cerebral lactate-to-pyruvate ratio. Both IL-8 and TNFα were significantly increased in the CO group compared with the Control group obtained from plasma. While not significant there was a trend to an increase in optically measured cerebral blood flow and hemoglobin concentration in the CO group.

CONCLUSIONS

Low-dose CO poisoning is associated with early mitochondrial disruption prior to an observable phenotype highlighting the important role of mitochondrial function in the pathology of CO poisoning. This may represent an important intervenable pathway for therapy and intervention.