SPINAL anesthesia is a known complication of epidural and caudal catheters. We report a case involving a 3-month-old infant in whom a spinal level from a caudal-to-thoracic catheter (threaded to the T4 level) was detected despite normal results of an epidurogram.
A 7-kg, 3-month-old infant underwent repair of a congenital right diaphragmatic hernia. After an unremarkable early infancy, the diagnosis of diaphragmatic hernia was made on the basis of typical findings on a chest radiograph obtained for symptoms of upper respiratory infection at the age of 2 months.
Following mask induction and intubation, the patient was placed in the lateral decubitus position. A 20-gauge stiletted catheter (Abbott Laboratories, North Chicago, IL) was threaded from the sacral hiatus 15 cm up the epidural space via an 18-gauge Insyte catheter (Becton-Dickinson Infusion Therapy Systems, Sandy, UT). The catheter has a terminal opening with no side pores. Insertion was uneventful; the catheter was threaded in a continuous, steady motion. It neither met resistance nor was partially withdrawn or rethreaded. Following aspiration of the catheter, which was negative for blood or cerebrospinal fluid (CSF), a test dose of 0.7 ml (0.1 ml/kg) lidocaine, 1.5%, with epinephrine (1:200,000) was administered without signs of intravascular injection. General anesthesia was maintained with isoflurane in oxygen. In addition, regional anesthesia was maintained with intermittent boluses of 0.25% bupivacaine via the epidural catheter. No opioids were administered intraoperatively.
Following an uneventful right thoracotomy and diaphragmatic hernia repair, the patient was extubated in the operating room. Prior to transport to the PACU, 0.7 ml Isovue M200 (Bracco Diagnostics, Princeton, NJ) was injected through the caudal catheter and yielded a typical epidurogram, with the catheter tip at the T4. A continuous epidural infusion of 2% chloroprocaine at a rate of 1 ml/h was started and maintained postoperatively. The infant was comfortable and did not require any other analgesics.
The patient was evaluated by an anesthesiologist prior to transfer to a close observation unit and had normal motor function of all extremities 4 h after the operation.
The next morning it was noted that the infant did not move his legs. His respiratory rate had remained in the low 30s (breaths/min), and the oxygen saturation remained greater than 95% throughout the night. The patient was immediately evaluated; vital signs were normal. Neither the respiratory rate nor effort had changed. He appeared comfortable, with no sign of distress or pain from the incision site. A spinal level with complete lower extremity motor and sensory block below the umbilicus and a sensory block two interspaces above and below the thoracotomy site (tested by exposure to ice) was found. The infusion was discontinued. The caudal catheter was easily aspirated, yielding 2 ml of clear fluid, which tested positive for glucose at 102 mg/dl.
Again, 0.7 ml Isovue M200 was injected through the caudal catheter and yielded normal epidurogram results (fig. 1
), with the position of the catheter tip unchanged at the T4 level. The caudal catheter was removed, and the infant had an uneventful postoperative course, with return of normal sensation and lower extremity muscle tone.
Epidural anesthesia has been used for decades 1
in infants and children with an overall impressive safety record. The French-Language Society of Pediatric Anesthesiology collected data on a total of 17,837 central nervous system blocks, consisting of 15,013 caudal blocks (single shot), 293 sacral epidural blocks, 2,396 lumbar epidural blocks, and 135 thoracic epidural blocks. Dural penetration occurred a total of eight times. 2
We commonly use thoracic epidural catheters placed via
the caudal approach 3
and continuous infusion of chloroprocaine for epidural analgesia in infants. 4–7
We confirm placement of the catheter intraoperatively by fluoroscopy. In this case we obtained an epidurogram after surgical repair and before transfer to the PACU. After we were able to aspirate CSF, we injected contrast medium into the catheter, expecting to find a myelogram, but again found a pattern consistent with epidural injection. Both films were reviewed subsequently by two different radiologists at different institutions (Maine Medical Center, Portland, ME, and Children's Hospital Boston, Boston, MA) and were deemed to show normal epidurogram results.
As a mechanism, we suggest that the stiletted catheter caused a rent in the sacral or lumbar dura at the time of placement, causing chloroprocaine to enter the spinal space and CSF to enter the epidural space. Leakage of chloroprocaine into and CSF out of the spinal space would have caused a low spinal level and positivity of the CSF aspirated from the epidural catheter while maintaining a functional epidural catheter with very good analgesia in the thoracic region. Since the infant remained in supine position postoperatively, the isobaric chloroprocaine did not cause a total spinal block secondary to the thoracic kyphosis. We cannot prove that the infant did not have a dense epidural lower extremity block, as well as a therapeutic thoracic level with a window of cold sensation in between, in addition to a false-positive result of the glucose test on the aspirate. However, this would be an unlikely combination of events with a single terminal orifice catheter.
Neither chloroprocaine nor any of the intravenous solutions contained glucose and could easily explain an aspirate glucose concentration of 102 mg/dl. We do not think that the 18-gauge intravenous catheter punctured the dura at the time of placement since we would have expected return of CSF, but it cannot be ruled out entirely.
This case report emphasizes the importance of close monitoring for motor and sensory block and of respiratory rate and effort in nonverbal infants undergoing epidural anesthesia to detect an inadvertent dense motor block, even when the results of an epidurogram are normal.
1. Ruston FG: Epidural anaesthesia in paediatric surgery. Can Anaesth Soc J 1961; 11: 12–34
2. Giaufre E, Dalens B, Gombert A: Epidemiology and morbidity of regional anesthesia in children: A one-year prospective survey of the French-Language Society of Pediatric Anesthesiologists. Anesth Analg 1996; 83: 904–12
3. Boesenberg AT, Bland BAR, Schulte-Steinberg O, Downing JW: Thoracic epidural anesthesia via caudal route in infants. A nesthesiology 1988; 69: 265–9
4. Gunter JB, Watcha MF, Forestner JE, Hirshberg GE, Dunn CM, Connor MT, Ternberg JL: Caudal epidural anesthesia in conscious premature and high-risk infants. J Pediatr Surg 1991; 26: 9–11
5. Henderson K, Sethna NF, Berde CB: Continuous caudal anesthesia for inguinal hernia repair in former pre-term infants. J Clin Anesth 1993; 5: 129–33
6. Tobias JD, Rasmussen GE, Holcomb GW, Brock JW, Morgan WM: Continuous caudal anesthesia with chloroprocaine as an adjunct to general anesthesia in neonates. Can J Anaesth 1996; 43: 69–72
7. Gunter JB: Benefits and risks of local anesthetics in infants and children. Paediatr Drugs 2002; 4: 649–72
© 2003 American Society of Anesthesiologists, Inc.