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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.

To investigate how effectively systemic immune-inflammation index (SII) and Monocyte-to-HDL-cholesterol ratio (MHR) predict the development of early cardio-cerebral complications in elderly patients who have experienced acute severe carbon monoxide poisoning (ASCMP). A retrospective analysis was conducted on 77 elderly patients with ASCMP admitted to the emergency department of Harrison International Peace Hospital from November 2020 to March 2022. The prevalence of early-onset complications among the 77 individuals was 38.96%. Binary Logistics regression analysis showed that SII and MHR were independent influencing factors of early cardio-cerebral complications in elderly patients with ASCMP. The complication group had a longer length of stay, a greater mortality rate, and a higher incidence of delayed encephalopathy after acute carbon monoxide poisoning ( p  < .05) than the non-complication group. The area under the curve (AUC) of SII and MHR in predicting early cardio-cerebral complications in elderly patients with ASCMP were 0.724 and 0.796, respectively, with 80.0% and 63.3% sensitivity, and 61.7% and 87.2% specificity. The incidence of early cardio-cerebral complications in elderly patients who had ASCMP is high and the prognosis is poor. SII and MHR can be utilized as independent predictors of early cardio-cerebral complications in elderly patients with ASCMP, allowing doctors to diagnose and treat cardio-cerebral complications earlier and improve prognosis.

Total blood carbon monoxide (TBCO) showed promising results in improving accuracy of CO determinations in blood and presenting better stability to different storage conditions. Therefore, it was proposed as an alternative biomarker to carboxyhemoglobin (COHb) for CO poisoning diagnosis. However, given that current interpretation reference values exist for COHb only, it is difficult to implement TBCO analysis in routine. Therefore, we aimed at determining TBCO reference values for postmortem CO poisoning cases. A previously validated method for TBCO analysis via gas chromatography-mass spectrometry was applied to cardiac, peripheral, cranial and spleen blood samples collected from 92 autopsies. Autopsy cases included 21 non-CO-related and 71 CO-related cases with varying postmortem intervals (PMIs). Statistical analyses were performed using statistical software R Studio. When comparing lower to higher PMIs for non-CO-related cases, no significant differences were found, which suggests that CO formation or degradation at low PMIs does not occur. Spleen blood showed potential as an alternative matrix to CO determinations in cases with sample availability issues but needs to be evaluated for CO-positive cases. Results for cardiac blood in CO-related autopsies showed a positive correlation between COHb and TBCO values (R = 0.78). This value is lower than what is found in the literature, suggesting that even though COHb and TBCO are correlated, a potential underestimation of the true CO exposure might occur if only COHb values are taken into consideration. Samples were divided into CO exposure groups based on COHb concentrations, and with the data obtained, classification into the following TBCO concentration groups is proposed: no significant CO exposure case <6 µmol/mL, medium CO exposure case 6-20 µmol/mL and high CO exposure case >20 µmol/mL. Even if a higher number of samples in each group would enable to increase the confidence, these results are very promising and highlight the importance of TBCO measurement., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site–for further information please contact journals.permissions@oup.com.)

Objective: Carbon monoxide (CO), a toxic gas, poses a significant threat to human health. Children, pregnant women, and elderly individuals are particularly vulnerable to this toxicity. This study aims to evaluate the demographic and clinical characteristics of pediatric, pregnant, and geriatric patients., Patients and Methods: The study included pediatric, pregnant, and geriatric patients with a confirmed diagnosis of CO poisoning, excluding those with complete file data and those with carboxyhemoglobin (COHb) levels below 5% (for children and pregnant patients) and 10% (for elderly patients). Patients aged < 18 years, > 65 years, and pregnant patients admitted to the adult and pediatric emergency departments were included in the study; statistical analyses were conducted using SPSS Inc., with a p-value of < 0.05 considered statistically significant., Results: For pediatric patients, a statistically significant difference was observed between the two groups in terms of their main complaints, which were primarily attributed to neurological and general symptoms. A positive correlation was found between follow-up time and several factors, including white blood cell (WBC) count and troponin, lactate, lactate dehydrogenase (LDH), and COHb levels. For pregnant patients, no in-hospital mortality was observed in the patients included in this study. A significant negative correlation was identified between age and both COHb and hemoglobin (Hb) levels. A strong positive correlation was found between the COHb levels and hospital follow-up time. For elderly patients, no significant differences were found between the two treatment modalities. Notably, higher COHb levels on admission were associated with a more fatal in-hospital course, with COHb levels > 40% of all patients requiring intubation., Conclusions: Vulnerable populations are at increased risk of exposure to CO, and the study results emphasize the necessity of heightened awareness and preventive measures to safeguard these individuals from CO poisoning.

No definitive prognostic biomarkers for carbon monoxide (CO) poisoning have been proposed. The aim of this study is to investigate, through a systematic literature review and pooled analysis, whether red blood cell distribution width (RDW) can predict disease severity in CO-poisoned patients. We performed an electronic search in Scopus and PubMed using the keywords: 'red blood cell distribution width' OR 'RDW' AND 'carbon monoxide' AND 'poisoning,' with no time or language restrictions (i.e. through August 2023) to find clinical studies that examined the value of RDW in patients with varying severity of CO poisoning. The analysis was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) 2020 reporting checklist. We identified 29 articles, seven of which were included in our analysis, with a total of 1979 CO-poisoned patients, 25.9% of whom were severely ill. In all but one of the studies, the RWD mean or median value was higher in CO-poisoned patients with severe disease. The weighted mean difference (WMD) of RDW was 0.36 (95% confidence interval (CI), 0.26-0.47)%. In the three articles in which the severity of illness in CO-poisoned patients was defined as cardiac injury, the WMD of the RDW was 1.26 (95%CI, 1.02-1.50)%. These results suggest that monitoring RDW in CO-poisoned patients may help to determine the severity of disease, particularly cardiac injury.

Introduction: The poisoning severity score (PSS) was developed to grade the severity of various types of poisoning. However, in its current form, it requires investigating many variables, some of which have been found not to be associated with carbon monoxide (CO) poisoning severity. Therefore, in this study, we modified the PSS for CO poisoning and compared its usefulness to that of the original PSS, as an early prognostic factor of short-term outcome in CO poisoning patients., Methods: This was a retrospective observational study conducted in patients with CO poisoning who visited the emergency department between January 2014 and December 2020. Patients' primary outcome was their Cerebral Performance Category (CPC) scale score at discharge, which classified those with CPC 1-2 as having a favorable outcome and those with CPC 3-5 as having a poor outcome. We calculated the patients' PSS and their CO-modified PSS by replacing blood and metabolic balance category in the original PSS with carboxyhemoglobin (COHb) and lactate levels, respectively., Results: This study included 891 patients, of which 852 (95.6%) and 39 (4.4%) were classified into the favorable and poor outcome groups, respectively. Using multivariate analysis, the PSS (odds ratio [OR], 22.961; 95% confidence interval [CI], 10.641-49.546; p < 0.001) and CO-modified PSS (OR, 28.856; 95% CI, 12.874-64.679; p < 0.001) were both found to be associated with poor outcomes at hospital discharge. The areas under the receiver operating characteristic curves for the PSS and CO-modified PSS were 0.874 (95% CI, 0.850-0.895) and 0.881 (95% CI, 0.858-0.901), respectively., Conclusion: The CO-modified PSS, with fewer variables than the original PSS, was not inferior to predict poor outcomes, and if COHb level is considered together with other parameters, then it can be used both for predicting prognosis and in diagnosis., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021. Published by Elsevier Inc.)

Background: 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 48-72 h, but there are no studies analyzing serial serum NSE in acute COP. Thus, we explored whether serum NSE levels measured three times at 24 h intervals after COP predicted the development of DNS., Methods: 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 72 h after presentation at hospital. We used logistic regression to explore the association between NSE levels and DNS development., Results: The NSE level was highest at 48 h, 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 48 h of >20.98 ng/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., Conclusion: 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 >20.98 ng/mL at 48 h 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).

Carbon monoxide (CO) poisoning is a common cause of death, leading to morbidity and mortality worldwide. Features of the CO poisoning with low carboxyhemoglobin (COHb) levels remain to be characterized. This study collected a total of 307 CO poisoning cases from Shanghai Public Security Bureau, an official organization that handles the most complicated and life-threatening cases across Shanghai municipality in China, and regrouped these cases into three categories: group 1, 10% < COHb% < 30% (n = 58); group 2, 30% ≤ COHb% < 50% (n = 79); group 3, COHb% ≥ 50% (n = 170). Epidemiological, demographic, and forensic aspects of the CO poisoning cases, particularly those with low COHb levels, were analyzed. Our results showed that group 2 and 3 were mostly observed in younger victims (≤ 30 years), while group 1 equally distributed to all age groups (p = 0.03). All the CO poisoning from group 2 and 3 occurred in enclosed spaces, whereas cases from group 1 died additionally in outdoor spaces (p = 0.01). 81.03% of group 1 cases died in fire circumstances, while only 45.57% from group 2 and 30.59% from group 3 were fire-related (p = 0.00). Accordingly, group 1 was mostly related with fire burns, while group 2 or 3 were largely associated with gas leakage (p = 0.00). A combination with alcohol, but not other psychotropic drugs, associated with significant higher levels of blood COHb% in fire-unrelated (p = 0.021) but not fire-related cases (p = 0.23). Five extremely low COHb% (< 30%)-related poisoning deaths were negative of any cardiopulmonary pathology and psychoactive substances. In conclusion, CO poisoning with low COHb% significantly associates with fire circumstances and outdoor spaces and has no age preference. Further diagnostic markers mandates to be identified in order to avoid disputes in cases of extremely low COHb%-related poisoning., (© 2021. The Author(s).)

Background: Acute carbon monoxide (CO) poisoning is one of the most common poisons worldwide and neuropsychiatric sequelae (NS) are the most frequent form of its morbidity., Objectives: This study aimed to measure the percentage of patients liable to NS, to evaluate the cognitive profile of patients with NS and to assess the role of neuron specific enolase (NSE) and glial fibrillary acidic protein (GFAP) in predicting the development of NS after acute CO poisoning., Methods: This prospective study included 50 patients with acute CO poisoning presented to the Poison Control Center, Ain Shams University Hospitals during the period from beginning of November 2015 till the end of January 2017. Patients' demographic characteristics, clinical manifestations and blood carboxyhemoglobin levels were recorded. Serum levels of NSE and GFAP were determined on admission. Every patient was invited to participate in a follow-up visit at a dedicated outpatient clinic one month after CO exposure. During the visit, a complete neurological examination, as well as a psychiatric evaluation using the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders version 4 Axis-I were performed for detection of neurological and psychiatric disorders. Wechsler memory scale test was administrated for detection of cognitive deficits. The patients were divided into two groups based on the presence or absence of NS., Results: Cognitive impairment was found in 38 % of patients in the NS group. The serum levels of NSE and GFAP were significantly high in the NS group in comparison to the non-NS group. Receiver operating characteristic curves (ROC) determined the cut-off level of NSE at 39 ng/mL achieved 100 % sensitivity with 88.64 % specificity to predict the development of NS after acute CO poisoning while GFAP had 95.24 % sensitivity and 69.23 % specificity at a cut-off value of 2.8 ng/mL., Conclusion: NSE and GFAP could be useful in the early identification of patients at risk of developing NS after CO poisoning helping in treatment plans and thus improving quality of care., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Abstract: The aim of this study was to investigate the associations between the levels of neuron-specific enolase (NSE) and S100B protein and coma duration, and evaluate the optimal cut-off values for prediction coma duration ≥ 72 hours in patients with acute carbon monoxide poisoning (ACOP).A total of 60 patients with ACOP were divided into 3 following groups according to their status of consciousness and coma duration at admission: Awake group [Glasgow Coma Scale score (GCS score) ≥ 13 points], Coma < 72 hours group (GCS score < 13 points and coma duration < 72 h), and Coma ≥ 72 hours group (GCS score < 13 points and coma duration ≥ 72 h). The levels of serum NSE and S100B protein were measured after admission.There were significant differences in GCS score, carbon monoxide (CO) exposure time, NSE, and S100B levels between the Coma ≥ 72 h group and the Awake group, and between the Coma < 72 h group and the Awake group. Significant differences in GCS score, NSE, and S100B levels were also found between Coma ≥ 72 h group and Coma < 72 h group. Correlation analysis showed that NSE and S100B were positively correlated (rs = 0.590, P < .01); NSE and S100B were negatively correlated with GCS score (rs = -0.583, rs = -0.590, respectively, both P < .01). The areas under the curve (AUCs) of NSE, S100B, and GCS score to predict the coma duration ≥ 72 hours were 0.754, 0.791, and 0.785, respectively. Pairwise comparisons did not show differences among the 3 groups (all P > .05). The sensitivity and specificity of NSE prediction with a cut-off value of 13 μg/L were 80% and 64%, respectively, and those of S100B prediction with a cut-off value of 0.43 μg/L were 70% and 88%, respectively.The NSE and S100B protein levels were significantly correlated with the degree of impaired consciousness and had the same clinical value in predicting coma duration of ≥ 72 hours in patients with ACOP., Competing Interests: The authors declare that they have no conflict of interest., (Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc.)

Introduction: 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., Methods: 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., Results: 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 1603 U/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., Conclusion: In patients with CO poisoning, initial creatine kinase concentrations of >1603 U/L can be used as an independent predictor of DNS., Competing Interests: Declaration of competing interest The authors report no conflict of interest., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Abstract: Briquette-based kotatsu, a traditional Japanese heating system, is still used in rural areas and has been linked to the development of acute carbon monoxide (CO) poisoning. This study aimed to investigate the occurrence of delayed neurologic sequelae (DNS) in patients with acute CO poisoning caused by briquette-based kotatsu.This retrospective study included 17 patients treated for acute CO poisoning due to briquette-based kotatsu, between April 2017 and March 2020. Patients were divided into either a sequelae group (3 patients) or a non-sequelae group (14 patients) based on the presence or absence, respectively, of DNS. Demographic data, kotatsu characteristics, clinical findings, and therapies were compared between the 2 groups.Significant differences were noted in patient posture during their initial discovery. Specifically, all non-sequelae patients only had their legs under the kotatsu quilt and all sequelae patients had their entire bodies under the kotatsu quilt (P = .001). There were no statistically significant differences in carbon monoxide levels in hemoglobin (CO-Hb) or the creatine-kinase myocardial band (CK-MB), between the 2 groups; however, troponin-I levels were significantly higher in the sequelae group (P = .026). Abnormal head imaging findings were noted in 2 sequelae-group patients, with a significant difference between the groups (P = .025).We speculate that acute CO poisoning, caused by briquette-based kotatsu, may lead to DNS more frequently in patients in who cover their entire body with the kotatsu quilt and are found in this position. Patients should be warned about the dangers of acute CO poisoning when using briquette-based kotatsu., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc.)

Background Delayed encephalopathy (DE) is the most severe complication after acute carbon monoxide (CO) poisoning, which seriously affects the outcome of patients and leads to a high disability rate. Prior studies have shown that hyperbaric oxygen (HBO 2 ) therapy is therapeutic for DE due to reducing immune-mediated neuropathology and thus improving cognitive performance. Methods In our present perspective study, five DE patients were treated regularly with HBO 2 therapy. The mini-mental state examination (MMSE) and Barthel index (BI) were intermittently collected during their hospitalization for mental and physical status evaluation, the peripheral bloods were serially sampled to determine the concentration changes of circulating stem cells, as well as corresponding BDNF and neural markers. Results MMSE and BI showed series of improvements after multiple HBO 2 therapies. The CD34 + /CD90 + and CD34 + /CD133 + dual positive cells, which were categorized as circulating stem cells, were observed an overall up-regulation since the beginning of the DE onset upon the application of HBO 2 therapy. Characteristic neurotrophin BDNF, neural markers such as nestin and synaptophysin (SYP) were also up-regulated after exposure of HBO 2 . Conclusion The application of HBO 2 therapy is of significance in improving the cognition of DE patients, along with mobilized circulating stem cells. We primarily infer that the CD34 + /CD90 + and CD34 + /CD133 + cells were mobilized by HBO 2 exposure and have played a positive role in cognition improvement on DE patients by up-regulation of BDNF, nestin and SYP. The altering amount of circulating stem cells mobilized in peripheral blood could be a potential marker on predicting the outcome of DE., Competing Interests: Declaration of competing interest We have no competing interests to declare., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Introduction: Carbon monoxide (CO) poisoning is a crucial cause of delayed neuropsychiatric syndrome (DNS). However, most biomarkers are not satisfactory for the prediction of DNS caused by CO poisoning. Thus, we evaluated the adequacy of the serum glucose/potassium (GLU/K) ratio, which may be an easy, quick, and readily available parameter that can be used in the emergency department for predicting DNS., Methods: We evaluated 281 patients who were admitted to our emergency department between January 2012 and December 2018. The patients were divided into two groups: DNS (+) and DNS (-). The GLU/K was compared for the groups., Results: Glucose, blood urea nitrogen, carboxyhemoglobin, and GLU/K ratios of patients in the DNS (+) group were statistically significantly higher than those patients in DNS (-) group (140 ± 34 vs. 110 ± 24, p < 0.001; 17.58 ± 6.14 vs. 14.27 ± 5.08, p = 0.003; 29 ± 5.1 vs. 18.9 ± 7.6, p < 0.001; and 38.35 ± 10.11 vs. 28.65 ± 6.53, p < 0.001, respectively). The area under the curve for GLU/K to predict DNS was measured as 0.791, and 35.9 as a cut-off value had 63.6% sensitivity and 89.6% specificity., Conclusions: DNS development in CO poisoning is a serious and feared complication. We suggest that the GLU/K ratio has a high potential as a rapid, easy preliminary marker for the exclusion of patients who will not subsequently develop DNS.

Introduction: This study aimed to assess the capability of a pulse CO-oximeter to continuously monitor carboxyhemoglobin (COHb) during hyperbaric oxygen (HBO2) therapy. We estimated limits of agreement (LOA) between blood gas analysis and pulse CO-oximeter for COHb during HBO2 therapy in patients suffering from acute CO poisoning. Furthermore, we did a medicotechnical evaluation of the pulse CO-oximeter in hyperbaric conditions., Methods: We conducted a prospective, non-clinical, observational study in which we included n=10 patients with acute CO poisoning referred for HBO2 therapy. We did five repeated measurements of COHb for each patient during the HBO2 therapy. Bland-Altman analysis for multiple observations per individual was used to assess the agreement. The a priori LOA was ±6% for COHb. For the medicotechnical evaluation continuous measurements were obtained throughout each complete HBO2 therapy. The measurements were visually inspected and evaluated., Results: The Bland-Altman analysis showed that the pulse CO-oximeter overestimated COHb by 2.9 % [±1.0%] and the LOA was ±7.3% [±1.8%]. The continuous measurements by pulse CO-oximetry showed fluctuating levels of COHb and summarized saturations reached levels above 100%. Measurements were not affected by changes in pressure., Conclusion: To our knowledge, this study is the first to assess LOA and demonstrate use of a non-invasive method to measure COHb during HBO2 therapy. The pulse CO-oximeter performed within the manufactures reported LOA (±6%) despite hyperbaric conditions and was unaffected by changes in pressure. However, summarized saturations reached levels above 100%., Competing Interests: The authors of this paper declare no conflicts of interest exist with this submission., (Copyright© Undersea and Hyperbaric Medical Society.)

Background: Carbon monoxide (CO), which is well known as silent killer, has many toxic effects on organs with high rate of metabolism such as heart and brain. CO-induced cardiotoxicity resulted in a wide range of disabilities including electrocardiogram (ECG) abnormalities, elevation in level of cardiac enzymes, arrhythmias, impairment of left ventricular and myocardial infarction (MI). Cardio-protective effects of Granulocyte colony-stimulating factor (G-CSF) on infarcted heart was proved previously in various reports., Objective: In this study, possible effect of G-CSF on cardiac function of patients with moderate to severe acute CO poisoning was investigated., Methods: Cardioprotective effects of G-CSF in CO-poisoned patients was evaluated through ECG, Holter monitoring, echocardiography, and biochemical studies. Continuous intravenous infusion of G-CSF (90 μg/kg) and normal saline were administered respectively to treatment and placebo groups., Results: The results demonstrated that in moderate to severe CO poisoning, myocardial injury is common. ECG changes (e.g., ST-segment and T-wave changes, QTC), cardiac arrhythmias (e.g., heart blocks and ventricular arrhythmias), serum level of Troponin I, left ventricular ejection fraction were determined after G-CSF administration. Frequencies of ST depression, inversion or flatting of T wave and QTC in ECG were significantly reduced after G-CSF treatment. In addition, incidence of cardiac arrhythmias due to CO poisoning were reduced after G-CSF treatment. However, G-CSF did not exert protective effects on TPI level and function of left ventricular in CO-poisoned patients., Conclusion: GCSF could probably reduce CO-induced cardiac ischemia in patients with acute CO poisoning., Clinical Trial Registration: The trial protocol was registered in the Iranian Registry of Clinical Trials (http://www.irct.ir) registry (Irct ID: IRCT201607232083N7)., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Background: High-flow nasal cannula oxygen (HFNC) creates a positive pressure effect through high-flow rates compared to conventional oxygen therapy. The purpose of this human pilot study is to compare the effects of HFNC and conventional oxygen therapy on the rate of carbon monoxide (CO) clearance from the blood in patients with mild to moderate CO poisoning., Methods: CO-poisoned Patients randomly received 100% oxygen from a rebreathing reserve mask (NBO 2 , flow of 15 L/min) or HFNC (flow of 60 L/min). The fraction of COHb value (fCOHb) was measured in 30-min intervals until it fell to under 10%. We determined the Half-life time of fCOHb (fCOHb t 1/2 )., Results: A total of 22 patients had fCOHb levels ≥ 10% at the time of ED arrival, with 9 of them having fCOHb level ranging between 25% and 50%. There was no significant difference in the fCOHbt 1/2 between the HFNC group and NBO 2 group. However, the mean fCOHbt 1/2 in the HFNC group (48.5 ± 12.4 min) has a smaller standard deviation than that in the NBO 2 group (99.3 ± 93.38 min). There were significant between-group differences in the mean COHbt 1/2 among the patients with fCOHb levels less than 25% (HFNC 43.6 ± 10.6 vs. NBO 2 134.2 ± 111.3)., Conclusions: In this pilot randomized controlled trial study, HFNC therapy did not reduce fCOHbt 1/2 compared to NBO 2 therapy but could be beneficial in maintaining a constant fCOHbt 1/2 as well as in reducing fCOHbt 1/2 in mild CO poisoning patients compared to conventional NBO 2 therapy. However, further studies with a larger number of patients are needed to establish HFNC therapy as an alternative therapy for CO poisoning patients., Competing Interests: Declaration of Competing Interest The authors have no conflict of interest to report., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Carbon monoxide (CO) is one of the major causes of poisoning worldwide. We aimed to investigate the efficacy of the continuous positive airway pressure (CPAP) use in CO poisoning., Methods: After CO poisoning, one group of patients was treated with a non-rebreather mask (NRB) and another group using the CPAP mode of mechanical ventilation (CPAP). All patients received at least 90 minute treatment. The carboxyhemoglobin saturation (SpCO) levels of all patients were measured from the fingertips with a portable CO-oximeter at 0, 30, 60 and 90 min. The rates of changes in the serially measured SpCO values were obtained using the Wilcoxon signed-rank test., Results: A total of 45 patients (24 in NRB and 21 in CPAP group) completed the study. The median initial SpCO levels were 24% (21-33) in NRB group, 25% (21-32) in CPAP group, with no statistically significant difference (p 0.323). At the 30th, 60th, and 90th minutes of treatment, significantly lower values were obtained from CPAP than NRB (p < 0.001). The COHb half-life was decreased significantly by CPAP [105(70-190) vs 45(30-120), p < 0.001]. In CPAP group, the fastest decline in the SpCO level was observed for the interval of 0-30 min [Median difference: 8(3-14), p < 0.001]., Conclusions: CPAP lowered the amount of CO in the blood faster than the mask; therefore, it may be effective in the treatment of CO poisoning., Competing Interests: Declaration of competing interest The authors declare that this manuscript has not been published nor is under simultaneous consideration for publication elsewhere., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Introduction: The affinity of hemoglobin for carbon monoxide (CO) is 250 times higher than that for oxygen. Therefore, exposure to CO leads to a reduction in oxygen delivery to tissues, resulting in cellular hypoxia and affects whole body. Hepatic dysfunction in critically ill patients is related to poor outcome, but few studies have been conducted on this subject that occurs after CO poisoning. This study aims to conduct a study of hepatic injury in CO-poisoned patients in emergency department (ED)., Methods: This retrospective observational study collected data from patients who were diagnosed with acute CO poisoning at the ED between June 2011 and May 2018 in local tertiary-care hospital (Wonju, Republic of Korea). The primary end point of this study was to describe the prevalence of hepatic injury in acute CO-poisoned patients. The secondary goals were to investigate the recovery trends of hepatic injury caused by acute CO poisoning and the relation to neurologic outcome and mortality., Results: Eight hundred ninety-four patients were enrolled in the final analysis, 128 cases (14.3%) had subclinical hepatic injury and 15 (1.6%) cases had hepatic injury. The relationship with mortality was not statistically significant. However, the hepatic injury group was higher incidence of intensive care unit admission and other complications. Patients in the hepatic injury group recovered through conservative management within 1 week of being admitted to the ED., Conclusions: While CO-induced hepatic injury is relatively uncommon, it can be associated with complications and poor neurologic outcome. However, CO-induced hepatic injury was not found to have a statistically significant effect on mortality rate.

Purpose: The aim of this study was to investigate the demographic and clinical characteristics and treatment modalities of elderly patients with carbon monoxide (CO) intoxication. The secondary aim was to evaluate the importance of plasma lactate values in the diagnosis of acute CO intoxication in geriatric patients., Methods: Data on geriatric patients who were admitted to the emergency department of Atatürk University Medical Faculty between January 2013 and April 2016 were analyzed retrospectively., Results: Of the 197 cases included in the study, 97 were in the intoxication group and 100 were in the control group; 82.5% of the intoxication cases had mild neurological symptoms and 17.5% had severe neurological symptoms. Carboxyhemoglobin levels were significantly higher in patients with severe neurological symptoms ( p = 0.031). All patients with severe neurological symptoms received hyperbaric-oxygen therapy ( p < 0.001). In the intoxication group, lactate levels were significantly higher than in the control group ( p = 0.001). The specificity for lactate 4 mmol/L and above was found as 98.0% with a positive predictive value and negative predictive value of 84.5% and 53.3%, respectively., Conclusion: High initial lactate levels may be a guide for cases with nonspecific symptoms in geriatric patients with suspected CO intoxication.

Objectives: Carbon monoxide (CO) poisoning is one of the leading causes of preventable death in the world. Our primary objective was to identify and treat individuals who are unaware of their exposure to carbon monoxide in emergency departments (EDs). Our secondary goal was to reduce the costs of diagnosis and treatment by preventing unnecessary diagnostic testing in EDs., Methods: In this cross-sectional study, carboxyhemoglobin (COHb) levels of patients presented with the signs of CO poisoning to the Emergency Department of Kayseri Training and Research Hospital between November 2012 and May 2013 were noninvasively measured during triage. Patients with elevated COHb levels were suspected of CO poisoning and subjected to further investigation., Results: A total of 4073 patients were enrolled in the study, and 106 (2.6%) of them were diagnosed with CO poisoning. Initial evaluation revealed headache to be the most common presenting complaint in patients with occult CO poisoning. Further evaluations to determine the accuracy of noninvasive measurements showed that noninvasive pulse CO-oxymeter and arterial blood gas (ABG) measurement were compatible., Conclusions: The use of noninvasive pulse CO-oxymeter might reduce the morbidity and mortality associated with occult CO poisoning in patients presented with suspected CO poisoning in emergency settings., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Smoke inhalation injury (SII) affects more than 50,000 people annually causing carbon monoxide (CO) poisoning. Although the increased blood level of carboxyhemoglobin (CO-Hb) is frequently used to confirm the diagnosis of SII, knowledge of its elimination in the acute phase is still limited. The aim of this study is to determine CO-Hb elimination rates and their differences in arterial (aCO-Hb) and mixed-venous (vCO-Hb) blood following severe SII in a clinically relevant ovine model. Forty-three chronically instrumented female sheep were subjected to SII (12 breaths, 4 sets) through tracheostomy tube under anesthesia and analgesia. After the SII, sheep were awakened and placed on a mechanical ventilator (FiO 2  = 1.0, tidal volume 12 mL/kg, and PEEP = 5cmH 2 O) and monitored. Arterial and mixed-venous blood samples were withdrawn simultaneously for blood gas analysis at various time points to determine CO-HB half-lifetime and an elimination curve. The mean of highest aCO-Hb level during SII was 70.8 ± 13.9%. The aCO-Hb elimination curve showed an approximated exponential decay during the first 60 min. Per mixed linear regression model analysis, aCO-Hb significantly (p < 0.001) declined (4.3%/minute) with a decay constant lambda of 0.044. With this lambda, mean lifetime and half-lifetime of aCO-Hb were 22.7 and 15.7 min, respectively. The aCO-Hb was significantly lower compared to vCO-Hb at all-time points (0-180 min). To our knowledge, this is the first report describing CO-Hb elimination curve in the acute phase after severe SII in the clinically relevant ovine model. Our data shows that CO-Hb is decreasing in linear manner with supportive mechanical ventilation (0-60 min). The results may help to understand CO-Hb elimination curve in the acute phase and improvement of pre-hospital and initial clinical care in patients with CO poisoning., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Delayed neurological sequels (DNS) have been described after carbon monoxide (CO) poisoning. There is a need to find a new prognostic marker to guide the use of hyperbaric oxygen (HBO) therapy., Aim: To evaluate serum S-100β level in patients presenting with acute CO poisoning as an indicator of poisoning severity and predictor of DNS occurrence and HBO need in those patients., Methods: This prospective cohort study included patients with acute CO poisoning. On admission, carboxyhemoglobin (COHb) and S-100β levels were measured. Patients were followed up for 6 months for signs of DNS., Results: Out of 50 patients, 6 only developed DNS. The mean of S-100β levels was significantly higher in patients with severe poisoning and those with DNS. Receiver operating characteristic curve analysis revealed that S-100β had an area under the curve 0. 871; at a cutoff value ≥ 0.67 µg/L, its sensitivity and specificity were 100% and 77.3%, respectively. The sensitivity of S-100β was significantly higher than that of COHb, while its specificity and overall accuracy were significantly higher than those of HBO criteria., Conclusion: Serum S-100β level on admission could be a marker of poisoning severity and a predictor of CO-induced DNS development that guides the use of HBO therapy.

The objective was to describe the prevalence of derangement of the partial pressure of arterial carbon dioxide (PaCO 2 ) and to determine the association between PaCO 2 and adverse cardiovascular events (ACVEs) in carbon monoxide (CO)-poisoned patients. Additionally, we evaluated whether the derangement of PaCO 2 was simply secondary to metabolic changes. This retrospective study included 194 self-breathing patients after CO poisoning with an indication for hyperbaric oxygen therapy and available arterial blood gas analysis at presentation and 6 h later. The incidence rate of hypocapnia at presentation after acute CO poisoning was 67.5%, and the mean PaCO 2 during the first 6 h was 33 (31-36.7) mmHg. The most common acid-base imbalance in 131 patients with hypocapnia was primary respiratory alkalosis. The incidence rate of ACVEs during hospitalization was 50.5%. A significant linear trend in the incidence of ACVEs was observed across the total range of PaCO 2 variables. In multivariate regression analysis, mean PaCO 2 was independently associated with ACVEs (odds ratio 0.051; 95% confidence interval 0.004-0.632). PaCO 2 derangements were common after acute CO poisoning and were not explainable as a mere secondary response to metabolic changes. The mean PaCO 2 during the first 6 h was associated with ACVEs. Given the high incidence of ACVEs and PaCO 2 derangement and the observed association between the mean PaCO 2 and ACVEs, this study suggests that (1) PaCO 2 should be monitored in the acute stage to predict and/or prevent ACVEs and (2) further investigation is needed to validate this result and explore the early manipulation of PaCO 2 as a treatment strategy.

Our objective was to determine how much PaO 2 levels increase after normobaric oxygen (NBO) therapy and whether NBO therapy exerts therapeutic effects regardless of the PaO 2 level. We suggest the optimal PaO 2 level to use during NBO therapy for the acute treatment of carbon monoxide (CO) poisoning. This retrospective study included 311 patients who received oxygen administration after CO poisoning and had a measurable PaO 2 level upon arrival. Baseline characteristics, clinical courses and long-term neurological outcome were collected and compared. The PaO 2 level upon arrival was 192 (161-225) mm Hg, and 272 (87.5%) of the patients presented with hyperoxia. The incidence of poor long-term neurological outcome was 11.3% at a median follow-up period of 35 months. PaO 2 levels upon arrival were higher in patients with good long-term neurological outcome than in those with poor outcome. The incidence of poor long-term neurological outcome was significantly dependent on the PaO 2 level when patients were stratified at 100-mm Hg increments. A multivariate regression analysis showed that PaO 2 levels, when considered a continuous, interval or ordinal variable, were associated with long-term neurological outcome in separate models. According to the three models, a PaO 2 level of 200-300 mm Hg has the lowest risk of poor long-term neurological outcome. The results of the analysis of the predicted probability of poor long-term outcome according to the PaO 2 level exhibited a U-shaped curve. Further large-scale studies are needed to confirm the association between 200-300 mm Hg of PaO 2 and long-term neurological outcome and evaluate the impact of PaO 2 levels above 300 mm Hg on acute CO poisoning outcome., (© 2019 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).)

Objectives: Carbon monoxide (CO) poisoning is a common and deadly form of poisoning that is often treated with hyperbaric oxygen. The characteristics of children exposed to CO and then treated with hyperbaric oxygen have not been delineated. The purpose of this study was to describe the clinical characteristics of children treated with hyperbaric oxygen therapy for CO poisoning at a regional hyperbaric referral center., Methods: The study is based on a retrospective review of data extracted from the medical records of children (age <19 years) who were referred to our center for hyperbaric oxygen therapy for CO poisoning between 2008 and 2013. Inferential analyses were used to compare demographic characteristics, serum carboxyhemoglobin (COHb) levels, and presenting symptoms., Results: Forty-seven children met our study criteria. Their mean age was 8.9 years, and their mean COHb level was 14.3% (range, 3.4%-30.1%). Severity of symptoms did not correlate with serum COHb levels; however, neurologic symptoms at presentation were more common in patients with a COHb level greater than 25%. There was a correlation between increasing age and higher COHb levels and between COHb and lactate levels., Conclusions: Our retrospective review of patients' records showed no correlation of serum COHb levels with symptoms on presentation; however, a correlation was found between increasing age and COHb level as well as lactate level and COHb level.

The present study aims to examine the clinical values of complete blood count (CBC) bioindicators and corrected QT (QT c ), T peak  - T end interval (T p-e ), T peak dispersion (T p disp ), and T p-e /QT ratio that are the parameters of myocardial repolarization (M-rep) for cardiotoxicity, which develops due to acute carbon monoxide (CO) intoxication in patients admitted to the emergency service. This retrospective, cross-sectional, observational, and single-center study was conducted between April and June 2019. Statistical analysis was performed using the SPSS 23.0 software. Data of 234 participants were analyzed. Of these, 54.9% (n = 129) were female. Neutrophil-to-lymphocyte ratio (NLR), QT c , T p-e values were significantly high in the CO intoxication group (p < 0.001, p < 0.001, and p < 0.001, respectively), whereas T p-e /QT c ratio was significantly lower in the CO intoxication group than that in the control group (p < 0.001). NLR, T p-e , T p disp values were significantly high in the myocardial injury (M-inj) group (p < 0.001, p = 0.003, and p = 0.018, respectively). Furthermore, T p-e /QT c ratio was significantly low in the M-inj group (p = 0.002). M-rep parameters and NLR are associated with CO intoxication and the development of M-inj. Moreover, these bioindicators and can provide clinicians an early indication of M-inj.

Objective: The aim of our study is to determine whether there is a change in the plasma levels of copeptin and there is a relationship among the plasma levels of carboxyhemoglobin (COHb), lactate, and copeptin levels in patients presenting to the emergency department with carbon monoxide (CO) poisoning., Methods: Fifty-seven patients admitted to the emergency department with CO poisoning were included in the study. The blood samples of the patients were collected on arrival 0th, 6th, and 12th hours for copeptin, lactate, and COHb levels. Data were analyzed using SPSS-17 statistical software., Results: Arrival serum copeptin levels of the patients were compared to copeptin levels of healthy individuals and a statistically significant difference was found between them ( p = 0.008). There was a statistically significant difference between the arrival levels of copeptin and 6th-hour ( p = 0.006) and 12th-hour ( p = 0.001) levels of copeptin. There was no significant difference between 6th-hour and 12th-hour copeptin levels ( p = 0.51). In terms of serum lactate levels, there was a significant difference between arrival and 6th h ( p < 0.001), arrival and 12th h ( p < 0.001), and 6th and 12th h ( p < 0.001). Likewise, in terms of serum COHb levels, there was a significant difference between arrival and 6th h ( p < 0.001), arrival and 12th h ( p < 0.001), and 6th and 12th h ( p < 0.001). There was a positive correlation between COHb and lactate levels on arrival ( r = 0.52; p = 0.001)., Conclusion: Copeptin as a stress hormone can be used in the diagnosis and monitoring of patients with CO poisoning. However, the copeptin level was not superior to COHb and lactate levels.

Despite established exposure limits and safety standards as well as the availability of carbon monoxide (CO) alarms, each year 50,000 people in the United States visit emergency departments for CO poisoning. Carbon monoxide poisoning can occur from brief exposures to high levels of CO or from longer exposures to lower levels. Common symptoms can include headaches, nausea and vomiting, dizziness, general malaise, and altered mental status. Some patients may have chest pain, shortness of breath, and myocardial ischemia, and may require mechanical ventilation and treatment of shock. Individuals poisoned by CO often develop brain injury manifested by neurological problems, including cognitive sequelae, anxiety and depression, persistent headaches, dizziness, sleep problems, motor weakness, vestibular and balance problems, gaze abnormalities, peripheral neuropathies, hearing loss, tinnitus, Parkinsonian-like syndrome, and other problems. In addition, some will have cardiac issues or other ailments. While breathing oxygen hastens the removal of carboxyhemoglobin (COHb), hyperbaric oxygen (HBO2) hastens COHb elimination and favorably modulates inflammatory processes instigated by CO poisoning, an effect not observed with breathing normobaric oxygen. Hyperbaric oxygen improves mitochondrial function, inhibits lipid peroxidation transiently, impairs leukocyte adhesion to injured microvasculature, and reduces brain inflammation caused by the CO-induced adduct formation of myelin basic protein. Based upon three supportive randomized clinical trials in humans and considerable evidence from animal studies, HBO2 should be considered for all cases of acute symptomatic CO poisoning. Hyperbaric oxygen is indicated for CO poisoning complicated by cyanide poisoning, often concomitantly with smoke inhalation., Competing Interests: The authors of this paper declare no conflicts of interest exist with this submission., (Copyright© Undersea and Hyperbaric Medical Society.)

Carbon monoxide (CO) poisoning presents with many different cardiac effects, but one important presentation is its effect as a CO stress test to reveal underlying coronary artery disease (CAD). There are a limited number of publications detailing this phenomenon, but after CO intoxication it is important to suspect CAD in association with mild troponin leak or non-ST segment elevation myocardial infarction (NSTEMI) shown on electrocardiogram (EKG). We recently treated three patients with CO poisoning who had underlying CAD. In the first case a man presented to the emergency department with CO toxicity and an ST segment elevation myocardial infarction (STEMI), resulting in emergent angioplasty and the discovery of severe CAD. The second case involved an individual who presented with CO poisoning with rising troponin levels. An angioplasty discovered a stable 90% occlusion. The third case was a patient with CO poisoning and transient inferior T wave inversion EKG with borderline troponin elevation. Angioplasty showed only 30% occlusion, so the patient's presentation was likely due to direct CO cardiac toxicity. These cases demonstrate the varied presentations that CO poisoning can have on patients with underlying heart disease., Competing Interests: The authors of this paper declare no conflicts of interest exist with this submission., (Copyright© Undersea and Hyperbaric Medical Society.)

Acute limb ischemia (ALI) as a complication of acute carbon monoxide (CO) poisoning is rare. Several reports have utilized hyperbaric oxygen therapy (HBO2) as an adjunctive therapy for peripheral arterial diseases. However, no study has yet described the use of HBO2 for ALI precipitated by CO poisoning. Herein we report successful limb salvage achieved with adjunctive HBO2 and conventional therapies in a patient with CO-induced ALI. A 69-year-old man was admitted with acute CO poisoning; ALI of both lower extremities occurred on hospitalization day 3. Pre-existing risk factors for ALI other than CO were not definite. After conventional treatments including catheter-directed thrombolysis and endovascular thrombectomy, the right-side lesion remained and a left-side lesion was newly developed. In addition to prior therapies, 47 sessions of serial HBO2 were administered as adjunctive therapy, resulting in limb salvage. Acute CO poisoning can cause ALI as a rare complication. HBO2 may be utilized as an adjunctive treatment in ALI., Competing Interests: The authors of this paper declare no conflicts of interest exist with this submission., (Copyright© Undersea and Hyperbaric Medical Society.)

Objective: To describe the structural sequelae of carbon monoxide (CO) poisoning on the heart assessed using stress cardiac MRI (CMR). CO poisoning is common. While acute cardiac injury is frequent among survivors, the mid- and long-term effects of CO on the myocardium are unclear., Methods: CMR studies performed between the years 2005 and 2014 for a primary diagnosis of CO poisoning at a tertiary care center were reviewed by an experienced cardiologist. Variables of interest were compared between patients with normal and abnormal studies to identify factors associated with cardiac dysfunction., Results: Eighty-eight patients underwent stress CMR, age 34 years (range 11-70); 49% were male, 74 had acute poisoning and 14 had chronic poisoning (CO exposure for longer than 24 hours). Time from CO poisoning to imaging was 24 months (1 day-120 months). Patients were stratified into four categories, which included those with acute poisoning imaged: ≤12 months; 12-60 months; >60 months from the event; and those with chronic poisoning. Overall, 26 studies (30%) were abnormal. The most common findings were: left ventricular systolic dysfunction in 14 patients, right ventricular systolic dysfunction in nine, and LV dilatation in six. Abnormalities were mild in most cases and were equally prevalent in all four patient categories. Dyspnea at the time of follow-up was more frequent among those with abnormal studies., Conclusion: Mild alterations in ventricular structure and function are frequent in survivors of CO poisoning. Myocardial scarring is rare, suggesting that acute hypoxic injury may not fully explain these abnormalities., Competing Interests: The authors of this paper declare no conflicts of interest exist with this submission., (Copyright© Undersea and Hyperbaric Medical Society.)

Carbon monoxide (CO) poisoning is the most common cause of death and injury among all poisonings. Myocardial injury is detected in one-third of CO poisonings. In this Case Report, a previously healthy 41-year-old man was referred for CO poisoning. The initial electrocardiogram (ECG) showed 1mm ST segment elevation in leads DII, DIII, and aVF. As the patient did not describe chest pain and had no cardiac symptoms, ECG was repeated 10 minutes later and it was seen that ST segment elevation disappeared. As the patient had a transient ST segment elevation and elevated high-sensitive Tn-T (HsTn-T), the patient was transferred to the coronary angiography laboratory. The patient's left coronary system was normal, but a thrombus image narrowing the lumen by approximately 60% was observed in the right coronary artery. Intravenous tirofiban was administered for 48 hours. Control coronary angiography showed continuing thrombus formation and a bare metal stent was successfully implanted. This is the first reported case with transient ST segment elevation associated with acute coronary thrombus caused by CO poisoning. It may be recommended that patients with CO poisoning should be followed-up with a 12-lead ECG monitor or 24-hour ECG Holter monitoring, even if they show no cardiac symptoms and echocardiography shows no wall motion abnormality. Early coronary angiography upon detection of such dynamic ECG changes in these recordings as ST segment elevation can reduce the risk of myocardial infarction (MI) and mortality in these patients.

Introduction: Approximately 50,000 patients per year present at emergency departments (EDs) because of carbon monoxide (CO) intoxication. The hypothesis of this study was that the half-life of CO and the regression period of complaints could be reduced more rapidly by applying oxygen with the Continuous Positive Airway Pressure (CPAP) modality using a non-invasive mechanical ventilator., Methods: The patients were divided into Group 1 and Group 2 in terms of the treatment method applied. Patients in Group 1 received FiO2 1.0 15 l/minute oxygen at room temperature for at least 30 minutes with a non-rebreather mask. Patients in Group 2 received FiO2 1.0 oxygen at 12 cmH2O pressure with non-invasive mechanical ventilation for at least 30 minutes with an oronasal mask in the CPAP modality., Results: The median values (interquartile range) of carboxyhemoglobin (COHb) levels at zero and 30 minutes of patients were 19% (8) and 14% (6) in Group 1 and 22% (8) and nine percent (3) in Group 2; a median difference of six percent (2) was detected in Group 1 and of 13% (4) in Group 2 in the first 30 minutes (P <.001). When the symptoms of the patients were examined, the median values of Group 1 and Group 2 at zero minutes were both eight units and at 30 minutes were five and three units, respectively. A decrease of five units was determined in the median of Group 2 in the first 30 minutes, and a decrease of two units in the median of Group 1 (P <.001)., Conclusion: The use of CPAP was determined to more rapidly reduce COHb level as opposed to high-flow oxygen therapy. It is also thought that it may enable earlier discharge by reducing the duration of the emergency follow-up since it provides a faster improvement in the symptoms of the patients.

Troponin is a marker that displays cardiac injury quickly and accurately. In adults, troponin elevation is usually associated with coronary artery disease and requires urgent cardiac catheterization. In healthy children, myocardial injury is rare and may develop due to many different causes. Therefore, troponin elevation in children and adolescents does not usually require emergency cardiac catheterization. The aim of this study is to assess the most common causes of troponin elevation in children and adolescents and to show which diagnostic tests are helpful in assessing pediatric patients with elevated troponin. Patients who had been diagnosed with troponin I elevation (> 0.06 ng/ml) at Dr. Sami Ulus Maternity, Children's Health and Disease Training and Research Hospital between 2007 and 2018 were retrospectively evaluated. Patients undergoing cardiac surgery and those with severe congenital heart disease were excluded from the study. The medical records of the patients were examined and age, gender, diagnostic tests, and diagnosis were evaluated. During the study period, the records of 972 patients were obtained. 213 patients were excluded from the study because of heart surgery, congenital heart disease, and neonatal asphyxia or sepsis. Of the remaining 759 patients, 58% were male, 42% were female, and the median age was 4 years (3 days to 17 years). The most frequent causes are myopericarditis (n: 164), drug intoxications (n: 85), carbon monoxide poisoning (n: 74), perimyocarditis (n: 65), and intensive inhalation β agonist use in acute asthma and lower respiratory tract infections (n: 70). Patients diagnosed with myocarditis and myopericarditis were admitted with a complaint of chest pain, and the diagnosis was made by history, physical examination, ECG, and echocardiographic findings. Unlike adults, troponin I elevation may be associated with many cardiac and non-cardiac pathologies in children. The most common pathologies in cardiac etiology are myopericarditis and perimyocarditis and can be diagnosed by history, physical examination, ECG, and echocardiography. Cardiac catheterization is not necessary except for rare cardiac pathologies and does not alter the prognosis.

Objective: In this study, we aimed to investigate oxidative stress and antioxidant parameter levels in patients with carbon monoxide (CO) poisoning., Methods: The study was conducted prospectively between March 1, 2015 and April 30, 2016 in the pediatric emergency department. Eligible patients included children aged 0-18 years old with a diagnosis of CO poisoning. To determination of oxidative stress and antioxidant parameter levels, venous blood with heparinized and urine samples were drawn during the admission and after normobaric oxygen (NBO) and hyperbaric oxygen (HBO) treatment., Results: Forty-seven children with CO poisoning for study group and 29 patients as control group were included to the study. Sixteen patients treated with HBO. Basal plasma malondialdehyde levels were found to be significantly higher in the CO poisoning group when compared with the control group ( p = 0.019). There is no significant difference in oxidative stress and antioxidant parameter levels except erythrocyte catalase enzyme levels in patients treated with NBO when comparing before and after NBO treatment ( p > 0.05). Decreasing of basal erythrocyte catalase enzyme levels were found statistically significant after NBO treatment ( p = 0.04). There was no significant difference in oxidative stress and antioxidant parameter levels in patients treated with HBO before and after therapy ( p > 0.05)., Conclusions: CO poisoning is associated with increased lipid peroxidation in children immediately after the poisoning. However, both treatment modalities including NBO or HBO do not have a significant effect on oxidative stress or antioxidant parameter levels.

Objectives: To describe health care quality indicators in cases of carbon monoxide (CO) exposure attended by prehospital services and to explore factors associated with the use of pulse CO-oximetry (SpCO) for the noninvasive estimation of CO saturation of arterial blood., Material and Methods: Cohort study of patients exposed to CO and transported by advanced life support units of the Emergency Medical Services of Catalonia between January 2015 and December 2017. We selected 11 applicable quality indicators and used multivariate analysis to explore factors associated with the recording of SpCO., Results: We studied 1676 cases of CO exposure. SpCO was recorded in 1108 cases (66.1%). CO saturation exceeded 10% in 358 patients (32.3%). Adherence was deficient in 5 of the 11 applicable quality indicators. Multivariate analysis showed less use of pulse CO-oximetry when another toxic exposure was present (odds ratio [OR], 0.34; 95% CI, 0.11- 1.00) and when the first responder was from the advanced life support service (OR, 0.43; 95% CI, 0.31-0.59). SpCO was used more in the presence of a history of mental health problems (OR, 3.01; 95% CI,1.27-7.17), headache (OR, 2.13; 95% CI, 1.2-3.72), and along with use of oxygen therapy (OR, 10.33; 95% CI, 5.46-19.53)., Conclusion: Prehospital attendance of episodes of CO exposure is marked by failure to comply with some health care quality indicators. We detected factors associated with under use of SpCO as well as areas to target for improvement.

Background: To investigate the role of fetuin-A as a potential biomarker for prognosis of fatality in patients with carbon monoxide (CO) poisoning., Methods: In a prospective study, 60 poisoned patients with CO who were admitted to the department of emergency medicine between August 2017 and April 2018 were compared to 40 paired control subjects from the same department., Results: Fetuin-A levels were significantly lower in the patients with CO poisoning, especially in those non-survive (68.9 ± 7.6 vs 59.5 ± 4.1, p = 0.019). The area under the curve in the ROC curve analysis for the fetuin-A was 0.914 with a cut off of 61.15 mmol/L., Conclusions: The decrease of Fetuin-A may indicate an early signal for the progression of fatality due to CO poisoning., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background and Objectives: Carbon monoxide is one of the most common causes of fatal intoxications in the United States, and multiple previous studies have demonstrated that cigarette smokers have higher levels of carbon monoxide in their blood. However, the potential negative effects due to acute carbon monoxide poisoning from excessive cigarette smoking have not been well established., Methods: This is a single patient case report., Results: In this case report, a 40-year-old male with a past medical history of depression, anxiety, panic attacks, and substance use disorder developed symptomatic, acute carbon monoxide poisoning secondary to heavy cigarette smoking in a confined space. In this patient, the cessation of clonazepam therapy coincided with increasing anxiety and panic disorder with agoraphobia triggering an escalation in his cigarette smoking. The patient smoked three packs of cigarettes in 3 hours and developed worsening of his symptoms. He required inpatient treatment with benzodiazepines and hyperbaric oxygen., Discussion and Conclusions: Therefore, it is important to recognize cigarette smoke as a significant source of carbon monoxide exposure., Scientific Significance: While the negative effects of cigarette smoking are often perceived as being chronic and only coming to fruition after numerous years of exposure, it is important for both physicians and patients to recognize the possibility for potentially life-threatening acute toxicity secondary to carbon monoxide exposure. (Am J Addict 2019;28:413-415)., (© 2019 American Academy of Addiction Psychiatry.)

Background: Carboxyhemoglobin (COHb) levels are obtained when there is suspicion for carbon monoxide (CO) exposure. Serial COHb levels are sometimes obtained despite the well-established half-life of COHb with oxygen supplementation. We sought to evaluate the trends and characteristics associated with obtaining serial carboxyhemoglobin levels., Methods: A retrospective review was performed at an academic medical center for all inpatient and emergency department cases with either single COHb or serial COHb levels from 1 April 2010 through 31 March 2015. Data collected included age, gender, pregnancy status, smoking history, encounter month, admission status, oxygen administration, fire or burn history, vital signs, presenting symptoms, hyperbaric oxygen (HBO2) therapy use, initial pH, troponin, lactate, and COHb levels. The time and change in values between serial levels were also obtained., Results: 624 cases were identified, with 106 (17%) having multiple carboxyhemoglobin levels. A mean of 2.6 (range 2 - 9) serial COHb levels were obtained. The average initial COHb was 8.9%. Subsequent serial levels were obtained on average at 353, 663 and 1,095 minutes and averaged 2.8%, 1.8% and 1.1% respectively. Serial COHb levels were obtained more commonly in burn patients, those admitted to the ICU and those who had HBO2 therapy. Four patients had an increase in COHb level on serial testing. The largest increase of these was from 2.0% to 3.9%., Conclusion: Serial COHb levels were not infrequent in this study. No clinically significant increase in COHb was identified by serial testing. Further studies should examine the clinical utility of such practices., Competing Interests: The authors of this paper declare no conflicts of interest exist with this submission., (Copyright© Undersea and Hyperbaric Medical Society.)

Carbon monoxide (CO) is an important cause of deaths via poisoning. CO poisoning causes inhibition of O 2 transport and development of tissue hypoxia, which then causes cell apoptosis. A significant indicator of cell apoptosis, soluble tumor necrosis factor-like weak inducer of apoptosis (sTWEAK) protein, is important for the stimulation of apoptosis. The primary purpose of this study is to determine whether apoptosis occurs during acute CO poisoning and to show that sTWEAK protein is an indicator of apoptosis that can be analyzed as a marker in the peripheral blood sample. The secondary aim is to determine the diagnostic and prognostic values of sTWEAK protein. The study was performed prospectively on 43 patients with CO poisoning and 30 healthy volunteer control individuals. The anamneses were taken from all patients, who also underwent physical examination. Complete blood count, biochemical markers, cardiac enzymes, and arterial blood gas measurements were analyzed. All the patients' sTWEAK protein levels were also analyzed. The sTWEAK protein level of patients with CO poisoning was 2278 pg/mL (1197-7234), while the level of the control group was 1609 pg/mL (310-3721). The patients' sTWEAK levels were significantly higher than the controls (area under the curve: 0.77 (0.66-0.89); p < 0.001), and the cutoff value was determined as 1895.50 pg/mL. The cutoff level had a sensitivity of 74.4%, a specificity of 76.7%, a positive predictive value of 82.0%, and a negative predictive value of 67.6%. sTWEAK is a significant indicator of apoptosis in CO poisoning that can be analyzed in the peripheral blood. However, further clinical trials are needed in terms of prognostic criteria.

This study aimed to assess the feasibility of using the plasma neutrophil gelatinase-associated lipocalin (NGAL) level at the time of presentation in the emergency department (ED) to predict acute kidney injury (AKI) and the long-term neurological outcomes of acute charcoal-burning carbon monoxide (CO) poisoning. This retrospective study included 260 patients who suffered acute charcoal-burning CO poisoning. The median plasma NGAL concentration at the time of presentation in the ED after acute charcoal-burning CO poisoning was 78 (54-115) ng/ml. The NGAL level was an independent predictor of AKI development and could be used to stratify the severity of AKI. However, the area under the receiver operating characteristic curve (AUC) of the predictive model for AKI that included both the plasma NGAL level and clinical parameters was comparable to that of the predictive model including only the clinical parameters. The plasma NGAL level at the time of presentation in the ED was an independent factor predicting long-term neurological outcomes in patients who did not develop AKI. In these patients, the plasma NGAL level significantly improved the predictive accuracy of the model when used in combination with clinical parameters. In contrast, the plasma NGAL level was not associated with long-term neurological outcomes in patients who developed AKI. Measurement of the plasma NGAL level at the time ED presentation might improve the prediction of long-term neurological outcomes in patients who do not develop AKI after acute charcoal-burning CO poisoning. However, it might not offer additional benefit for AKI prediction compared to previously used markers.

To assess myocardial injury related to acute carbon monoxide (CO) poisoning, serial troponin I is measured in patients not presenting with troponin I elevation. This retrospective study investigated whether parameters related to white blood cell (WBC) counts (total and differential WBC counts, neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio) improved predictive accuracy for troponin I elevation (> 0.04 ng/ml) in patients not presenting with evidence of myocardial injury. Serial parameters, troponin I values, and clinical courses were collected in 241 patients. Troponin I was elevated in 33 (13.7%) patients after hospitalization. The median lag times to troponin I elevation in patients with undetectable and detectable troponin I (0.015 ng/ml ≤ troponin I ≤ 0.04 ng/ml) at presentation were 5.9 h and 3.0 h, respectively. Patients with troponin I elevation after presentation had higher total WBC and neutrophil counts and NLRs and a lower lymphocyte count during the first 4 h after presentation than patients without troponin I elevation during hospitalization. Total WBC count, neutrophil count, and log NLR at presentation were selected as independent predictive factors for troponin I elevation after presentation. However, only the neutrophil count and log NLR at presentation improved the predictive accuracy in combination with clinical parameters compared with that achieved with a predictive model including only clinical parameters. The optimal cut-off neutrophil count and NLR were 5.21 × 10 3  /uL and 4.02, respectively. The total neutrophil count and NLR, which are widely available and inexpensive parameters obtained in the emergency department (ED), are promising screening tools for predicting the risk of troponin I elevation in patients without evidence of myocardial injury-related acute CO poisoning at presentation.

Objective: The aim of the study was to assess netrin-1 levels in carbon monoxide (CO) poisoning to determine its relationship with poisoning severity and neurotoxicity., Methods: This is a cross-sectional prospective study. The patients older than 18 years with CO poisoning were included. The patients were categorized into two groups on the basis of neurological involvement. Both the patient and the control groups were sampled for netrin-1 at 0th hour, and the patient group only was sampled for netrin-1 at 4th hour., Results: A total of 84 patients and 50 healthy controls were enrolled. The median 0th hour netrin-1 level of the patient group (765.1 pg/mL (619.8-983.1) was significantly higher than the control group (484 pg/mL (376-1031.6)) ( p < 0.001). There was also a significant difference between the 0th hour and 4th hour netrin-1 (888.9 pg/mL (700.3-1175.5)) levels in the patient group ( p < 0.001).There was no significant statistical difference between patients with and without neurological involvement ( p = 0.62) and between those who underwent hyperbaric oxygen therapy (HBOT) and those who did not ( p = 0.76) with respect to 4th hour netrin-1 levels., Conclusion: The significantly higher netrin-1 levels in patients with CO poisoning, suggests that netrin-1 is elevated as a stress marker. Although there is no significant difference in netrin-1 levels in patients with neurological impairment in CO poisonings, netrin-1 may show subclinically neurological effects. Hence, we believe that netrin-1 cannot be used as a marker of poisoning severity.

Background: This study was conducted to assess and clarify the predictive risk factor of neurologic outcome in patients with acute carbon monoxide (CO) poisoning., Methods: A total of 453 patients with acute CO poisoning were admitted to the emergency department of Samsung Changwon Hospital from January 2010 to June 2017. Patients with acute CO poisoning who were followed for >6 months were studied. Initial Glasgow Coma Score (GCS), serum neuron-specific enolase (NSE), and lactate were measured after emergency department arrival. Patients were divided into two groups (good vs poor neurologic outcome)., Results: A total of 432 patients (median age: 55 years, range: 17-91 years) were enrolled. There was a statistical difference between the good neurologic outcome group and the poor neurologic outcome group in terms of Exposure time, WBC, aspartate aminotransferase (AST), CK-MB, Troponin-I, creatinine kinase, NSE, lactate, CO-Hb, and GCS. NSE, lactate, and GCS were the early predictors of development of poor neurologic outcome. The areas under the curve in the ROC curve analysis for the GCS, NSE, and lactate were 0.842, 0.795, and 0.894, respectively., Conclusion: Initial serum lactate level may correlate with the patient neurologic outcomes and prove to be a useful prognostic factor. Also NSE, and GCS might be a useful additional parameters that could predict the neurologic outcome on acute CO poisoned patients., (Copyright © 2018. Published by Elsevier Inc.)

Introduction: Waterpipe (hookah) smoking is popular; in Dutch surveys, 26% of the respondents have smoked a waterpipe at least once. However, waterpipe smoking is not without risk. We present a series of carbon monoxide (CO) poisonings after waterpipe smoking and discuss the etiology and treatment of CO intoxication after waterpipe smoking., Case Descriptions: We present three patients who presented with syncopial episodes and a variety of other neurological and circulatory symptoms after smoking a waterpipe. All patients had significantly elevated carboxyhaemoglobin levels (26%, 19% and 26%). Patients were treated with oxygen, following Dutch guidelines; one patient was admitted for eight hours of oxygen therapy. The other two patients were observed shortly, diverging from the guidelines because symptoms passed and the carboxyhaemoglobin normalised., Discussion: Reviewing combustion chemistry, the formation of CO is a logical consequence of using burning coals as a heat source. This is due to CO2 reduction with carbon. This chemical process has not previously been related to waterpipe smoking. Dutch guidelines advise eight hours of oxygen therapy. The research this guideline is based on, justifies therapy directed at symptom relief and carboxyhaemoglobin normalisation. This strategy may prevent unnecessary hospital admissions and exposure to high-dose oxygen., Conclusion: We described three cases of CO intoxication after waterpipe smoking and argue why this may not be an incidental finding. Greater awareness of this risk is urgently needed. We conclude that the literature does not firmly support a fixed treatment duration.

Background: Carbon monoxide (CO) is one of the most common causes of unintentional poisonings resulting in death. Patients with more severe findings such as loss of consciousness and persistent neurological or cardiovascular dysfunction require hospitalization. Although there are clinical findings which determine hospitalization criteria in patients presenting with CO poisoning, there is some ambiguity regarding laboratory biomarkers which determine length of hospital stay (LOS) in these patients. In this study, we aimed to identify the effectiveness of initial blood gases and biochemical parameters in predicting LOS in patients presenting to the emergency department with CO poisoning by retrospective analysis of medical records., Methods: This study was conducted in the Emergency Department (ED) of Samsun Training and Research Hospital by analyzing from medical records retrospectively of 275 patients who were admitted to the hospital following acute CO poisoning between January 2014 and July 2017. The patients were divided into 3 groups according to LOS: Group I, patients with LOS < 24 hours; group II, those with LOS > 24 hours and < 3 days; and group III, those with LOS > 3 days., Results: In comparisons regarding lactate and troponin-I, it was found that there were significant differences in both parameters among the three groups (p = 0.000) and that both lactate and troponin-I levels were higher in group III than groups I and II, with group I being lowest (group III > group II > group I). While there was a mod¬erate positive statistically significant correlation between LOS and lactate (r: 0.43, p = 0.001) and troponin (r: 0.31, p = 0.001), a weak positive correlation was determined with CK (r: 0.19, p = 0.04). In this study, it was found that lactate and troponin-I values were more effective in predicting LOS when compared to carboxyhemoglobin levels and other biochemical parameters., Conclusions: The results of this study may guide clinicians to predict LOS in patients who present with CO poi-soning and have high troponin-I and lactate levels at the time of admission to EDs.

Objective: Carbon monoxide poisoning (COP) is the leading cause of mortality and morbidity due to poisoning worldwide. Because children are affected more quick and severely from COP, they may require a longer treatment period, even if carboxyhemoglobin (CO-Hb) and/or lactate levels return to normal. Therefore, a new marker that predicts the duration of treatment and the final outcomes of COP is needed., Methods: This case control study was conducted on 32 carbon monoxide-poisoned patients younger than 18 years who had been admitted to pediatric emergency department. The control group included age- and sex-matched 30 healthy children. Blood samples were obtained for analysis of arterial blood gases, CO-Hb percent, methemoglobine, lactate, and asymmetric dimethylarginine (ADMA)., Results: Asymmetric dimethylarginine levels were significantly increased (P < 0.05) in patients with COP on admission and after the treatment when compared with controls (1.36 [0.89-6.94], 1.69 [0.76-7.81], 1.21 [0.73-3.18] nmol/L, respectively). There was no positive correlation between CO-Hb and ADMA levels on admission and at 6 hours (P = 0.903, r = 0.218, P = 0.231, r = 0.022, respectively). Positive correlation was found between lactate and CO-Hb levels on admission (P = 0.018, r = 0.423)., Conclusions: This study showed that ADMA levels were still high after 6 hours of 100% oxygen therapy in children with COP, even CO-Hb and/or lactate levels return to normal range. On the basis of these results, we consider that ADMA may be a useful biomarker in patient with COP.