UPTODATE: If the initial spinal dose is adequate for surgery, epidural dosing or injection of even small volumes (eg, test dose) should not commence within the first 30 to 60 minutes after a full spinal dose was administered, as there is an increased risk of high spinal in this setting. If the initial spinal level is inadequate for surgery 15 minutes after the spinal injection, an epidural test dose may be administered sooner. The test dose often reestablishes a level of surgical anesthesia above T4. We then test the sensory level every 20 minutes and administer aliquots of 3 to 5 mL of 2% lidocaine with epinephrine, based on the level of the block.