Fetal/Maternal ratios of various local anaesthetics.
| Local Anaesthetic |
pKb |
%Protein Bound |
F/M Ratio |
pH *
|
| Lidocaine |
7.9 |
64% |
0.5 |
Plain ~ 6.3 + E ~ 3.82
|
| Bupivacaine |
8.2 |
96% |
0.2-0.4 |
Plain ~ 5.7 + E ~ 3.8 |
| Chloroprocaine |
8.9 |
|
0.92 |
Plain ~ 3.0
|
* Moore DC, Anesth Analg 1981;60:833
+ E = Commercial solution with epinephrine