BLOOD ALCOHOL CONCENTRATION AND ROAD TRAFFIC ACCIDENTS - AN OBJECTIVE BASED REVISION

The first aim of this work was to study the Blood Alcohol Concentration (BAC) distribution among subjects involved in road accidents occurred between 2006 and 2010 in Verona Province. This was possible because all the individuals involved in road accidents admitted to Emergency Room of the hospitals on province of Verona undergo toxicological analysis to determine drugs of abuse and/or alcohol. The second aim was to find a possible relation between BAC and the severity of crash-related injuries and analyze if alcohol is, besides an accident risk, even a risk factor for the severity of injury. We collected 3035 blood alcohol tests carried out by HS-GC (Head Space-Gas-Chromatography) at the Toxicology Lab of Department of Public Health and Community Medicine – Section of Forensic Medicine, University of Verona, from subjects involved in traffic accidents in Verona Province admitted to Hospitals of Verona, Hospital of San Bonifacio, Hospital of Peschiera, Hospital of Legnago and Hospital of Bussolengo. BAC analysis was performed by Head-Space Gas-Chromatography (HS-GC). Clinical and anamnestic data were also collected from 1706 subjects involved in road accidents from 2006 to 2009, in order to evaluate the severity of the injuries. Blood samples from 393 subjects involved in traffic accidents with injuries were collected at admission to hospitals of Verona Province during 2010-2011 and CDT was determined by High Performance Liquid Chromatography (HPLC). On the basis of BAC value, there were 11% of subjects with a BAC ≤0.5 g/L, 8% with a BAC ranging from 0.5 to 0.8 g/L, 24% with a BAC ranging from 0.8 to 1.5 g/L, 39% with a BAC ranging from 1.5 to 2.5 g/L and, finally, 18% with a BAC >2.5 g/L. It is worth to stress that 81% of subjects with alcohol in blood had more than 0.8 g/L, and 57% had even above 1.5 g/L. The average BAC was 1.69 g/L, 88% were male, 72% Italian; the average age was 37 years (but 66% of the population ranged from 20 to 40 years old). The highest BAC average (2.05 g/L) resulted in subjects of 41-50 years old. To analyze possible correlation between blood alcohol concentration and severity of injuries, we considered as criteria the “Triage” code, prognosis and presence of relevant fractures; moreover the cases were classified as “severe” or “not severe” (where “severe” patients had at least one of the following factors: Red or Yellow triage code, admission from ER into another hospital division, relevant fracture/s); we considered also a “trauma index score” assigned to each subject. A sub classification was applied also by type of vehicle involved. The present study confirms the data of the current international scientific literature that the risk of road accident relating motor vehicles is neatly increased when the BAC >0.8 g/L (where it is grouped the 81% of the sample). In addition we found a statistically significative difference between BAC positive and BAC negative group about severity of injuries. Correlation with BAC positive subjects seems to be particularly strong in motorbikers. Finally the results of the present study suggest that elevated CDT concentrations are associated with a higher risk of causing or being involved in traffic accidents with injuries.