Excretion of lidocaine and bupivacaine in breast milk following epidural anesthesia for cesarean delivery

Background: There is a lack of information and knowledge about the practica l importance of even low concentrations of the excretion of local anestheti cs into breast milk, particularly concerning bupivacaine. The present work aims to confirm, under practical clinical conditions of admission of partur ients, the passage of local anesthetics (lidocaine and bupivacaine) into br east milk after an epidural anesthesia. Methods: Twenty-seven pregnant women admitted for cesarean delivery receive d epidural anesthesia with 0.5% bupivacaine and 2% lidocaine. Blood and mil k samples were simultaneously collected at 2, 6 acid 12 h after the beginni ng of the epidural infusion. Lidocaine, bupivacaine and its main metabolite , pipecolylxylidide (PPX), were determined in serum and milk by a gas-liqui d chromatographic technique. APGAR scores were systematically performed at delivery and a clinical examination was done 24 h after delivery. Results: Our data indicate that lidocaine and bupivacaine as well as PPX ar e excreted into breast milk. The milk/serum ratio based upon area under the curve values were 1.07+/-0.82, 0.34+/-0.24 and 1.37+/-0.61 mean+/-SD for l idocaine, bupivacaine and PPX, respectively. Most of the newborns had a max imal APGAR score. Our study does not reveal any adverse reactions related t o the excretion of local anesthetics into breast milk. Conclusion: This study documents the magnitude of excreted lidocaine, bupiv acaine and PPX in breast milk, and indicates that the use of both lidocaine and bupivacaine for epidural anaesthesia is safe with regard to breast-fee ding.