Block Problems

Unilateral Block

Unilateral block is one of the more common problems. It may be due to the catheter lying laterally in the epidural space. Patients often have a poor block on one side and a dense sensory and motor block on the other side due to repeated boluses.

Here are some suggestions in order of decreasing ease and increasing likelihood of working.

  1. Try another bolus of local anaesthetic and hope some will spread to the other side.
  2. Pull back the catheter and give another bolus
  3. If the analgesia is acceptable to the patient, persevere despite imperfection.
  4. Repeat the epidural.

Midwives often position patients from side to side hoping gravity will fix the block. It won't.

"Patchy Block"

A bilateral block is present but seems to skip levels. Why this happens is a mystery. It may be due to septae in the epidural space or because you used "loss of resistance to air".

Try giving 50mg of pethedine in 10mls of normal down the epidural catheter or giving another bolus of local anaesthetic.

If the analgesia remains inadequate you may have to re-site the epidural.

No Block

The catheter may be outside the epidural space or intravascular.

Check for a sensory level with ice. If you have already given a full loading dose and waited 30 minutes then you can save time and energy now by re-siting your epidural.

Sub Dural Block

The catheter is between the dura and the arachnoid mater

The block is characteristically higher than expected for the given volume of local anaesthetic. It is usually patchy and can have motor sparing.

Talk to your consultant about resiting the catheter.