Carboxyhämoglobin nach Brandgasexposition - Eine Untersuchung zur postexpositionellen Belastung von Feuerwehreinsatzkräften

Carbon monoxide (CO) is a colorless gas, which arises from an incomplete combustion in an oxygen free surrounding. The main toxicity of fire smoke is due to CO. The inhalation of CO leads to an excessive binding of CO to hemoglobin because the affinity of CO to hemoglobin is 240 times higher than oxygen´s affinity to the protein. A general hypoxia in nearly every tissue is the result. Hypoxia leads to dizziness, headache, nausea, weakness, convulsions, angina pectoris, collapse and coma. Chronic carbon monoxide intoxication increases the risk for heart failure and different neurological symptoms. Fighting a fire in an oxygen free surrounding, as it can be found in burning houses, a special education of the fire fighters and special equipment is needed. The special equipment contains fire protective clothing, a protective mask and a compressed air cylinder. In this study, fire fighters were surveyed in training surrounding and real fires. The question to be answered was whether the fire fighters show increased levels of carboxyhemoglobin even if they are protected adequately. The factors surveyed are physiological parameters as well as differences on personal protection equipment and specific behavior during operation. Finally, the data from training and real fires was compared. From September 2008 to April 2011 about 170 fire fighters from the cities of Marburg, Northeim and Göttingen was measured either after a hot-fire training or after having taken part in a real fire fighting operation. With the pulsoxymeter Rad 57 by Masimo we measured heart rate, carboxyhemoglobin, oxygen saturation and methemoglobin. In addition to the physical data a standardized questionnaire captured the behavior before and after the operation. Especially safety procedures and whether safety checks were performed correctly were of interest. The measured data was analyzed with descriptive data analysis. The comparison of the different scenarios was analyzed with the Mann-Whitney-U-test. In the training scenario 4.2% of the study volunteers had an increased COHb-level. After the real fire operation 15.8% of the fire fighters showed an increased COHb-level. More than 20% of study volunteers in training showed a COHb trend that indicates that they have inhaled larger amounts of CO right before and after the training. There is a statistically significant difference between the COH- levels in training and after a real fire event. One reason for the increased level could be different safety equipment. The analysis of the questionnaire showed that especially in real fire operations fire fighters do not stick to all safety regulations strictly. The measured data of the heart rates additionally shows that the fitness of the firefighters is not adequate in all cases. This study shows that the knowledge about carbon monoxide and the possible risks connected to intoxication should be emphasized during training of the fire fighters. Additionally especially in real fire situations it should be paid more attention to safety regulations.