[Horner's syndrome following lumbar epidural anaesthesia--subdural block?]

A 28 year old primipara (37th gestational week) was scheduled to undergo delivery by caesarean section under epidural anaesthesia. An epidural catheter was easily inserted in the L3/L4 interspace. After a negative aspiration test 5 ml of bupivacaine 0.25% plus adrenaline 1:200,000 were injected and five minutes later 2 x 5 ml of bupivacaine 0.5% plus fentanyl 0.005 mg/ml were given. Ten minutes after the test dose the patient reported warmth and paraesthesia in the right leg and pelvis and numbness in the right periorbital region. The catheter was drawn back 1.5 centimeters and the operation could be performed under regional anaesthesia with supplemental doses of bupivacaine. Sensory level at the end of the operation was Th 4 which decreased continuously in the following two hours. Ocular symptoms (miosis, ptosis, right-sided numbness) as well as numbness in the right hand and leg persisted four hours longer. The most probable explanation for this peripheral Horner's syndrome is a subdural blockade caused by the first bupivacaine doses. The only known prophylaxis is a fractioned epidural injection of local anaesthetics.