When using spinal anaesthesia for caesarean section after the epidural has failed, the normal dose of spinal anaesthetic should be used

Cardiac arrest in obstetric patients receiving anaesthetic care: results from the 7th National Audit Project of the Royal College of Anaesthetists

“…spinal injection of local anaesthetic [36]. It is reassuring that there were no cardiac arrests related to difficulties associated with airway management.…”

“…after a failed ‘top‐up’ of a labour epidural) [34]. When spinal and epidural techniques are undertaken together, either as a specific technique, combined spinal‐epidural or sequentially as part of a rescue approach for an inadequate block, the effect of the two may be synergistic, affecting the speed of onset and height of the block [35, 36]. An epidural injectate volume can compress the dural sac, resulting in a higher block with a subsequent spinal injection of local anaesthetic [36].…”

“…When spinal and epidural techniques are undertaken together, either as a specific technique, combined spinal‐epidural or sequentially as part of a rescue approach for an inadequate block, the effect of the two may be synergistic, affecting the speed of onset and height of the block [35, 36]. An epidural injectate volume can compress the dural sac, resulting in a higher block with a subsequent spinal injection of local anaesthetic [36]. A dural puncture by the spinal needle can also facilitate the translocation of epidural local anaesthetic into the cerebrospinal fluid, augmenting a spinal injection of local anaesthetic [37].…”

“…A dural puncture by the spinal needle can also facilitate the translocation of epidural local anaesthetic into the cerebrospinal fluid, augmenting a spinal injection of local anaesthetic [37]. The unpredictability of these effects in different individuals in different circumstances makes the choice of safe effective dose used in a repeat neuraxial technique uncertain and difficult [36].…”

A Rare Case of C2 Sensory Blockade with Preserved Phrenic Nerve Function in an Obstetric Patient

“…The incidence of high neuraxial block requiring intubation or conversion to general anesthesia was recently reported to be 1 of 4,336 neuraxial anesthetics in obstetric patients [ 2 ]. High neuroblockade has been associated with unrecognized intrathecal administration of local anesthetic [ 2 , 3 ] and with spinal anesthesia after failed epidural block [ 2 , 4 , 5 ] but can also occur with epidural catheter dosing [ 2 , 3 ]. While an unrecognized intrathecal catheter cannot be completely ruled out in this case, it is very unlikely given the patient had a continuous epidural infusion for three hours without developing high neuroblockade and catheter aspiration remained negative for CSF.…”