Delayed Neuropsychiatric Sequelae Research Articles

Development of a risk prediction nomogram for delayed neuropsychiatric sequelae in patients with acute carbon monoxide poisoning

Objectives Delayed neuropsychiatric sequelae (DNS) are critical complications following acute carbon monoxide (CO) poisoning that can substantially affect the patient’s life. Identifying high-risk patients for developing DNS may improve the quality of follow-up care. To date, the predictive DNS determinants are still controversial. Consequently, this study aimed to construct a practical nomogram for predicting DNS in acute CO-poisoned patients. Methods This retrospective study was conducted on patients with acute CO poisoning admitted to the Tanta University Poison Control Center (TUPCC) from December 2018 to December 2022. Demographic, toxicological, and initial clinical characteristics data, as well as laboratory investigation results, were recorded for the included patients. After acute recovery, patients were followed up for six months and categorized into patients with and without DNS. Results Out of 174 enrolled patients, 38 (21.8%) developed DNS. The initial Glasgow Coma Scale (GCS), carboxyhemoglobin (COHb) level, CO exposure duration, oxygen saturation, PaCO2, and pulse rate were significantly associated with DNS development by univariate analysis. However, the constructed nomogram based on the multivariable regression analysis included three parameters: duration of CO exposure, COHb level, and GCS with adjusted odd ratios of 1.453 (95% CI: 1.116–1.892), 1.262 (95% CI: 1.126–1.415), and 0.619 (95% CI: 0.486–0.787), respectively. The internal validation of the nomogram exhibited excellent discrimination (area under the curve [AUC] = 0.962), good calibration, and satisfactory decision curve analysis for predicting the DNS probability. Conclusions The proposed nomogram could be considered a simple, precise, and applicable tool to predict DNS development in acute CO-poisoned patients.

Association between serum neuron-specific enolase at admission and the risk of delayed neuropsychiatric sequelae in adults with carbon monoxide poisoning: A meta-analysis.

Delayed neuropsychiatric sequelae (DNS) significantly impact the quality of life in patients following acute carbon monoxide poisoning (COP). This systematic review and meta-analysis aimed to assess the relationship between serum neuron-specific enolase (NSE) levels at admission and the risk of DNS in adults after acute COP. Relevant observational studies with longitudinal follow-up were identified through searches in PubMed, Embase, Web of Science, Wanfang, and China National Knowledge Infrastructure databases. The random-effects model was used to aggregate results, accounting for potential heterogeneity. Nine cohort studies, including 1501 patients, were analyzed, with 254 (16.9%) developing DNS during follow-up. The pooled data indicated that elevated serum NSE in the early phase was linked to a higher risk of subsequent DNS (odds ratio per 1 ng/mL increase in NSE: 1.10, 95% confidence interval: 1.06 to 1.15, P < 0.001). Moderate heterogeneity (I2 = 46%) among the studies was entirely attributed to one study with the longest follow-up duration (22.3 months; I2 = 0% after excluding this study). Subgroup analyses based on country, study design, sample size, age, sex, admission carboxyhemoglobin levels, DNS incidence, follow-up duration, and quality score yielded consistent results (P for subgroup differences all > 0.05). In summary, high serum NSE levels in the early phase of acute COP are associated with an increased risk of developing DNS during follow-up.

Demographics and clinical characteristics of carbon monoxide poisoning for patients attending in the emergency department at a tertiary hospital in Riyadh, Saudi Arabia

BackgroundCarbon Monoxide (CO) is one of the most common environmental causes of acute intoxication globally. It can lead to the development of Delayed Neuropsychiatric Sequelae (DNS) which may develop in 2-40 days after remission of acute CO poisoning. DNS is defined by recurrent-transient neurological, cognitive, or psychological manifestations. This study was intended to describe the demographics and characteristics of CO poisoning patients attending at the Emergency Department (ED) and assess the association between CO intoxication and the development of DNS in a tertiary hospital, Riyadh, Saudi Arabia.MethodsA retrospective descriptive cross-sectional study was conducted in subjects who were diagnosed with CO poisoning and attended to the ED at King Abdulaziz Medical City (KAMC) and King Abdullah Specialist Children’s Hospital (KASCH) in Riyadh during the period from January 2016 to December 2021. Patient demographics, vitals, diagnostic tests, and oxygen therapy at initial presentation were documented. Patient medical records were reviewed at 2-40 days following CO poisoning for development of DNS. Ethical approval was obtained from King Abdullah International Medical Research Center (KAIMRC).ResultsA total of 85 patients were diagnosed with CO poisoning and met the study inclusion criteria. Of those, 76% were adults with an average age of 32.36 (SD ± 15.20) and 51% were male adults. Five (6%) of the 85 patients developed DNS. Common symptoms included dizziness, nausea, and decreased visual acuity in 40% of the cases. The development of DNS manifestations was most likely (80%) to occur at 2 to 10 days after the initial incident. Inferential statistics showed that BMI (p-value = 0.021) and age group (p-value = 0.029) were significantly associated with COHb level, which was not the case for gender and the presence of clinical manifestation. Furthermore, Gender was significantly associated with the development of DNS (20% male vs. 80% female, p = 0.050).ConclusionsThe findings of this study are consistent with previous published studies showing low proportions of patients who were exposed to CO poisoning at risk of developing DNS. Further larger-scale multicenter studies are needed to assess the factors associated with the development of DNS for patients with CO poisoning.

Patterns of carbon monoxide poisoning and its association with delayed neuropsychiatric sequela at a tertiary hospital in Riyadh, Saudi Arabia.

Background: Carbon Monoxide (CO) is one of the most common environmental causes of acute intoxication globally. It occurs due to impaired tissue oxygenation which has a detrimental impact on systems with high oxygen demands such as cardiovascular and neurological systems. It can lead to Delayed Neuropsychiatric Sequelae (DNS) which may develop in 2-40 days after remission of acute CO poisoning. DNS is defined by recurrent-transient neurological, cognitive, or psychological manifestations. This study was intended to explore the development of DNS for patients exposed to CO intoxication in Saudi Arabia. Methods: A retrospective descriptive cross-sectional study was conducted in subjects who were diagnosed with CO poisoning at King Abdulaziz Medical City (KAMC) and King Abdullah Specialist Children&amp;apos;s Hospital (KASCH) in Riyadh during the period from January 2016 to December 2021. Patient demographics, vitals, diagnostic tests, and oxygen therapy at initial presentation were documented. Patient medical records were reviewed at 2-40 days following CO poisoning for development of DNS. The type of developed DNS and the onset time were also documented. Ethical approval was obtained from King Abdullah International Medical Research Center (KAIMARC). Results: A total of 85 patients were diagnosed with CO poisoning and met the study inclusion criteria. Of these, 76% were adults with an average age of 32.36 (SD± 15.20) and 51% were male adults. The majority of the incidents occurred in the winter season (76%), especially in enclosed spaces (84%). 25% of the patients were smokers. Of those 85 patients, only 5 (6%) developed DNS. Common symptoms included dizziness, nausea, and decreased visual acuity in 40% of the cases. The development of DNS manifestations was most likely (80%) to occur at two to ten days after the initial incident. Inferential statistics showed that BMI (p-value = 0.021) and age group (p-value = 0.029) were significantly associated with COHb level, which was not the case for gender and the presence of clinical manifestation. Furthermore, there was no statistically significant association between gender, age, BMI, gender, type of exposure, presence of clinical manifestations, and COHb level with the development of DNS. Only one reported death in this study. Conclusion: The findings of this study showed that few patients who were exposed to CO poisoning have developed DNS. BMI and age group were significantly associated with COHb level. Further larger-scale multicenter studies are needed to assess the factors associated with the development of DNS for patients with CO poisoning.

Multifocal Peripheral Neuropathies, Rhabdomyolysis, and Dermal Change in Carbon Monoxide Intoxication

Carbon monoxide poisoning is common cause of fatal intoxication. When carbon monoxide is absorbed into the blood, it interferes with the oxygen supply to the cells, causing damage to tissues and organs. Delayed neuropsychiatric sequelae (DNS) manifested by cognitive dysfunction, motor disorder, micturition disorder are widely known complication of carbon monoxide intoxication. But neuromuscular complication is a rare DNS of carbon monoxide intoxication. We herein report a 42-year-old patient with multifocal neuropathies, rhabdomyolysis, and dermal change due to carbon monoxide intoxication.

Effectiveness of Initial Troponin I and Brain Natriuretic Peptide Levels as Biomarkers for Predicting Delayed Neuropsychiatric Sequelae in Patients with CO Poisoning: A Retrospective Multicenter Observational Study.

Delayed neuropsychiatric sequelae (DNS) are a severe complication of carbon monoxide (CO) poisoning, and predicting DNS is difficult. This study aimed to investigate whether cardiac markers can be used as biomarkers to predict DNS occurrence following acute CO poisoning. This was a retrospective observational study that included patients with acute CO poisoning who visited two emergency medical centers in Korea from January 2008 to December 2020. The primary outcome was whether the occurrence of DNS was associated with laboratory results. Of the 1327 patients with CO poisoning, 967 patients were included. Troponin I and BNP were significantly higher in the DNS group. As a result of multivariate logistic regression analysis, it was found that troponin I, mentality, creatine kinase, brain natriuretic peptide, and lactate levels independently influenced DNS occurrence in CO poisoning patients. The adjusted odds ratios for DNS occurrence were 2.12 (95% CI 1.31-3.47, p = 0.002) for troponin I and 2.80 (95% CI 1.81-3.47, p < 0.001) for BNP. Troponin I and BNP might be useful biomarkers for predicting the occurrence of DNS in patients with acute CO poisoning. This finding can help to identify high-risk patients who require close monitoring and early intervention to prevent DNS.

Association between Early Phase Serum Lactate Levels and Occurrence of Delayed Neuropsychiatric Sequelae in Adult Patients with Acute Carbon Monoxide Poisoning: A Systematic Review and Meta-Analysis.

The primary goal of treating carbon monoxide (CO) poisoning is preventing or minimizing the development of delayed neuropsychiatric sequelae (DNS). Therefore, screening patients with a high probability for the occurrence of DNS at the earliest is essential. However, prognostic tools for predicting DNS are insufficient, and the usefulness of the lactate level as a predictor is unclear. This systematic review and meta-analysis investigated the association between early phase serum lactate levels and the occurrence of DNS in adult patients with acute CO poisoning. Observational studies that included adult patients with CO poisoning and reported initial lactate concentrations were retrieved from the Embase, MEDLINE, Google Scholar and six domestic databases (KoreaMED, KMBASE, KISS, NDSL, KISTi and RISS) in January 2022. Lactate values were collected as continuous variables and analyzed using standardized mean differences (SMD) using a random-effect model. The risk of bias was evaluated using the Quality in Prognosis Studies (QUIPS) tool, and subgroup, sensitivity and meta regression analyses were performed. Eight studies involving a total of 1350 patients were included. The early phase serum lactate concentration was significantly higher in the DNS group than in the non-DNS group in adult patients with acute CO poisoning (8 studies; SMD, 0.31; 95% CI, 0.11–0.50; I2 = 44%; p = 0.002). The heterogeneity decreased to I2 = 8% in sensitivity analysis (omitting Han2021; 7 studies; SMD, 0.38; 95% CI, 0.23–0.53; I2 = 8%; p < 0.001). The risk of bias was assessed as high in five studies. The DNS group was associated with significantly higher lactate concentration than that in the non-DNS group.

Potential markers for predicting delayed encephalopathy in patients with acute carbon monoxide poisoning

BackgroundAcute carbon monoxide poisoning (ACOP) commonly results in delayed neuropsychiatric sequelae (DNS). Currently, there are no reliable predictors. The aim of this article is to establish a practical model for predicting the development of delayed encephalopathy clinically. MethodsRetrospective analysis of clinical data were performed at a single institution for the past 6 years. 107 patients with ACOP were recruited, of who 67 developed DNS and 40 did not. Clinical characteristics of the patients were analyzed between the two groups. The risk factors associated with DNS development were screened to identify the potential markers for predicting DNS. A predictive model was then built, and the receiver operating characteristic (ROC) curve analysis was used to assess its predictive ability. ResultsThere were significant differences in 13 clinical features between the two groups. Four potential markers were identified. They were age, source of CO, Glasgow Coma Scale score and the initiation of HBOT. The potential predictive model showed an area under the curve (AUC) of 0.93 in the training set and 0.97 in the testing set. ConclusionsOur model could calculate the probability of DNS after acute CO poisoning.

Real-world effectiveness of hyperbaric oxygen therapy for delayed neuropsychiatric sequelae after carbon monoxide poisoning

To assess real-world effectiveness of hyperbaric oxygen therapy (HBOT) on delayed neuropsychiatric sequelae (DNS) after carbon monoxide (CO) poisoning we conducted a retrospective review of patients with CO poisoning admitted to Linkou Chang-Gung Memorial Hospital, Taiwan’s largest medical center, during 2009–2015. We included patients developing DNS after CO poisoning and compared improvements in neuropsychiatric function, with and without HBOT, after 12 months post-DNS to understand differences in recovery rates. DNS improvement-associated factors were also evaluated. We used receiver operating characteristic (ROC) curve analysis to assess the role of time elapsed between DNS diagnosis and HBOT initiation in predicting DNS improvement. A total of 62 patients developed DNS, of whom 11 recovered while the rest did not. Possible factors predicting DNS improvement included receiving HBOT post-DNS (72.7% vs 25.5%; P = 0.006), and treatment with more than three HBOT sessions during acute stage CO poisoning (81.8% vs 27.5%; P = 0.003). The relevant area under the ROC curve was 0.789 (95% CI 0.603–0.974), and the best cut-off point was 3 days post-DNS diagnosis, with 87.5% sensitivity and 61.5% specificity. Early HBOT in patients who developed DNS after CO poisoning significantly improved their DNS symptoms, with treatment effects sustained for 1 year after DNS diagnosis.

Prediction of delayed neuropsychiatric sequelae after carbon monoxide poisoning via serial determination of serum neuron-specific enolase levels.

Neuron-specific enolase (NSE) is released into serum when nerve cells are damaged, and the levels thereof are used to determine neurological prognosis in patients who have suffered cardiac arrest or stroke. Delayed neuropsychiatric sequelae (DNS), a major complication of carbon monoxide poisoning (COP), can be caused by inflammatory response which is a mechanism of neuronal injury in cardiac arrest and stroke. NSE is known as a predictor of neurological prognosis in ischemic brain injury after cardiac arrest, and it is also reported as a predictor of DNS in acute COP. When serum NSE is measured serially in cardiac arrest patients, the best time to predict neurological prognosis is known at 48-72h, but there are no studies analyzing serial serum NSE in acute COP. Thus, we explored whether serum NSE levels measured three times at 24h intervals after COP predicted the development of DNS. This prospective observational study was conducted on patients treated for COP from May 2018 to April 2020 in a tertiary care hospital in Korea. Neuron-specific enolase levels were assessed 24, 48, and 72h after presentation at hospital. We used logistic regression to explore the association between NSE levels and DNS development. The NSE level was highest at 48h, and the difference between the DNS group and the non-DNS group was greatest on the same time point. On multivariable logistic regression analysis, the NSE level at 48h of >20.98ng/mL (odds ratio [OR], 3.570; 95% confidence interval [CI], 1.412-9.026; P = .007) and the initial Glasgow Coma Scale (GCS) score of <9 (OR, 4.559; 95% CI, 1.658-0.12.540; P = .003) was statistically significant for DNS development. Early identification of those who will experience DNS in acute COP patients is clinically important for deciding treatment. In this study, we revealed that NSE level of >20.98ng/mL at 48h time point can be used as an independent predictor of DNS (OR, 3.570; 95% CI, 1.412-9.026; P = .007; AUC, 0.648).

Effects of smoking on delayed neuropsychiatric sequelae in acute carbon monoxide poisoning: A prospective observational study.

Smoking is a well-known risk factor for cardio-cerebrovascular disease. However, several studies have reported the “smoker's paradox” whereby smokers have a better prognosis for cardio-cerebrovascular diseases. Similar to cardio-cerebrovascular diseases, hypoxia is one of the major mechanisms of injury in carbon monoxide (CO) poisoning. This study investigated the association between smoking and delayed neuropsychiatric sequelae (DNS) in acute CO poisoning.This study involved patients with CO poisoning treated at a university hospital in Bucheon, Korea between September 2017 and March 2020. The exclusion criteria were age <18 years, discharge against medical advice, loss to follow-up, persistent neurological symptoms at discharge, transfer from another hospital 24 hours after exposure, and transfer from another hospital after hyperbaric oxygen therapy. Logistic regression analysis was performed to find factors associated with DNS.Two hundred sixty three patients visited the hospital due to CO poisoning and of these, 54 were excluded. DNS was evaluated up to 3 months after discharge, and until this time, DNS occurred in 35 (16.8%) patients. And the incidence rate of DNS was lower in smokers than non-smokers (15, 12% vs 20, 23.8%, P = .040). Multivariable logistic regression analysis revealed that CO exposure time (odds ratio [OR] 1.003; confidence interval [CI] 1.001–1.005; P = .003), the Glasgow coma scale (GCS) (OR 0.862; CI 0.778–0.956; P = .005), and pack-years (OR 0.947; CI 0.903–0.993; P = .023) were statistically significant for DNS development.These results indicate that more pack-years smoked were associated with reduced risk of the development of DNS in acute CO poisoning, and that CO exposure time and GCS is a predictive factor for DNS occurrence.

Hyperbaric Oxygen Therapy Did Not Prevent Delayed Neuropsychiatric Sequelae in a Prospective Observational Study With Propensity Score Matching in 224 Patients With Acute Carbon Monoxide Toxicity.

It is important to prevent the development of delayed neuropsychiatric sequelae (DNS) in acute carbon monoxide (CO) intoxication, but no effective treatment has been clearly identified. Hyperbaric oxygen (HBO) therapy is one of the treatment options in acute CO poisoning; however, whether it can prevent the development of DNS is controversial. The purpose of this study is to compare the effectiveness of normobaric oxygen (NBO) and HBO in preventing DNS. This prospective observational study was conducted on all patients with CO poisoning admitted to the emergency department of a tertiary hospital from 2016 to 2019. We followed-up patients to determine whether symptoms of DNS occurred at ≤6months. We matched the propensity score to an equivalent distribution of potential covariates. A total of 224 patients with CO poisoning were enrolled in this study. NBO was used for 26 patients and HBO for 198 patients. DNS occurred in 40 patients. There were significant differences between the NBO and HBO groups in terms of carboxyhemoglobin, loss of consciousness, dizziness, chest pain, hospitalization, and length of hospital stay. The incidence of DNS was 19.2% in the HBO group, which was higher than the 7.7% observed in the NBO group, but the difference was not significant (p=0.18). After propensity score matching, the incidence of DNS did not differ between the NBO and HBO groups (8.3% vs. 10.4%, p>0.99). There was no difference in the incidence of DNS between groups receiving HBO and NBO in acute CO intoxication.

Optimal sessions of hyperbaric oxygen therapy in patients with carbon monoxide poisoning: A prospective observational study.

Hyperbaric oxygen (HBO) therapy may be a useful treatment to prevent the development of delayed neuropsychiatric sequelae (DNS) in patients with acute carbon monoxide (CO) poisoning. However, there is no clear consensus regarding the optimal number of HBO therapy sessions in patients with CO poisoning. Here, we compared the development of DNS after 3 and>3 sessions of HBO therapy in patients with acute CO poisoning. This prospective observational study recruited 299 patients with CO poisoning. Demographic and clinical information were obtained, including comorbidities, vital signs, and symptoms. Patients were divided into two groups according to whether they received 3 or>3 sessions of HBO therapy (3 HBO vs. >3 HBO). A propensity score-matching process was used to balance potential prognostic factors in both groups. Of the 299 patients with acute CO poisoning enrolled in this study, 183 (59.0%) were included in the analysis. Patients were excluded for the following reasons: age<18years, not underwent HBO therapy, discharged against medical advice, and loss to follow-up. The overall rate of DNS development was 17.5%. The >3 HBO group had a higher incidence of DNS development compared to the 3 HBO group (36.3% vs. 16.3%; p=0.09). Propensity score-matching analysis revealed similar incidences of DNS (31.3% vs. 28.1%, respectively; p>0.99). There is a critical need to determine the optimal number of HBO therapy sessions for patients with acute CO poisoning. This study showed no difference in DNS development after 3 and>3 sessions of HBO therapy.

Longitudinal gray matter changes of the pain matrix in patients with carbon monoxide intoxication: A voxel-based morphometry study

PurposeCarbon monoxide (CO) intoxication causes gray matter (GM) changes and headache symptom in patients with CO intoxication, but the headache-associated GM changes are not well understood. The purpose of this study was to perform a voxel-based morphometry (VBM) analysis to investigate longitudinal GM changes of brain pain matrix in patients with CO intoxication. MethodsThis prospective study enrolled 24 patients with CO intoxication and 20 healthy controls. Whole brain high-resolution T1-weighted images were acquired in both groups and were repeated in patients at 1 week, and 1, 3, and 9 months after CO exposure. VBM was performed to detect global GM changes in patients with CO intoxication, and the automated anatomical labeling template was utilized to estimate the distribution of significant GM clusters in the brain. ResultsGM volumes were significantly decreased mainly in the frontal and occipital lobes, including several pain-matrix regions 1 week after CO intoxication. The regions with significant GM changes further involved the central GM structures and the periaqueductal gray (pain-modulating center) at 1 and 3 months after CO intoxication, but the alterations were partially normalized in the frontal lobe and cerebellum 9 months after CO intoxication. Significant negative correlations were revealed between GM volume and duration of coma in the pain matrix regions. Moreover, five patients exhibited delayed neuropsychiatric sequelae (DNS) and had greater GM volume changes than non-DNS patients. ConclusionVBM analysis is helpful to understand the longitudinal GM changes of the pain matrix in patients with CO intoxication.

Initial creatine kinase level as predictor for delayed neuropsychiatric sequelae associated with acute carbon monoxide poisoning.

The primary goal of treating patients with carbon monoxide (CO) poisoning is preventing delayed neuropsychiatric sequelae (DNS). It is difficult to predict DNS because there is no precise diagnostic method in the early phase of CO poisoning. In this study, we aimed to investigate the optimal cut-off value for creatine kinase level to predict DNS. This retrospective observational study included patients with CO poisoning visiting a single tertiary center from January to July 2018. They were divided into two groups according to the presence of DNS. We compared baseline characteristics with variables that could affect the presence of DNS. The optimal cut-off value of initial creatine kinase concentration for DNS was calculated. Additionally, multivariate analysis was performed to confirm whether creatine kinase could be an independent predictor of DNS. Of the 138 patients, 12 patients developed DNS. Univariate analysis showed significant differences in the Glasgow Coma Scale, duration of exposure, laboratory tests, abnormal finding on MRI in acute phase, the number of hyperbaric oxygen therapy sessions, and duration of hospitalization. Receiver operating characteristic analyses of creatine kinase were performed (AUC=0.92; 95% CI, 0.86-0.96) with a cut-off value of 1603U/L; DNS was predicted with a sensitivity of 91.7% and specificity of 88.1%. In multivariate analysis, the adjusted odds ratio of creatine kinase was 51.516. In patients with CO poisoning, initial creatine kinase concentrations of >1603U/L can be used as an independent predictor of DNS.

Amantadine Improves Delayed Neuropsychiatric Sequelae of Carbon Monoxide Poisoning: A Case Report

Carbon monoxide (CO) poisoning causes severe brain damage, including delayed neuropsychiatric sequelae (DNS), which occur after a lucid interval following recovery from the insult of acute CO poisoning. We describe a 39-year-old male who developed DNS, including gait disturbance, trunk ataxia, and fecal/urine incontinence, after remission of acute CO poisoning. Furthermore, he showed confusion, with disorientation in terms of time and space. All symptoms, including cognitive impairment, were dramatically improved by amantadine monotherapy. The present case illustrates the possibility of amantadine treatment for cognitive impairment as well as Parkinsonism induced by CO poisoning.

Predictive Role of QTc Prolongation in Carbon Monoxide Poisoning-Related Delayed Neuropsychiatric Sequelae

Objective Delayed neuropsychiatric sequelae (DNS) are serious complications of carbon monoxide (CO) poisoning that adversely affect poisoned patients' quality of life as well as socioeconomic status. This study aimed to determine clinical predictors of DNS in patients with CO poisoning. Methods This retrospective study included all CO-poisoned patients admitted to the emergency department (ED) of Linkou Chang Gung Memorial Hospital in Taiwan from 1 January 2009 to 31 December 2015. The medical records of all patients with CO poisoning were carefully reviewed, and relevant data were abstracted into a standardised form. Univariate and multivariate logistic regression models were used to identify predictors of DNS after CO poisoning. Receiver operating characteristic (ROC) curve analysis was used to determine the ideal cut-off value for continuous variables that predict the development of DNS. Results A total of 760 patients with CO poisoning were identified during the study period. Among them, 466 were eligible for the analysis of predictors of DNS. In multivariate analysis, Glasgow Coma Scale <9 (odds ratio [OR], 2.74; 95% confidence interval [CI], 1.21–6.21), transient loss of consciousness (OR, 3.59; 95% CI, 1.31–9.79), longer duration from CO exposure to ED presentation (OR, 1.05; 95% CI, 1.03–1.08), and corrected QT (QTc) prolongation (OR, 2.61; 95% CI, 1.21–5.61) were found to be associated with a higher risk of DNS. The area under the ROC curve (AUC) for QTc interval measured within 6 h after exposure best predicted the development of DNS, with a result of 0.729 (95% CI 0.660–0.791). Moreover, the best cut-off value of the QTc interval was 471 ms, with a sensitivity of 53.3% and a specificity of 85.1%. Conclusions We identified several potential predictors of DNS following CO poisoning. Among them, QTc prolongation found within 6 h after exposure is a novel predictor of DNS, which may be helpful in the future care of patients with CO poisoning.

The usefulness of diffusion-weighted magnetic resonance imaging performed in the acute phase as an early predictor of delayed neuropsychiatric sequelae in acute carbon monoxide poisoning.

Delayed onset of neuropsychiatric symptoms after apparent recovery from acute carbon monoxide (CO) poisoning has been described as delayed neuropsychiatric sequelae (DNS). No previous study has determined whether early use of diffusion-weighted magnetic resonance imaging (DWI) can predict which patients will develop DNS in the acute CO poisoning. This retrospective observational study was performed on adult patients with acute CO poisoning consecutively treated over a 17-month period. All included patients with acute CO poisoning underwent DWI to evaluate brain injury within 72 h after CO exposure. DWI was evaluated as follows: (1) presence of pathology, (2) number of pathologies, (3) asymmetry, and (4) location of pathology. Patients were divided into two groups. The DNS group was composed of patients with delayed sequelae, while the non-DNS group included patients with no sequelae. A total of 102 patients with acute CO poisoning were finally enrolled in this study. DNS developed in 10 patients (9.8%). Between the DNS group and the non-DNS group, presence of pathology on DWI and initial Glasgow Coma Scale (GCS) showed significant difference. There was also a statistical difference between the non-DNS group and DNS group in terms of CO exposure time, troponin I, rhabdomyolysis, acute kidney injury, and pneumonia. The presence of pathology in DWI and initial GCS (cutoff: <12) at the emergency department served as an early predictors of DNS.

Serum neuron-specific enolase as an early predictor of delayed neuropsychiatric sequelae in patients with acute carbon monoxide poisoning.

Delayed onset of neuropsychiatric symptoms after apparent recovery from acute carbon monoxide (CO) poisoning has been described as delayed neuropsychiatric sequelae (DNS). To date, there have been no studies on the utility of serum neuron-specific enolase (NSE), a marker of neuronal cell damage, as a predictive marker of DNS in acute CO poisoning. This retrospective observational study was performed on adult patients with acute CO poisoning consecutively treated over a 9-month period. Serum NSE was measured after emergency department arrival, and patients were divided into two groups. The DNS group comprised patients with delayed sequelae, while the non-DNS group included patients with none of these sequelae. A total of 98 patients with acute CO poisoning were enrolled in this study. DNS developed in eight patients. The median NSE value was significantly higher in the DNS group than in the non-DNS group. There was a statistical difference between the non-DNS group and the DNS group in terms of CO exposure time, Glasgow Coma Scale (GCS), loss of consciousness, creatinine kinase, and troponin I. GCS and NSE were the early predictors of development of DNS. The area under the curve according to the receiver operating characteristic curves of GCS, serum NSE, and GCS combined with serum NSE were 0.922, 0.836, and 0.969, respectively. In conclusion, initial GCS and NSE served as early predictors of development of DNS. Also, NSE might be a useful additional parameter that could improve the prediction accuracy of initial GCS.

Successful Hyperbaric Oxygen Therapy with Thyrotropin-Releasing Hormone Therapy for Delayed Neuropsychiatric Sequelae after Acute Carbon Monoxide Poisoning: A Case Study

Delayed neuropsychiatric sequelae (DNS) after acute carbon monoxide (CO) poisoning is a complication of CO intoxication. Hyperbaric oxygen (HBO) therapy is one of the only established treatments for CO poisoning, but as there is no specific treatment for DNS, the prognosis of DNS patients is generally poor. A 40-year-old male patient, following attempted suicide by CO poisoning, was referred to our department after having received HBO therapy at another hospital, but treatment had been subsequently discontinued due to patient agitation. The patient was diagnosed with DNS after acute CO poisoning, and we reinitiated HBO therapy. However, due to manifestation of symptoms of severe dementia, treatment was discontinued. After initiating thyrotropin-releasing hormone (TRH) therapy, psychiatric symptoms, such as difficulty in following instructions, improved, enabling the resumption of HBO therapy. Daily activities returned to premorbid levels following treatment. Thus, TRH therapy could be effective for patients with DNS due to acute CO poisoning who experience difficulty with HBO therapy.