A new chapter, developed from the previous Anaesthetic chapter in the previous Edition. Covering the physiology and management of a regional anaesthetic, spinal or epidural, that has become too high and is therefore causing compromise to the woman and/or baby. Key learning points: Understand that high regional block and total spinal occur on a continuum, and that breathlessness and feeling ‘not quite right’ can rapidly lead to cardiorespiratory collapse. Call for help early if there are any warning signs. Early intervention by the anaesthetic team is crucial. Be aware that with a total spinal, the priority is maintaining and supporting ABC to prevent deterioration into cardiac arrest. Always stay with the woman once a high regional block is recognised, as symptoms can progress rapidly.