Post-mortem blood lead analysis; a comparison between LeadCare II and graphite furnace atomic absorption spectrometry...

A comparison of the LeadCare II (LCII) point-of-care (POC) device with the gold standard graphite furnace atomic absorption spectroscopy (GFAAS) device was done in the context of post-mortem blood lead concentrations to determine comparability for screening value.

Consecutive autopsy cases from March 2018 to March 2019 were examined by the forensic medicine center. Blood samples with lead concentrations <10 μg dL^-1 by LCII analysis were excluded from GFAAS analysis. Samples were collected from femoral veins or cardiac chambers. Bland-Altman analysis was conducted to evaluate the agreement between both GFAAS and LCII lead values. Linear regression modeling was performed to predict GFAAS results based on LCII results. Five-hundred post-mortem blood samples were evaluated by LCII for blood lead. For 46 cases with LCII blood lead level (BLL) values more than 10 μg dL^-1, further analysis was performed by GFAAS.

Mean difference of BLL between the two methods was 5.92 μg dL^-1 (SD = 7.51; range: -14 to 23.7). GFAAS BLL values were significantly higher than LCII values (p = 0.029). Moreover, substance-user samples had significantly higher GFAAS BLLs (p = 0.006; mean difference = 11.62 μg dL^-1). A significant regression equation was found (F [1, 44] = 108.44, p < 0.001, with an R2 of 0.711). Based on Bland-Altman plot averages for both predicted GFAAS BLL and measured GFASS BLL showed a mean difference was 0.014 (SD = 7.51; range: -17.9 to 20).

In conclusion, on post-mortem BLL samples, LCII and GFAAS show favorable correlation. LCII can be used as a screening technique for post-mortem blood lead analysis.