Sumatriptan Relieves Migrainelike Headaches Associated With Carbon Monoxide Exposure

We report a 58-year-old woman with long-standing migraine who developed a pattern of weekend headaches which occurred only while staying at her Connecticut vacation home The headaches promptly responded to sumatriptan. Investigation revealed a high carbon monoxide level in her home due to a defective furnace. Replacing the furnace eliminated the headaches. This case highlights the importance of searching for secondary causes of headache even in patients responsive to sumatriptan. It also suggests that carbon monoxide may trigger headaches mediated by trigeminovascular inflammation.     

Cardiac Damage in Pediatric Carbon Monoxide Poisoning

Background: Cardiovascular disorders including myocardial ischemia and heart failure have been described in both laboratory animals and humans following carbon monoxide poisoning. Carbon monoxide cardiotoxicity may be clinically occult and often remains undiagnosed because of the lack of overt symptoms and specific ischemic changes in the electrocardiogram. Routine myocardial necrosis markers have low diagnostic efficiency, particularly in patients with concomitant skeletal muscle necrosis or multiple organ failure complicating carbon monoxide poisoning. Carbon monoxide-induced cardiotoxicity has been investigated rarely in children. Case Report: This paper describes carbon monoxide poisoning in a 12-year-old child who suffered from occult cardiac damage despite mild symptoms and low carboxyhemoglobin concentrations. Myocardial and mitral valve dysfunctions were observed, suggesting an ischemia-like syndrome. Cardiac damage was completely reversible within 1 month. Conclusion: This case report supports that a prolonged carbon monoxide exposure can cause cardiac damage in children even in the absence of specific symptoms, cerebral failure and high carboxyhemoglobin concentrations.     

Toxic CO-ingestions in Intentional Carbon Monoxide Poisoning

Background

Intentional carbon monoxide (CO) poisoning is responsible for two-thirds of the deaths from CO poisoning in this country and an estimated 15,000 Emergency Department visits annually.

Objectives

In an attempt to optimize medical management of such patients, this study was conducted to examine the frequency and types of toxic co-ingestions that may accompany CO inhalation.

Methods

Records of all patients treated with hyperbaric oxygen for acute, intentional CO poisoning at a regional referral center for hyperbaric medicine in Seattle from 1980 to 2005 were reviewed. For those where co-ingestions were identified, information about type of poison(s) and results of toxicology screens was recorded and analyzed.

Results

Over the 25-year period examined, 433 patients were treated for intentional CO poisoning and records were available for 426. Of those, 188 (42%) had ingested one or more poisons in addition to CO. Ethanol was most common, but a wide variety of other drug classes were also identified. Toxicology screening studies of some type were performed in 49 patients.

Conclusions

Toxic co-ingestions seem to be relatively common in patients treated for intentional CO poisoning. For this reason, providers should be vigilant and open to clinical signs that can’t be explained with CO exposure alone, and ready to treat clinical issues that arise from co-ingestions.     

Victim of Carbon Monoxide Poisoning Identified by Carbon Monoxide Oximetry

Background: Carbon monoxide (CO) is known as a leading cause of unintentional poisoning death in many countries. Diagnosis is usually made by measuring carboxyhemoglobin (COHb), but due to the non-specific symptoms, the crucial step is considering CO poisoning. A possible solution might be screening emergency department (ED) patients. A cutaneous sensor that measures oxygen and CO saturation simultaneously could accomplish that. Objectives: We report a case in which CO-oximetry screening helped to identify CO poisoning in a patient with otherwise non-specific complaints presenting to a busy university hospital ED. Case Report: A 53-year-old woman presented to our ED, reporting non-specific but common symptoms including emesis and diarrhea, one-sided headache, paresthesia, and palpitations. Whereas conventional pulse oximetry showed normal results, a COHb level of 28% was measured using a CO-oximeter. This allowed a diagnosis of CO poisoning to be made at admission. The patient was treated with 100% oxygen continuous positive airway pressure ventilation, and CO washout was monitored continuously and non-invasively. In the meantime, the local fire department was alerted and found a malfunctioning water heater as the source of CO in the patient's residence. As COHb fell to normal levels and the patient reported feeling well, she was discharged the next day. Conclusion: CO-oximetry served as a powerful tool in both identifying and monitoring a CO-poisoned patient in a busy ED. Future studies should address possible sources of error using this method on a long-term basis and its level of acceptance by ED staff.     

Carbon Monoxide Poisoning from Spray Paint Inhalation

This case report emphasizes the varied manifestation of CO poisoning and its genesis from methylene chloride. Because DCM is now an ingredient in many popular spray paints, the ingredients should be checked routinely in toxic exposures. Manufacturer's suggestions concerning the use these products in ventilated areas to avoid harmful effects do not always protect the consumer, and the public should be well informed regarding this issue.     

Routine Carbon Monoxide Screening by Emergency Medical Technicians

Residential carbon monoxide (CO) poisoning represents a significant cause of unintentional morbidity and mortality in the United States. Screening by fire departments and utility companies is usually limited to instances in which there are symptoms of CO poisoning or there is activation of a home CO detector. OBJECTIVES: To determine whether emergency medical services (EMS) personnel can perform routine CO screening during 911 calls. METHODS: A prospective observational study was conducted in an urban EMS system using emergency medical technicians (EMTs) to screen for elevated CO levels during emergency responses. The EMTs carried hand-held CO meters that detect as little as one part per million of CO. Readings were taken at the patient's side during indoor patient contacts. If time allowed, a brief questionnaire was then administered to patients or by-standers concerning knowledge about CO poisoning, type of household heating system, and presence of home CO detectors. RESULTS: In a three-month convenience sample of emergency responses, there were 264 residential CO readings obtained. There were nine (3.4%) positive residential readings, all with chief complaints believed to be unrelated to CO toxicity. Two hundred twelve surveys were completed during these emergency responses, with 145 of 212 (68%) participants familiar with the term "carbon monoxide poisoning." Only 54 of 145 (37%) participants could name any signs or symptoms of CO poisoning. Of those surveyed, 133 of 212 (63%) participants reported an oil- or gas-powered heating system in their residence. Carbon monoxide detectors were absent in 185 of 212 (87%) residences, including all domiciles in which a positive CO reading was obtained. CONCLUSIONS: Emergency medical services personnel can perform routine CO screening and detect occult elevations in CO levels during 911 responses. Public knowledge of CO poisoning is limited and the use of home CO detectors is rare in this study population.     

Unrecognized Carbon Monoxide poisoning Leads To a Multiple-Casualty Incident

Background

Carbon monoxide (CO) is regarded as a leading cause of morbidity and mortality. It endangers not only patients, but also health care professionals, especially emergency medical services (EMS) personnel because CO exposure is often unknown at the time EMS is called.

Objective

Our objective was to report a case of unrecognized CO exposure during the treatment of a patient that finally led to the hospitalization of 11 EMS personnel.

Case Report

A 71-year-old man was found unconscious in the basement of his house. EMS was called and, due to ST-segment elevations on electrocardiogram, the patient was treated for acute coronary syndrome. Unknown to EMS personnel, ongoing CO exposure was the cause of the patient's symptoms. EMS staff finally had to be evacuated by firefighters, and a total of 12 persons, including the initial patient, had to be hospitalized.

Conclusions

In the prehospital setting, hazardous environments always have to be considered as potential causes of a patient's altered status. Together with the correct use of modern equipment, such as permanently switched-on CO detectors, this can help avoid harm to both patients and staff.     

A Novel Method for Continuous Environmental Surveillance for Carbon Monoxide Exposure to Protect Emergency Medical Service Providers and Patients

Background

Carbon monoxide exposure is an important, but frequently undiagnosed, cause for Emergency Medical Services (EMS) response. Its elusive characteristics and non-specific symptoms make detection difficult without monitoring devices. Consequently, both patients and EMS providers are at increased risk of harm from such exposures.

Case Series

We report a series of five cases of carbon monoxide encounters, in which carbon monoxide exposure was not suspected, whereby portable (pager-sized) environmental carbon monoxide detectors, that provide continuous surveillance of the ambient air, were utilized. These devices were carried within, or attached to, the first-in medical jump bags, alerting EMS crews to potentially harmful levels of carbon monoxide.

Conclusion

This case series highlights the importance of environmental surveillance for carbon monoxide by EMS providers, particularly in such cases where its presence is not suspected. This was, in fact, the case in all the encounters presented herein.     

磁共振扩散成像在一氧化碳中毒脑病中的应用

目的:探讨磁共振扩散成像(DWI)对一氧化碳(CO)中毒脑病的诊断价值。方法:CO中毒患者59例,其中迟发脑病15例,均进行DWI检查。结果:59例患者病变区域脑白质平均ADC值为(0.51±0.09)×10-3mm2/s,明显低于正常对照白质ADC值为(0.91±0.07)×10-3mm2/s,前者低于后者(P<0.05)。结论:CO中毒脑病的病变区域脑白质水分子扩散水平明显下降。     

Pathophysiology and Treatment of Carbon Monoxide Poisoning

Abstract

Carbon monoxide poisoning is the leading cause of poisoning deaths in the US, and published reports of carbon monoxide related morbidity and mortality can vary widely. Common morbidity involves myocardial and/or neurologic injury including delayed neurologic sequelae. The pathophysiology of this entity is complex, involving hypoxic stress on the basis of interference with oxygen transport to the cells and possibly impairing electron transport. Carbon monoxide can also affect leukocytes, platelets and the endothelium, inducing a cascade of effects resulting in oxidative injury. Carboxyhemoglobin levels are valuable for confirming carbon monoxide exposure but cannot be used to stratify severity of poisoning, predict prognosis, or indicate a specific treatment plan. Oxygen therapy is the key treatment of carbon monoxide intoxication, and hyperbaric oxygen has been shown to interdict and improve clinical outcome in some patients. Immediate treatment with a high fraction of inspired oxygen and careful clinical evaluation are mandatory. Timely referral for hyperbaric oxygen is indicated for patients with any history of unconsciousness, cardiovascular instability or ischemia, and persistent mental and/or neurologic deficits. Hyperbaric oxygen should also be considered in certain other patient subsets.     

急性CO中毒349例患者的护理体会

CO与血液中的血红蛋白（hemoglobin．Hb）结合后形成碳氧血红蛋白,使氧气不能与Hb结合．血液携氧能力下降,直接造成组织缺氧。同时CO可通过阻断细胞线粒体呼吸链,造成细胞呼吸障碍。产生直接的细胞毒性。     

急性一氧化碳中毒后迟发性脑病24例临床特征

目的 总结急性一氧化碳中毒后迟发性脑病（DEACMP）的有关临床特征。方法 对本院2000年6月至2006年6月收治的24例DEACMP患者临床表现、影像学、脑电图、心电图、治疗及预后等进行回顾分析。结果 24例均有意识障碍（主要表现为意识内容改变。少数表现为意识水平受损）持续时间（12．5±5．8）h，假愈期（10．5±6．2）d；14例有锥体外系功能障碍。部分病例有锥体系功能障碍。心电图检查异常率为43．5％（10／24），脑电图异常率为100％（24／24），CT异常率为66．69／6（16／24）。MRI83．3％（10／12）。全组痊愈16例。好转7例，死亡1例。结论 DEACMP主要表现为意识障碍、锥体外系和锥体系功能障碍，一经发生治疗较困难，致残率高。     

Acute Wood or Coal Exposure with Carbon Monoxide Intoxication Induces Sister Chromatid Exchange

Objective: The object of this study was to investigate the genotoxic effect of acute overexposure to combustion products originating from coal or wood stoves in patients presenting with acute carbon monoxide intoxication. Study Design: In a prospective study, we analyzed the frequency of sister chromatid exchange and the carboxyhemoglobin concentration in 20 consecutive patients without a history of smoking or drug use who had been treated in the Emergency Care Unit of Istanbul Medical Faculty due to acute carbon monoxide intoxication. All of these cases were domestic accidents due to dysfunctioning coal or wood stoves. The results were compared with a control group of 20 nonsmoking, nondrug-using healthy individuals matched for age, sex, and absence of other chemical exposure. Results: The mean sister chromatid exchange frequency per metaphase was significantly higher in the study group compared to the control group: 8.11±2.39 vs. 6.33±1.60 (p=0.008). We found that there was no positive correlation between the blood carboxyhemoglobin concentration and sister chromatid exchange frequency. Conclusions: These results suggest that acute exposure to combustion products of wood or coal is genotoxic to DNA. Potential causes of genotoxicity include known mutagenic compounds present in coal or wood smoke and ash, oxygen radicals formed during combustion, as well as hypoxic and reperfusion injury mechanisms initiated by carbon monoxide intoxication. Additional studies on separate carbon monoxide exposure from smoke and ash are needed to understand individual genotoxic contributions and mechanisms.     

内源性一氧化碳在慢性阻塞性肺疾病的变化

目的　探讨内源性一氧化碳 ( CO)在慢性阻塞性肺疾病 ( COPD)中的作用。方法　应用拜尔 85 5血气分析仪直接检测 30名 COPD急性发作期患者及 30名对照组动脉血一氧化碳血红蛋白 ( COHb)含量、p H、PO2 、PCO2 等指标 ,同时测定了各组的血浆一氧化氮 ( NO)水平。结果　 COPD与对照组 COHb分别为 :2 .0 6± 0 .5 3% ,0 .82± 0 .38% ;NO分别为 46.8± 1 5 .7,71 .2± 8.9μmol/L。两组比较 t值分别为1 0 .2和 7.4( P均 <0 .0 1 ) ,差异均有显著性 ,COPD患者血 COHb与血浆 NO水平呈显著负相关 ( r=-0 .5 73,P<0 .0 1 )。结论　内源性 CO是在 NO之外的又一个内源性介质参与 COPD的一系列病理生理过程 ,其生物学作用及其临床价值需进一步探讨。     

Effects of Inspiratory Oxygen Concentration on Endtidal Carbon Monoxide Concentration

Objective. Carbon monoxide (CO) is eliminated mainly via the lungs so that exhaled carbon monoxide concentration reflects endogenous production. In this context, we studied the effects of inspiratory oxygen concentration and endotracheal intubation on endtidal CO concentrations. Methods. In patients undergoing general anaesthesia, endtidal CO concentrations were measured while breathing room air, oxygen as well as after induction of general anaesthesia and endotracheal intubation. To exclude time-dependent effects, patients were assigned to two groups. Patients in group 1 (n = 20) were preoxygenated for 5 minutes, whereas patients in group 2 (n = 20) were preoxygenated for 10 minutes. We also studied the effects of different inspiratory oxygen concentrations in volunteers (n = 20) breathing room air, 50% and 100% oxygen. Results. Breathing oxygen for 5 minutes increased endtidal carbon monoxide concentrations in all patients (in group 1 from 7.6±4.9 to 12.6± 5.0 ppm, p < 0.001; in group 2 from 7.1±6.1 to 16.4 ± 8.6 ppm, p < 0.001). No further change of CO concentration was detected after 10 minutes of preoxygenation (16.4 ± 9.0 vs. 16.4 ± 8.6 ppm, p > 0.05). Endtidal CO values however significantly increased with induction of anaesthesia and endotracheal intubation (in group 1 to 21.5 ± 6.3 ppm, p < 0.001, in group 2 to 26.1 ± 13.1 ppm, p < 0.001). In volunteers, mean endtidal CO values increased from 10.7 ±5.9 to 14.8±7.3 ppm after breathing 50% oxygen for 3 minutes (p < 0.001). Breathing pure oxygen had no additional effect on endtidal CO values (16.0 ± 6.0 ppm, p > 0.05). Conclusions. Endtidal carbon monoxide levels are influenced by inspiratory oxygen concentrations. Induction of anaesthesia and endotracheal intubation further increases endtidal CO concentrations beyond the effects attributable to preoxygenation alone.     

Detection of Carbon Monoxide Production as a Result of the Interaction of Five Volatile Anesthetics and Desiccated Sodalime with an Electrochemical Carbon Monoxide Sensor in an Anesthetic Circuit Compared to Gas Chromatography

OBJECTIVES: There is a continuing risk of production of toxic levels of carbon monoxide (CO) as a result of interaction of volatile anesthetics and desiccated strong base carbon dioxide absorbents like soda lime. The aim of this study is to establish the reliability of detection of CO levels by an electrochemical carbon monoxide sensor compared to gas chromatography. METHODS: Completely desiccated sodalime was conducted through a circle anesthesia system connected to an artificial lung. For different rates of CO production, a low flow anesthesia with a oxygen/nitrous oxide mixture was maintained using five volatile anesthetics. For quantification of CO production, a portable gas chromatograph (GC) was connected to this setup, as well as a Bedfont EC40 electrochemical carbon monoxide sensor (ES) with a claimed reliable sensitivity of 0-200 parts per million (ppm) and a maximum detection range of more than 5500 ppm. To assess the agreement between the GC and ES measurements the intra class correlation coefficient (ICC) and the 95% limits of agreement were calculated. Bland and Altman scatterplots were made to visualize the difference between measurements. RESULTS: For concentrations up to 200 ppm, no significant differences between the GC and ES mean CO measurements were found in the halothane experiments. However CO was not accurately measured at every moment during these experiments by the ES. For concentrations above 200 ppm the results of the two instruments differed significantly. The ES malfunctioned when exposed to sevoflurane and desiccated sodalime. CONCLUSIONS: From these data we conclude that the ES can only be used as an indicator of CO production. When this sensor is used with sevoflurane and desiccated sodalime it is not capable of normal operation. The use of a strong base free carbon dioxide absorbent is therefore recommended.     

急性CO中毒患者血清NSE测定的意义

[目的]探讨急性CO中毒患者血清神经元特异性烯醇化酶(NSE)的动态改变及其与患者的病情预后的关系.[方法]对185例CO中毒患者和30名健康体检者行NSE检测,并监测65例中重型住院患者d2、d3的动态变化.[结果]中重型CO中毒患者入院时血清NSE水平明显高于对照组和轻型CO中毒患者,死亡组d2 NSE水平明显升高,中重型CO中毒患者d2NSE水平与意识障碍时间成正相关.[结论]动态检测CO中毒患者NSE水平能有效地判断患者的病情和预后.