Fentanyl Concentrations (ng/mL)
  CB PB C:P Ratio
N 166 166 166
Min 1.8 1.7 0.03
Max 176 373 2.43
Mean 20.18 21.16 1.23
Median 12.00 11.00 1.03
    Standard Deviation 0.57
CB = Central Blood, PB = Peripheral Blood, C/P = Central/Peripheral Blood
Table 4: Summary of 166 fentanyl positive cases (13 cases removed).