Glasgow Coma Scale and laboratory markers are superior to COHb in predicting CO intoxication severity

Carbon monoxide (CO) intoxications can affect several organ systems and lead to coma or death in severe cases. To date, COHb is routinely used as a marker for detecting CO intoxication. In this retrospective study, we investigated 173 patients admitted with CO intoxication to our intensive care unit (ICU) over a period of 8 years. Standardised blood tests, chest X-ray and neurological status evaluation were performed on admission and throughout the inpatient treatment. The duration of inpatient treatment was considered to be an indication of the severity of CO-related illness. Interestingly, the data did not reveal a significant correlation between initial COHb level and the duration of inpatient treatment. Instead, a significant inverse correlation was found between the initial Glasgow Coma Scale and the duration of inpatient treatment. Furthermore, significant correlations were found between the duration of inpatient treatment and the occurrence of elevated leucocyte numbers, elevated C-reactive protein (CRP) serum concentrations and the presence of lung infiltrates. In conclusion, we postulate that clinical parameters, such as the Glasgow Coma Scale and the laboratory markers CRP and leucocyte count are adequate supportive tools for evaluating the severity of CO-related illness, and further, that the measurement of COHb alone is insufficient for this purpose.