Absorption and Elimination of Carbon Monoxide by Inactive Young Men
TL;DR: Several model equations were tested against the absorption and excretion data; one theoretical equation accurately predicted COHb levels resulting from continuous and discontinuous exposures to unvarying concentrations and from continuous exposure to a steadily rising concentration.
Abstract: Human volunteers were exposed to carbon monoxide at concentrations of < 1, 25, 50, 100, 200, 500, and 1,000 ppm for periods of one-half to 24 hours. Blood samples for carboxyhemoglobin (COHb) were obtained during the exposures and for up to 23 hours into the postexposure periods. Postexposure treatment with oxygen at 1.0 and 3.0 atmospheres was included. Several model equations were tested against the absorption and excretion data; one theoretical equation accurately predicted COHb levels resulting from continuous and discontinuous exposures to unvarying concentrations and from continuous exposure to a steadily rising concentration.
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01 Jan 2008
TL;DR: LaRonde as mentioned in this paper analyzes the conflict in Xinjiang and concludes that the Chinese continue to defeat the separatist movement through a strategy that counters Mao's seven fundamentals of revolutionary warfare, concluding that Mao, as well as the communist leaders who followed him, was also successful at waging protracted counterinsurgency.
Abstract: PROTRACED COUNTERINSURGENCY: CHINESE COIN STRATEGY IN XINJIANG by MAJ J. Scott LaRonde, USA, 95 pages. In 1949, following the conclusion of its revolutionary war against the Chinese Nationalist forces, the People’s Liberation Army (PLA) peacefully occupied China’s western most province of Xinjiang. For nearly sixty years, the PLA has conducted a counterinsurgency against several, mostly Uyghur-led, separatist movements. Despite periods of significant violence, particularly in the early 1950s and again in the 1990s, the separatist forces have not gained momentum and remained at a level one insurgency. Mao ZeDeng is revered as a master insurgent and the father of Fourth Generation Warfare. Strategists in armies worldwide study his writings on revolutionary and guerilla warfare. This monograph concludes that Mao, as well as the communist leaders who followed him, was also successful at waging protracted counterinsurgency. For nearly sixty years, separatist movements in Xinjiang, Tibet, and Taiwan have all failed. This monograph analyzes the conflict in Xinjiang and concludes that the Chinese continue to defeat the separatist movement in Xinjiang through a strategy that counters Mao’s seven fundamentals of revolutionary warfare.
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TL;DR: From the Department of Hyperbaric Medicine, LDS Hospital; and theDepartment of Medicine, University of Utah School of Medicine — both in Salt Lake City; andThe Department of hyperbaric medicine, Intermountain Medical Center, Murray, Utah.
Abstract: From the Department of Hyperbaric Medicine, LDS Hospital; and the Department of Medicine, University of Utah School of Medicine — both in Salt Lake City; and the Department of Hyperbaric Medicine, Intermountain Medical Center, Murray, Utah. Address reprint requests to Dr. Weaver at the Department of Hyperbaric Medicine, LDS Hospital, Eighth Ave. and C St., Salt Lake City, UT 84143, or at lindell.weaver@imail.org.
549 citations
TL;DR: The physiologic and biochemical bases of carbon monoxide effects in pregnant women, fetuses, and newborn infants and their clinical implications are reviewed.
448 citations
TL;DR: An analysis of toxicological findings in fire and nonfire deaths and the results of animal exposures to smoke from a variety of burning materials indicate that carbon monoxide is still likely to be the major toxicant in modern fires.
Abstract: This review is an attempt to present and describe the major immediate toxic threats in fire situations. These are carbon monoxide, a multitude of irritating organic chemicals in the smoke, oxygen depletion, and heat. During the past 50 years, synthetic polymers have been introduced in buildings in very large quantities. Many contain nitrogen or halogens, resulting in the release of hydrogen cyanide and inorganic acids in fire smoke as additional toxic threats. An analysis of toxicological findings in fire and nonfire deaths and the results of animal exposures to smoke from a variety of burning materials indicate that carbon monoxide is still likely to be the major toxicant in modern fires. However, the additional toxic threats mentioned above can sometimes be the principal cause of death or their addition can result in much lower than expected carboxyhemoglobin levels in fire victims. This analysis also revealed that hydrogen cyanide is likely to be present in appreciable amounts in the blood of fire victims in modern fires. The mechanisms of action of acute carbon monoxide and hydrogen cyanide poisonings are reviewed, with cases presented to illustrate how each chemical can be a major contributor or how they may interact. Also, lethal levels of carboxyhemoglobin and cyanide in blood are suggested from an analysis of the results of a large number of fire victims from different fire scenarios. The contribution of oxygen depletion and heat stress are more difficult to establish. From the analysis of several fire scenarios, they may play a major role in the room of origin at the beginning of a fire. The results in animal studies indicate that when major oxygen depletion (<10%) is added to lethal or sublethal levels of carbon monoxide or hydrogen cyanide its major role is to substantially reduce the time to death. In these experiments the carboxyhemoglobin level at death was slightly reduced from the expected level with exposure to carbon monoxide alone. However, blood cyanide was reduced by a factor of ten from the expected level with exposure to hydrogen cyanide alone. This is another factor (among many other presented) complicating the task of establishing the contribution of cyanide in the death of fire victims, from its analysis in their blood. Finally the role of ethanol intoxication, as it may influence carboxyhemoglobin levels at death, is reviewed. Its role is minor, if any, but the data available on ethanol in brain tissue and blood of fire victims confirmed that brain ethanol level is an excellent predictor of blood ethanol.
421 citations
Cites methods from "Absorption and Elimination of Carbo..."
...The model developed by Coburn, Forster, and Kane (1965), the CFK equation, was first used and verified by Peterson and Stewart (1970; 1975), with volunteers inhaling low concentrations of CO between 50 and 1000 ppm....
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TL;DR: Breath CO concentration provides an easy, noninvasive, and immediate way of assessing a patient's smoking status, and a reading > 6 ppm strongly suggests that an outpatient is a smoker.
379 citations
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TL;DR: The CO concentrations in air samples taken from smoke-filled conference rooms, a small nonventilated room that was purposely filled with smoke by burning cigarettes, and a rural area well away from automobile combustion were measured.
Abstract: were analyzed for CO concentrations with an infrared CO meter. This instrument has an error (SD) of 4-0.00004% CO and requires a 200-ml sample. These samples were col- lected during the summer of 1964. Smoking is prohibited in the areas where these samples were collected. We also measured the CO concentrations in air samples taken from smoke-filled conference rooms, a small nonventilated room that we purposely filled with smoke by burning cigarettes, and a rural area well away from automobile combustion. Diurnal changes in blood (COHb) were measured in one subject and compared with the changes in percentage of CO in his environment. Blood (COHb) was determined by a method in which gas extracted from a 2-ml blood sample is measured in the infrared CO meter. This method has an error (SD) of 40.03% (COHb)( 10).
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TL;DR: Exposures producing carboxyhemoglobin saturations greater than 15% to 20% resulted in delayed headaches, changes in the visual evoked response, and impairment of manual coordination in sedentary males.
Abstract: Human volunteers were exposed to carbon monoxide at concentrations of < 1, 25, 50, 100, 200, 500, and 1,000 ppm for periods of one-half to 24 hours. No untoward effects were observed in sedentary males exposed to 100 ppm for eight hours. Exposures producing carboxyhemoglobin saturations greater than 15% to 20% resulted in delayed headaches, changes in the visual evoked response, and impairment of manual coordination.
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