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Objective: This study aimed to evaluate the effects of coma on the prognosis and delayed encephalopathy in patients with acute carbon monoxide poisoning (DEACMP) and to analyze the predictive factors affecting the prognosis of these patients., Methods: Patients with acute carbon monoxide poisoning were divided into comatose and non-comatose groups. The primary outcomes included clinical cure and the occurrence of DEACMP. Multivariate logistic regression analysis was performed to identify independent predictors of clinical outcome., Results: Multivariate analysis indicated that coma (clinical cure: adjusted odds ratio [aOR] 0.24, 95% CI 0.12-0.47; DEACMP: aOR 42.5, 95% CI 7.99-789), longer the time from onset to the first HBOT (clinical cure: aOR 0.43, 95% CI 0.24-0.77; DEACMP: aOR 3.21, 95% CI 1.56-6.78) and abnormal chest CT findings (clinical cure: aOR 0.23, 95% CI 0.12-0.45; DEACMP: aOR 5.36, 95% CI 2.41-12.60) were associated with a lower rate of clinical cure and a higher proportion of DEACMP; and lower age was an independent predictor of clinical cure (aOR 0.96, 95% CI 0.94-0.98), but not of DEACMP (aOR 0.99, 95% CI 0.96-1.01). In comatose patients, both the duration of coma and abnormal chest CT findings were an independent factor for clinial cure (aOR 0.96, 95% CI 0.93-0.99; aOR 0.34, 95% CI 0.15-0.74) and DEACMP (aOR 1.09, 95% CI 1.06-1.14; aOR 4.93, 95% CI 1.67-16.30)., Conclusion: Coma and the duration of coma were significant predictors of clinical cure and DEACMP in patients; the older the patient, the longer the duration of coma, and the longer the time from onset to the first hyperbaric oxygen therapy (> 6 h), indicating that the patient's prognosis is often worse; abnormal chest CT manifestations were also an independent risk factor for a poor patient's prognosis., Competing Interests: Declarations. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Carbon monoxide (CO) is a colorless, odorless, toxic, and polluting gas produced by the incomplete combustion of carbon-containing substances such as coal and petroleum. CO is also a gaseous signaling molecule, which participates in and regulates a series of physiological and pathological processes. In this work, two kinds of CO-activated fluorescence probes 2 and 4 were designed and synthesized for the rapid detection of CO and evaluation of acute CO poisoning by hyperbaric oxygen therapy. Specifically, 2 and 4 both used the allyl formate group as the CO response unit and when they reacted with CO, the response group broke off and the fluorescence burst effect subsided, allowing them to regain fluorescence. In addition, because of the excellent optical properties of 4 (especially, colorimetric and near-infrared (NIR) fluorescence), subsequent experiments were performed with 4 as a representative for imaging CO in zebrafish and mice with impressive results. Interestingly, 4 has been successfully used for assessing acute CO poisoning by hyperbaric oxygen therapy with satisfactory results, revealing practical application in the connection between CO and hyperbaric oxygen therapy., 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 © 2024 Elsevier B.V. All rights reserved.)

Carbon monoxide (CO) poisoning is one of the most common causes of injury and death from poisoning. The primary objective of therapy is to eliminate CO from the patient as quickly as possible to prevent acute and long-term effects. The ideal treatment is hyperbaric oxygen in a pressure chamber. However, pressure chambers are scarce, and therefore, the most common treatment is normobaric oxygen (NBO), which, however, has limited efficacy. Here, we present a full-scale batch system for extracorporeal hyperoxygenation therapy (EHT), which facilitates CO elimination extracorporeally by increasing the dissolved oxygen concentration in the blood. The EHT was characterized in vitro, resulting in a minimum carboxyhemoglobin half-life of 3.26 ± 0.11 min. In large animal trials the EHT reduced the median carboxyhemoglobin half-life by 42% (29.77 min EHT vs. 70.8 min control (NBO)). However, the EHT also induced oscillations in hemodynamic pressures due to changes in the animals' circulatory volume during operation. After optimization, the EHT could be a promising option for treating CO poisoning., Competing Interests: Declarations. Competing interests: RWTH Aachen University has filed a patent application entitled “System for the extracorporeal elimination of carbon monoxide” (WO2017153034A1), the inventors are P.C.S., T.S.-R., and U.S.. N.B.S., P.C.S., and M.F.M. are co-founders of a company to commercialize the technology described in this manuscript. The other authors declare that they have no conflict of interest., (© 2025. The Author(s).)

Acute carbon monoxide poisoning (ACOP) is a cause of accidental or deliberate deaths worldwide. Subsequent complications, particularly delayed neurological sequelae (DNS), are preventable and treatable based on their pathophysiology. Hyperbaric oxygenation therapy (HBO) is a potential procedure for preventing and treating DNS; however, the effects of HBO on DNS are unclear and debated. In the present study, we investigated which factors are associated with the development of DNS and the effects of HBO in patients with ACOP. We performed retrospective subanalyses of the COP-J registry, focusing on adults who underwent HBO, regardless of whether they developed DNS. The multivariable analysis showed that the Glasgow coma scale (GCS) on admission was significantly associated with DNS (odds ratio 0.736; 95% confidence interval 0.608-0.892; P = 0.002). The receiver operating characteristic curve analysis of GCS for DNS revealed a cutoff value of 12.5 according to Youden's index (sensitivity 80.8%, specificity 76.9%). This retrospective analysis of a nationwide Japanese registry of ACOP showed that low GCS scores on admission could be a predictive factor for DNS, with a possible cutoff value of ≤12, in patients who undergo HBO.

Aim: To evaluate variations in diagnostic criteria and management recommendations for smoke inhalation injury (SII) amongst the burn networks of England, Scotland, and Wales., Methods: A descriptive cross-sectional study examining SII guidelines provided by adult burn units and centres in England, Scotland and Wales., Results: All 16 adult burn units and centres responded. Fourteen (87.5 %) had guidelines. Due to sharing of guidelines, ten unique guidelines were assessed. Diagnostic criteria showed variability with no universal criterion shared amongst guidelines. Bronchoscopy was recommended by 90 % of guidelines, but the timing varied. The use of bronchoscopic scoring systems was recommended by four guidelines. Bronchoalveolar lavage (BAL) was recommended by four, with considerable variation in frequency and choice of lavage fluid. All guidelines advised at least one nebulised agent: heparin (n = 8); N-acetyl cysteine (NAC) (n = 8); or salbutamol (n = 8). All guidelines included advice on carbon monoxide poisoning; however, carboxyhaemoglobin (COHb) cut-off levels for treatment varied (5 % [n-4], 10 % [n = 3], 15 % [n = 1]). All recommended high-flow oxygen. Seven (70 %) guidelines offered guidance on cyanide poisoning. Reduced/altered consciousness was the only consistent diagnostic criterion. Five (50 %) guidelines provided intubation guidance, emphasising the role of a 'senior clinician' as the intubator. Ventilatory guidance appeared in eight guidelines, focusing on lung protective ventilation (n = 8); oxygenation goals (n = 3); and permissive hypercapnia (n = 3). Within lung-protective ventilation, advice on tidal volume (6, or 6-8 ml/kg) and plateau pressures (>30 cmH2O) were presented most commonly (n = 7)., Conclusion: This study has outlined the substantial variations in guidance for the management of SII. The results underscore the need for a national guideline outlining a standardised approach to the diagnosis and management of SII, within the limitations of the current evidence., Competing Interests: Declaration of Competing Interest The authors have no conflicting interests to disclose., (Copyright © 2024 Elsevier Ltd and International Society of Burns Injuries. All rights reserved.)

Objective: High-definition transcranial direct current stimulation (HD-tDCS) has the potential to improve cognitive functioning following neurological injury and in neurodegenerative conditions. In this case report, we present the first use of HD-tDCS in a person with severe anterograde amnesia following carbon monoxide poisoning., Method: The participant underwent two rounds of HD-tDCS that were separated by 3 months (Round 1 = 30 sessions; Round 2 = 31 sessions). We used finite element modeling of the participant's structural MRI to develop an individualized montage that targeted multiple brain regions involved in memory encoding, as identified by Neurosynth., Results: Overall, the participant's objective cognitive functioning improved significantly following Round 1, declined during the 2 months without HD-tDCS, and again improved following Round 2. Subjective informant reports from family and medical personnel followed this same pattern of improvement following each round with a decline in between rounds. We also provide preliminary evidence of altered brain activity during a learning/memory task using functional near-infrared spectroscopy, which may help establish the physiological effects of HD-tDCS in future work., Conclusion: Overall, these findings reinforce the potential value of HD-tDCS as a user-friendly method of enhancing cognition following anoxic/hypoxic brain injury.

Carbon monoxide is a colourless, tasteless and odourless gas that is a by-product of incomplete combustion of hydrocarbons such as gas or coal. Carbon monoxide poisoning is associated with high levels of mortality and morbidity, although the symptoms of exposure are non-specific and difficult to diagnose. Historically, healthcare professionals who work directly in service users' homes have faced a higher risk of exposure to environments contaminated with carbon monoxide. Despite improved heating engineering and greater protective legislation, there still remains a tangible risk for community nurses and service users, particularly in homes still using open fires, old heating systems and poorly maintained heating appliances. This article provides a scientific summary of carbon monoxide poisoning for nurses working in the community setting. It outlines evidence-based guidance on prevention and initial treatment actions, along with safety instructions to follow in the event of exposure to carbon monoxide.

Background: Compartment syndrome following carbon monoxide (CO) poisoning and compression, can have a devastating impact on neuromuscular structures, depending on a time-based dosage., Purpose: To investigate multidimensional physiotherapy's short-term and long-term outcomes in identical twin cases who developed compartment syndrome due to CO poisoning and prolonged compression., Study Design: Case report., Methods: This study was conducted with two male cases, a 21-year-old identical twin. The loss of consciousness due to CO poisoning lasted for 15 hours. Case one had compartment syndrome that caused damage to the median and ulnar nerves in the right forearm, while Case two had compartment syndrome that caused damage to the radial nerve in the left forearm. No surgical intervention was performed (Fasciotomy etc)., Results: The disability, dexterity, hand health status, sensory-motor function, and edema were evaluated. Initial evaluations showed severe sensory and motor dysfunction, disability, and edema. Treatment included Complex decongestive physiotherapy, electrical stimulation, therapeutic ultrasound, orthotics, and exercises. On the 144th day (discharge day), both cases still exhibited weakness in functional strength and sensory loss compared to the uninjured side. At the ninth month, all parameters except strength were similar to the uninjured side in both cases. By the 53rd month, strength also reached normal values., Conclusions: Multidimensional physiotherapy effectively manages edema, improves sensory-motor function, and enhances hand function in the short and long term., Competing Interests: Declaration of Competing Interest None., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Acute carbon monoxide (CO) poisoning may cause liver damage and liver dysfunction. Therefore, in this study, we aimed to compare the efficiency of normobaric oxygen (NBO) and high-flow nasal cannula oxygen (HFNCO) treatments on liver injury. For that purpose, 28 male Wistar albino rats were divided into four groups (Control, CO, CO + NBO, and CO + HFNCO). The control group was allowed to breath room air for 30 min. Acute CO poisoning in CO, CO + NBO, CO + HFNCO was induced by CO exposure for 30 min. Thereafter, NBO group received 100% NBO with reservoir mask for 30 min. HFNCO group received high-flow oxygen through nasal cannula for 30 min. At the end of the experiment, all animals were sacrificed by cardiac puncture under anesthesia. Serum liver function tests were measured. Liver tissue total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI) levels, tissue histomorphology and immunoexpression levels of Bax, Caspase 3, TNF-α, IL-1β, and NF-κB were also examined. Our observations indicated that acute CO poisoning caused significant increases in blood COHb, serum aminotransferase (AST), alanine aminotransferase (ALT0, alkaline phosphatase (ALP), total protein, albumin, and globulin levels but a decrease in albumin to globulin ratio (all, p  < 0.05). Furthermore, acute CO poisoning significantly increased the OSI value, and the immunoexpresssion of Bax, Caspase 3, TNF-α, IL-1β, and NF-κB in liver tissue (all, p  < 0.05). These pathological changes in serum and liver tissue were alleviated through both of the treatment methods. In conclusion, both the NBO and HFNCO treatments were beneficial to alleviate the acute CO poisoning associated with liver injury and dysfunction.

Carbon monoxide poisoning can occur as part of smoke exposure in the burn population. Here we report the case of a 32-year-old, previously healthy male, with carbon monoxide-related blindness after smoke exposure in an apartment fire. Cerebral hypoperfusion was diagnosed using magnetic resonance imaging of the brain, and the patient was diagnosed with cortical visual impairment. He was treated with hyperbaric oxygen therapy following which he had partial recovery of his vision. There is a paucity of information regarding this phenomenon and its treatment., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Burn Association. 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.)

Background: Carbon monoxide (CO) results from incomplete combustion of carbon-based materials, causing symptoms such as headaches, dizziness, nausea, chest pain, confusion, and, in severe cases, unconsciousness. Normobaric oxygen therapy (NBOT) is the standard therapy, whereas hyperbaric oxygen therapy (HBOT) is recommended in severe cases of organ damage. This study examined the early and late adverse outcomes in patients with severe CO poisoning., Materials and Methods: This study analyzed severe cases of CO poisoning among patients admitted to the emergency department between January 2020 and May 2022. The demographic, clinical, and laboratory data of symptomatic individuals and those requiring HBOT were examined. The study recorded early outcomes, such as intubation and in-hospital mortality, and late outcomes, such as delayed neurological sequelae and 1-year mortality. Chi-square tests, Spearman's rho correlation tests, and logistic regression analyses were performed to identify factors affecting these outcomes., Results: Patients who received HBOT showed a significant difference in delayed neurological sequelae (DNS) compared to those who received NBOT (p = 0.037). Significant differences were observed in the need for intubation, in-hospital mortality, and 1-year mortality between patients based on COHb levels, but no significant differences were found in DNS. The 1-year mortality probability was significantly influenced by COHb level (odds ratio = 1.159, 95% CI [1.056-1.273]). Patients receiving NBOT had a higher odds ratio for DNS risk than those receiving HBOT (odds ratio = 8.464, 95% [1.755-40.817], p = 0.008)., Conclusion: The study showed no differences in intubation, in-hospital mortality, and 1-year mortality rates between the HBOT and NBOT groups. However, significant differences in DNS suggest that treatment modalities have different effects on neurological outcomes. High COHb levels are associated with an increased risk of intubation, and mortality underscores the significance of monitoring COHb levels in clinical evaluations., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Vural, Dolanbay. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Carbon monoxide (CO) is a relatively frequent cause of poisoning evaluated in emergency departments. The risk of neurologic injuries, such as cognitive, psychological, vestibular, and motor deficits, is 25% to 50%. However, the risk of cardiac injuries should also be considered. Among patients with CO poisoning, the mortality in patients with myocardial injury is approximately 3 times greater than that in patients without myocardial injury. In large-scale studies, up to 69.2% of patients with acute CO poisoning exhibiting elevated troponin I levels and no underlying cardiovascular illnesses had late gadolinium enhancement on cardiac magnetic resonance, suggesting covert CO-induced myocardial fibrosis. Myocardial damage can be evaluated using electrocardiography, echocardiography, computed tomography, and cardiac magnetic resonance. This paper offers recommendations for cardiac evaluations based on our collective experience of managing >2,000 cases of acute CO poisoning with supporting information taken from peer-reviewed published reports on CO poisoning., Competing Interests: Funding Support and Author Disclosures This work was supported in part by the National Research Foundation of Korea, which is funded by the Korean government (Ministry of Science and Information and Communications Technology, grant number NRF-2021R1A2C200492211) and by a grant from the National Institutes of Health (National Institute of Neurological Disorders and Stroke) (R01-NS122855). The sponsors had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and the decision to submit the manuscript for publication. The authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2024 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: The use of both edaravone (EDA) and hyperbaric oxygen therapy (HBOT) is increasingly prevalent in the treatment of delayed encephalopathy after carbon monoxide poisoning (DEACMP). This meta-analysis aims to evaluate the efficacy of using EDA and HBOT in combination with HBOT alone in the treatment of DEACMP., Methods: We searched and included all randomized controlled trials (RCTs) published before November 6, 2023, from 12 Chinese and English databases and clinical trial centers in China and the United States. The main outcome indicator was the total effective rate. The secondary outcome indicators included the Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), National Institutes of Health Stroke Scale (NIHSS), Barthel Index (BI), Hasegawa Dementia Scale (HDS), Fugl-Meyer Assessment (FMA), Superoxide Dismutase (SOD), and Malondialdehyde (MDA). Statistical measures utilized include risk ratios (RR), weighted mean difference (WMD), and 95 % confidence intervals (95 % CI)., Results: Thirty studies involving a combined total of 2075 participants were ultimately incorporated. It was observed that the combination of EDA with HBOT for the treatment of DEACMP demonstrated an improvement in the total effective rate (RR: 1.25; 95 % CI: 1.20-1.31; P < 0.01), MMSE (WMD: 3.67; 95 % CI: 2.59-4.76; P < 0.01), MoCA (WMD: 4.38; 95 % CI: 4.00-4.76; P < 0.01), BI (WMD: 10.94; 95 % CI: 5.23-16.66; P < 0.01), HDS (WMD: 6.80; 95 % CI: 4.05-9.55; P < 0.01), FMA (WMD: 8.91; 95 % CI: 7.22-10.60; P < 0.01), SOD (WMD: 18.45; 95 % CI: 16.93-19.98; P < 0.01); and a reduction in NIHSS (WMD: -4.12; 95 % CI: -4.93 to -3.30; P < 0.01) and MDA (WMD: -3.05; 95 % CI: -3.43 to -2.68; P < 0.01)., Conclusion: Low-quality evidence suggests that for DEACMP, compared to using HBOT alone, the combined use of EDA and HBOT may be associated with better cognition and activity of daily living. In the future, conducting more meticulously designed multicenter and large-sample RCTs to substantiate our conclusions is essential., 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 © 2024. Published by Elsevier Ltd.)

Objective: To identify and characterize the population of Pediatric patients referred to our hyperbaric oxygen therapy center., Methods: Retrospective and observational study, including pediatric patients treated with hyperbaric oxygen therapy, from 2006 to 2021, at the hyperbaric medicine reference center in the north of Portugal. Variables of interest were extracted from electronic medical records., Results: Our study included 134 patients. The most frequent reasons for referral were carbon monoxide poisoning (n=59) and sudden sensorineural hearing loss (n=41). In 75 cases (56%), treatment was initiated in an urgent context. Symptom presentation at Emergency Department varied among patients, the most frequent being headache and nausea/vomiting. Concerning carbon monoxide poisoning, the most common sources were water heater, fireplace/brazier, and boiler. Regarding adverse effects, it was identified one case of intoxication by oxygen and four cases of middle ear barotrauma., Conclusions: The most frequent cause for referral was carbon monoxide poisoning. All patients evolved favorably, with few side effects being reported, emphasizing the safety of this therapy. While most pediatricians may not be aware of the potential benefits arising with hyperbaric oxygen therapy, it is of upmost importance to promote them, so that this technique is increasingly implemented.

In this study, we analyzed the factors influencing the development of delayed encephalopathy in patients with acute carbon monoxide poisoning (ACOP) (DEACMP) following conventional treatment such as hyperbaric oxygen therapy (HBOT). Between January 2012 and January 2022, we retrospectively analyzed 775 patients with ACOP, who were admitted to the Second Department of Rehabilitation Medicine and received HBOT in the Second Hospital of Hebei Medical University. These patients were divided into the non-DEACMP and DEACMP groups based on their follow-up; we then compared the general data, clinical characteristics, admission examination, and treatment between the two groups to identify risk factors for the development of DEACMP. The DEACMP group comprised of 168 cases, while the non-DEACMP group consisted of 607 cases. Univariate analysis showed that there were 20 possible prognostic factors in the non-DEACMP and DEACMP groups. The results of multivariable regression analyses suggested that the occurrence of DEACMP was significantly correlated with advanced age, the combination of multiple medical histories, the duration of CO exposure, the duration of coma, poisoning degree, the Interval between ACOP and the first HBOT, the total number of HBOTs, and the combination with rehabilitation treatment. DEACMP patients who are older, have more comorbidities, prolonged CO exposure, prolonged coma, severe intoxication, long intervals between ACOP and the first HBOT, fewer HBOT treatments, and who are not treated with a combination of rehabilitative therapies have a poor prognosis., (© 2024. The Author(s).)

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.

Carbon monoxide (CO) poisoning is a leading cause of poison-related morbidity and mortality worldwide. By binding to hemoglobin and other heme-containing proteins, CO reduces oxygen delivery and produces tissue damage. Prompt treatment of CO-poisoned patients is necessary to prevent acute and long-term complications. Oxygen therapy is the only available treatment. Visible light has been shown to selectively dissociate CO from hemoglobin with high efficiency without affecting oxygen affinity. Pulmonary phototherapy has been shown to accelerate the rate of CO elimination in CO poisoned mice and rats when applied directly to the lungs or via intra-esophageal or intra-pleural optical fibers. The extracorporeal removal of CO using a membrane oxygenator with optimal characteristic for blood exposure to light has been shown to accelerate the rate of CO illumination in rats with or without lung injury and in pigs. The development of non-invasive techniques to apply pulmonary phototherapy and the development of a compact, highly efficient membrane oxygenator for the extracorporeal removal of CO in humans may provide a significant advance in the treatment of CO poisoning., Competing Interests: Declaration of competing interest Luca Zazzeron, Walfre Franco, Rox Anderson are listed as inventors on two patent applications submitted by the Massachusetts General Hospital on the use of phototherapy to treat carbon monoxide poisoning., (Copyright © 2024 Elsevier Inc. All rights reserved.)

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

Aim: We aimed to investigate whether there is a difference in the rate of decrease in carboxyhemoglobin (COHB) values between high-flow nasal oxygen (HFNO) and normobaric oxygen (NBO) therapy., Material and Method: This retrospective observational study included patients with carbon monoxide poisoning who were treated with HFNO or NBO (control group). All patients were started on NBO therapy with a non-rebreather face mask at a rate of 15 L/min. In the NBO group, NBO treatment was continued until the COHB value fell below 10%. In the HFNO group, as soon as the preparation of the HFNO device was completed, NBO treatment was terminated and HFNO treatment was started and continued until the COHB value fell below 10%. The primary outcome of the study was the difference between HFNO and NBO in terms of COHB half-life rates., Results: A total of 81 patients were included in the study, 44 in the HFNO group and 37 in the NBO group. The median of COHB t 1/2 values between HFNO and the NBO treatment groups were 47.3 (IQR: 25-75%: 31.5-65.4) and 46 (IQR: 25-75%: 32.3-56.2), respectively, but this difference was not statistically significant (p = 0.81)., Conclusion: The results of this study suggest that HFNO treatment does not have a significant advantage over NBO treatment in the carbon monoxide elimination rate within the first 60 min of treatment., (© 2023. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Objectives: To identify predictors for developing delayed neurological syndrome (DNS) after an initial episode of carbon monoxide (CO) poisoning in the interest of detecting patients most likely to develop DNS so that they can be followed., Material and Methods: Retrospective review of cases of CO poisoning treated in the past 10 years in the emergency departments of 4 hospitals in the AMICO study (Spanish acronym for the multicenter analysis of CO poisoning). We analyzed demographic characteristics of the patients and the clinical characteristics of the initial episode. The records of the cohort of patients with available follow-up information were reviewed to find cases of DNS. Data were analyzed by multivariant analysis to determine the relationship to characteristics of the initial exposure to CO., Results: A total of 240 cases were identified. The median (interquartile range) age of the patients was 36.2 years (17.6-49.6 years); 108 patients (45.0%) were men, and the poisoning was accidental in 223 cases (92.9%). The median carboxyhemoglobin concentration on presentation was 12.7% (6.2%-18.7%). Follow-up details were available for 44 patients (18.3%). Eleven of those patients (25%) developed DNS. A low initial Glasgow Coma Scale score predicted the development of DNS with an odds ratio (OR) of 0.61 (95% CI, 0.41-0.92) and an area under the receiver operating characteristic curve of 0.876 (95% CI, 0.761-0.990) (P .001)., Conclusion: The initial Glasgow Coma Scale score seems to be a clinical predictor of DNS after CO poisoning. We consider it important to establish follow-up protocols for patients with CO poisoning treated in hospital EDs.

Introduction: Hyperbaric oxygen treatment (HBOT) remains a recognised treatment for acute carbon monoxide (CO) poisoning, but the utility of HBOT in treating CO-induced delayed neurological sequelae (DNS) is not yet established., Case Description: A 26-year old woman presented with reduced consciousness secondary to CO exposure from burning charcoal. She underwent a single session of HBOT with US Navy Treatment Table 5 within six hours of presentation, with full neurological recovery. Eight weeks later, she represented with progressive, debilitating neurological symptoms mimicking Parkinsonism. Magnetic resonance imaging of her brain demonstrated changes consistent with hypoxic ischaemic encephalopathy. The patient underwent 20 sessions of HBOT at 203 kPa (2 atmospheres absolute) for 115 minutes, and received intravenous methylprednisolone 1 g per day for three days. The patient's neurological symptoms completely resolved, and she returned to full-time professional work with no further recurrence., Discussion: Delayed neurological sequelae is a well-described complication of CO poisoning. In this case, the patient's debilitating neurocognitive symptoms resolved following HBOT. Existing literature on treatment of CO-induced DNS with HBOT consists mainly of small-scale studies and case reports, many of which similarly suggest that HBOT is effective in treating this complication. However, a large, randomised trial is required to adequately determine the effectiveness of HBOT in the treatment of CO-induced DNS, and an optimal treatment protocol., (Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.)

Carbon monoxide poisoning is one of the most common forms of poisoning in the world. Although the primary mode of treatment, oxygen therapy, is highly effective in many cases, there are instances in which it is inadequate or inappropriate. Whereas oxygen therapy relies on high levels of a low-affinity ligand (O 2 ) to displace a high-affinity ligand (CO) from metalloproteins, an antidote strategy relies on introducing a molecule with a higher affinity for CO than native proteins (K antidote,CO  > K protein,CO ). Based on the fundamental chemistry of CO, such an antidote is most likely required to be an inorganic compound featuring an electron-rich transition metal. A review is provided of the protein-, supramolecular complex-, and small molecule-based CO poisoning antidote platforms that are currently under investigation., 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 © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Delayed neuropsychiatric syndrome (DNS) is a well-known complication following carbon monoxide (CO) poisoning and develops in up to 50 % of adult survivors. The syndrome is probably immunologically mediated. Common symptoms are slowness, Parkinsonism and cognitive impairment., Case Presentation: A woman in her forties started to show gradually increasing symptoms of DNS a few days after an episode of severe CO poisoning. She received methylprednisolone 1 g intravenously on 3 consecutive days at around 7 weeks after the poisoning, with an immediate positive response to motor deficit symptoms. Thereafter, she gradually recovered and returned to full-time employment 4.5 months after the steroid treatment., Interpretation: The role of steroids in this patient's recovery is uncertain. However, successful high-dose steroid treatment for patients with ongoing DNS progression after CO poisoning has been reported previously in the literature. The authors recommend more attention to the risk of DNS after CO poisoning and further research on treatment options.

Carbon monoxide (CO) poisoning leads to 50,000-100,000 emergency room visits and 1,500-2,000 deaths each year in the United States alone. Even with treatment, survivors often suffer from long-term cardiac and neurocognitive deficits, highlighting a clear unmet medical need for novel therapeutic strategies that reduce morbidity and mortality associated with CO poisoning. This review examines the prevalence and impact of CO poisoning and pathophysiology in humans and highlights recent advances in therapeutic strategies that accelerate CO clearance and mitigate toxicity. We focus on recent developments of high-affinity molecules that take advantage of the uniquely strong interaction between CO and heme to selectively bind and sequester CO in preclinical models. These scavengers, which employ heme-binding scaffolds ranging from organic small molecules to hemoproteins derived from humans and potentially even microorganisms, show promise as field-deployable antidotes that may rapidly accelerate CO clearance and improve outcomes for survivors of acute CO poisoning.

Carbon monoxide (CO) and cyanide poisoning are frequent causes of morbidity and mortality in cases of house and industrial fires. The 14th edition of guidelines from the Undersea and Hyperbaric Medical Society does not recommend hyperbaric oxygen (HBO 2 ) treatment in those patients who have suffered a cardiac arrest and had to receive cardiopulmonary resuscitation. In this paper, we describe the case of a 31-year-old patient who received HBO 2 treatment in the setting of cardiac arrest and survived., Competing Interests: The authors of this paper declare no conflicts of interest exist with this submission., (Copyright© Undersea and Hyperbaric Medical Society.)

Despite established exposure limits and safety standards, and the availability of carbon monoxide (CO) alarms, each year an estimated 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. If the CO exposure is sufficiently high, unconsciousness and death occur quickly, and without symptoms. With non-lethal exposures to CO, common symptoms 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. As with brain injury from non- CO causes such as traumatic brain injury, the clinical expression of brain injury caused by CO poisoning includes the domains of cognition, affect, neurological, and somatic. Common problems are neurological: imbalance, motor weakness, neuropathies, hearing loss, tinnitus, Parkinson's-like syndrome, vestibular, gaze, auditory processing, cognitive, anxiety and depression, posttraumatic stress, personality change, persistent headaches, dizziness, sleep problems, and others. In addition, some will have cardiac or other problems. While breathing oxygen hastens the removal of carboxyhemoglobin (COHb), hyperbaric oxygen (HBO 2 ) 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 CO-induced adduct formation of myelin basic protein. Based upon supportive randomized clinical trials in humans and considerable evidence from animal studies, HBO 2 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.)

Emergency hyperbaric oxygen treatment capability is limited in the United States, and there is little documentation of calls received by centers available 24 hours a day, seven days a week, 365 days a year. Our study aimed to calculate the number of calls received for urgent hyperbaric oxygen (HBO 2 ). We logged calls from two HBO 2 chambers on the East Coast of the United States that serve a densely populated region in 2021. The total number of emergency calls was 187 at the University of Maryland (UMD) and 127 at the University of Pennsylvania (UPenn). There were calls on 180/365 (46%) days during the study period at UMD and 239/365 (63%) days at UPenn. The most common indication was carbon monoxide toxicity. The peak month of calls was March. Emergency HBO 2 calls are common, and more centers must accept emergency cases. Data from geographically diverse centers would add generalizability to these results and capture more diving-related emergencies., Competing Interests: The authors of this paper declare no conflicts of interest exist with this submission., (Copyright© Undersea and Hyperbaric Medical Society.)

Introduction: Carbon monoxide (CO) is a colorless and odorless gas that is a leading cause of environmental poisoning in the USA with substantial mortality and morbidity. The mechanism of CO poisoning is complex and includes hypoxia, inflammation, and leukocyte sequestration in brain microvessel segments leading to increased reactive oxygen species. Another important pathway is the effects of CO on the mitochondria, specifically at cytochrome c oxidase, also known as Complex IV (CIV). One of the glaring gaps is the lack of rigorous experimental models that may recapitulate survivors of acute CO poisoning in the early phase. The primary objective of this preliminary study is to use our advanced swine platform of acute CO poisoning to develop a clinically relevant survivor model to perform behavioral assessment and MRI imaging that will allow future development of biomarkers and therapeutics., Methods: Four swine (10 kg) were divided into two groups: control (n = 2) and CO (n = 2). The CO group received CO at 2000 ppm for over 120 min followed by 30 min of re-oxygenation at room air for one swine and 150 min followed by 30 min of re-oxygenation for another swine. The two swine in the sham group received room air for 150 min. Cerebral microdialysis was performed to obtain semi real-time measurements of cerebral metabolic status. Following exposures, all surviving animals were observed for a 24-h period with neurobehavioral assessment and imaging. At the end of the 24-h period, fresh brain tissue (cortical and hippocampal) was immediately harvested to measure mitochondrial respiration., Results: While a preliminary ongoing study, animals in the CO group showed alterations in cerebral metabolism and cellular function in the acute exposure phase with possible sustained mitochondrial changes 24 h after the CO exposure ended., Conclusions: This preliminary research further establishes a large animal swine model investigating survivors of CO poisoning to measure translational metrics relevant to clinical medicine that includes a basic neurobehavioral assessment and post exposure cellular measures., (© 2023. American College of Medical Toxicology.)

In clinical management of carbon monoxide (CO) poisoning, serum cardiac enzyme biomarkers and electrocardiogram (ECG) are both highly recommended emergency check-ups to evaluate myocardial injuries. Medical imaging - including head CT or MRI - are not routine for CO poisoning emergency management. We herein report on a comatose patient who was diagnosed with cerebral infarction secondary to 24 hours previous acute CO poisoning, warned by a typical cerebral-type T waves on ECG in advance, and confirmed by a head MRI. Fortunately, the patient made a full recovery based on a timely treatment with medications and hyperbaric oxygen (HBO 2 ) therapy. We would like to propose that a vital, stable, conscious CO poisoning patient who remains a higher risk for hemorrhagic or ischemic stroke should be closely monitored for potential neurological abnormalities, and a continuous ECG monitoring should be reinforced throughout the treatment. A head MRI or CT is a priority in evaluating the secondary cerebral stroke and should be arranged immediately in the event of an abnormal ECG or if unusual new symptoms are apparent., 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 odorless and colorless gas that can lead to fulminant and life-threatening intoxications. Besides an early diagnosis, an appropriate treatment of the intoxication is important. In this context the reduction of CO concentration in blood and tissues is crucial revealing hyperbaric oxygen treatment (HBO) as a highly promising tool. However, the benefit of HBO in CO intoxications is still considered controversial. In this review, we discuss the evidence of the role of HBO treatment in isolated CO intoxication., Competing Interests: Declaration of Competing Interest All authors declare no conflict of interest., (Copyright © 2023 Elsevier Ltd and International Society of Burns Injuries. All rights reserved.)

Objectives: Delayed encephalopathy after acute carbon monoxide poisoning (DEACMP) is the most severe complication of carbon monoxide poisoning, which seriously endangers patients' quality of life. This study aims to investigate the efficacy of hyperbaric oxygen (HBO 2 ) on improving dementia symptoms in patients with DEACMP., Methods: A retrospective analysis was performed on DEACMP patients, who visited Xiangya Hospital, Central South University from June 2014 to June 2020. Among them, patients who received conventional drug treatment combined with HBO 2 treatment were included in an HBO 2 group, while those who only received conventional drug treatment were included in a control group. HBO 2 was administered once daily. Patients in the HBO 2 group received 6 courses of treatment, with each course consisting of 10 sessions. The Hasegawa Dementia Scale (HDS) was used to diagnose dementia, and the Clinical Dementia Rating (CDR) was used to grade the severity of dementia for DEACMP. The Alzheimer's Disease Assessment Scale-Cognitive Section (ADAS-Cog), the Functional Activities Questionnaire (FAQ), the Neuropsychiatric Inventory (NPI), and the Clinician's Interview-Based Impression of Change-Plus Caregiver Input (CIBIC-Plus) were performed to assess cognitive function, ability to perform activities of daily living (ADL), behavioral and psychological symptoms, and overall function. The study further analyzed the results of objective examinations related to patients' dementia symptoms, including magnetic resonance imaging detection of white matter lesions and abnormal electroencephalogram (EEG). The changes of the above indicators before and after treatment, as well as the differences between the 2 groups after treatment were compared., Results: There was no significant difference in the HDS score and CDR grading between the 2 groups before treatment (both P >0.05). After treatment, the score of ADAS-Cog, FAQ, NPI, and CIBIC Plus grading of the 2 groups were significantly improved, and the improvement of the above indicators in the HBO 2 group was greater than that in the control group (all P <0.05). The effective rate of the HBO 2 group in treating DEACMP was significantly higher than that of the control group (89.47% vs 65.87%, P <0.05). The objective examination results (white matter lesions and abnormal EEG) showed that the recovery of patients in the HBO 2 group was better than that in the control group., Conclusions: Hyperbaric oxygen can significantly relieve the symptoms of dementia in patients with DEACMP.

Background: Delayed encephalopathy after acute carbon monoxide poisoning (DEACMP) is a severe complication that can arise from acute carbon monoxide poisoning (ACOP). This study aims to identify the independent risk factors associated with DEACMP and to develop a nomogram to predict the probability of developing DEACMP., Methods: The data of patients diagnosed with ACOP between September 2015 and June 2021 were analyzed retrospectively. The patients were divided into the two groups: the DEACMP group and the non-DEACMP group. Univariate analysis and multivariate logistic regression analysis were conducted to identify the independent risk factors for DEACMP. Subsequently, a nomogram was constructed to predict the probability of DEACMP., Results: The study included 122 patients, out of whom 30 (24.6%) developed DEACMP. The multivariate logistic regression analysis revealed that acute high-signal lesions on diffusion-weighted imaging (DWI), duration of carbon monoxide (CO) exposure, and Glasgow Coma Scale (GCS) score were independent risk factors for DEACMP (Odds Ratio = 6.230, 1.323, 0.714, p < 0.05). Based on these indicators, a predictive nomogram was constructed., Conclusions: This study constructed a nomogram for predicting DEACMP using high-signal lesions on DWI and clinical indicators. The nomogram may serve as a dependable tool to differentiate high-risk patients and enable the provision of personalized treatment to lower the incidence of DEACMP., Competing Interests: The authors declare no conflict of interest., (© 2023 The Author(s). Published by IMR Press.)

Aims: In this study, cardiac biomarkers, blood parameters, electrocardiography (ECG), and echocardiography were investigated in children with carbon monoxide (CO) poisoning, and the diagnostic value of these parameters was investigated., Methods: The demographical, clinical, and laboratory data of children aged 0-18 years who were admitted to the pediatric emergency department due to CO poisoning between January 2019 and January 2022 were retrospectively scanned from medical records. The patients were divided into two groups as troponin-I positive and troponin-I negative., Results: There were 107 children aged 0-18 years (average age, 10.46 ± 5.77 years; 51% female) with CO poisoning. There were 13 patients with troponin-I positive myocardial injury. Troponin-I was positive in 3 patients whose carboxyhemoglobin (COHb) level was below 2% at the time of admission. In one patient, troponin-I, which was normal at admission, increased by the 24th hour of hospitalization. Hyperbaric oxygen therapy was given due to headache in one patient, although the COHb level of that patient was below 25%. An NT-proBNP level of ≥ 219.5 ng/L predicted the development of troponin-I positivity with a sensitivity of 70% and a specificity of 86.7% (AUC, 0.967 (0.58-0.994); p = 0.017). White blood cell (WBC), neutrophil, neutrophil-to-lymphocyte ratio (NLR), immature granulocyte (IG), and IG% levels were found to be significantly higher in the troponin-positive patient group. DISCUSSION AND CONCLUSION: NT-proBNP has been shown to be an early diagnostic marker for myocardial dysfunction. Additionally, when cardiac markers are not available, full blood parameters may assist clinicians for patient treatment and referral., (© 2022. The Author(s), under exclusive licence to Royal Academy of Medicine in Ireland.)

Carbon monoxide (CO) can cause "irreversible" severe-to-profound sensorineural hearing loss. However, there are few reports of detailed hearing test results. Here, we report a case of acute sensorineural hearing loss caused by acute CO poisoning with partial hearing recovery, evaluated by a detailed hearing examination. A 25-year-old woman was brought to the emergency department for attempted suicide. On admission, her consciousness was impaired, and she was treated for severe CO poisoning, including using hyperbaric-oxygen therapy. After regaining consciousness, symptoms of hearing loss and tinnitus were discovered, and a detailed audiological examination revealed bilateral hearing loss, suggesting cochlear damage. Steroids were systemically administered, and her hearing impairment was partially resolved. Sensorineural hearing loss caused by acute CO poisoning includes cochlear pathology and may be partially treatable. The early evaluation of hearing in patients with severe CO poisoning is advisable for early treatment.

Abstract: Diagnosis of carbon monoxide (CO) poisoning is challenging, as it is generally based on a history of present illness leading to clinical suspicion. CO is a tasteless, odorless, and colorless gas that has become known as the "silent killer." CO poisoning affects approximately 50,000 people in the United States each year and presents with wide range of nonspecific symptoms. Patients often do not know that they are being exposed to CO gas; it is therefore important to ask pertinent questions when taking a patient's history. Treatment consists of oxygen therapy. If a diagnosis is not made and treatment is not administered promptly, complications may occur., (Copyright © 2023 American Academy of Physician Associates.)

Background: Hydranencephaly is a rare malformation of the brain system with an incidence of 0.5 per 1000 births. Its principal etiologies are bilateral occlusion of the internal carotid arteries and congenital infections., Case: We reported an uncommon case of hydranencephaly diagnosed in 50-day old infant and attributable to carbon monoxide (CO) poisoning during the first trimester of pregnancy., Conclusions: We recommend a prompt diagnosis and management of CO poisoning in pregnant women since it can dramatically affect both the fetus and mother., (© 2023 Wiley Periodicals LLC.)

BACKGROUND AND OBJECTIVES: Approximately 50,000 emergency department visits per year due to carbon monoxide (CO) poisoning occur in the United States alone. Tissue hypoxia can occur at very low CO concentration exposures because CO binds with a 250-fold higher affinity than oxygen to hemoglobin. The most effective therapy is 100% hyperbaric oxygen (HBO) respiration. However, there are only a limited number of cases with ready accessibility to the specialized HBO chambers. In previous studies, we developed an extracorporeal veno-venous membrane oxygenator that facilitates exposure of blood to an external visible light source to photo-dissociate carboxyhemoglobin (COHb) and significantly increase CO removal from CO-poisoned blood (photo-extracorporeal veno-venous membrane oxygenator [p-ECMO]). One objective of this study was to describe in vitro experiments with different laser wavelength sources to compare CO elimination rates in a small unit-cell ECMO device integrated with a light-diffusing optical fiber. A second objective was to develop a mathematical model that predicts CO elimination rates in the unit-cell p-ECMO  device design upon which larger devices can be based., Study Design/material and Methods: Two small unit-cell p-ECMO devices consisted of a plastic capillary with a length and inside diameter of 10 cm and 1.15 mm, respectively. Either five (4-1 device) or seven (6-1 device) gas exchange tubes were placed in the plastic capillary and a light-diffusing fiber was inserted into one of the gas exchange tubes. Light from lasers emitting either 635 nm or 465 nm wavelengths was coupled into the light-diffusing fiber as oxygen flowed through the gas exchange membranes. To assess the ability of the device to remove CO from blood in vitro, the percent COHb reduction in a single pass through the device was assessed with and without light. The Navier Stokes equations, Carreau-Yesuda model, Boltzman equation for light distribution, and hemoglobin kinetic rate equations, including photo-dissociation, were combined in a mathematical model to predict COHb elimination in the experiments., Results: For the unit-cell devices, the COHb removal rate increases with increased 635 nm laser power, increased blood time in the device, and greater gas exchange membrane surface-to-blood volume ratio. The 6-1 device COHb half-life versus that of the 4-1 device with 4 W at 635 nm light was 1.5 min versus 4.25 min, respectively. At 1 W laser power, 635 nm and 465 nm exhibited similar CO removal rates. The COHb half-life times of the 6-1 device were 1.25, 2.67, and 8.5 min at 635 nm (4 W), 465 nm (1 W), and 100% oxygen only, respectively. The mathematical model predicted the experimental results. An analysis of the in vivo COHb half-life of oxygen respiration therapy versus an adjunct therapy with a p-ECMO device and oxygen respiration shows a reduction from 90 min to as low as 10 min, depending on the device design., Conclusion: In this study, we experimentally studied and developed a mathematical model of a small unit-cell ECMO device integrated with a light-diffusing fiber illuminated with laser light. The unit-cell device forms the basis for a larger device and, in an adjunct therapy with oxygen respiration, has the potential to remove COHb at much higher rates than oxygen therapy alone. The mathematical model can be used to optimize the design in practical implementations to quickly and efficiently remove CO from CO-poisoned blood., (© 2023 Wiley Periodicals LLC.)

Carbon monoxide (CO) poisoning can cause neurological complications such as movement disorders and cognitive impairment through hypoxic brain damage. Although peripheral neuropathy of the lower extremities is a known complication of CO poisoning, hemiplegia is very rare. In our case, a patient who developed left hemiplegia due to acute CO poisoning received early hyperbaric oxygen treatment (HBOT). The patient had left hemiplegia and anisocoria at the beginning of HBOT. Her Glasgow coma score was 8. A total of five sessions of HBOT at 243.2 kPa for 120 minutes were provided. At the end of the 5th session, the patient's hemiplegia and anisocoria were completely resolved. Her Glasgow coma score was 15. After nine months of follow-up, she continues to live independently with no sequelae, including delayed neurological sequelae. Clinicians should be aware that CO poisoning can (rarely) present with hemiplegia., (Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.)

In conventional clinical toxicology practice, the blood level of carboxyhemoglobin is a biomarker of carbon monoxide (CO) poisoning but does not correspond to the complete clinical picture and the severity of the poisoning. Taking into account articles suggesting the relationship between oxidative stress parameters and CO poisoning, it seems reasonable to consider this topic more broadly, including experimental biochemical data (oxidative stress parameters) and patients poisoned with CO. This article aimed to critically assess oxidative-stress-related parameters as potential biomarkers to evaluate the severity of CO poisoning and their possible role in the decision to treat. The critically set parameters were antioxidative, including catalase, 2,2-diphenyl-1-picryl-hydrazyl, glutathione, thiol and carbonyl groups. Our preliminary studies involved patients ( n = 82) admitted to the Toxicology Clinical Department of the University Hospital of Jagiellonian University Medical College (Kraków, Poland) during 2015-2020. The poisoning was diagnosed based on medical history, clinical symptoms, and carboxyhemoglobin blood level. Blood samples for carboxyhemoglobin and antioxidative parameters were collected immediately after admission to the emergency department. To evaluate the severity of the poisoning, the Pach scale was applied. The final analysis included a significant decrease in catalase activity and a reduction in glutathione level in all poisoned patients based on the severity of the Pach scale: I°-III° compared to the control group. It follows from the experimental data that the poisoned patients had a significant increase in level due to thiol groups and the 2,2-diphenyl-1-picryl-hydrazyl radical, with no significant differences according to the severity of poisoning. The catalase-to-glutathione and thiol-to-glutathione ratios showed the most important differences between the poisoned patients and the control group, with a significant increase in the poisoned group. The ratios did not differentiate the severity of the poisoning. The carbonyl level was highest in the control group compared to the poisoned group but was not statistically significant. Our critical assessment shows that using oxidative-stress-related parameters to evaluate the severity of CO poisoning, the outcome, and treatment options is challenging.

Carbon monoxide (CO) poisoning typically occurs from inhalation of CO at excessive levels. Rhabdomyolsis is not an uncommon complication following acute CO poisoning, yet there are very few reported cases in the literature. It is characterised by rapid breakdown of skeletal muscles and release of its contents into the circulation, leading to acute kidney injury (AKI). Early diagnosis and treatment are crucial to avoid anticipated morbidity and mortality. We are presenting a case of a woman in her 40s with 28% flame burn in a closed space. The patient developed CO poisoning, which led to rhabdomyolysis as evidenced by clinical manifestations and laboratory findings (creatine kinase had reached an unmeasurable level). The patient developed AKI and was successfully managed in our ICU. Here, we are highlighting the importance of considering CO poisoning as one of the potential causes of rhabdomyolysis in burn victim., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

This study aimed to investigate the prevalence of carbon monoxide (CO) poisoning and the provision of hyperbaric oxygen therapy (HBOT) in South Korea. We used data from the Korea Health Insurance Review and Assessment service. In total, 44,361 patients with CO poisoning were identified across 10 years (2010-2019). The prevalence of CO poisoning was found to be 8.64/10,000 people, with a gradual annual increment. The highest prevalence was 11.01/10,000 individuals, among those aged 30-39 years. In 2010, HBOT was claimed from 15 hospitals, and increased to 30 hospitals in 2019. A total of 4,473 patients received HBOT in 10 years and 2,684 (60%) were treated for more than 2 hours. This study suggested that the prevalence of both CO poisoning and HBOT in Korea gradually increased over the past 10 years, and disparities in prevalence were observed by region., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2023 The Korean Academy of Medical Sciences.)

Competing Interests: Les auteurs déclarent n’avoir aucun lien d’intérêts.

Background: Extracorporeal membrane oxygenators (ECMO) are currently utilized to mechanically ventilate blood when lung or lung and heart function are impaired, like in cases of acute respiratory distress syndrome (ARDS). ARDS can be caused by severe cases of carbon monoxide (CO) inhalation, which is the leading cause of poison-related deaths in the United States. ECMOs can be further optimized for severe CO inhalation using visible light to photo-dissociate CO from hemoglobin (Hb). In previous studies, we combined phototherapy with an ECMO to design a photo-ECMO device, which significantly increased CO elimination and improved survival in CO-poisoned animal models using light at 460, 523, and 620 nm wavelengths. Light at 620 nm was the most effective in removing CO., Objective: The aim of this study is to analyze the light propagation at 460, 523, and 620 nm wavelengths and the 3D blood flow and heating distribution within the photo-ECMO device that increased CO elimination in CO-poisoned animal models., Methods: Light propagation, blood flow dynamics, and heat diffusion were modeled using the Monte Carlo method and the laminar Navier-Stokes and heat diffusion equations, respectively., Results: Light at 620 nm propagated through the device blood compartment (4 mm), while light at 460 and 523 nm only penetrated 48% to 50% (~2 mm). The blood flow velocity in the blood compartment varied with regions of high (5 mm/s) and low (1 mm/s) velocity, including stagnant flow. The blood temperatures at the device outlet for 460, 523, and 620 nm wavelengths were approximately 26.7°C, 27.4°C, and 20°C, respectively. However, the maximum temperatures within the blood treatment compartment rose to approximately 71°C, 77°C, and 21°C, respectively., Conclusions: As the extent of light propagation correlates with efficiency in photodissociation, the light at 620 nm is the optimal wavelength for removing CO from Hb while maintaining blood temperatures below thermal damage. Measuring the inlet and outlet blood temperatures is not enough to avoid unintentional thermal damage by light irradiation. Computational models can help eliminate risks of excessive heating and improve device development by analyzing design modifications that improve blood flow, like suppressing stagnant flow, further increasing the rate of CO elimination., (© 2023 The Authors. Lasers in Surgery and Medicine published by Wiley Periodicals LLC.)

Objectives: Carbon monoxide poisoning (COP) is extremely common throughout the world. The purpose of this study was to assess the demographic, clinical, and laboratory characteristics predicting the severity COP in children., Methods: The study included 380 children diagnosed with COP between January 2017 and January 2021 and 380 healthy controls. Carbon monoxide poisoning was diagnosed based on the medical history and a carboxyhemoglobin (COHb) level of more than 5%. The patients were classified as mild (COHb 10%), moderate (COHb 10%-25%), or severely (COHb > 25%) poisoned., Results: The mean age of the severe group was 8.60 ± 6.30, for the moderate group was 9.50 ± 5.81, for the mild group was 8.79 ± 5.94, and for the control group was 8.95 ± 5.98. The most common place of exposure was at home and all cases were affected accidentally. The coal stove was the most common source of exposure, followed by natural gas. The most common symptoms were nausea/vomiting, vertigo, and headache. Neurologic symptoms such as syncope, confusion, dyspnea, and seizures were more common in the severe group. A total of 91.3% of the children had hyperbaric oxygen therapy, 3.8% were intubated, and 3.8% were transferred to intensive care in the severe group, whereas no death or sequela was observed. Mean platelet volume and red cell distribution width had the highest area under the curve in the receiver operating characteristic analysis (0.659; 0.379). A positive and low statistically significant relationship was found between COHb levels and troponin and lactate levels in the severe group ( P < 0.05)., Conclusions: Carbon monoxide poisoning progressed more severely in children presented with neurological symptoms and have elevated red cell distribution width and mean platelet volume. Even in severe COP cases, satisfactory results have been obtained with early and appropriate treatment., Competing Interests: Disclosure: The authors declare no conflict of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

BACKGROUND A venous air embolism is a rare condition but could have a disastrous effect on vital organs. It usually occurs due to iatrogenic sources, such as central venous catheter insertion, neurosurgery, and other invasive procedures. In most cases, hyperbaric oxygen therapy (HBOT) is the best treatment for those conditions. However, multiple venous air emboli after hyperbaric oxygen therapy has not been reported in the literature. CASE REPORT An 82-yr-old woman came to the Emergency Department after inhalation of fumes at the scene of a house fire. She had dizziness and nausea. Her vital signs were normal at the time of presentation. She received HBOT for carbon monoxide poisoning. Soon after the HBOT, the patient started to have dizziness, abdominal pain, and leg pains. Computed tomography scans showed multiple systemic venous air emboli throughout the portal venous system and femoral veins. The air emboli totally disappeared after HBOT with a longer ascent time. CONCLUSIONS To the best of our knowledge, this is the first case of multiple systemic venous air bubbles after emergent HBOT. Physicians should be aware of any kind of complications when treating patients who need HBOT in the emergent setting. Although decompression sickness following HBOT is extremely rare, it should not be ignored by emergency physicians.

This short review addresses the mechanisms of injury mediated by carbon monoxide (CO) and current information on efficacy of hyperbaric oxygen therapy (HBOT). Recent clinical series involving large, country-wide databases and prospective randomized trials are summarized. We conclude that there is an abundance of basic science and preclinical and clinical research supporting the use of HBOT for acute CO poisoning. With appropriate consideration for pathology and therapeutic mechanisms, HBOT at a dose of 2.5-3.0 atm absolute is a necessary treatment for this toxidrome., (© 2022 British Pharmacological Society.)