Horner's syndrome during epidural analgesia in labor: an alarming sign or a benign phenomenon?

Horner's syndrome has been reported as a complication of epidural analgesia for labor. In all such cases Bupivacaine 0.5%-0.25% was used. Recently, Bupivacaine of much lower concentration has become a routine anesthetic for labor. We present, for the first time, two parturients who developed Horner's syndrome with diluted Bupivacaine. We suggest that with the absence of other neurological signs, once subdural and subarachnoid injections are excluded, further investigations are not required during the first 24 hours since in most of the cases the Horner's syndrome is due to high rostral spread of the epidural block and disappears within 24 hours. Epidural analgesia can be carefully continued albeit appearance of the syndrome.