Anaesthetic Challenges in a Case of Parturient With Achondroplasia for Emergency Caesarean Section

Abstract

Achondroplatic patients have limited neck extension, large head, large tongue and narrowed nasal, oral, tracheal and pharyngeal airway (1). Airway oedema and large breast from term pregnancy further complicates airway management. Developmental stenosis of the cervical and lumbar canals is common in achondroplasia due to a premature fusion of the vertebrae. They can also have narrow spinal canal, reduced epidural space, kyphoscoliosis and vertebral body deformities. An MRI study by Jeong et al. found that their spinal canal interpedicular distance progressively narrows instead of widens (2).This may lead to failure of CNB and unpredictable block height. The dose of CNB has to be balanced with the risk of severe hypotension and high block. In addition, the gravid uterus in term pregnancy further increases block height. Danelli et al indicated the minimum effective dose of intrathecal bupivacaine providing effective spinal block in 95% of the women undergoing caesarean section is 0.06 mg/cm height (3). However, as surgical time could be longer than expected in our patient, CSE allows titration of block height and duration as required.