Ropivacaine 0.75% for extradural anaesthesia in elective caesarean section: an open clinical and pharmacokinetic study in mother and neonate

Abstract

In an open study we have investigated the efficacy of 20 ml of 0.75% ropivacaine (7.5 mg ml-1) to provide extradural anaesthesia for elective Caesarean section. Plasma concentrations (total and free) were estimated in the mother and neonate. Anaesthesia was effective and safe. Plasma concentrations of ropivacaine in the mother and neonate were within safe limits and consistent with previous studies. Two mothers received accidental i.v. injections of ropivacaine 75 mg and 150 mg, respectively, without serious adverse effects.

Flip-flop kinetics of ropivacaine during continuous epidural infusion influences its accumulation rate

“…[5,6,9,14,15,16] Only 2 patients (5%) reached ropivacaine plasma levels higher than 3.0 µg/mL, namely 3.8 and 4.0 Table II.…”

Epidural ropivacaine hydrochloride during labour: protein binding, placental transfer and neonatal outcome

“…These include uterine blood flow, the phase of uterine contraction [16] and drug factors (molecular mass, degree of ionisation, lipid solubility). A further explanation for the lack of association between maternal unbound ropivacaine and placental transfer (UV/MV) is offered by Morton et al [17] who suggested that equilibrium between the maternal and umbilical venous concentrations might not be attained at the time of delivery.…”

Bupivacaína levógira a 0,5% pura versus mistura enantiomérica de bupivacaína (S75-R25) a 0,5% em anestesia peridural para cirurgia de varizes

“…There are no statistical differences in upper motor block between 20 ml of 0.75% and 1% S(-) ropivacaine (Bromage 3) 13,14 . The same rational is true for 20 ml of 0.5% S(-) bupivacaine 15 .…”

“…A utilização de S(-)ropivacaína a 1% com volume proporcional à estatura promove bom nível de analgesia, porém proporciona um bloqueio motor de membros inferiores pouco intenso, adequado apenas para realização de procedimentos de parede abdominal e períneo 12 . O uso de 20 ml de S(-)ropivacaína a 0,75% e 1% não exibe diferenças significativas relacionadas ao bloqueio motor máxi-mo (Bromage 3) 13,14 . O mesmo raciocínio é válido para o volume de 20ml de S(-)bupivacaína a 0,5% 15 .…”