Lumbar erector spinae plane block obtunding knee and ankle reflexes

The erector spinae plane block (ESPB) has recently been described as an effective analgesic strategy for various surgeries at ventral and dorsal parts of body. The block has been utilized for postoperative pain relief in hip surgeries. Cadaveric and clinical studies performed at the lumbar level depict a dorsal spread and minimal ventral spread in the lumbar plexus. So far to our knowledge there is one case report which has described reduced quadriceps strength in a parturient after caesarean section. We report two patients who presented with absent knee reflexes (decreased quadriceps strength) and one patient with absent ankle reflex (foot drop) following continuous ESPB at the level of L3. The initial bolus was with 30 ml of 0.1% bupivacaine followed by a continuous infusion of 0.1% ropivacaine at 8ml/hour. The loss of knee reflexes in two patients and diminished reflexes in one patient suggested spread of local anaesthetic (LA) to the lumbosacral plexus. The LA infusion were stopped in all 3 patients. The average duration of motor block was 18 hours. These complications should be considered if early ambulation is mandatory for patients.