Red blood cell distribution width (RDW) reflects disease severity in patients with carbon monoxide poisoning: systematic literature review and meta-analysis.

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.

Waterpipe vs non-Waterpipe carbon monoxide poisoning: Comparison of patient characteristics, clinical presentation and outcomes.

OBJECTIVE: The aim of this study is to describe the difference between carboxyhemoglobin (CO-Hb) acute poisoning caused by waterpipe vs non-waterpipe exposures as they relate to demographics, clinical presentations and outcome of patients. DESIGN: Retrospective cohort study conducted in the Emergency Department (ED) at the Lebanon. PATIENTS: All adult patients presenting with a CO-Hb level ≥ 10 between January 2019 and August 2023 with exposure types stratified as waterpipe or non-waterpipe. MEASUREMENTS AND MAIN RESULTS: 111 ED visits were identified. Among these, 73.9% were attributed to waterpipe exposure, while 26.1% were non-waterpipe sources. These included cigarette smoking (17.2%), burning coal (24.1%), fire incidents (3.6%), gas leaks (6.9%), heating device use (10.3%), and undocumented sources (37.9%). Patients with waterpipe-related carbon monoxide exposure were younger (41 vs 50 years, p = 0.015) women (63.4 vs 41.4%, p = 0.039) with less comorbidities compared to non-waterpipe exposures (22.2 vs 41.4%, p = 0.047). Waterpipe smokers were more likely to present during the summer (42.7 vs 13.8%, p = 0.002) and have shorter ED length of stays (3.9 vs 4.5 h, p = 0.03). A higher percentage of waterpipe smokers presented with syncope (52.4 vs 17.2%, p = 0.001) whereas cough/dyspnea were more common in non-waterpipe exposures (31 vs 9.8%, p = 0.006). The initial CO-Hb level was found to be significantly higher in waterpipe exposure as compared to non-waterpipe (19.7 vs 13.7, p = 0.004). Non-waterpipe exposures were more likely to be admitted to the hospital (24.1 vs 4.9%, p = 0.015). Waterpipe smokers had significantly higher odds of experiencing syncope, with a 5.74-fold increase in risk compared to those exposed to non-waterpipe sources (p = 0.004) irrespective of their CO-Hb level. Furthermore, males had significantly lower odds of syncope as compared to females, following carbon monoxide exposure (aOR 0.31, 95% CI 0.13-0.74). CONCLUSION: CO-Hb poisoning related to waterpipe smoking has distinctive features. Syncope is a commonly associated presentation that should solicit a focused social history in communities where waterpipe smoking is common. Furthermore, CO-Hb poisoning should remain on the differential in patients presenting with headache, syncope, dizziness, vomiting or shortness of breath, even outside of the non-waterpipe exposure peaks of winter season.

Delayed neuropsychiatric syndrome after carbon monoxide poisoning. / Forsinket nevropsykiatrisk syndrom etter kullosforgiftning.

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.

Screening patients for unintentional carbon monoxide exposure in the Emergency Department: a cross-sectional multi-centre study.

BACKGROUND: Low-level exposure to carbon monoxide (CO) is a significant health concern but is difficult to diagnose. This main study aim was to establish the prevalence of low-level CO poisoning in Emergency Department (ED) patients. METHODS: A prospective cross-sectional study of patients with symptoms of CO exposure was conducted in four UK EDs between December 2018 and March 2020. Data on symptoms, a CO screening tool and carboxyhaemoglobin were collected. An investigation of participants' homes was undertaken to identify sources of CO exposure. RESULTS: Based on an ED assessment of 4175 participants, the prevalence of suspected CO exposure was 0.62% (95% CI; 0.41-0.91%). CO testing in homes confirmed 1 case of CO presence and 21 probable cases. Normal levels of carboxyhaemoglobin were found in 19 cases of probable exposure and in the confirmed case. CONCLUSION: This study provides evidence that ED patients with symptoms suggestive of CO poisoning but no history of CO exposure are at risk from CO poisoning. The findings suggest components of the CO screening tool may be an indicator of CO exposure over and above elevated COHb. Clinicians should have a high index of suspicion for CO exposure so that this important diagnosis is not missed.

Clinical and Laboratory Characteristics Predicting the Severity of Carbon Monoxide Poisoning in Children: A Single-Center Retrospective Study.

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.

The Critical Assessment of Oxidative Stress Parameters as Potential Biomarkers of Carbon Monoxide Poisoning.

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 poisoning: Diagnosis and management.

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.

Exercise-induced myocardial ischemia presenting as exercise intolerance after carbon monoxide intoxication and smoke inhalation Injury: case report.

BACKGROUND: Carbon monoxide intoxication and smoke inhalation injury can lead to severe disorders, and the current literature has elaborated on the importance of major cardiopulmonary impairment. Exercise intolerance has seldom been discussed, particular in patient with low cardiovascular risk. CASE PRESENTATION: Two young male fire survivors who presented with exercise intolerance after CO intoxication and smoke inhalation injury. Both received bronchodilator and glucocorticoid therapy, high-flow oxygen therapy, and hyperbaric oxygen therapy for airway edema and CO intoxication during acute care. Serum carboxyhemoglobin levels improved after treatment (8.2-3.9% in Case A and 14.8-0.8% in Case B). However, subjective exercise intolerance was noted after discharge. Cardiopulmonary exercise testing revealed exercise-induced myocardial ischemia during peak exercise (significant ST-segment depression on exercise electrocardiogram). They were instructed to exercise with precaution by setting the intensity threshold according to the ischemic threshold. Their symptoms improved, and no cardiopulmonary events were reported in the 6-month follow-up. CONCLUSION: The present case report raised the attention that exercise intolerance after carbon monoxide intoxication and smoke inhalation injury in low cardiovascular risk population may be underestimated. Cardiopulmonary exercise testing help physician to discover exercise-induced myocardial ischemia and set up the cardiac rehabilitation program accordingly.

Symptoms and functional limitations related to respiratory health and carbon monoxide poisoning in Tanzania: a cross sectional study.

BACKGROUND: The burden of chronic respiratory symptoms and respiratory functional limitations is underestimated in Africa. Few data are available on carbon monoxide (CO) poisoning in sub-Saharan Africa and existing data is derived from CO in ambient air, but not from biomarkers in the blood. METHODS: Data from the Tanzanian Lung Health study, a cross-sectional study on lung health among outpatients and visitors to an urban as well as a rural hospital in Tanzania, was analyzed to describe respiratory symptoms and functional limitations. Saturation of peripheral blood with carbon monoxide (SpCO) was measured transcutaneously and non-invasively in participants using a modified pulse oxymeter indicative of CO poisoning. Univariate and multivariate analysis was performed. RESULTS: Nine hundred and ninety-seven participants were included in the analysis, the median age of participants was 46 years (49% male). 38% of participants reported some degree of chronic shortness of breath and 26% felt limited in their daily activities or at work by this symptom. The median SpCO was 7% (IQR 4-13, range 2-31%) among all participants without active smoking status (N = 808). Participants cooking with gas or electricity had the lowest SpCO (median 5%), followed by participants cooking with charcoal (median 7%). Cooking with wood, particularly using a stove, resulted in highest SpCO (median 11.5%). Participants from households where cooking takes place in a separate room had the lowest SpCO as compared to cooking outside or cooking in a shared room inside (6% vs. 9% vs.10.5%, p < 0.01). Sex or the activity of cooking itself was not associated with a difference in SpCO. Multivariate analysis confirmed cooking in a separate room (as compared to cooking outside) and living in a rural vs. urban setting as protective factors against high SpCO. CONCLUSION: The findings demonstrate a high burden of chronic respiratory symptoms which also cause socioeconomic impact. High levels of SpCO indicate a relevant burden of carbon monoxide poisoning in the local population. The level of CO in the blood is more dependent on shared exposure to sources of CO with the type of housing and type of cooking fuel as most relevant factors, and less on person-individual risk factors or activities.

Experience of carbon monoxide poisoning and the outcome predicting score: A multicenter retrospective study.

BACKGROUND: Carbon monoxide poisoning (COP), resulting from accidental and intentional exposure, is a leading cause of fatal poisoning worldwide. Except for early death, neurological sequelae are common and impose a large burden on patients, caregivers, and the society. MATERIALS AND METHODS: This retrospective study included patients who visited the emergency departments (EDs) of the medical institutes of Chang Gung Memorial Hospital after COP with a carboxyhemoglobin level > 10% between January 2009 and October 2018. Patients who experienced out-of-hospital cardiac arrest (OHCA) were excluded. Poor outcome was defined as mortality or a Glasgow coma scale (GCS) <13 at discharge. Stepwise regression analysis was performed, and a receiver operating characteristic (ROC) curve was applied to analyze our newly created scoring system for prognosis prediction. RESULTS: This study enrolled 1171 patients. Fire scene (F) (aOR, 20.635; 95% CI, 8.345-51.023), intentional CO exposure (I) (aOR, 2.634; 95% CI, 1.335-5.196), respiratory failure (R) (aOR, 9.944; 95% CI, 5.533-17.873), every point of reduced GCS (E) (aOR, 1.253; 95% CI, 1.186-1.323), and diabetes mellitus (D) (aOR, 2.749; 95% CI, 1.201-6.292) were identified as predictors of poor outcomes. The FIRED score was created. CONCLUSION: The FIRED score could predict the outcomes of non-OHCA patients with a carboxyhemoglobin level > 10% after COP using five factors that can be obtained by history taking and basic examination. An FIRED score ≥ 10 was associated with a poor outcome (sensitivity, 89.6%; specificity, 82.4%; AUC0.930).

Prospective Study Investigating Change in Carboxyhemoglobin Blood Level During Operative Hysteroscopy.

STUDY OBJECTIVES: To evaluate whether the use of radiofrequency energy during resectoscopy leads to increases in patient blood levels of carboxyhemoglobin (COHb) and investigate procedural variables associated with these elevations. DESIGN: A prospective cross-sectional study of 40 subjects undergoing a hysteroscopic procedure using bipolar radiofrequency energy. SETTING, PATIENTS, AND INTERVENTIONS: The study was conducted at an ambulatory surgery center. Procedures for uterine leiomyoma, septa, products of conception, or a combination of these pathologies were included. We measured blood COHb levels before and immediately after the surgery. Abnormal postoperative COHb level was defined as an increase of plasma COHb ≥3.0%. All patients with abnormal postoperative levels were contacted and screened for carbon monoxide toxicity symptoms. Summary statistics included frequency for categorical variables and averages for continuous variables. p values were reported without modification. MEASUREMENTS AND MAIN RESULTS: A total of 17.5% of subjects met the criteria for abnormal postoperative COHb levels. None of these subjects reported symptoms of carbon monoxide toxicity. One subject with an elevated postoperative COHb level had intraoperative hemodynamic changes possibly related to COHb elevation. An abnormal postoperative COHb level was associated with a higher fluid deficit (p = .024) and greater myoma volume (p = .04). CONCLUSION: This study demonstrates that systemic absorption of carbon monoxide is a reproducible phenomenon in hysteroscopic resections using bipolar diathermy. Greater absorption is associated with a higher fluid deficit and greater myoma volume. Although none of the subjects with an abnormal increase screened positive for symptoms in the postoperative setting and only 1 experienced hemodynamic changes intraoperatively, our study looked at a healthy and young patient population. More research is needed on the safety of this COHb exposure in patients with medical comorbidities. Special consideration should be given to the possibility of carbon monoxide absorption and the uncertain long-term effects when planning extensive hysteroscopic resections.

Study of the value of homocysteine levels in predicting cognitive dysfunction in patients after acute carbon monoxide poisoning.

PURPOSE: The purpose of this research was to assess the value of homocysteine (HCY) levels in predicting cognitive dysfunction in patients after acute carbon monoxide (CO) poisoning. METHODS: A total of 115 patients who were admitted to the emergency department of Yinzhou NO. 2 Hospital after CO poisoning between January 2017 and December 2021 were enrolled in this retrospective study. All patients were followed up for 1 month. According to the Mini-Mental State Examination (MMSE) scores, patients were divided into two groups. The demographic and clinical characteristics and magnetic resonance imaging (MRI) results were gathered and statistically analysed. RESULTS: Twenty-six and 89 patients were ultimately enrolled in the cognitive dysfunction and control groups, respectively. There were significant differences between the groups in terms of age, coma duration, and carboxyhaemoglobin (COHB), lactate and HCY levels (p < 0.05), but there were no significant differences in white blood cell (WBC) counts or aspartate transaminase (AST), alanine transaminase (ALT), creatinine, troponin T, creatinine kinase (CK), or creatinine kinase muscle and brain (CK-MB) levels (p > 0.05). Univariate and multivariate analyses identified that a higher HCY level (OR 2.979, 95% CI 1.851-5.596, p < 0.001) was an independent risk factor for patient cognitive dysfunction after acute CO poisoning. Linear regression analysis showed a negative correlation between MMSE scores and HCY levels (r = - 0.880, P < 0.001). According to the MRI results, the most common lesion site was the globus pallidus, and the central ovale, diffuse white matter, corona radiata, basal ganglia (other than the globus pallidus) and cerebral cortex were also involved. CONCLUSIONS: Higher HCY levels were associated with cognitive impairment and were independent risk factors for cognitive impairment after acute CO poisoning. The level of HCY was negatively correlated with the degree of cognitive impairment.

Three cases of clinically significant inaccurate carboxyhemoglobin measurement.

Background: Clinicians often rely on measurement of carboxyhemoglobin (COHb) to confirm or rule out a diagnosis of carbon monoxide (CO) poisoning. Methods: We report two cases of false negative COHb in patients with CO poisoning and one case of false positive COHb in a patient without CO poisoning. Results: In the first case, a 20-year-old male developed headache, confusion, and near-syncope while operating a gasoline-powered pressure washer in an enclosed space. In the emergency department (ED), his COHb was 1.8%, but this level was disregarded, and he was referred for hyperbaric oxygen. His COHb just before hyperbaric oxygen was 4.1%, and later analysis of his blood collected at ED arrival revealed a COHb of 20.1%. The referral ED blood gas machine calibration and controls were within specification. In the second case, a 45-year-old male presented with several others to the ED with symptoms of CO poisoning after exposure at a conference. All others had elevated COHb levels, but his COHb was 2%. He was discharged but returned shortly with continued symptoms and requested his COHb be repeated. The repeat COHb was 17% (84 minutes after the first). After three hours of oxygen, his COHb was 7%. In the final case, an 83-year-old non-smoking male presented to an ED with breathlessness and tachypnea and was diagnosed with COVID-19 pneumonia. His COHb was 7.1%, but he reported living in an all-electric home. Another adult who lived with him and rode with him to the ED was asymptomatic and had a COHb of 3%. Later, COHb of 1.9% was measured from blood collected at ED arrival, and gas chromatography/mass spectrometry confirmed this result (2%). Conclusions: COHb levels are not always accurate. Clinicians should use clinical judgment to manage their patients, including rejecting laboratory values that do not fit the clinical situation.

Evaluation of Data Sources for Carbon Monoxide Poisoning Surveillance in New York City.

CONTEXT: Carbon monoxide (CO) exposure can be life-threatening. Suspected and confirmed cases of CO poisoning warranting health care in New York City (NYC) are reportable to the NYC Poison Control Center (PCC). OBJECTIVES: We evaluated 4 hospital-based sources of CO surveillance data to identify ways to improve data capture and reporting. DESIGN: Suspected and confirmed CO poisoning records from October 2015 through December 2016 were collected from the NYC emergency department (ED) syndromic surveillance system, New York State Statewide Planning and Research Cooperative System (SPARCS) ED billing data, NYC PCC calls made from hospitals, and the Electronic Clinical Laboratory Reporting System (ECLRS). Syndromic and SPARCS records were person- and visit-matched. SPARCS and ECLRS records were also matched to PCC records on combinations of name, demographic characteristics, and visit information. SETTING: Hospitals in NYC. PARTICIPANTS: Individuals who visited NYC hospitals for CO-related health effects. MAIN OUTCOME MEASURES: We assessed the validity of syndromic data, with SPARCS records as the gold standard. We matched SPARCS and ECLRS records to PCC records to analyze reporting rates by case characteristics. RESULTS: The sensitivity of syndromic surveillance was 60% (225 true-positives detected among 372 visit-matched SPARCS cases), and positive predictive value was 46%. Syndromic records often missed CO flags because of a nonspecific or absent International Classification of Diseases code in the diagnosis field. Only 15% of 428 SPARCS records (total includes 56 records not visit-matched to syndromic) and 16% of 199 ECLRS records were reported to PCC, with male sex and younger age associated with higher reporting. CONCLUSIONS: Mandatory reporting makes PCC useful for tracking CO poisoning in NYC, but incomplete reporting and challenges in distinguishing between confirmed and suspected cases limit its utility. Simultaneous tracking of the systems we evaluated can best reveal surveillance patterns.

[Clinical significance of bispectral index monitoring in patients with acute severe carbon monoxide poisoning].

Objective: To analyze the correlation of bispectral index (BIS) with the prognosis of patients with acute severe carbon monoxide poisoning (ASCMP) and its predictive value of adverse outcomes. Methods: In March 2021, 106 ASCMP patients who were treated in Harrison International Peace Hospital Affiliated to Hebei Medical University from January 2019 to December 2020 were taken as research objects. All patients underwent 24-hour BIS monitoring after admission, and were divided into good prognosis group (n=75) and poor prognosis group (n=31) according to the prognosis of the patients' cranial nerve function after 60 d. The general conditions, Acute Physiology and Chronic Health Evaluation Ⅱ (APACHEⅡ) score, Glasgow Coma Scale (GCS) score at admission and 24-hour BIS mean were compared between the two groups. Pearson correlation analysis was used to analyze the correlations between the 24-hour BIS mean and GCS score at admission, APACHEⅡ score and coma time. The receiver operating characteristic (ROC) curve was drawn to analyze the predictive value of 24-hour BIS mean, GCS score at admission, APACHEⅡ score and coma time on adverse outcome of ASCMP patients. Results: The coma time and APACHEⅡ score of the patients in the poor prognosis group were significantly higher than those in the good prognosis group, the GCS score at admission and 24-hour BIS mean were significantly lower than those in the good prognosis group (P<0.05) . Pearson correlation analysis showed that the 24-hour BIS mean was positively correlated with the GCS score at admission, and negatively correlated with the APACHEⅡ score, coma time (r=0.675, -0.700, -0.565, P<0.001) . The 24-hour BIS mean had the highest predictive value for adverse outcome of ASCMP patients, with a cut-off value of 74, the area under the curve was 0.883 (95%CI: 0.814-0.951, P<0.001) , and the sensitivity and specificity were 73.3% and 87.1%, respectively. Conclusion: The 24-hour BIS mean has a good correlation with the acute brain nerve injury, the severity of the disease and coma time of patients with ASCMP. And it has a high predictive value for the adverse outcome in patients with ASCMP.

Metabolic changes during carbon monoxide poisoning: An experimental study.

Carbon monoxide (CO) is the leading cause of death by poisoning worldwide. The aim was to explore the effects of mild and severe poisoning on blood gas parameters and metabolites. Eleven pigs were exposed to CO intoxication and had blood collected before and during poisoning. Mild CO poisoning (carboxyhaemoglobin, COHb 35.2 ± 7.9%) was achieved at 32 ± 13 minutes, and severe poisoning (69.3 ± 10.2% COHb) at 64 ± 23 minutes from baseline (2.9 ± 0.5% COHb). Blood gas parameters and metabolites were measured on a blood gas analyser and nuclear magnetic resonance spectrometer, respectively. Unsupervised principal component, analysis of variance and Pearson's correlation tests were applied. A P-value ≤ .05 was considered statistically significant. Mild poisoning resulted in a 28.4% drop in oxyhaemoglobin (OHb) and 12-fold increase in COHb, while severe poisoning in a 65% drop in OHb and 24-fold increase in COHb. Among others, metabolites implicated in regulation of metabolic acidosis (lactate, P < .0001), energy balance (pyruvate, P < .0001; 3-hydroxybutyrc acid, P = .01), respiration (citrate, P = .007; succinate, P = .0003; fumarate, P < .0001), lipid metabolism (glycerol, P = .002; choline, P = .0002) and antioxidant-oxidant balance (glutathione, P = .03; hypoxanthine, P < .0001) were altered, especially during severe poisoning. Our study adds new insights into the deranged metabolism of CO poisoning and leads the way for further investigation.

Postmortem magnetic resonance imaging revealed bilateral globi pallidi lesions in a death associated with prolonged carbon monoxide poisoning: a case report.

A man and a woman were found dead in the same car with a burned coal briquette. The cause of death of the woman was assigned to acute carbon monoxide (CO) poisoning without difficulty based on typical findings associated with this condition, including elevation of carboxyhaemoglobin (COHb). However, the man had an unremarkable elevation of COHb and a higher rectal temperature compared to that of the woman. Postmortem computed tomography (PMCT) revealed ambiguous low-density areas in the bilateral globi pallidi. Further analysis by postmortem magnetic resonance (PMMR) imaging showed these lesions more clearly; the lesions appeared as marked high signal intensity areas on both the T2-weighted images and the fluid-attenuated inversion recovery sequences. A subsequent autopsy revealed signs of pneumonia, dehydration, starvation, and hypothermia, suggesting that the man died from prolonged CO poisoning. Both globi pallidi contained grossly ambiguous lesions, and a detailed neuropathologic investigation revealed these lesions to be coagulative necrotic areas; this finding was compatible with a diagnosis of prolonged CO poisoning. This case report shows that postmortem imaging, especially PMMR, is useful for detecting necrotic lesions associated with prolonged CO poisoning. This report further exemplifies the utility of PMMR for detecting brain lesions, which may be difficult to detect by macroscopic analysis.

Think about acute shisha carbon monoxide intoxication: that's one small step for the patient, one giant leap for our society.

The number of people in the world consuming chicha is constantly increasing. However, several studies have shown that regular shisha smokers, whether active or passive, are exposed to the same risks as tobacco smokers. Shisha is also responsible for acute carbon monoxide (CO) poisoning, which is often unknown to emergency doctors, leading to under-diagnosis of this pathology and inappropriate treatment. We report in this series 3 cases of acute carbon monoxide poisoning following active or passive consumption of chicha. The prehospital percentage carboxyhemoglobin level measured by the pulse CO-oximeter is 22 and 27% for active smokers and 10% for the passively intoxicated patient. The individual and societal consequences of CO intoxication are significant. We believe it is important to make all those involved in emergency medicine aware of this pathology in order to treat it correctly from the initial phase and thus reduce its morbi-mortality and the risks of long-term complications.

The diagnostic value of neurogranin in patients with carbon monoxide poisoning: Can it show early neurological damage?

BACKGROUND AND AIM: Carbon monoxide poisoning is a toxicological emergency that causes neurological complications. High serum neurogranin can be detected in acute or chronic conditions where brain tissue is damaged. This study aimed to investigate the diagnostic value of serum neurogranin level and its role in demonstrating neurological damage in patients admitted to the emergency department with carbon monoxide poisoning. MATERIALS AND METHODS: The study was conducted prospectively on patients with carbon monoxide poisoning (patient group) and healthy volunteers (control group). Demographic characteristics and serum neurogranin level of all participants and symptoms at admission, neurological examination findings, laboratory results, and Diffusion-Weighted Magnetic Resonance Imaging results of the patient group were recorded. We used an independent sample t-test to compare neurogranin levels and bivariate correlation analysis to compare the relationship between serum neurogranin levels and data belonging to the patient group. RESULTS: Sixty eight participants (patient group, n = 36; control group, n = 32) were included in the study. Serum neurogranin level was significantly higher in patients with carbon monoxide poisoning (0.31 ± 0.16 ng/ml) compared to control group (0.22 ± 0.10 ng/ml) (p = 0.015). The mean Glasgow Coma Scale of the patients with carbon monoxide poisoning was 14.59 ± 0.23, and of Diffusion Weighted Magnetic Resonance Imaging results were completely normal in 94.4% (n = 34). There was no correlation between serum neurogranin level and Diffusion Weighted Magnetic Resonance Imaging results (r = -0.011; p = 0.953). CONCLUSION: Serum neurogranin level may be a new diagnostic biomarker in patients admitted to the emergency department with carbon monoxide poisoning. The high serum neurogranin levels detected in patients with normal diffusion-weighted imaging after carbon monoxide poisoning suggest that there is neurological damage in these patients, even if imaging methods cannot detect it.

Predictors of Severe Clinical Course in Children With Carbon Monoxide Poisoning.

OBJECTIVE: Carbon monoxide (CO) is a gas, which is produced by incomplete combustion of hydrocarbon-containing substances, and causes significant tissue and organ damage in the common event of CO poisoning. This study aims to evaluate the demographic, clinical, and laboratory characteristics of patients diagnosed with CO poisoning in the emergency department and to determine the factors associated with severe course in the acute phase of poisoning. METHODS: A total of 331 patients diagnosed with CO poisoning in Hacettepe University Children's Hospital, Pediatric Emergency Unit, between January 2004 and March 2014 were included in the study. Their demographic characteristics, presenting complaints, physical examination findings, Glasgow Coma Scale scores, carboxyhemoglobin, leukocyte, hemoglobin, troponin T, pH and lactate levels, type of treatment (normobaric or hyperbaric oxygen), intensive care unit admissions, and outcome of poisoning were investigated. RESULTS: Ninety-three patients were given hyperbaric oxygen. Fifty-one patients were admitted to the pediatric intensive care unit, 18 patients have had a severe clinical course, and 6 patients have died. The risk factors associated with severe disease course were determined to be low Glasgow Coma Scale score, high leukocyte count, and high troponin T levels at presentation. CONCLUSIONS: Glasgow Coma Scale score, leukocyte count, and troponin T level may be beneficial in predicting clinical outcomes and tailoring therapy in children with CO poisoning.