A novel source of carbon monoxide for suicide attempt.

Carbon monoxide (CO) inhalation is a common method of suicide. The combination of formic acid with sulfuric acid creates carbon monoxide. This novel method is described in readily accessible internet-based resources. We present the case of a 35-year-old woman who developed CO toxicity by using this method. It is important for hyperbaric medicine physicians to be aware of this source of CO toxicity.

The History of Carbon Monoxide Intoxication.

Intoxication with carbon monoxide in organisms needing oxygen has probably existed on Earth as long as fire and its smoke. What was observed in antiquity and the Middle Ages, and usually ended fatally, was first successfully treated in the last century. Since then, diagnostics and treatments have undergone exciting developments, in particular specific treatments such as hyperbaric oxygen therapy. In this review, different historic aspects of the etiology, diagnosis and treatment of carbon monoxide intoxication are described and discussed.

Pharmacological treatment of inhalation injury after nuclear or radiological incidents: The Chinese and German approach.

Inhalation injury is often associated with burns and significantly increases morbidity and mortality. The main toxic components of fire smoke are carbon monoxide, hydrogen cyanide, and irritants. In the case of an incident at a nuclear power plant or recycling facility associated with fire, smoke may also contain radioactive material. Medical treatments may vary in different countries, and in this paper, we discuss the similarities and differences in the treatments between China and Germany. Carbon monoxide poisoning is treated by 100% oxygen administration and, if available, hyperbaric oxygenation in China as well as in Germany. In addition, antidotes binding the cyanide ions and relieving the respiratory chain are important. Methemoglobin-forming agents (e.g., nitrites, dimethylaminophenol) or hydroxocobalamin (Vitamin B12) are options. The metabolic elimination of cyanide may be enhanced by sodium thiosulfate. In China, sodium nitrite with sodium thiosulfate is the most common combination. The use of dimethylaminophenol instead of sodium nitrite is typical for Germany, and hydroxocobalamin is considered the antidote of choice if available in cases of cyanide intoxications by fire smoke inhalation as it does not further reduce oxygen transport capacity. Systematic prophylactic use of corticosteroids to prevent toxic pulmonary edema is not recommended in China or Germany. Stable iodine is indicated in the case of radioiodine exposure and must be administered within several hours to be effective. The decorporation of metal radionuclides is possible with Ca (DTPA) or Prussian blue that should be given as soon as possible. These medications are used in both countries, but it seems that Ca (DTPA) is administered at lower dosages in China. Although the details of the treatment of inhalation injury and radionuclide(s) decorporation may vary, the general therapeutic strategy is very similar in China and Germany.

Fasudil alleviates brain damage in rats after carbon monoxide poisoning through regulating neurite outgrowth inhibitor/oligodendrocytemyelin glycoprotein signalling pathway.

Carbon monoxide (CO) poisoning can lead to many serious neurological symptoms. Currently, there are no effective therapies for CO poisoning. In this study, rats exposed to CO received hyperbaric oxygen therapy, and those in the Fasudil group were given additional Fasudil injection once daily. We found that the escape latency in CO poisoning group (CO group) was significantly prolonged, the T1 /Ttotal was obviously decreased, and the mean escape time and the active escape latency were notably extended compared with those in normal control group (NC group, P < 0.05). After administration of Fasudil, the escape latency was significantly shortened, T1 /Ttotal was gradually increased as compared with CO group (>1 week, P < 0.05). Ultrastructural damage of neurons and blood-brain barrier of rats was serious in CO group, while the structural and functional integrity of neuron and mitochondria maintained relatively well in Fasudil group. Moreover, we also noted that the expressions of neurite outgrowth inhibitor (Nogo), oligodendrocyte-myelin glycoprotein (OMgp) and Rock in brain tissue were significantly increased in CO group, and the elevated levels of the three proteins were still observed at 2 months after CO poisoning. Fasudil markedly reduced their expressions compared with those of CO group (P < 0.05). In summary, the activation of Nogo-OMgp/Rho signalling pathway is associated with brain injury in rats with CO poisoning. Fasudil can efficiently down-regulate the expressions of Nogo, OMgp and Rock proteins, paving a way for the treatment of acute brain damage after CO poisoning.

Pulmonary Phototherapy to Treat Carbon Monoxide Poisoning in Rats.

BACKGROUND: Carbon monoxide (CO) poisoning is a common cause of poison-related mortality. CO binds to hemoglobin in the blood to form carboxyhemoglobin (COHb), impairing oxygen delivery to peripheral tissues. Current treatment of CO-poisoned patients involves oxygen administration to rapidly remove CO and restore oxygen delivery. Light dissociates CO from COHb with high efficiency. Exposure of murine lungs to visible laser-generated light improved the CO elimination rate in vivo. The aims of this study were to apply pulmonary phototherapy to a larger animal model of CO poisoning, to test novel approaches to light delivery, and to examine the effect of chemiluminescence-generated light on the CO elimination rate. METHODS: Anesthetized and mechanically ventilated rats were poisoned with CO and subsequently treated with air or oxygen combined with or without pulmonary phototherapy delivered directly to the lungs of animals at thoracotomy, via intrapleural optical fibers or generated by a chemiluminescent reaction. RESULTS: Direct pulmonary phototherapy dissociated CO from COHb reducing COHb half-life by 38%. Early treatment with phototherapy in critically CO poisoned rats improved lactate clearance. Light delivered to the lungs of rats via intrapleural optical fibers increased the rate of CO elimination without requiring a thoracotomy, as demonstrated by a 16% reduction in COHb half-life. Light generated in the pleural spaces by a chemiluminescent reaction increased the rate of CO elimination in rats breathing oxygen, reducing the COHb half-life by 12%. CONCLUSIONS: Successful application of pulmonary phototherapy in larger animals and humans may represent a significant advance in the treatment of CO-poisoned patients.

Hyperbaric oxygen preserves neurotrophic activity of carbon monoxide-exposed astrocytes.

In astrocytes, carbon monoxide (CO) poisoning causes oxidative stress and mitochondrial dysfunction accompanied by caspase and calpain activation. Impairment in astrocyte function can be time-dependently reduced by hyperbaric (3bar) oxygen (HBO). Due to the central role of astrocytes in maintaining neuronal function by offering neurotrophic support we investigated the hypothesis that HBO therapy may exert beneficial effect on acute CO poisoning-induced impairment in intrinsic neurotrophic activity. Exposure to 3000ppm CO in air followed by 24-72h of normoxia caused a progressive decline of gene expression, synthesis and secretion of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) to different extent. 1h treatment with 100% oxygen disclosed a pressure- and time-dependent efficacy in preserving astrocytic neurotrophic support. The beneficial effect was most evident when the astrocytes were exposed to HBO 1-5h after exposure to CO. The results further support an active role of hyperbaric, not normobaric, oxygenation in reducing dysfunction of astrocytes after acute CO poisoning. By preserving endogenous neurotrophic activity HBO therapy might promote neuronal protection and thus prevent the occurrence of late neuropsychological sequelae.

The effect of Asian dust on asthma by socioeconomic status using national health insurance claims data in Korea.

CONTEXT: Asian dust events are associated with increased asthma incidence, asthma exacerbation, decreased lung function and increased risk for hospitalization. OBJECTIVE: The purpose of this study was to evaluate the effect of Asian dust events on asthma exacerbation by socioeconomic status using national health insurance claims data. MATERIALS AND METHODS: A case-crossover design was used to analyze asthma-related national health insurance claims, air pollutant and climate data from 2007 to 2013 in Seoul and Incheon, Korea. We stratified our analysis by socioeconomic status (health insurance versus medical aid subscribers) and calculated the maximum air pollutant levels and average climate values per day. The number of asthma-related visits to medical institutions per day was compared between "event" and "control" days. RESULTS: Compared with "control days", the average number of asthma-related visits to medical institutions decreased on "event" days and increased 1-5 d thereafter. The number of visits by health insurance subscribers also decreased on "event" days and increased 1-5 d thereafter, while the number of visits by medical aid subscribers did not change on "event" days but increased 1-4 d thereafter. DISCUSSION AND CONCLUSION: Our study confirms that Asian dust events result in an increased number of asthma-related visits to medical institutions. This effect differed by socioeconomic status.

Síndrome neurológico tardío tras intoxicación por monóxido de carbono / Delayed neurological syndrome following carbon monoxide poisoning

Introducción. La intoxicación por monóxido de carbono es la más frecuente en nuestro medio a consecuencia de la exposición a gases tóxicos. Los efectos de la intoxicación por monóxido de carbono no se limitan a la exposición aguda porque, tras la aparente recuperación de la intoxicación, pueden aparecer alteraciones neurológicas o del comportamiento. Pacientes y métodos. Se realizó un estudio de las intoxicaciones por monóxido de carbono en un área sanitaria de 80.000 habitantes durante un período de 10 años. Posteriormente se hizo un seguimiento de estos pacientes y se valoró la aparición de síndrome neurológico tardío (SNT) y su relación con diferentes variables en la exposición inicial al monóxido de carbono, en el tratamiento administrado o en la gravedad de la intoxicación. Resultados y conclusiones. Se observó que el 9,1% de los intoxicados por monóxido de carbono detectados en el área sanitaria de Salnés desarrollan el SNT, que es más frecuente en los pacientes con criterios analíticos de gravedad y muy poco probable en los que no los tienen. Los pacientes con SNT no expresaron manifestaciones clínicas ni analíticas diferentes a los que no presentaron el síndrome; tampoco se observaron diferencias en relación con la terapia con oxígeno administrada. La tasa de SNT en el área sanitaria de Salnés entre 2002 y 2012 es de 0,84 casos por 100.000 habitantes y año (AU)

Introduction. Poisoning by carbon monoxide is the most frequent form of intoxication in our milieu as a result of exposure to poisonous gases. The effects of carbon monoxide poisoning are not limited to acute exposure, since, following apparent recovery from the acute intoxication, neurological or behavioural disorders may appear. Patients and methods. A study was conducted to examine the cases of carbon monoxide poisoning that had occurred in a healthcare area of 80,000 inhabitants over a 10-year period. These patients were then submitted to a follow-up to appraise the appearance of delayed neurological syndrome (DNS) and its relationship with different variables in the initial exposure to the carbon monoxide, in the treatment that was administered or in the severity of the intoxication. Results and conclusions. It was observed that around 9.1% of those intoxicated by carbon dioxide detected within the healthcare district of Salnés went on to develop DNS, which is more frequent in patients with severe analytical criteria and very unlikely in those who do not have them. Patients with DNS did not express any clinical or analytical manifestations that differed from those who did not have the syndrome; no differences were observed in relation to the oxygen therapy that was administered. The rate of DNS within the healthcare district of Salnés between 2002 and 2012 is 0.84 cases per 100,000 inhabitants per year. (AU)

Carbon monoxide toxicity after lighting coals at a hookah bar.

INTRODUCTION: Unintentional non-fire-related (UNFR) carbon monoxide (CO) poisonings continue to account for a significant health and economic burden in the United States. While most of these poisonings are related to faulty central heating or water heaters in private dwellings, less common sources should also be considered when a patient presents with any signs or symptoms suggestive of CO toxicity. CASE REPORT: The authors present a case where a patient was found to have severe CO poisoning, a COHgb level of 33.8 %, after lighting coals for a water pipe called a hookah. The patient was initially unconscious and was found to have electrocardiogram (ECG) changes consistent with cardiac ischemia that resolved following treatment with hyperbaric oxygen therapy. DISCUSSION: In recent years, hookah bars have gained in popularity, especially in urban areas and around college campuses. This was the first case to identify the potential occupational exposure of employees working at hookah bars to CO. Furthermore, the patient's COHb level of 33.8 % was higher than any previously reported in the literature with exposure via hookah pipe. The practitioner should consider CO poisoning in patients who smoke tobacco via a hookah and consider early hyperbaric oxygen therapy in those experiencing significant symptoms.

In vitro exposure of Ostrya carpinifolia and Carpinus betulus pollen to atmospheric levels of CO, O3 and SO 2.

Ostrya spp. and Carpinus spp. pollen was in vitro exposed to three atmospheric pollutants: CO, O3 and SO2. Two levels of each pollutant were used, and the first level corresponds to a concentration about the atmospheric hour-limit value acceptable for human health protection in Europe and the second level to about the triple of the first level. Experiments were done under artificial solar light with temperature and relative humidity controlled. The viability of the exposed pollen samples showed a significant decrease. Also, the germination percentage showed a significant decrease in both exposed pollens, and the effect was most pronounced for SO2, followed by O3 and CO. A general decreasing trend in the total soluble protein content of the exposed pollen samples when compared with the control was observed, but it was only statistically significant for the Ostrya spp pollen. The results showed marked effects were observed on the Ostrya spp. and Carpinus spp. pollen when exposed to air pollutant levels that can be considered safe for human health protection.

[A 25-year study (1983-2008) of children's health outcomes after hyperbaric oxygen therapy for carbon monoxide poisoning in utero]. / Devenir des enfants intoxiqués au monoxyde de carbone en période foetale et traités par oxygéno- thérapie hyperbare--etude d'une cohorte constituée sur 25 ans de 1983 a 2008.

Carbon monoxide (CO) poisoning during pregnancy can be fatal for the fetus, or cause bone malformations or encephalopathy, depending on the stage of pregnancy at which the poisoning occurs. Fewer cases of death and encephalopathy have been reported since the adoption of maternal hyperbaric oxygen (HBO) therapy in this setting, but these children's long-term psychomotor development and growth remains to be documented. A prospective single-center cohort study spanning 25 years (1983 - 2008) included all pregnant women living in the Nord-Pas-de-Calais region of France who received HBO for CO poisoning and who gave birth to a living child. A descriptive analysis of the women and children was performed first. A control group of children was created by matching with anonymous files from local authorities. The results of the children's compulsory health & development assessments were used to compare the two groups. 406 women were included in the study, of whom 6 were expecting twins. The psychomotor development of 412 children was monitored, up to the day 8 assessments in 388 cases, the year 2 assessments in 276 cases, and the year 6 assessments in 232 cases. Sixty children have not yet reached the age of 6 years. No significant differences in psychomotor or height/weight criteria (p > 0.05 for both) were found between the exposed and unexposed children. No malformations were reported. These findings support the use of HBO therapy for all expectant mothers exposed to CO poisoning. No specific follow-up of the children is necessary if their neonatal status is normal.

Air quality biomonitoring through pollen viability of Fabaceae.

In this study, pollen viability and germination of three plant species, Cercis siliquastrum L., Robinia pseudoacacia L., and Spartium junceum L., belonging to the Fabaceae family, was evaluated in sites with different intensity of road traffic, constantly monitored with continuous analysers for air pollutants (carbon monoxide (CO), sulphur dioxide (SO(2)), and nitrogen dioxide (NO(2))) by the Municipality of Catania. Two sites, in which road traffic was absent, were selected, too. The percentages of viable pollen by 2,3,5-trypheniltetrazolium chloride (TTC) test ranged from 59.0 to 90.2 % in C. siliquastrum, from 61.5 to 83.5 % in S. junceum and from 67.5 to 84.3 % in R. pseudoacacia. The percentages of germination varied from 41.0 to 72.7 % in C. siliquastrum, from 42.0 to 64.7 % in S. junceum and from 38.3 to 66.3 % in R. pseudoacacia. The highest percentages of viable pollens were found in no-road traffic stations by either TTC or germination tests, while the lowest values were detected in a site characterised by heavy road traffic. In the monitored period (2007-2009), pollen viability, germinability and tube length of C. siliquastrum resulted in a significant negative correlation to CO, SO(2) and NO(2), whereas data from TTC and germination tests on S. junceum and R. pseudoacacia pollens were not well correlated to air pollutants. The results showed that pollen viability, germination and tube growth in C. siliquastrum were affected by air pollution. S. junceum and R. pseudoacacia were not very influenced by air pollutants, suggesting a different pollen sensitivity of these species.

Investigation into the oxidative potential generated by the formation of particulate matter from incense combustion.

The formation of aerosols during combustion plays an important role in allowing released products to interreact, leading to an increase in particulate matter oxidative potential. This study investigated the physicochemistry of incense combustion-derived pollutants, which were emitted into the ambient air as solid and gas phases, followed by the determination of their oxidative potential. Upon combustion of a joss stick, approximately 60% of the mass of incense raw ingredients was released into the ambient air as combustion products including 349.51 mg/g PM(10), 145.48 mg/g CO and 0.16 mg/g NOx. Furthermore, incense combustion produced significant number of primary particles (<50 nm) at 0.99×10(5) 1/h. The NOx generated during incense combustion was able to react with CaCO(3) to produce the final product of Ca(NO(3))(2) in the ambient air. Moreover, coagulation could be a vital process for the growth of primary incense combustion particles through the intermixing with volatile organics. The incense particle's reactions with other combustion-derived products could be responsible for their significant oxidative capacity of 33.1-43.4% oxidative DNA damage. This study demonstrated that the oxidative potential of incense particles appeared to be related to the process of particle formation, and also provided novel data for the respiratory exposure assessment.

Intoxicación por monóxido de carbono: una patología poco valorada en urgencias / Carbon monoxide poisoning: an undervalued event in the emergency department

La intoxicación aguda por monóxido de carbono (CO) es una urgencia médica que, de no tratarse oportunamente, puede dejar considerables secuelas neurológicas o incluso provocar la muerte del paciente. El cuadro clínico depende de la intensidad de la exposición a este gas y varía según el grado de afectación de los distintos órganos involucrados. La administración de oxígeno normobárico (NBO) es el tratamiento utilizado en la mayoría de los servicios de urgencias hasta la resolución de los síntomas y la normalización de los niveles de carboxihemoglobina (COHb), siendo dados de alta los pacientes en la práctica común sin seguimiento posterior. Presentamos el caso de un paciente que acude a urgencias por síncope y nos cuestionamos si la utilización de oxigeno hiperbárico (HBO) frente a (NBO) disminuye las secuelas neurológicas, así como la existencia de indicaciones con evidencia científica para su uso (AU)

Carbon monoxide (CO) poisoning is a medical emergency, which if not treated properly could leave considerable neurological sequelae or even cause the death of the patient. The signs and symptoms depend on the intensity of the exposure to the gas and vary according to the degree to which the different organs are affected. Administration of normobaric oxygen (NBO) is the treatment used in most emergency services. This gas is administered until symptoms are resolved and carboxyhemoglobin (COHb) levels have returned to normal. The patient is then discharged with no subsequent follow-up. We present the case of a patient who came to the emergency department due to syncope. We ask ourselves whether the use of hyperbaric oxygen (HBO) compared to NBO decreases neurological sequelae, and if there is scientific evidence for its use in this indication (AU)

Impact of organic solvents and environmental pollutants on the physiological function in petrol filling workers.

Long term exposure to solvents and air pollutants can lead to deleterious effects on respiratory, haematological and thyroid functioning. The aim of this study was to investigate whether chronic exposure to solvents like benzene and pollutants like carbon monoxide in petrol filling workers had adverse effect on blood parameters, thyroid and respiratory functions. The study group consisted of 42 healthy, non-smoker petrol filling workers, aged 20-50 years with work (exposure) duration from 2-15 years while 36 healthy subjects of the same age group served as controls. Physical examination and measurement of pulmonary functions by portable electronic spirometer were performed. Complete blood pictures (CBP) were determined by normal haematology lab procedure and hormones by Chemiluminescence immunoassay (CLIA) light absorption techniques. There was a significant decrease in the lung volumes and capacities; the restrictive pattern was more prevalent in the workers when compared with the control groups. But in the workers exposed for long period (more than 10 years) the restrictive pattern was changed to mixed pattern. A significant increase in haemoglobin (Hb) (>16 mg %) and red blood cells (RBC) (5.4 million cells/mm3) were observed in workers with longer period of exposure when compared with the control subjects (14.483 mg% and 4.83 million cells/mm3 for Hb and RBC respectively). White blood cell count except eosinophils and platelets were significantly lower in workers compared to controls. Marked increase in the tetra iodothyroinine (T4), free thyroxine (T4F) level and significant decrease in thyroid stimulating hormones (TSH), and tri-iodothyronine (T3) were observed between long term exposed and non-exposed groups. Till now researchers focused only on the effect of solvents in workers professionally exposed to solvents without considering the effect of concomittant air pollution. The result obtained from present study indicates that there is a significant toxic effect of solvents and air pollutants on workers exposed for longer duration. Improved detection and prevention technologies are needed to answer environmentally related health questions for petrol filling workers.

Carbon monoxide intoxication: an updated review.

Carbon monoxide (CO), a highly toxic gas produced by incomplete combustion of hydrocarbons, is a relatively common cause of human injury. Human toxicity is often overlooked because CO is tasteless and odorless and its clinical symptoms and signs are non specific. The brain and the heart may be severely affected after CO exposure with carboxyhemoglobin (COHb) levels exceeding 20%. Damage occurs because the affinity of hemoglobin for CO is 210 times higher than for O(2). Hypoxic brain damage predominates in the cerebral cortex, cerebral white matter and basal ganglia, especially in the globus pallidus. Diagnosis requires clinical acumen and a high index of suspicion, combined with epidemiological data, clinical examination, analysis of ambient air CO and patient COHb levels; also required are cardiology evaluation including ECG as well as neurological evaluation including brain imaging (CT and/or MRI, MR spectroscopy), and neuropsychological testing. Although immediate O(2) breathing is sometimes an adequate treatment, hyperbaric oxygen therapy (HBO) is favored. Subsequently, only symptomatic therapy is available for the long-term sequelae of CO poisoning.

Carbon monoxide: the bad and the good side of the coin, from neuronal death to anti-inflammatory activity.

The double origin of carbon monoxide (CO) as an atmospheric pollutant or as an endogenous gaseous modulator of many pathophysiological processes prompted us to review some aspects of the bad side and of the good side of coin among the pleiotropic effects of CO. On the bad side of the coin, we focus on the interval form in acute CO poisoning, discussing experimental evidence suggesting that the delayed neuropathology after CO poisoning is a free radical-driven event. In this context, we challenge the mandatory place of hyperbaric oxygen therapy (HBO) in CO poisoning as a possible summation of oxy-radicals generated by HBO and the free radical cascade set in motion during the reoxygenation phase of acute CO-poisoning. We also discuss an opposing view, which provides evidence suggesting that HBO therapy actually decreases the load of free radicals in acute CO-poisoning and may be beneficial in preventing delayed neuropsychiatric sequelae.On the good side of the coin, we briefly outline the endogenous generation of CO and the leading role of heme-oxygenases (HO) in relation to the place of CO in biology and medicine. The main focus of this section is on the growing literature on CO and inflammation. Here we report on in-vitro and in-vivo studies on the modulation afforded by exogenously administered/endogenously produced CO in a variety of experimental and clinical settings of inflammation. Our recent studies on experimental models of allergic inflammation are also discussed, and the CO-releasing molecules envisaged as potential anti-inflammatory drugs suitable for clinical use.

Toxicity associated with carbon monoxide.

Carbon monoxide is an insidious poison that accounts for thousands of deaths each year in North America. Clinical effects maybe diverse and include headache, dizziness, nausea, vomiting,syn-cope, seizures, coma, dysrhythmias, and cardiac ischemia. Children, pregnant women, and patients who have underlying cardiovascular disease are particularly at risk for adverse out-comes. Treatment consists of oxygen therapy, supportive care, and, in selected cases, hyperbaric oxygen therapy.