What to do if an epidural (peridural anesthesia) is not effective, as evidenced by lack of numbness and patient movement despite multiple test doses, during an excision of a prerenal mass under General Endotracheal Anesthesia (GETA) with epidural?

Management of Ineffective Epidural During Surgery Under General Anesthesia

If the epidural is clearly not working despite multiple test doses (no sensory block, patient movement, no motor block), and you are already under general anesthesia with the surgery proceeding, abandon the epidural and rely on your general anesthetic with systemic analgesia—the epidural has failed and further attempts to salvage it intraoperatively are futile and potentially dangerous. 1

Why This Epidural Failed

Your clinical scenario demonstrates classic signs of epidural failure:

• No sensory block (no numbness) despite multiple test doses 1
• No motor block (patient still moving, Bromage score indicates inadequate block) 1
• Negative hemodynamic response (no heart rate changes with test doses) 1
• Catheter likely misplaced outside the epidural space—either subdural, intramuscular, or subcutaneous 2, 3

The fact that you're not seeing tachycardia during abdominal incision under adequate general anesthesia confirms your GA is working, but this doesn't validate epidural function 1.

Immediate Intraoperative Management

Do NOT attempt to rescue the epidural during surgery:

• Remove or ignore the epidural catheter for the remainder of the case 1
• Deepen your general anesthetic with volatile agents and/or IV anesthetics as needed 4
• Use systemic opioids (fentanyl, remifentanil, or morphine) for intraoperative analgesia 4
• Consider IV lidocaine infusion (1.5 mg/kg bolus, then 2 mg/kg/h) as an alternative analgesic adjunct with anti-inflammatory properties 4

Why not try to fix it now:

• Up to one-third of epidurals fail to function satisfactorily, with incorrect catheter placement being the primary cause 5, 1
• Negative aspiration is unreliable—failure to aspirate CSF does not confirm epidural placement 4, 1
• Repositioning or redosing carries risks including inadvertent intrathecal injection if the catheter has migrated, potentially causing total spinal anesthesia 4, 1
• Intraoperative manipulation is dangerous and unlikely to succeed 2, 3

Postoperative Analgesia Planning

Since your epidural has failed, plan alternative postoperative pain management:

Multimodal systemic analgesia:

• IV opioids via PCA (morphine or hydromorphone) 4
• Scheduled acetaminophen (paracetamol) 1g every 6 hours 4
• NSAIDs or COX-2 inhibitors (if no contraindications and considering anastomotic concerns in bowel surgery) 4
• Continue IV lidocaine infusion into the postoperative period if initiated 4
• Consider ketamine as an adjunct for opioid-sparing effects 4

Alternative regional techniques (if feasible postoperatively):

• TAP blocks (transversus abdominis plane) can provide abdominal wall analgesia, though evidence is limited compared to functional epidurals 4
• Wound infiltration catheters with continuous local anesthetic infusion 4
• Single-shot spinal is NOT appropriate postoperatively for ongoing analgesia 4

Common Pitfalls and Prevention

Why epidurals fail:

• Incorrect initial placement using loss of resistance technique—most common cause 1, 2
• Catheter migration after correct placement 2, 3
• Inadequate dosing (though not your issue given multiple test doses) 2
• Operator inexperience significantly increases failure rates 1, 6
• Patient anatomy (obesity, scoliosis, previous back surgery) 3

What should have been done differently:

• Test the epidural BEFORE induction of general anesthesia with cold/pinprick testing to confirm sensory block 5
• Verify bilateral sensory block to at least T10 level for abdominal surgery 5
• If no block develops within 20 minutes of adequate dosing, the catheter should be replaced or abandoned before starting surgery 1, 2
• Never assume the epidural works without objective sensory testing 5, 1

Critical safety point:

The requirement for multiple supplemental boluses or test doses is a red flag that the catheter is not functioning properly and should be replaced or abandoned 6. In labor epidural studies, increased need for boluses during labor predicted failure to convert to surgical anesthesia in 8% of cases 6.

Documentation and Follow-up

• Document the epidural failure clearly in the anesthetic record 1
• Remove the catheter at the end of surgery or early postoperative period 1
• Do not blame coincident nerve injuries on the failed epidural—surgical factors (positioning, tourniquet, retraction) are more likely causes 7
• Inform the surgical team that postoperative analgesia will be systemic rather than epidural-based 4