the commonest reasons for high spread of regional blocks are large volumes of local anesthetics and/or high placement of epidural catheters . monoparesis following lumbar epidural block is a rare occurrence , with few cases reported in literature . a healthy , 63 kg , 30-year - old primigravida requested for labor analgesia . as per the institutional protocol , a combined spinal epidural technique ( csea ) was administered . lumbar puncture was done in l3l4 interspace and 25 mcg of fentanyl was injected intrathecally . the epidural space was identified with loss of resistance to saline , at a depth of 5 cm to the skin , and a catheter was fixed with the 10-cm mark at the entry point . the patient had satisfactory pain relief and received two epidural top - up doses of 6 ml 0.125% bupivacaine each , at 60 min intervals . about 45 min after the administration of the last dose , it was decided that a cesarean section be performed as the labor had not progressed . in the operating room , the block was extended with a mixture of 15 ml 2% lignocaine with 50 mcg fentanyl titrated over 10 min to achieve a t6 level block . neurological examination showed right upper limb power of 2/5 ( biceps flexion 2/5 , shoulder abduction 2/5 ) , full power of 5/5 of the left upper limb , and bilateral lower limb power of 4/5 . the sensory examination revealed loss of pin prick sensation at dermatomes c6 , c7 , c8 and t1 of the right arm . there was no involvement of cranial nerves . the epidural catheter was removed and the patient was kept under observation in the recovery room . the incidence of neurological complications in obstetric epidural anesthesia ranges from 0.3 to 2 in 10,000 blocks . commonly described complications of cnb include technical failure , nausea , pruritis , urinary retention , postdural puncture headache , hypotension , bradycardia , and cardiac arrest . jenkins , in a study comprising 145,550 epidurals , found the incidence of high or total spinal block to be 1 in 16,200 epidurals . scott and hibbard observed that neuropathy was the most common complication following epidural anesthesia in the obstetric population . scott and tunstall reported 8 reversible neuropathies in 14,856 obstetric spinal blocks and 38 reversible neuropathies in 108,133 obstetric epidural blocks . the cause of the above was postulated as either trauma due to needle / catheter or maternal obstetric palsies . the rate of permanent neurological injury after spinal and epidural anesthesia ranges from 0 to 4.2 per 10,000 and from 0 to 7.6 per 10,000 , respectively . other reported complications of cnb are cranial nerve palsies with or without horner 's syndrome and monoparesis . the incidence of cranial nerve palsy ranges from 1 to 3.7 in 100,000 obstetric regional anesthesia . involvement of optic nerve , trigeminal nerve , abducent nerve , facial nerve and vestibulocochlear nerve too has been reported . all these complications have been attributed to loss of cerebrospinal fluid ( csf ) or high spread of block after epidural anesthetic secondary to excessive cephalad spread , with full recovery within 45 h. horner 's syndrome following cnb is seen in obstetric practice and is not an uncommon complication , and its occurrence may be attributed to low anatomical origin of the ocular sympathetic supply , with fibers arising from as low as t4 . the block to this level is not uncommon in obstetrics practice , and it can lead to cranial nerve involvement . our patient had weakness in the right upper limb , involving both sensory and motor components at the end of surgery . though the volume of local anesthetic used in epidural was 15 ml , the patient complained of weakness of the right upper limb . the exact mechanism for the high spread to local anesthetic to cause monoparesis is difficult to define . a case of upper limb monoparesis following epidural anesthesia has been reported . according to the authors , the length of the epidural catheter of more than 6.5 cm in epidural space probably resulted in unilateral migration into a higher intervertebral foramen , leading to a high unilateral block . unilateral upper limb involvement may occur due to the presence of septa in the epidural space . epidural catheters placed 68 cm within the epidural space are less likely to get dislodged and require replacement than the catheters placed 24 cm when prolonged labor is anticipated . the volume of local anesthetic injected into the epidural space alone is not the reason for the high spread of local anesthetic . using epidurograms , showed that volumes greater than 40 ml injected in the lumbar or caudal region reach the thoracic and lower cervical segments . conversely , cranial nerve block after test dose through the epidural catheter has been reported . the present case shows that delayed extension of epidural block , though rare , can occur and the attending anesthesiologist must be aware of such a complication so that it can be managed effectively . the management includes reassuring the patient , and taking adequate care of the airway , breathing and circulation .
monoparesis following lumbar epidural block is a rare occurrence , with few cases reported in the literature . 
 we report development of transient brachial monoparesis following epidural anesthesia in a parturient for cesarean section . 
 the patient received a mixture of 15 ml of 2% lignocaine with 50 mcg fentanyl epidurally to achieve a blockade up to t6 level . 
 she remained hemodynamically stable throughout the procedure , with no respiratory distress or desaturation . 
 however , near the end of surgery , she developed weakness in the right upper limb . 
 the weakness lasted for 90 min , followed by complete neurological recovery . 
 subsequent hospital stay was uneventful .