Long-Term Complications of Epidural Steroid Injections | SpringerLink
On the basis of current literature, serious long-term complications are rare yet can have devastating results.
Potential etiologies for long-term complications associated with ESI include infection, bleeding, endocrine effects, neurotoxicity, and neurologic injury. Despite the multitude of literature on ESI, there is still a lack of studies specifically addressing possible long-term complications. Further research is therefore warranted. Epidural steroid injections ESI are among the most commonly performed pain-relief procedures in modern medicine.
Although the literature on the efficacy and safety of ESI is substantial, there remains a paucity of studies addressing possible long-term complications. This may be related to the lack of mandatory reporting of complications from ESI in the US, which also makes determining the true incidence of serious adverse effects essentially impossible. There was much debate about the overall safety of ESI with the unfortunate outbreak of fungal meningitis in the US in , which occurred after administration of contaminated steroid and resulted in more than cases of fungal infection and over 48 deaths [ 1 ].
The American Society of Anesthesiologists Closed Claims Study also reported major complications supposedly caused by ESI resulting in malpractice litigation; these included nerve injury, infection, death, brain damage, headache, and increased pain or lack of relief [ 2 ].
Despite controversy about safety, current literature suggests serious long-term complications as a result of epidural steroid administration are rare. A recent retrospective analysis studied 1, patients who received, over a seven-year period, 4, ESI, including lumbar interlaminar injections, 17 caudal injections, 3, lumbar transforaminal injections, and cervical interlaminar injections.
The study identified an incidence of complications of 2. Another study, from , of patients who received fluoroscopically guided transforaminal epidural injections found the incidence of minor complications to be 9. Despite the rarity of serious adverse effects after ESI, the long-term complications that have been reported arise from both mechanical and chemical sources.
These potential long-term complications are primarily related to infection, bleeding, endocrine effects, and neurologic complications. Infectious complications after ESI are rare. They include such significant infections as epidural abscess, discitis, osteomyelitis, and meningitis. Among the conditions listed, the highest incidence is of spinal epidural abscess, but this accounts for only 1—2 cases per 10, among all patients admitted to hospital [ 2 ].
Although back pain, fever, and leukocytosis are the classical features, epidural abscess may mimic other medical conditions. The patient may present with abdominal or flank pain in the absence of fever, neck stiffness, or elevated white cell count [ 5 ]. The erythrocyte sedimentation rate ESR was elevated in all patients for whom this was measured, suggesting ESR enables highly sensitive study for epidural abscess.
The efficacy of appropriate treatment in restoring neurological function has been documented by case reports of patients who developed spinal epidural abscess after ESI [ 7 ]. Widespread outbreaks of infection after ESI are nearly always associated with contaminated injectate. At the time of writing, the most recent instance was a widespread outbreak of fungal infections in , because of contaminated methylprednisolone acetate prepared by a single compounding pharmacy [ 8 ].
Aspergillus fumigatus and Exserohilum rostratum contamination of vials of methylprednisolone were associated with meningitis, cauda equina syndrome, focal infection, and posterior circulation stroke. According to the Center for Disease Control, more than 48 deaths and instances of illness were associated with this outbreak.
Clinical and regulatory oversight are both required to ensure the sterile conditions necessary to limit infections from ESI. Bleeding occurs with a range of clinical severity from injection site bruising to neurologically catastrophic epidural hematoma. The prevalence of all bleeding complications is low and one prospective evaluation of 10, fluoroscopically directed epidural injections observed the intravascular entry of needle in 4.
Although rare, an epidural hematoma is a potentially devastating complication of epidural steroid injection. The reported incidence of spinal hematoma after intervention is estimated to be between 1 in 70, and 1 in , [ 10 , 11 ].
A case report notes some classical features of this complication for a patient who had received a cervical ESI: A spinal epidural hematoma occurs when buildup of blood occurs between the dura mater and the spinal cord, often because of iatrogenic trauma of an epidural vein.
Hematogenous compression of the spinal cord can lead to permanent paralysis and death if not treated as an emergency by surgical evacuation. Suspension of antithrombotic and thrombolytic therapy before an epidural steroid injection is common practice [ 13 ]. Although recommendations have been made by a variety of societies, including the Third Consensus Conference on Regional Anesthesia and Anticoagulation, there is a limitation on the use of evidence -based reviews because the rarity of spinal hematoma defies a prospective randomized study, and there is no current laboratory model.
According to Horlocker et al. Although there was no appreciable increase in risk of bleeding, the rarity of spinal hematoma precludes more definitive assessment of risk.
The authors note that their survey of interventional pain practitioners found the risk of complications from thromboembolism was three times more prevalent than epidural hematomas, and concluded that clinicians must balance the risk of thromboembolism and bleeding for each patient before routine discontinuation of antiplatelet therapy.
An INR of 1. Thus shortage of quality evidence and the bias toward preventing epidural hematomas over prevention of thrombosis has led to a focus that generally errs toward the side of antiplatelet and anticoagulant cessation before ESI.
The effect of epidural steroids on the hypothalamic—pituitary—adrenal HPA axis was first noted in case reports [ 18 , 19 , 20 ]. Knight and Burnell [ 18 ] documented four case histories of patients who developed cushingoid symptoms after injections of methylprednisolone and bupivacaine into the epidural space. The symptoms emerged about a month after the intervention and included malaise, facial swelling, palpitations, vocal weakness, small raised scaly lesions on the scalp and over the upper trunk, and a hump between the shoulder blades.
In another case report, diagnosis of an exogenous hypercortisolism was confirmed by laboratory studies [ 19 ]. The patient had a reduced morning and afternoon cortisol level on the day after admission of 3. A week after admission the patient had an increased cortisol level in an ACTH stimulation test.
By four weeks after admission the patient had normal morning cortisol levels and by six weeks after admission had resolution of clinical stigmata of her cushingoid syndrome. Midazolam, similar to other benzodiazepines, suppresses the HPA axis. The study demonstrated acute suppression of both plasma ACTH and cortisol after an mg dose of epidural triamcinolone: This study demonstrates that serologically detectable suppression of the HPA axis occurs within an hour after a single clinically used dose, is amplified by concomitant administration of midazolam, and would be expected to return to baseline after cessation of exogenous steroids.
In contrast with the effect on the HPA axis, epidural steroid injections have a clinically limited effect on blood glucose levels among patients with diabetes mellitus. One study found that blood glucose levels after an ESI rose from a baseline value of The average increase of There was no association between the degree of change in blood sugar level and the hemoglobin A1C level.
These findings suggest that epidural injection of standard doses of steroids does not adversely affect glycemic control in a clinically relevant manner, and any persistent elevation of blood glucose beyond baseline levels should prompt a search for an alternative etiology, for example infection.
Similar to the complications listed above, neurotoxicity and neurologic injury are rare and, given the lack of mandatory reporting, as already mentioned, data on the incidence and prevalence of long-term complications from ESI are lacking. Case reports have shown that when neurologic complications do occur they can have devastating effects that lead to long-term and even permanent neurologic deficits and pain.
The most common causes of neurologic injury seem to be direct needle trauma to the spinal cord or nerve roots, intra-vascular injection of steroid leading to infarction, and compression of the spinal cord and roots related to an epidural hematoma or abscess [ 25 , 29 ]. Less commonly, direct compression of the surrounding neurologic structures, for example the dorsal root ganglia, can occur [ 26 ]. These complications can often be avoided by appropriate patient selection and use of suitable techniques [ 26 ].
The possibility of long-term neurologic deficits should be considered for any patient with significant new neurologic deficits in the acute and subacute post-procedure period.
Acute examples include immediate hemiplegia, paraplegia, or quadriplegia after possible direct spinal cord needle trauma or intravascular steroid injection. Subacute examples include progressive weakness a few days to weeks post procedure related to an epidural abscess or hematoma causing spinal cord compromise. New or progressive neurologic complications several months or years after ESI seem to be exceedingly rare but have been documented in atypical cases of delayed occurrence of arachnoiditis [ 27 , 28 ].
The American Society of Anesthesiologists Closed Claims Study published in found and evaluated claims from 35 professional liability companies between and related to epidural injections with or without local anesthetic [ 2 ]. In , a follow-up study [ 29 ] by the Closed Claims Group specifically evaluating malpractice claims related to interventional pain treatment of the cervical spine between and the end of was published.
This study reported combined damaging outcome results of all cervical procedure cases and not just epidural injections. This included a total of 64 claims, most of which were procedural: Twenty percent of the claims were non-procedure-related, for example failure to diagnose, patient fall, wrong procedure, etc. A sub-analysis was performed of the 38 patients with spinal cord injury claims. Direct needle trauma was determined to be the most common cause of spinal cord injury SCI with 20 claims, of which six SCI claims were related to cord infarction from an intra-arterial injection and three SCI claims were related to cord compression from a hematoma.
Arachnoiditis, more severe chronic adhesive arachnoiditis, and aseptic meningitis are other feared serious complications that could potentially lead to significant long-term complications.
The incidence and prevalence of each after epidural steroid injections are unclear, but these also seem to be quite rare. Arachnoiditis, or inflammation of the meninges and subarachnoid space, can be caused by a multitude of other etiologies, including infection, previous surgery, dural tears, bleeding, myelograms, and intrathecal anesthesia [ 31 ].
If this inflammation persists, scarring, fibrosis, and adhesion can lead to chronic pain syndromes and neurologic deficits weakness, numbness, cauda equina syndrome some of which can be progressive.
Aseptic meningitis, which is caused by serous inflammation of the meninges, often presents with a fever, headache, and altered mental status. It is typically diagnosed after CSF examination revealing a lymphocytic pleocytosis, slightly elevated protein, and normal glucose.
The offending agent within steroid suspensions is unclear. Largely on the basis of bench-top and animal trials, poly ethylene glycol and benzyl alcohol have been most suspected of causing neurotoxic effects. Celestone, a betamethasone product in an aqueous vehicle without those agents, is believed to be possibly less neurotoxic and potentially less likely to lead to arachnoiditis.
Most SCI and nerve injuries seem to occur when a patient is over-sedated and fails to respond appropriately to direct needle compression or injection.
Infarctions and strokes tend to occur most frequently after cervical ESI with use of large particulate suspensions. Arachnoiditis and aseptic meningitis possibly related to a neurotoxic effect of the steroid suspension are, by far, most common with intrathecal injections and not epidural injections. Long-term complications from ESI are rare overall, but can be devastating, especially when involving a serious neurologic injury.
Most long-term complications arise from acute injuries that worsen over time rather than from long-term effects that occur directly from the steroid injection itself. Much research has been conducted to address the efficacy and safety of ESI, although little research has focused specifically on long-term complications.
This could be related to under-reporting, because there is currently no requirement in the US to report complications from ESI when they do occur. Nevertheless, the current literature shows that serious long-term complications from ESI are uncommon, but given the lack of literature specifically directed at potential long-term complications further investigation with prospective studies is warranted. Jung declares no conflicts of interest.
Ignatius declares no conflicts of interest. Davis declares no conflicts of interest. Jim declares no conflicts of interest. This article does not contain any studies with human or animal subjects performed by any of the authors.
Introduction Epidural steroid injections ESI are among the most commonly performed pain-relief procedures in modern medicine. Human and Animal Rights and Informed Consent This article does not contain any studies with human or animal subjects performed by any of the authors.