Bilateral analgesia and unilateral paresis after lumbar epidural blockade

Some epidurographic explanations for incomplete epidural analgesia coverage in the absence of a catheter

STUDY OBJECTIVE

To determine the impact of the plica mediana dorsalis (PMD) on injected contrast media spread in the epidural space.

DESIGN

Prospective interventional study.

SETTING

Academic medical center.

PATIENTS

30 chronic pain patients ranging in age from 37 to 71 years, undergoing epidural steroid injection.

INTERVENTIONS AND MEASUREMENTS

Epidurograms were evaluated for the 1) presence or absence of a PMD and 2) bilateral differential density and the extent of contrast spread on either side of the midline, horizontally and vertically.

RESULTS

The PMD (defined as midline radiolucency in epidurograms) was observed in (80%) 24/30 patients based on the epidurograms that were evaluated. Denser contrast spread on one side was found in (79%) 19/24 patients who had the PMD and in (33%) 2/6 patients who did not have the PMD (P = 0.03). Horizontal and vertical asymmetrical spread of the contrast was observed in (67%) 16 of 24 patients with the PMD and in (50%) 3 of 6 of patients without the PMD in each direction independently.

CONCLUSION

The difference in density of contrast spread on either side of the midline carries important clinical implications in understanding the pathogenesis of inadequate epidural analgesia and/or unilateral excessive motor weakness or numbness.

Single dermatome analgesia sparing in an obstetric patient following previous radiation to that region

We present a case of an obstetric patient with prior radiation therapy for Hodgkins lymphoma to the right hip, right flank region and lumbar spine, who suffered persistent right sided L1 dermatone distribution sensory and analgesia sparing after routine epidural placement despite additional boluses of local anesthetic. We postulate that the previous radiation therapy received by our patient left sufficient epidural fibrosis as a barrier to prevent spread of local anesthetic to cover the L1 dermatome. Subsequent replacement, using a combined spinal-epidural technique at a higher lumbar space, overcame this obstruction. In patients who have received substantial radiation therapy to the lumbosacral region in the past, awareness of this potential problem may assist in clinical management.

The epidural dorsomedian septum as a possible cause for unilateral anaesthesia in an infant

Unilateral epidural anaesthesia occurring in an infant is reported. An epidurogram revealed the presence of a midline structure suggestive of the dorsomedian septum. Epidural anatomy is reviewed and implications for threading epidural catheters in infants are discussed.

Radiographic findings of unilateral epidural block

In 236 consecutive lumbar epidural anesthesia patients, epidurography was performed in seven patients who developed unilateral loss of cold sensation to clarify the cause of unilateral block. Epidurography demonstrated the epidural catheter tip location in the anterior epidural space in four patients (57%) and in the transforaminal passage in three patients (43%). In all seven patients, successful bilateral epidural anesthesia was obtained by a second puncture using another catheter. Our results showed that the most frequent cause of unilateral epidural blockade was the misplacement of the catheter into the anterior epidural space.