Subdural Injection of Morphine for Analgesia Following Cesarean Section

Pneumocephalus during continuous epidural block

“…The effectiveness of subdural opioid administration is not extensively documented, but some reports suggest that subdural administration works in the same way as epidural administration. Chadwick et al [14] reported that, in three patients with post-cesarean section analgesia, a dose of 2-3 mg of morphine administered through a catheter that had been inadvertently placed subdurally produced no remarkable side effects. Bernards and Hill [15] have demonstrated, in an in-vitro experimental system, that the arachnoid mater is the major barrier to the diffusion of morphine between the epidural space and spinal cord.…”

Unintentional paediatric subdural catheter with oculomotor and abducens nerve palsies

“…Accidental subdural placement of an epidural catheter has rarely been previously reported in a paediatric patient (1). It is a recognized complication in adults, the majority in obstetric cases (2–16). Of the nonobstetric cases, epidural insertion was uncomplicated in only three cases (6, 17, 18), the remainder being associated with either previous back surgery (19), difficulty locating the epidural space (20), difficulty in feeding the catheter into the epidural space (21) or dural puncture (19).…”

“…The 18‐h delay and absence of recent bolus administration of local anaesthetic before the development of symptoms is unusual. In subdural catheter syndromes reported previously, the majority were diagnosed after the administration of a bolus of local anaesthetic, usually with concentrated solutions (2–16). Multihole catheters with low flow infusions pass fluid from proximal eyes while rapidly injected fluid exits from the distal holes (22).…”

“…Radiological verification of suspected subdural catheterization is diagnostic (5). Fluoroscopic observation of the injected dye allows differentiation between epidural, subdural and subarachnoid by defining position, form and movement (39).…”