Fentanyl Concentrations
  Liver (μg/kg) PB (ng/mL) L/P Ratio
N 16 16 16
Min 3.8 0.65 2.30
Max 270 66 19.50
Mean 74.10 14.70 6.90
Median 43.5 9 5.90
    Standard Deviation 4.30
L = Liver, PB = Peripheral Blood, L/P = Liver/Peripheral Blood
Table 8: Summary of 16 fentanyl cases from the San Diego Medical Examiner’s Office (L/P Ratios).