Glover D J
Anaesthesia. 1977 May;32(5):499-503. doi: 10.1111/j.1365-2044.1977.tb09990.x.
Eleven patients in uncomplicated labour received a continuous infusion of 0-125 or 0-25% bupivacaine solutions into the epidural space, using a simple rotary pump. Maternal and umbilical cord venous plasma bupivacaine levels were measured and were found to be within safe limits for mother and baby. Incidence of complications were noted.