• 한국세라믹학회지
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• 제52권5호
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• pp.308-314
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• 2015

The electrochemical performance and Cr poisoning behavior of $La_{1-x}Ba_xCo_{0.9}Fe_{0.1}O_{3-{\delta}}$ (LBCF, x = 0.3, 0.4, 0.5) and $La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_{3-{\delta}}$ (LSCF) cathodes were investigated for solid oxide fuel cells (SOFCs). The polarization resistance of the LBCF/GDC/LBCF symmetrical cell was found to decrease with increasing Ba content (x value). This phenomenon might be associated with the high oxygen vacancy concentration in the LBCF sample, with x = 0.5. In addition, there was no chromium poisoning in the LBCF cathode. On the other hand, the polarization resistance of the LSCF cathode was found to significantly increase after exposure to gaseous chromium species; it appears that this result stemmed from the formation of $SrCrO_4$ phase. Therefore, it can be expected that LBCF can be a durable potential cathode material for intermediate-temperature solid oxide fuel cells (IT-SOFC).

• Journal of Preventive Medicine and Public Health
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• 제17권1호
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• pp.5-24
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• 1984

There has been an immense need for elaborate studies on the complications and the neuological sequelae generated by acute carbon monoxide (CO) poisoning which is highly prevalent in Korea due to widespread adoption of the anthracite coal briquette as domestic fuel for heating and for cooking. For this epidemiological study, a total of 444 subjects who received hospital emergency care for acute CO poisoning during the period of March 1982 to February 1983 were randomly selected from the emergency patients's lists of 13 general hospitals in Seoul area. Informations on the neurological sequelae were elucidated by means of home visiting with prearranged questionnaire consisting questions and concise neurological examination. The findings obtained were summarized as follows; 1. The complications were found in 18% of the surveyed and acute decubitus was comprised 67.5% of the complications. 2. The total cumulative incidence of the neurological sequelae was 41.2 per 100 patients and the absolute incidence rate regardless of the duration after poisoning was 40.8%. 3. The incidence of the neurological sequelae was higher in the older age than in the younger and also higher in female than in male. Twice higher incidence was observed in the admitted patients than in the non-admitted patients and the incidence became higher in proportion to the duration of CO exposure, coma and admission. The poorer the consciousness level of patients found, at emergency room and at discharge, the higher the incidence. The incidence of the neurological sequelae by emergency care was higher in hyperbaric oxygen therapy group(51.9%) than in 100% $O_2$ group(38.0%) 4. A total of five variables significantly associated with the occurrence of the neurological sequelae were selected by the stepwise discriminant analysis. The variables were following course of emergency care, age, consciousness level at discharge, admission duration, and consciousness level at emergency room in their sequence of discriminant power. Eight variables were selected as those associated with the degree of the neurological sequelae through the stepwise multiple regression analysis. Of these variables, the acute decubitus alone explained 21.1% of the total variation ana all the eight variables could explain 36.5% of the same. The remaining seven variables listed in the order of their relative importance were: age, consciousness level at discharge, admission duration, coma duration and consciousness level at emergency room. 5. It was postulated that unexpectedly high incidence of the neurological sequelae of the CO poisoning in this epidemiological study was mainly due to the inadequate emergency care and the lack of efficient and sophisticated treatment measure. In the effort to minimize the incidence of grave neurological sequelae of acute CO poisoning, new guidelines for the emergency care and treatment should be pursued with efficient ways.

• Journal of Trauma and Injury
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• 제32권4호
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• pp.252-257
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• 2019

Hyperbaric oxygen therapy (HBOT) is used to treat carbon monoxide (CO) poisoning. However, untreated pneumothorax is an absolute contraindication for HBOT. More caution is needed with regard to monoplace hyperbaric chambers, as patient monitoring and life-saving procedures are impossible inside these chambers. Central catheterization is frequently used for various conditions, but unnecessary catheterization must be avoided because of the risk of infection and mechanical complications. Herein, we describe a case of CO poisoning in which iatrogenic pneumothorax developed after unnecessary subclavian central catheterization. The patient did not need to be catheterized, and HBOT could not be performed because of the pneumothorax. Hence, this case reminds us of basic-but nonetheless important-principles of catheterization.

• 대한임상독성학회지
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• 제17권2호
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• pp.102-107
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• 2019

Purpose: Acute carbon monoxide (CO) poisoning is one of the most common types of poisoning and a major health problem worldwide. Treatment options are limited to normobaric oxygen therapy, administered using a non-rebreather face mask or hyperbaric oxygen. Compared to conventional oxygen therapy, high-flow nasal cannula oxygen (HFNC) creates a positive pressure effect through high-flow rates. The purpose of this human pilot study is to determine the effects of HFNC on the rate of CO clearance from the blood, in patients with mild to moderate CO poisoning. Methods: CO-poisoned patients were administered 100% oxygen from HFNC (flow of 60 L/min). The fraction of COHb (fCOHb) was measured at 30-min intervals until it decreased to under 10%, and the half-life time of fCOHb (fCOHb t_1/2) was subsequently determined. Results: At the time of ED arrival, a total of 10 patients had fCOHb levels ≥10%, with 4 patients ranging between 10% and 50%. The mean rate of fCOHb elimination patterns exhibits logarithmic growth curves that initially increase quickly with time (HFNC equation, Y=0.3388*X+11.67). The mean fCOHbt_1/2 in the HFNC group was determined to be 48.5±12.4 minutes. Conclusion: In patients with mild to moderate CO poisoning, oxygen delivered via high flow nasal cannula is a safe and comfortable method to treat acute CO toxicity, and is effective in reducing the COHb half-life. Our results indicate HFNC to be a promising alternative method of delivering oxygen for CO toxicity. Validating the effectiveness of this method will require larger studies with clinical outcomes.

• Journal of Preventive Medicine and Public Health
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• 제5권1호
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• pp.17-23
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• 1972

Carbon Monoxide poisoning is one of the most serious Public health problems in Korea. The incidence rate. officially reported has been known to be the highest in the world. This high incidence is mainly due to the wide prevalence of anthracite coal briquette as the domestic fuel for unique Korean heating system called 'ondol,' The coal briquette gas contains around 3-5% of Carbon Monoxide. A nation-wide effort to eliminate or reduce this serious hazards has produced little effect and the most hospitals are offering very ineffective measures such as oxygen inhalation through nasal catheter. Author has believed that this preventable accident should be approached by the secondary preventive measure because of our socio-economic status do not allow us optimistic results from primary preventive measure as far as the problem of CO poisoning is concerned. Author has treated 466 patients during 30 months period by Hyperbaric Oxygenation at Seoul National University Hospital. The results found are as follows. 1. Female has a higher incidence rate than male and the age group between 15-29 years showed highest incidence. 2. The recovery time depends on the time when the patients arrived at hospital. Earlier the arrival time, shorter the recovery time. 3. Some objective signs are representing typical physiological response to tissue hypoxia. 4. Therapeutic effectiveness of Hyperbaric Oxypenation is confirmed by such indices as recovery rate, Admission rate and average stay in hospital. Futher, these results are cocordant with other reports on the clinical value of Hyperbaric Oxygenation in the treatment of CO poisoning.

• 대한임상독성학회지
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• 제9권2호
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• pp.88-94
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• 2011

Purpose: Delayed neuropsychological sequelae (DNS) commonly occurs after recovery from acute carbon monoxide poisoning. The aim of this article is to identify the factors associated with DNS development. Methods: We retrospectively evaluated patients, admitted to the medical center emergency department from June 2005 to March 2011, who were suffering from acute carbon monoxide (CO) poisoning. We categorized the patients into two groups - those with DNS, and those without DNS. Multiple regression analysis was performed to identify the factors related to manifestation of DNS. Results: Of the total one hundred fifty seven patients (157) recruited for the study, twenty two (22) developed DNS. Longer CO exposure times and lower GCS scores were positively associated with development of DNS symptoms. Conclusion: Our study identified two potential factors which are predictive of DNS development in CO intoxication, however, more studies are needed. Adequate follow-up after hospital discharge to monitor for and accurately identify manifestation of DNS, is also important.

• 대한임상독성학회지
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• 제13권1호
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• pp.46-49
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• 2015

Carbon monoxide (CO) intoxication is a leading cause of severe neuropsychological impairments. Peripheral nerve injury has rarely been reported. Following are brief statements describing the motor peripheral neuropathy involved bilateral lower extremities of a patient who recovered following acute carbon monoxide poisoning. After inhalation of smoke from a fire, a 60-year-old woman experienced bilateral leg weakness without edema or injury. Neurological examination showed diplegia and deep tendon areflexia in lower limbs. There was no sensory deficit in lower extremities, and no cognitive disturbances were detected. Creatine kinase was normal. Electroneuromyogram patterns were compatible with the diagnosis of bilateral axonal injury. Clinical course after normobaric oxygen and rehabilitation therapy was marked by complete recovery of neurological disorders. Peripheral neuropathy is an unusual complication of CO intoxication. Motor peripheral neuropathy involvement of bilateral lower extremities is exceptional. Various mechanisms have been implicated, including nerve compression secondary to rhabdomyolysis, nerve ischemia due to hypoxia, and direct nerve toxicity of carbon monoxide. Prognosis is commonly excellent without sequelae. Emergency physicians should understand the possible-neurologic presentations of CO intoxication and make a proper decision regarding treatment.

• Journal of Preventive Medicine and Public Health
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• 제15권1호
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• pp.145-151
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• 1982

산모(産母)와 태아(胎兒)에서의 CO 배출양상(排出樣相)의 차이(差異)가 hemoglobin의 CO와의 결합력(結合力)의 차이(差異)에서 기인(起因)된 것인지의 여부(與否)를 산소분압(酸素分壓)에 따른 HbCO의 해리양상(解離樣相)으로써 규명(糾明)하고 이를 토대(土臺)로 임신부(姙娠婦) 및 영아가 CO에 중독(中毒)되었을 때의 적절(適切)한 산소치료방식(酸素治療方式)을 모색(模索)하고자 본(本) 실험(實驗)을 실시(實施)하여 다음과 같은 성적(成績)을 얻었다. 1. 성인혈(成人血)과 태아혈(胎兒血)의 total hemoglobin량(量)은 각각(各各) $16.1{\pm}0.50gm%,\;15.7{\pm}0.32gm%$였으며 fetal hemoglobin 비율(比率)은 각각(各各) $1.2{\pm}0.15%,\;72.7{\pm}3.01%$ 였다. 2. 성인혈(成人血)과 태아혈(胎兒血)을 100% HbCO로 포화(飽和)시킨 뒤 일반대기(一般大氣), 100% $O_2$, 3기압산소(氣壓酸素)에 30분간(分間) 폭로(曝露)시킨 직후(直後)의 혈중(血中) HbCO 포화도(飽和度)는 성인혈(成人血)에서 각각(各各) 96.7%, 70.9% 및 52.8%였으며 태아혈(胎兒血)에서 각각(各各) 98.5%, 76.1% 및 62.2%로 감소(減少)하여 3기압산소(氣壓酸素)에서 가장 현저(顯著)한 감소(減少)를 보여 HbCO의 해리(解離)는 산소분압(酸素分壓)에 비례(比例)함이 확인(確認)되었으며 또 전(全) 실험군(實驗群)에서 성인혈(成人血)보다 태아혈(胎兒血)의 HbCO 해리(解離)가 늦은 양상(樣相)을 보였다. 3. 실험군(實驗群)에 대(對)한 각(各) 산소분압별(酸素分壓別) 폭로(曝露)가 끝난 후(後) $36.5^{\circ}C$의 일반대기하(一般大氣下)에서 시간경과(時間經過)에 따른 성인혈(成人血)과 태아혈중(胎兒血中) HbCO의 해리양상(解離樣相)은 거의 비슷하게 완만(緩慢)하였다. 4. 이상(以上)의 소견(所見)으로 미루어 볼 때 임신부(姙娠婦)의 CO 중독(中毒)은 산모(産母)보다 태아(胎兒)에서 더 큰 위해(危害)를 초래(招來)할 가능성(可能性)이 크며 또 HbF의 구성점유율(構成占有率)이 높은 6개월(個月) 이하(以下)의 영아에서도 그 위해도(危害度)가 클 것으로 간주(看做)된다. 따라서 임신부(姙娠婦) 또는 생후(生後) 6개월(個月) 이하(以下)의 영아가 CO 중독(中毒)되었을 때는 고압산소요법(高壓酸素療法)이 효과적(效果的)인 치료법(治療法)으로 보이며 그 치료시간(治療時間)을 성인환자(成人患者)에 있어서의 그것보다 좀 더 길게하는 것이 CO 중독(中毒)에 의한 위해(危害)를 감소(減少)시켜 줄 것으로 기대(期待) 된다.

• 대한임상독성학회지
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• 제3권1호
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• pp.27-32
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• 2005

Purpose: The frequency of carbon monoxide poisoning has been decreased in the interior of the Korea. But occasionally it is occurred and the risk of exposure is high in working place so far. Because of the characteristics of gas, the detection of exposure and poisoning could be delayed and fatality is high. We should apprehend of carbon monoxide poisoning. So we would report analysis of patients with carbon monoxide poisoning. Methods: A retrospective review of CO poisoned patients visited emergency department from January 2000 to December 2004 was conducted. Results: 24 patients were enrolled. Their average of age was $37.6\pm20.9$ years old and COHb was $19.4\pm13.32\%$. The blood level of initial COHb and mental status on arrival were not correlated each other. The blood level of initial COHb and loss of consciousness were not correlated, too. Initial electrocardiography (EKG) was not correlated with cardiac enzymes such as CK-MB and troponin I. But base excess was correlated with mental status on arrival and complication such as rhabdomyolysis. Hyperbaric oxygen therapy was correlated with base excess and mental status on arrival. Conclusion: The clinical features of carbon monoxide poisoning are nonspecific. For proper diagnosis, it is important that we should consider patient's environment and take patient's history carefully. The blood level of initial COHb does not reflect severity of poisoning accurately. So We should determine the treatment of choice depending on patient's status.

• 대한응급의학회지
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• 제29권5호
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• pp.519-528
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• 2018

Objective: Delayed neuropsychiatric sequelae (DNS) following carbon monoxide (CO) poisoning, which may result from a demyelinating leukoencephalopathy, is a disease with a poor prognosis. This study examined the factors affecting the long-term prognosis of DNS and the efficacy of hyperbaric oxygen therapy (HBOT) in patients with DNS. Methods: This retrospective study included 84 patients with DNS following CO poisoning from January 2013 to June 2016. HBOT was given to 24 patients. The patients were divided into an improvement group and non-improvement group based on their clinical condition on a telephone interview at intervals between 3 months and 3 years after the onset of DNS. The improvement group was defined as having Cerebral Performance Category (CPC) scores in their daily life that improve to 1 or 2 grade. Results: Of the 594 patients, DNS were found in 18.2%, and 70.2% (59 of 84) of the patients with DNS improved. The prognostic factors for the improvement of DNS were an age of 45 years or less (odds ratio [OR], 12.068; 95% confidence interval [CI], 2.393-60.858; P<0.005), CPC score of 1 or 2 group at the time of DNS onset (OR, 12.361; 95% CI, 3.161-48.330; P<0.005), and a lucid interval longer than 20 days (OR, 5.164; 95% CI, 1.393-19.141; P<0.01). HBOT was not associated with the improvement of DNS in CO poisoning (OR, 0.467; 95% CI, 0.172-1.269; P>0.1). Conclusion: Patients aged less than 45 years, low grade CPC score of 1 and 2, and lucid interval longer than 20 days are more likely to have a good prognosis. On the other hand, HBOT failed to produce a benefit for DNS patients.