Neurological Complications of Pediatric Regional Anesthesia

By Harshad Gurnaney, MBBS and Arjunan Ganesh, MBBS
Department of Anesthesiology and Critical Care
The Children’s Hospital of Philadelphia and Perelman School of Medicine
University of Pennsylvania
Philadelphia, Pennsylvania

The practice of pediatric regional anesthesia has been gaining in popularity over the last couple of decades, particularly after the publication of this large prospective observational study, which demonstrated a very low incidence of side effects1. Neurological complications are one of the most devastating complications of pediatric regional anesthesia, but fortunately rare in occurrence. In this article, neurological complications related to neuraxial and peripheral nerve blockade will be discussed.

Neuraxial Blockade
Neurological complications include seizures resulting from local anesthetic systemic toxicity (LAST), transient neurological symptoms (TNS), epidural hematoma, epidural abscess, radiculopathy, spinal cord injury, and cauda equina syndrome. Seizures occurring from LAST will be discussed in a separate article.

The incidence of TNS is very rare following epidural anesthesia when compared to intrathecal injection of local anesthetic injection2. In a series of 220 children who received epidural analgesia following cardiac surgery, 3.3% experienced transient paresthesia3. Intrathecal lidocaine is more likely to cause TNS that bupivacaine or ropivacaine4. Although TNS is more likely following spinal anesthesia than when compared to epidural anesthesia, no instances were reported in a large single-center case series of 1,132 patients5.

Epidural hematomas and abscesses following neuraxial anesthesia and analgesia are rarely seen in pediatric practice. In several large multicenter prospective and retrospective studies, no cases of epidural hematoma were reported1,6-8. Although several reports of epidural hematoma exist in the adult literature it is very rare in children9. In a single case report, an epidural hematoma was diagnosed early following a thoracic epidural placement in a child with worsening liver function and was successfully managed by early intervention leading to complete neurological recovery in six months. The incidence of epidural abscess in children is extremely low. In a large prospective five-year audit of epidurals in Great Britain and Ireland two cases of epidural abscesses were reported, one was lost to follow up and the other was successfully managed with antibiotics7. In a recently published study, a single case of epidural abscess was reported in a series of 13,120 epidural catheters (0.76:10,000, 95% CI 0 to 4.8:10,000)8. This occurred in a two-month old patient, who made a full recovery following a lumbar laminectomy.

The incidence of radiculopathy, spinal cord injury and cauda equina syndrome is very rare following pediatric epidural analgesia. Neurologic symptoms were primarily sensory in nature in this large study8 and resolved over a period of weeks to months. There were no instances of motor deficit in this study (95% CI, 0–0.4:10,000).

Another large prospective study in children with over 10,000 neuraxial blocks had similar findings; reporting only four patients who had sensory symptoms that resolved spontaneously with time6. Five cases of nerve injury attributed to the epidural was reported in this large prospective audit7, in which two of them had prolonged pain and sensory deficit that resolved within a year after gabapentin therapy in a chronic pain clinic. In the same study7, a four month-old patient inadvertently receive a three-fold dose of local anesthetic via the epidural catheter due to a pump programming error and developed cauda equina syndrome and continued to have residual neurologic deficit even after a year. Despite several large series demonstrating a low risk of neurological complications following neuraxial block, severe adverse events can occur, even in experienced hands. A case series of four patients who developed long-standing motor and sensory deficits (permanent in 3)10, illustrates patients who developed ischemic injury of the spinal cord. Severe hypotension could have been a contributing factor in one of the cases where, it was suggested, that the catheter could have been intrathecally placed.

Suggestions to decrease the incidence of neurological complications following neuraxial anesthetic procedures are well described in “The Second ASRA Practice Advisory on Neurologic Complications Associated with Regional Anesthesia and Pain Medicine: Executive Summary 2015”11. The advisory recommends that in those with pre-existing peripheral neuropathy (hereditary and acquired), inflammatory neuropathy (like GBS), CNS disorders, spinal canal pathology (previous surgery, neural tube defects, etc.), regional anesthesia should be used after careful consideration of risk and benefits and the possibility of deterioration of certain neurological symptoms, if present, should be discussed with the patient and/or family. Avoiding prolonged hypotension during neuraxial anesthesia is recommended based on several case reports10,11. There is now extensive data confirming that performing regional anesthetic procedures in children who are under general anesthesia or deep sedation, does not increase the risk of neurological complications when compared to those in awake adults8,11,12.

Peripheral Nerve Blockade
Peripheral nerve blocks (PNBs) are increasingly used to provide post-operative pain control after surgery8,13. The benefits of these blocks include superior postoperative pain control and recovery compared to general anesthesia with opioid analgesia. One of the devastating complications of PNBs is postoperative neurologic injury11. The morbidity associated with this kind of injury is variable; ranging from localized sensory impairment to complete neural damage with loss of all neurologic function in the distribution of the peripheral nerve14. Although rare, the occurrence of these neurologic complications can be devastating to the patient.

The incidence of this rare but devastating complication is difficult to discern. The incidence of peripheral nerve injury (PNI) reported by different reports is variable. Also, peripheral nerve injury can vary from early transient postoperative neurologic symptoms (PONSs) that are more common in the first days to month after peripheral nerve blockade to prolonged sensory and motor abnormalities lasting longer than six months. In one report the incidence of PONS with all PNBs was found to reduce sequentially with time from 0% to 2.2% at three months, 0% to 0.8% at six months, and 0% to 0.2% at one year11. The incidence of PONS after PNBs was found to be variable based on the site of PNBs. The four nerve block which have a relatively higher rate of PONS are: interscalene brachial plexus block 2.84:100 (95% CI 1.33–5.98:100), axillary brachial plexus block 1.48:100 (95% CI: 0.52– 4.11:100), and femoral nerve block 0.34:100 (95% CI: 0.04 –2.81:100)15.

As nerve injury after peripheral nerve blocks is rare, a large cohort of patients undergoing PNBs needs to be followed for an extended period (about six months) postoperatively to capture the incidence of neurological complications. Also, the risk of PONS after different PNBs is different based on the location of the PNB. Small prospective cohort studies have looked at the incidence of PONS after PNBs with active follow-up, serial neurological examinations and neurologic testing of the patients for 6-9 months at regular intervals16. These studies are limited by the small sample size leading to wide confidence for the estimated incidence of PONS. One of the examples of a prospective cohort study is a cohort of 521 adults followed for nine months after interscalene nerve blocks. This study found that the incidence of PONS (paresthesia, dysesthesia or pain unrelated to the surgery) to be 14% at ten days, 7.9% at one month, 3.9% at three months, 0.9% at six months and 0.2% at nine months17.

Longitudinal retrospective reviews of single institutional or regional anesthesia databases at regional or national level (for e.g. PRAN database) for PNBs, may be limited by under-reporting of complications as they are based on self-report by the participating institutions who may have different systems for follow-up after PNBs8. To the best of our knowledge, none of the large databases actively follow-up their patients for 6 months. A common strategy used for follow-up being of patient self-report during a follow-up phone call after patients have been discharged home for 24-48 hours or till resolution of the symptoms related to the PNBs.

In the pediatric literature, the first nationwide report on complications related to PNBs was from the ADARPEF study which used a survey of anesthesia providers in France to investigate complications related to PNBs1. They found no complications reported after PNBs. In a follow-up of this study in 2010 found no complications related to peripheral nerve injury after PNBs6. The Pediatric Regional Anesthesia Network (PRAN), a multicenter collaborative supporting a registry that collects data on every regional nerve block performed or supervised by an anesthesiologist at more than 20 children’s hospitals. Their latest report examines the incidence of major complications related to pediatric regional anesthesia in over 100,000 blocks. They reported no permanent neurologic deficits after either neuraxial blocks or PNBs (95% CI; 0 to 0.4:10,000). This report found the risk of transient neurological deficit after PNBs to be 2.8: 10,000 (95% CI, 1.6 to 4.7: 10,000). Neurologic complications were primarily sensory in nature and resolved over a period of weeks to months, with only two cases demonstrating a sensory deficit beyond three months8.

The mechanism of PNI related to the use of PNB traditionally falls into one of three broad categories: mechanical and injection injury (traumatic), vascular (ischemic), and chemical (neurotoxic) and inflammatory18. Mechanical compression injury can result from forceful needle-nerve contact from an approaching needle or injection inside the nerve itself. Damage to the nerve vasculature during nerve blocks can result in local or diffuse ischemia related to direct injury. Nerves with an abundance of connective tissue may be less susceptible to compression. Chemical nerve injury results from tissue toxicity of injected solutions (local anesthetics or the additives). The site of local anesthetic application (increasing order of risk from extraneural, to intraneural, to interfascicular and the highest risk with intrafascicular) may be the primary determinant of the risk of neurotoxicity19. There is evidence that many local anesthetics can have neurotoxic effects in various tissues under certain conditions20.

Several studies have investigated the rate of unintentional intraneural injections reporting the rate to range from 9-18%16,21. Among reports using ultrasound guidance for placement of PNBs the incidence for the proximal sciatic nerve blocks was 16.3%, for the proximal brachial plexus block it was 15.5% for interscalene and 17.7% for supraclavicular approaches and for a femoral nerve block it was 9%22,23. The incidence of PONS was 10% in one report after intraneural injection and there was one case of long-term neurologic injury at four weeks in another report24.

The degree of nerve damage from needle trauma to the nerve depends on bevel type as well as the needle gauge25. In general, short-bevel needles are preferred for PNB as they are less likely to penetrate the perineurium. Also, needle gauge is shown to be directly proportional to the extent of nerve damage. Avoidance of deliberate trauma to nerves including intraneural injection is a key safety principle that should be observed while performing any PNBs. There is currently no evidence to support the use of any one needle guidance technique to reduce the incidence of PONS26-28. The use of ultrasound guidance could help detect an unintentional intraneural injection with signs including visualization of the needle tip within the nerve, increase in the cross-sectional area of the nerve by 15% or spread of the local anesthetic injection within the epineurium of the nerve.

The incidence of long-term neurological injury after a peripheral nerve block is rare with an incidence reported in the literature of long-term neurological injury after PNBs to be between 2.4 to 4 per 10,000, whereas transient neurologic deficits lasting up to two weeks occur more frequently with an incidence around 3% but with some reports suggesting rates as high as 15%11,14,15.

Diagnosis and Management of Neurological Complications Following Regional Anesthetic Procedures
Following neuraxial anesthesia, any evidence of spinal cord dysfunction should undergo emergent neuro-imaging11. Although MRI is preferred, a CT scan may be obtained, if there is any delay, to rule out any compressive lesions. Most epidural hematomas and epidural abscesses will require emergent decompression although some may be treated conservatively7-9. Neurological consultation is recommended for peripheral nerve injuries and early EMG followed by nerve conductions studies later may be helpful in diagnosis11. Neuropathic pain can be managed by a pain medicine specialist and often combines pharmacological, psychological and physical therapy.

Finally, a proportion of cases of postoperative neurological complications are unrelated to the regional anesthetic procedure and it is important for the anesthesiologist to understand the potential complications of the surgical procedure and other position related injuries. This needs to be discussed with the perioperative team to properly manage a child with this complication postoperatively.

References

  1. 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(5):904-912.
  2. Bourlon-Figuet S, Dubousset AM, Benhamou D, Mazoit JX. Transient neurologic symptoms after epidural analgesia in a five-year-old child. Anesth Analg. 2000;91(4):856-857, table of contents.
  3. Peterson KL, DeCampli WM, Pike NA, Robbins RC, Reitz BA. A report of two hundred twenty cases of regional anesthesia in pediatric cardiac surgery. Anesth Analg. 2000;90(5):1014-1019.
  4. Freedman JM, Li DK, Drasner K, Jaskela MC, Larsen B, Wi S. Transient neurologic symptoms after spinal anesthesia: an epidemiologic study of 1,863 patients. Anesthesiology. 1998;89(3):633-641.
  5. Puncuh F, Lampugnani E, Kokki H. Use of spinal anaesthesia in paediatric patients: a single centre experience with 1132 cases. Paediatr Anaesth. 2004;14(7):564-567.
  6. Ecoffey C, Lacroix F, Giaufre E, Orliaguet G, Courreges P, Association des Anesthesistes Reanimateurs Pediatriques d'Expression F. Epidemiology and morbidity of regional anesthesia in children: a follow-up one-year prospective survey of the French-Language Society of Paediatric Anaesthesiologists (ADARPEF). Paediatr Anaesth. 2010;20(12):1061-1069.
  7. Llewellyn N, Moriarty A. The national pediatric epidural audit. Paediatr Anaesth. 2007;17(6):520-533.
  8. Walker BJ, Long JB, Sathyamoorthy M, et al. Complications in Pediatric Regional Anesthesia: An Analysis of More than 100,000 Blocks from the Pediatric Regional Anesthesia Network. Anesthesiology. 2018;129(4):721-732.
  9. Sathyamoorthy M, Walker B, Rhodes MM, Eriator I. Spinal epidural hematoma following a thoracic epidural in a child with sickle cell disease. Clin Case Rep. 2017;5(7):1115-1118.
  10. Meyer MJ, Krane EJ, Goldschneider KR, Klein NJ. Case report: neurological complications associated with epidural analgesia in children: a report of 4 cases of ambiguous etiologies. Anesth Analg. 2012;115(6):1365-1370.
  11. Neal JM, Barrington MJ, Brull R, et al. The Second ASRA Practice Advisory on Neurologic Complications Associated With Regional Anesthesia and Pain Medicine: Executive Summary 2015. Reg Anesth Pain Med. 2015;40(5):401-430.
  12. Ivani G, Suresh S, Ecoffey C, et al. The European Society of Regional Anaesthesia and Pain Therapy and the American Society of Regional Anesthesia and Pain Medicine Joint Committee Practice Advisory on Controversial Topics in Pediatric Regional Anesthesia. Reg Anesth Pain Med. 2015;40(5):526-532.
  13. Gurnaney H, Kraemer FW, Maxwell L, Muhly WT, Schleelein L, Ganesh A. Ambulatory continuous peripheral nerve blocks in children and adolescents: a longitudinal 8-year single center study. Anesth Analg. 2014;118(3):621-627.
  14. Sondekoppam RV, Tsui BC. Factors Associated With Risk of Neurologic Complications After Peripheral Nerve Blocks: A Systematic Review. Anesth Analg. 2017;124(2):645-660.
  15. Brull R, McCartney CJ, Chan VW, El-Beheiry H. Neurological complications after regional anesthesia: contemporary estimates of risk. Anesth Analg. 2007;104(4):965-974.
  16. Sala-Blanch X, Lopez AM, Pomes J, Valls-Sole J, Garcia AI, Hadzic A. No clinical or electrophysiologic evidence of nerve injury after intraneural injection during sciatic popliteal block. Anesthesiology. 2011;115(3):589-595.
  17. Borgeat A, Ekatodramis G, Kalberer F, Benz C. Acute and nonacute complications associated with interscalene block and shoulder surgery: a prospective study. Anesthesiology. 2001;95(4):875-880.
  18. Brull R, Hadzic A, Reina MA, Barrington MJ. Pathophysiology and Etiology of Nerve Injury Following Peripheral Nerve Blockade. Reg Anesth Pain Med. 2015;40(5):479-490.
  19. Whitlock EL, Brenner MJ, Fox IK, Moradzadeh A, Hunter DA, Mackinnon SE. Ropivacaine-induced peripheral nerve injection injury in the rodent model. Anesth Analg. 2010;111(1):214-220.
  20. Radwan IA, Saito S, Goto F. The neurotoxicity of local anesthetics on growing neurons: a comparative study of lidocaine, bupivacaine, mepivacaine, and ropivacaine. Anesth Analg. 2002;94(2):319-324, table of contents.
  21. Robards C, Hadzic A, Somasundaram L, et al. Intraneural injection with low-current stimulation during popliteal sciatic nerve block. Anesth Analg. 2009;109(2):673-677.
  22. Bigeleisen PE, Moayeri N, Groen GJ. Extraneural versus intraneural stimulation thresholds during ultrasound-guided supraclavicular block. Anesthesiology. 2009;110(6):1235-1243.
  23. Hara K, Sakura S, Yokokawa N, Tadenuma S. Incidence and effects of unintentional intraneural injection during ultrasound-guided subgluteal sciatic nerve block. Reg Anesth Pain Med. 2012;37(3):289-293.
  24. Bigeleisen PE. Nerve puncture and apparent intraneural injection during ultrasound-guided axillary block does not invariably result in neurologic injury. Anesthesiology. 2006;105(4):779-783.
  25. Sala-Blanch X, Ribalta T, Rivas E, et al. Structural injury to the human sciatic nerve after intraneural needle insertion. Reg Anesth Pain Med. 2009;34(3):201-205.
  26. Barrington MJ, Watts SA, Gledhill SR, et al. Preliminary results of the Australasian Regional Anaesthesia Collaboration: a prospective audit of more than 7000 peripheral nerve and plexus blocks for neurologic and other complications. Reg Anesth Pain Med. 2009;34(6):534-541.
  27. Neal JM. Ultrasound-Guided Regional Anesthesia and Patient Safety: Update of an Evidence-Based Analysis. Reg Anesth Pain Med. 2016;41(2):195-204.
  28. Sites BD, Taenzer AH, Herrick MD, et al. Incidence of local anesthetic systemic toxicity and postoperative neurologic symptoms associated with 12,668 ultrasound-guided nerve blocks: an analysis from a prospective clinical registry. Reg Anesth Pain Med. 2012;37(5):478-482.

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