Paraplegia following thoracic and lumbar transforaminal epidural steroid injections: how relevant is physician negligence?

Non-Particulate Steroids (Betamethasone Sodium Phosphate, Dexamethasone Sodium Phosphate, and Dexamethasone Palmitate) Combined with Local Anesthetics (Ropivacaine, Levobupivacaine, Bupivacaine, and Lidocaine): A Potentially Unsafe Mixture

Purpose

Particulate steroids used in epidural steroid injections have been suspected as a cause of post-procedural embolic events. Some particulate steroids have been suspended only when the transforaminal approach is used for an epidural block of the spine. In contrast, non-particulate steroids are generally accepted for safety during epidural steroid injections. However, the safety of using a mixture of non-particulate steroids and local anesthetics is unknown. This study analyzed whether mixtures of commonly used non-particulate steroids and local anesthetics form crystals in solution.

Methods

We mixed non-particulate steroids (betamethasone sodium phosphate, dexamethasone sodium phosphate, and dexamethasone palmitate) and local anesthetics (ropivacaine, levobupivacaine, bupivacaine, and lidocaine) at different ratios. We used fluorescence microscopy to observe whether crystals formed in mixed solutions; we also measured the pH of each steroid, local anesthetic, and the mixtures.

Results

Ropivacaine or levobupivacaine and betamethasone sodium phosphate produced large crystals (>50 µm). Ropivacaine or levobupivacaine and dexamethasone sodium phosphate produced small crystals (<10 µm). Lidocaine and all non-particulate steroids produced no identifiable crystals; dexamethasone palmitate and all local anesthetics did not form significant particulates. Betamethasone sodium phosphate and dexamethasone sodium phosphate demonstrated basic pH, while all local anesthetics demonstrated acidic pH. Mixtures showed a wide pH range.

Conclusion

Non-particulate steroids can form crystals upon combination with local anesthetics. Crystal formation may be caused by alkalinization of steroids. The mixing of ropivacaine or levobupivacaine and betamethasone sodium phosphate may require caution during an epidural steroid injection. Lidocaine or bupivacaine is recommended as a local anesthetic. Dexamethasone palmitate is a candidate for a mixture, but additional studies on its safety and effectiveness are needed.

Neurological complications associated with epidural steroid injections

Multiple case reports of neurological complications resulting from intraarterial injection of corticosteroids have led the Food and Drug Administration (FDA) to issue a warning, requiring label changes, warning of serious neurological events, some resulting in death. The FDA has identified 131 cases of neurological adverse events, including 41 cases of arachnoiditis. A review of the literature reveals an overwhelming proportion of the complications are related to transforaminal epidural injections, of which cervical transforaminal epidural injections constituted the majority of neurological complications. Utilization data of epidural injections in the Medicare population revealed that cervical transforaminal epidural injections constitute only 2.4 % of total epidural injections and <5 % of all transforaminal epidural injections. Multiple theories have been proposed as the cause of neurological injury including particulate steroid, arterial intimal flaps, arterial dissection, dislodgement of plaque causing embolism, arterial muscle spasm, and embolism of a fresh thrombus following disruption of the intima.

Key safety considerations when administering epidural steroid injections

Neurological and other complications of epidural steroid injections have been widely discussed in recent years. Consequently, the US FDA issued a warning about serious neurological events, some resulting in death, and consequently is requiring label changes. Neurological adverse events numbering 131, including 41 cases of arachnoiditis, have been identified by the FDA, and 700 cases of fungal meningitis following injection of contaminated steroids. A review of the literature reveals an overwhelming proportion of the complications are related to transforaminal epidural injections, with the majority of them to cervical transforaminal epidural injections. This perspective describes the prevalence of administering epidural injections, complications, pathoanatomy, mechanism of injury and various preventive strategies.

Comparison of the efficacy of saline, local anesthetics, and steroids in epidural and facet joint injections for the management of spinal pain: A systematic review of randomized controlled trials

BACKGROUND

The efficacy of epidural and facet joint injections has been assessed utilizing multiple solutions including saline, local anesthetic, steroids, and others. The responses to these various solutions have been variable and have not been systematically assessed with long-term follow-ups.

METHODS

Randomized trials utilizing a true active control design were included. The primary outcome measure was pain relief and the secondary outcome measure was functional improvement. The quality of each individual article was assessed by Cochrane review criteria, as well as the criteria developed by the American Society of Interventional Pain Physicians (ASIPP) for assessing interventional techniques. An evidence analysis was conducted based on the qualitative level of evidence (Level I to IV).

RESULTS

A total of 31 trials met the inclusion criteria. There was Level I evidence that local anesthetic with steroids was effective in managing chronic spinal pain based on multiple high-quality randomized controlled trials. The evidence also showed that local anesthetic with steroids and local anesthetic alone were equally effective except in disc herniation, where the superiority of local anesthetic with steroids was demonstrated over local anesthetic alone.

CONCLUSION

This systematic review showed equal efficacy for local anesthetic with steroids and local anesthetic alone in multiple spinal conditions except for disc herniation where the superiority of local anesthetic with steroids was seen over local anesthetic alone.