Breach in the epidural catheter by a spinal needle: Is it just a theoretical risk?

Sir,

We report a case of pericatheter leakage from epidural catheter in an 81-year-old female with left supracondylar femur fracture post bilateral total knee replacement scheduled for an open reduction and internal fixation. She was obese (BMI 43.1), diabetic and hypertensive, and bedridden since last 3 weeks. Combined spinal-epidural (CSE) anaesthesia was planned with two separate needles in the same interspace in anticipation of age-related degenerative spine. A CSE set with extra long Tuohy needle was not available. The epidural catheter was flushed prior to insertion, with normal saline to eliminate dead space. The catheter was intact with all three eyes patent. After inserting the epidural catheter, while giving intrathecal injection, the catheter migrated inwards. It was readjusted and was fixed at 15 cm. The surgery went on for 6 h and 30 min and was uneventful. It was well managed with initial intrathecal injection followed by epidural bolus and infusion after 90 min of intrathecal injection. Postoperatively, the patient was started on epidural infusion through elastomeric pump.

We received a call from ward after 5 h for soakage of the epidural dressing with clear fluid but the patient was comfortable. The dressing was removed to examine the catheter insertion site. The catheter had not migrated and was at the 15-cm mark at the skin as was fixed previously. An epidural bolus of normal saline was given and a minor pericatheter leak was observed, which was negative for glucose. Since the patient was comfortable, we decided to observe with a new dressing. The patient was reviewed after 4 h. The patient was not very comfortable (VAS 4 at rest), and the dressing was soaked again. Epidural catheter was removed this time and examined for any damage; a breach near 15-cm mark was revealed as shown in the image [Figure 1a and b].

Figure 1

Clockwise from left upper image. (a) Breach in epidural catheter. (b) Breach in the catheter under microscope. (c) Drug delivery via catheter during bolus. (d) Drug delivery during continuous infusion

Retrospectively, on analysis, we hypothesised that the damage may have occurred while giving spinal injection due to contact of spinal needle with the epidural catheter due to which the catheter had migrated. Anaesthesia was adequate intraoperatively as the drug was given as a bolus; hence, adequate drug volume crossed the area of breach. Similarly, patient had pain relief (VAS 1 at rest) 5 h postoperatively, as she received a bolus towards the end of surgery. But, when the infusion was running at a lower volume as with a continuous infusion, the drug followed the path of least resistance and leaked out through the breach in the catheter. [Figure 1c and d]; this is demonstrated well in the attached video [Video 1].

A theoretical risk of damage to the catheter from contact with the spinal needle during its insertion if an epidural catheter is placed before the introduction of the spinal needle exists.[1] On reviewing the literature, there are many case reports on broken epidural catheter, but we found only few case reports of sheared or breached epidural catheter due to similar mechanism.[2] Whittey et al. encountered a large subcutaneous fluid collection at the back due to a presumed breach in an epidural catheter documented on MRI spine.[3]

This case illustrates that this complication is not limited to a theoretical risk, and can only be avoided by CSE with needle-through-needle technique or separate injection in a lower interspace. Another option could be passing epidural catheter after giving spinal injection. In our case, due to age-related changes in spine, spinal injection at lower interspace was not feasible.

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