RESUMEN
The loss of carbon monoxide (CO) from whole blood or hemolysates has been investigated. Blood samples were exposed to the atmosphere or to a limited volume of air for various storage periods at three temperatures. The initial hemoglobin (Hb) concentration and the percent carboxyhemoglobin (%COHb) saturation were varied in separate experiments. In addition, the effect of repeated exposure of blood to air was evaluated. The %COHb saturation decreased from 80 to 50% following storage of a 1-mL blood sample with 49 mL of air in a sealed container at room temperature for 45 hr. Greater decreases in the %COHb saturation were observed in samples which were exposed to the atmosphere. Lesser, but significant, losses occurred when samples were stored in a refrigerator or freezer. The concentration of Hb in the samples as well as the initial %COHb saturation were found to influence the decrease in the %COHb saturation.
Asunto(s)
Intoxicación por Monóxido de Carbono/sangre , Aire , Conservación de la Sangre , Carboxihemoglobina/análisis , Estabilidad de Medicamentos , Hemoglobinas/análisis , Humanos , Nitrógeno/sangre , Oxígeno/sangre , Cambios Post Mortem , Propiedades de Superficie , TemperaturaRESUMEN
A method is described for the gas chromatographic quantitation of carbon monoxide by means of thermal conductivity detection. Carbon monoxide is released from blood samples as small as 0.02 mL using a unique extraction chamber. The method was compared to a standard gas chromatographic and spectrophotometric method of carbon monoxide quantitation. It was comparable to the former with all samples evaluated and apparently more reliable than the latter with decomposed samples.
Asunto(s)
Monóxido de Carbono/sangre , Cromatografía de Gases/instrumentación , Cromatografía de Gases/métodos , Humanos , Indicadores y Reactivos , Espectrofotometría/métodosRESUMEN
A simple and reliable method has been developed for the detection of benzoylecgonine in urine by UV spectrophotometry. Benzoylecgonine was isolated by liquid-liquid extraction and subsequently identified based on its hydrolysis by NaOH. The decrease in absorbance at 235 nm caused by this NaOH hydrolysis was used to identify benzoylecgonine even in the absence of its characteristic spectrum. None of the other drugs evaluated interfered with the method, which has a detection limit of 1.25 micrograms/mL.
Asunto(s)
Cocaína/análogos & derivados , Espectrofotometría Ultravioleta/métodos , Cocaína/orina , HumanosRESUMEN
A study was made on the effect of I.P. injection of 100% CO in dogs. Although elevated concentrations of COHb were obtained, no Co toxicity occurred. Inasmuch as the combination of CO and erythrocytes after I.P. injection of CO should be similar to that after inhaling CO, The lack of toxicity cannot be explained by Drabkin's "Haldane effect." It is suggested that the lack of CO toxicity after I.P. injection was due to removal of dissolved CO from the blood by passage through the lungs. On the contrary, when Co is inhaled there is significant dissolved CO in the blood leaving the lungs and when it reaches the organs, especially the heart and brain. To cause toxicity, dissolved CO must be present in the blood to cross into the tissues and interfere with the combination of O2 and cytochrome a3. It is concluded that random COHb values may not be related to those obtained in studies of the relationship of human responses to COHb concentrations.
Asunto(s)
Intoxicación por Monóxido de Carbono/sangre , Monóxido de Carbono/toxicidad , Carboxihemoglobina/análisis , Hemoglobinas/análisis , Medicina Aeroespacial , Animales , Monóxido de Carbono/metabolismo , Perros , Medicina Legal , Inyecciones IntraperitonealesRESUMEN
Our studies indicate that a high concentration of carboxyhemoglobin (COHb) does not interfere with the O2--carrying capacity of the blood. In dogs, both the transfusion of erythrocytes containing 80 percent COHb and the i.p. injection of carbon monoxide (CO) gas do not produce CO toxicity even though the COHb is above 50 percent. Dogs inhaling CO (13 percent in air) for 15 minutes died within 15 minutes to 65 minutes with an average COHb level of 65 percent. The probable toxic action of CO is on the cellular respiration taking place in the mitochondria when CO competes with O2 for cytochrome a3. The presence of dissolved CO in plasma, which is necessary for CO to enter the tissue, probably occurs when the exchange takes place between alveolar air and the blood in the lungs. When air containing CO is inhaled, there will be a significant CO tension in the blood when it leaves the lungs and when it reaches the organs especially the heart and brain. While COHb level is useful as a clinical measure of CO exposure, the most important mechanism by which CO causes toxicity is its combination with cytochrome oxidase.
Asunto(s)
Monóxido de Carbono/farmacología , Animales , Monóxido de Carbono/administración & dosificación , Monóxido de Carbono/sangre , Perros , Eritrocitos/metabolismo , Hemoglobinas/metabolismo , Inyecciones Intraperitoneales , Factores de TiempoAsunto(s)
Intoxicación por Monóxido de Carbono/sangre , Monóxido de Carbono/toxicidad , Anemia Hemolítica/sangre , Animales , Transfusión Sanguínea , Monóxido de Carbono/administración & dosificación , Intoxicación por Monóxido de Carbono/mortalidad , Carboxihemoglobina/administración & dosificación , Carboxihemoglobina/análisis , Perros , Relación Dosis-Respuesta a Droga , Hipotermia/sangre , Inyecciones Intraperitoneales , RespiraciónRESUMEN
The probable toxic action is CO is on the cellular respiration, in which CO competes with O2 for cytochrome a3. Our studies indicate that a relatively high concentration of COHb (50%) does not interfere with the O2-carrying capacity of the blood. The dissolved CO in plasma, which is necessary for CO to enter the tissue, probably occurs when the exchange takes place between alveolar air and the blood in the lungs. This would explain why the central nervous system could be impaired when COHb levels are below 10% and death could occur at 35%.