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Background and Aims Neuraxial analgesia is preferred for labor pain, but carries risks of inadvertent intravascular injection. A retrospective analysis found a 0.25% incidence of epidural catheter migration into the vascular space.

Methods Description of a case of intravascular migration of a previously functioning epidural catheter for labor analgesia. Informed consent obtained for publication.

Results A 34-year-old primigravida, ASA-II, with 37 weeks twin pregnancy requested epidural analgesia for labor pain relief. Using an 18G Tuohy needle at L3-L4 space, a multi- orifice 20G epidural catheter was inserted, with confirmed loss of resistance at 5 cm from the skin. During catheter insertion, blood reflux occurred, which resolved after saline flushing and fixation at a depth of 9 cm. Subsequent tests showed negative blood aspiration and no blood drainage with gravity. An 10mL bolus (8mg ropivacaine with 10mcg sufentanil) was administered in divided doses. Two hours later, due to recurrent pain, 6mL of 0.2% ropivacaine was dispensed. After 30 minutes, the pain remained, and no evident sensory block was observed. Despite negative aspiration, 5 mL of 2% lidocaine was injected, resulting in perioral paresthesia and metallic taste, without hemodynamic manifestations. Suspected intravascular administration was confirmed by a positive aspiration test, with symptoms resolving within 10 minutes without intervention. The catheter was removed and repositioned in another intervertebral space and labor proceeded uneventfully.

Conclusions This case highlights the possibility of migration of a previously functional epidural catheter into the intravascular space. Anesthesiologists should continuously monitor for signs of LAST despite negative aspiration results.