Robinson J, Fernando R, Sun Wai W Y, Reynolds F
Specialist Registrar in Anaesthesia, Consultant Anaesthetist and Honorary Senior Lecturer, and Specialist Registrar in Anaesthesia, Department of Anaesthesia, Royal Free Hospital, London NW3 2QG, UK.
Anaesthesia. 2000 Sep;55(9):853-8. doi: 10.1046/j.1365-2044.2000.01471.x.
Epinephrine and sodium bicarbonate may be added to local anaesthetic solutions in order to reduce the onset time and enhance the quality of epidural anaesthesia for Caesarean section. Such mixtures are sometimes prepared several hours in advance for subsequent use in emergency Caesarean section through a pre-existing epidural catheter. To evaluate this practice, we studied the chemical stability in solution over 24 h of nine epidural mixtures consisting of different combinations of bupivacaine, lidocaine, epinephrine and sodium bicarbonate. In mixtures alkalinised with sodium bicarbonate, epinephrine concentrations decreased significantly over 24 h (p<0.0001), whereas those in nonalkalinised mixtures did not change with time. Bupivacaine and lidocaine concentrations in all mixtures did not decrease over time regardless of alkalinisation. We do not recommend adding epinephrine to alkalinised epidural solutions that are to be stored for a prolonged period before clinical use.
为了缩短起效时间并提高剖宫产硬膜外麻醉的质量，可将肾上腺素和碳酸氢钠添加到局部麻醉溶液中。此类混合液有时会提前数小时配制，以便随后通过预先置入的硬膜外导管用于急诊剖宫产。为评估这种做法，我们研究了由布比卡因、利多卡因、肾上腺素和碳酸氢钠不同组合构成的9种硬膜外混合液在溶液中24小时内的化学稳定性。在用碳酸氢钠碱化的混合液中，肾上腺素浓度在24小时内显著降低（p<0.0001），而未碱化混合液中的肾上腺素浓度则不随时间变化。无论是否碱化，所有混合液中布比卡因和利多卡因的浓度均不随时间降低。我们不建议在临床使用前长时间储存的碱化硬膜外溶液中添加肾上腺素。
