Post-mortem alcohol analysis in synovial fluid: an alternative method for estimation of blood alcohol level in medico-legal autopsies?

Abstract

To evaluate the effectiveness of synovial fluid alcohol concentration in prediction of blood alcohol concentration, synovial fluid and blood was studied of 50 autopsy cases and the alcohol levels determined by using Head Space Gas Chromatography method. To exclude the effect of decomposition on alcohol levels, corpses with post-mortem intervals less than 24 hours and not showing signs of decomposition were selected. Of 50 cases, alcohol was detected in 15 cases both in blood and in synovial fluid. In 35 cases alcohol analysis was negative both in blood and synovial fluid. No false positive results were seen in terms of synovial fluid. In two of the 15 cases, the alcohol determined was methyl alcohol and in others the alcohol was ethyl alcohol. In these 15 cases, only in one case was SAC level lower than the BAC level, and in 14 cases; SAC levels were higher than those of BAC. BAC (Blood Alcohol Concentration)/SAC (Synovial Fluid Alcohol Concentration) ratios were determined, and in 13 ethanol cases the mean ratio was determined to be 0.95 (0.90 ± 0.07). The regression analysis showed a fairly linear relationship between the BAC and SAC, with a correlation coefficient of 0.984 (y = 0.86x + 10.4). The present study demonstrates that the synovial fluid is a valuable body fluid that can be used in prediction of blood alcohol concentration in forensic autopsy cases in which blood can not be properly obtained.