RESUMEN
BACKGROUND: Few studies have been published concerning the excretion of bupivacaine and lidocaine into the breast milk and none concerning ropivacaine. AIM: The aim of this study was to determine the levels of ropivacaine in plasma and breast milk after combined spinal-epidural anesthesia for cesarean delivery and postoperative patient-controlled epidural analgesia (PCEA), as well as possible adverse effects from these levels on the neonate. METHODS: Twenty-five parturients admitted for cesarean delivery under combined spinal-epidural anesthesia participated in the study. The PCEA regimen was prepared as 0.15% ropivacaine and fentanyl 2 microg/mL (basal rate, 6 mL/h; demand dose, 4 mL/20 min). Blood samples were collected before anesthesia and from the umbilical cord immediately after birth, followed by blood and breast milk samples 18 and 24 hrs after initiation of PCEA. The newborns were clinically appraised with the Apgar score at delivery and Neurological and Adaptive Capacity Score 24 hrs later. Local anesthetic side effects were recorded. Ropivacaine levels were determined by high-performance liquid chromatography with a UV detector. RESULTS: Ropivacaine excretion into the breast milk produced concentrations that significantly correlated with those in the plasma 18 and 24 hrs after administration, achieving milk-plasma ratios (mean +/- SD) of 0.25 +/- 0.08 and 0.23 +/- 0.07, respectively. Most newborns had maximal Apgar and Neurological and Adaptive Capacity Scores. No adverse effects from ropivacaine were noted in mothers or neonates. CONCLUSIONS: The milk-plasma concentration ratio of ropivacaine was found to be lower than that reported for other local anesthetics It seems that PCEA with ropivacaine/fentanyl after cesarean delivery is not associated with excessive milk-plasma concentrations of ropivacaine.