Epidural anaesthesia for caesarean delivery in triple and quadruple pregnancies

Background: Mechanical and/or hormonal factors may increase the spread of epidural anaesthesia in pregnancy, and hormonal changes are more pronounced in high-order pregnancies. However, no previous study has evaluated the dose requirements and haemodynamic effects of epidural anaesthesia for caesarean delivery in this latter situation.
Methods: The anaesthetic requirements to obtain a T4 upper sensory level were restrospectively compared in triple (n=19) or quadruple (n=2) pregnancies to 31 singleton pregnancies who received epidural anaesthesia for elective caesarean delivery using 2% lidocaine with 1/200 000 adrenaline.
Results: In high-order pregnancies, the gestational age at delivery was lower than in singleton pregnancies (34.9±1.9 weeks vs 38.2±1.1 weeks; P =0.0001) whereas maternal body weight (76.5±8.7 kg vs 73.4±14.8 kg; NS) and lidocaine requirements (428±95 mg vs 426±98 mg; NS) were similar. Moreover, although the overall incidence of hypotension was not different (multiple pregnancy; 65% vs 58% in singletons), ephedrine (5.4±5.3 mg vs 10.7±13.8 mg; P <0.05) and additional fluid requirements during onset of the block (4.3±1.7 mL/kg vs 5.3±2.6 mL/kg; P =0.03) were less than in singletons.
Conclusion: We found surprisingly similar anaesthetic requirements for epidural anaesthesia in high-order and singleton pregnancies. Mechanical factors may have played an important role. Moreover, the need for ephedrine and fluids was less in high-order pregnancies. This could be related to more pronounced physiological changes or to different physician attitudes.