Neurologic complications of lumbar epidural anesthesia and analgesia

Feasibility of continuous epidural analgesia in patients with failed back surgery syndrome and spinal stenosis

PURPOSE

The purpose of this study was to outline the feasibility of continuous epidural analgesia in the treatment of failed back surgery syndrome (FBSS) or spinal stenosis.

METHODS

We queried our prospective collected institutional database to include all consecutive patients, who underwent continuous epidural analgesia with accompanying intensive physiotherapeutic exercise within a timeframe of 4 years. Patients suffered from FBSS or spinal stenosis; protocolled continuous epidural analgesia was planned for 4 days within the framework of an inpatient multimodal pain therapy concept. The instillation technique of the epidural catheter, the capability to attend in accompanying physiotherapy, and the peri-interventional complications were evaluated.

RESULTS

153 patients with an average age of 57.4 years (± 11.9) were enrolled in this study. 105 patients suffered from FBSS and 48 patients had spinal stenosis. Overall, 148 patients (96.7%) reported the pain reduction and were able to perform daily intensified physiotherapeutic exercise. There were no serious adverse events, neither infection nor bleeding, no cardiopulmonary complication or permanent neurological deficits. The most common side effect was neurological impairment, such as numbness, dysesthesia, or weakness of the lower limbs with complete regression after flow rate adjustment. Patients with FBSS were more likely to develop dysesthesia (p = 0.007).

CONCLUSIONS

Continuous epidural analgesia is feasible in patients with FBSS or spinal stenosis. This treatment enables extensive physiotherapeutic treatment even in patients with severe pain conditions and can be considered as an alternative to epidural injections. An increased complication rate in comparison to short-term perioperative or perinatal application was not observed.

Regional Anesthesia for Lumbar Spine Surgery: Can It Be a Standard in the Future?

This paper is an overview of various features of regional anesthesia (RA) and aims to introduce spine surgeons unfamiliar with RA. RA is commonly used for procedures that involve the lower extremities, perineum, pelvic girdle, or lower abdomen. However, general anesthesia (GA) is preferred and most commonly used for lumbar spine surgery. Spinal anesthesia (SA) and epidural anesthesia (EA) are the most commonly used RA methods, and a combined method of SA and EA (CSE). Compared to GA, RA offers numerous benefits including reduced intraoperative blood loss, arterial and venous thrombosis, pulmonary embolism, perioperative cardiac ischemic incidents, renal failure, hypoxic episodes in the postanesthetic care unit, postoperative morbidity and mortality, and decreased incidence of cognitive dysfunction. In spine surgery, RA is associated with lower pain scores, postoperative nausea and vomiting, positioning injuries, shorter anesthesia time, and higher patient satisfaction. Currently, RA is mostly used in short lumbar spine surgeries. However, recent findings illustrate the possibility of applying RA in spinal tumors and spinal fusion. Various researches reveal that SA is an effective alternative to GA with lower minor complications incidence. Comprehensive insight on RA will promote spine surgery under RA, thereby broadening the horizon of spine surgery under RA.

Disorders of the Cauda Equina

PURPOSE OF REVIEW

Cauda equina dysfunction (often referred to as cauda equina syndrome) is caused by a diverse group of disorders that affect the lumbosacral nerve roots. It is important to recognize dysfunction of the cauda equina quickly to minimize diagnostic delay and lasting neurologic symptoms. This article describes cauda equina anatomy and the clinical features, differential diagnosis, and management of cauda equina disorders.

RECENT FINDINGS

The diagnosis of disorders of the cauda equina continues to be a challenge. If a compressive etiology is seen, urgent neurosurgical intervention is recommended. However, many people with clinical features of cauda equina dysfunction will have negative diagnostic studies. If the MRI is negative, it is important to understand the diagnostic evaluation and differential diagnosis so that less common etiologies are not missed.

SUMMARY

Cauda equina dysfunction most often occurs due to lumbosacral disk herniation. Nondiskogenic causes include vascular, infectious, inflammatory, traumatic, and neoplastic etiologies. Urgent evaluation and surgical intervention are recommended in most cases of compressive cauda equina syndrome. Other types of treatment may also be indicated depending on the etiology.

Incidence and pattern of epidural spread during lumbar facet joint injection: a prospective study

Background

In clinical practice, we have often observed contrast material spreading into the epidural space during lumbar facet joint injection. However, the exact incidence of epidural spread and contrast pattern have not been reported.

Purpose

To evaluate the incidence and pattern of epidural spread in lumbar facet joint injection.

Material and Methods

One hundred consecutive patients (38 men, 62 women; mean age 68 years; age range 20–88 years) who underwent lumbar facet joint injection at two sites between April 2014 and June 2014 were investigated in this prospective study. Initial oblique, final anteroposterior, and lateral fluoroscopic images were obtained and evaluated for the presence of epidural spread and its contrast pattern (based on direction and extent) with the consensus of three radiologists. The relationship between epidural spread and its potential predictors was analyzed using the chi-squared test, Fisher’s exact test, and the t-test.

Results

The incidence of epidural spread during lumbar facet joint injection was 64.6% (n=64) in 99 patients and 49.5% (n=95) in 192 procedures; ventral spread occurred in 29.2% and foraminal spread in 18.8%. When epidural spread occurred, the most commonly identified distributions were unilateral (73.7%), dorsal (92.6%), and cephalad (92.6%). Epidural spread increased significantly in the caudocephalic direction ( P < 0.0001), in men (relative risk [RR]=1.478), in the adjacency of posterior fusion level (RR=1.545), in patients with spondylolisthesis (RR=1.454), and when there was no other leakage (RR=0.334).

Conclusion

Epidural spread occurred at about half the number of lumbar facet joint injections and showed a contrast pattern similar to that seen with the interlaminar approach.

Transient Horner's syndrome following thoracic epidural anesthesia for mastectomy: a prospective observational study

PURPOSE

Transient Horner's syndrome is an uncommon complication of epidural anesthesia, though its exact incidence in thoracic epidural anesthesia is not clear. Therefore, this study prospectively evaluated the incidence of Horner's syndrome after thoracic epidural anesthesia for mastectomy.

METHODS

Patients scheduled for mastectomy, with or without breast reconstruction, were enrolled in this prospective observational study from September 2010 to December 2013. Intraoperative thoracic epidural anesthesia was established using 0.375% or 0.5% ropivacaine 15 mL with thoracic epidural analgesia continued postoperatively with a continuous infusion of 0.15% ropivacaine 2 mL·hr(-1) with fentanyl 8 μg·hr(-1). Signs of Horner's syndrome (miosis, ptosis, and hyperemia) were assessed at one and two hours as well as one, two, and three days postoperatively.

RESULTS

Thoracic epidural anesthesia was successful in 439 patients, with six (1.4%) of these patients acquiring Horner's syndrome. All signs of Horner's syndrome resolved gradually within 180 min of discontinuing the epidural infusion. In one patient with Horner's syndrome, a radiographic contrast injection confirmed that the drug had spread to the cervical epidural level.

CONCLUSION

The incidence of Horner's syndrome following thoracic epidural anesthesia and continuous thoracic epidural analgesia for mastectomy was 1.4%. The mechanism was consistent with cephalic spread of the epidural local anesthetic. This trial was registered at: Clinicaltrials.gov, number: NCT02130739.

Neuraxial techniques in patients with pre-existing back impairment or prior spine interventions: a topical review with special reference to obstetrics

Many anaesthetists consider neurological disorders of all kinds as a contraindication for regional anaesthesia particularly for neuraxial techniques. This hesitation is partly rooted in fears of medicolegal problems but also in the heterogeneous literature. Therefore, the present topical review is an attempt to describe the feasibility and the risks of neuraxial techniques in patients with spinal injury, anatomical compromise, chronic back pain or previous spinal interventions, ranging from 'minor' types like epidural blood patches to major surgery such as Harrington fusions. Most reviews and case reports were describing experiences in obstetrics as these patients are more likely to insist on neuraxial blocks. In the acute phase of new neurologic injury, general anaesthesia may be the technique of choice to prevent further haemodynamic and respiratory deterioration. After the acute phase, current evidence is mostly reassuring with respect to the risks of neuraxial blocks as they may even be recommendable in some conditions. Ultrasound technology may be of additional help to increase the success rate. A careful pre-operative examination remains mandatory, while patients should be sufficiently informed about technical aspects and possible relapses or progression of their disease. When necessary, patients should have additional technical and clinical examinations as close as possible to surgery to establish the actual pre-operative status. Most patients may benefit more from spinal techniques rather than from less reliable epidural ones. High concentrations and volumes of local anaesthetics should be avoided at all times, especially in patients with nerve compression, large disc herniation or spinal stenosis.

Acute epidural haematoma following epidural steroid injection in a patient with spinal stenosis

Extradural haematoma is a rare but known complication of neuraxial procedures. Although the literature quotes an incidence of 1:150,000 and 1:220,000 after epidural and spinal procedures, respectively, there is only a limited number of case reports described in pain practice. This case report describes an unusual occurrence of thoracic extradural haematoma following a lumbar epidural steroid injection. An entirely unique feature was its occurrence at a level distant to the site of injection, which has not been reported previously unless associated with catheterisation. We would like to highlight this report as it raises several pertinent and challenging questions; both for regional anaesthesia and pain practice.

Epidural cyst with cauda equina syndrome after epidural anesthesia

A 40-year-old woman without remarkable medical history received epidural anesthesia for uterine cervix conization. Six hours after the operation, cauda equina syndrome occurred. Magnetic resonance imaging of the spine revealed epidural fluid accumulation around L5, as well as L4/5 herniated intervertebral disc found incidentally. Surgical decompression was performed with H-reflex monitoring. Epidural injection could result in cystic accumulation complicated with cauda equina syndrome.

Peripheral neuropathy masquerading as an epidural complication

BACKGROUND

Epidural anaesthesia generally provides safe postoperative pain control, but does carry a small risk of nerve damage.

CASE DESCRIPTION

A 30-year-old woman with long standing rheumatoid arthritis underwent a primary total knee replacement under general anaesthetic. Postoperatively, a continuous epidural infusion was used for pain relief. On discontinuation of the epidural, she was confirmed to have a foot drop. Her subsequent investigation and management for neuropathic pain was coordinated by the acute pain service. Magnetic resonance imaging excluded a central lesion. Nerve conduction studies 6 weeks later confirmed peripheral nerve lesions. The patient's neurological deficit was not due to her epidural, but rather her intraoperative tourniquet.

DISCUSSION

The episode raises a number of discussion points for our pain service around the use of epidurals for knee replacement surgery, the management of nerve injury and the ease at which the epidural can be blamed for coincident injuries. International evidence would suggest that neurological complications following knee replacement are more likely to be related to surgery can epidural analgesia.

Anaesthetic considerations for patients with a pre-existing neurological deficit: are neuraxial techniques safe?

Pre-existing neurological and muscular disease may be a specific concern for anaesthetists as they need to consider the effect of anaesthesia upon the disease, vice versa, and the interaction of anaesthesia with the medication taken by the patient. Despite a lack of controlled studies, many anaesthetists, being afraid of a claim, will prefer general rather than regional anaesthesia in these patients. Nevertheless regional anaesthesia certainly merits its place because it offers undeniable advantages. A good pre-operative examination is very important while patients should also be informed about peri-operative implications of anaesthesia, surgery and stress. Paraesthesias, epinephrine and high concentrations of local anaesthetics should be avoided in the majority of the diseases. Some diseases may benefit from epidural anaesthesia while for others a spinal technique may be the technique of preference. Special attention should be paid to patients with spinal stenosis despite recent reassuring reports with respect to safety of regional anaesthetic techniques. Anaesthetists should not automatically take all responsibility in case of progressive or new deficit after the procedure.

Case report: Anesthetic management for sequential Cesarean delivery and laminectomy

PURPOSE

To describe the anesthetic considerations for a near-term parturient with progressive cauda equina syndrome who required Cesarean delivery followed immediately by decompression lumbar discectomy and laminectomy in the prone position.

CLINICAL FEATURES

A 33-yr-old woman presented at 35 weeks gestation with severe L5-S1 disc herniation causing motor and sensory neuronal dysfunction in the lower limbs accompanied by bowel and bladder dysfunction. After urgent multidisciplinary consultations, a decision was made to proceed with general anesthesia for Cesarean delivery in the supine position with left uterine displacement, followed immediately thereafter by L5-S1 discectomy and laminectomy in the prone position. Anesthesia concerns included the risks of hemorrhage from the combined surgeries and upper airway edema from the prone position, and the physiologic changes of pregnancy. The surgeries proceeded without complication, and both mother and baby recovered uneventfully.

CONCLUSION

With a multidisciplinary approach, two surgeries in two different positions with unique anesthetic considerations were performed safely under general anesthesia in advanced pregnancy in a parturient with cauda equina syndrome.

Spinal cord infarction and paraplegia after peripheral vascular surgery with spinal anesthesia

Paraplegia after peripheral vascular surgery under spinal anesthesia is rare and may be a result of multiple factors, including hematoma, trauma from the needle, toxic injection, and spinal cord infarction. We report a case of T(10) paraplegia after uncomplicated spinal anesthesia in a patient undergoing emergency thrombectomy and femoral-popliteal bypass.

Regional Anaesthesia in the Elderly

The number of elderly patients presenting for anaesthesia and surgery has increased exponentially in recent years. Regional anaesthesia is frequently used in elderly patients undergoing surgery. Although the type of anaesthesia (general versus regional anaesthesia) has no substantial effect on perioperative morbidity and mortality in any age group; it intuitively makes sense that elderly patients would benefit from regional anaesthesia because they remain minimally sedated throughout the procedures and awaken with excellent postoperative pain control. However, a multitude of factors influence the outcome, such as the type, duration and invasiveness of the operation, co-existing medical and mental status of the patient and the skill and expertise of the anaesthesiologist and surgeon. These factors make it difficult to decide if and when one technique is equivocally better than another. Thus, it is more important to optimise the overall management of the patient during the perioperative period and, in most cases, it is the quality of the anaesthetic administered rather than the type of anaesthetic which is most important. Sedatives used for regional anaesthesia in the elderly should be short acting, easy to administer, have a low adverse effect profile and high safety margin. Midazolam, lorazepam, ketamine, propofol and low-dose opioids have been successfully used for sedation in the elderly. Aging affects the pharmacokinetics and pharmacodynamics of local anaesthetics, composition and characteristics of tissues and organs within the body, and physiological functions of the body. Changes in the systematic absorption, distribution and clearance of local anaesthetics lead to an increased sensitivity, decreased dose requirement and a change in the onset and duration of action in the elderly. Decreases in neural population, neural conduction velocity and inter-Schwann cell distance can lead to an increased sensitivity to local anaesthetics in the elderly. The addition of an opioid and epinephrine (adrenaline) has been shown to be useful in central neuraxial blockade. Epinephrine also can prolong the duration of peripheral nerve blocks. However, caution must be exercised as epinephrine has the potential for causing ischaemic neurotoxicity in peripheral nerves. Regional anaesthesia appears to be safe and beneficial in elderly patients; however, every anaesthetic administered must be assessed on a case-by-case basis and particular consideration should be given to the health status of the patient, the operation being performed and the expertise of the anaesthesiologist.

Unexpected complication of attempted epidural anaesthesia: cauda equina syndrome

Cauda equina syndrome after regional anaesthesia is a serious and devastating complication. Its occurrence after epidural anaesthesia is rare. We report a 46-year-old male who received epidural anaesthesia for ureterorenoscopic lithotripsy and developed cauda equina syndrome postoperatively. Despite one failed attempt at entering the epidural space with an epidural needle resulting in dural puncture, an epidural catheter was inserted and 20 ml pH adjusted lignocaine 2% with 1:200,000 adrenaline injected via the catheter without untoward event. The possible causes of this complication are discussed. Fortunately, this patient recovered almost completely ten months later.

Neurologic deficits and arachnoiditis following neuroaxial anesthesia

Of late, regional anesthesia has enjoyed unprecedented popularity; this increase in cases has brought a higher frequency of instances of neurological deficit and arachnoiditis that may appear as transient nerve root irritation, cauda equina, and conus medullaris syndromes, and later as radiculitis, clumped nerve roots, fibrosis, scarring dural sac deformities, pachymeningitis, pseudomeningocele, and syringomyelia, etc., all associated with arachnoiditis. Arachnoiditis may be caused by infections, myelograms (mostly from oil-based dyes), blood in the intrathecal space, neuroirritant, neurotoxic and/or neurolytic substances, surgical interventions in the spine, intrathecal corticosteroids, and trauma. Regarding regional anesthesia in the neuroaxis, arachnoiditis has resulted from epidural abscesses, traumatic punctures (blood), local anesthetics, detergents, antiseptics or other substances unintentionally injected into the spinal canal. Direct trauma to nerve roots or the spinal cord may be manifested as paraesthesia that has not been considered an injurious event; however, it usually implies dural penetration, as there are no nerve roots in the epidural space posteriorly. Sudden severe headache while or shortly after an epidural block using the loss of resistance to air approach usually suggests pneumocephalus from an intradural injection of air. Burning severe pain in the lower back and lower extremities, dysesthesia and numbness not following the usual dermatome distribution, along with bladder, bowel and/or sexual dysfunction, are the most common symptoms of direct trauma to the spinal cord. Such patients should be subjected to a neurological examination followed by an MRI of the effected area. Further spinal procedures are best avoided and the prompt administration of IV corticosteroids and NSAIDs need to be considered in the hope of preventing the inflammatory response from evolving into the proliferative phase of arachnoiditis.

Horner's syndrome and trigeminal nerve palsy after lumbar epidural analgesia for labor and delivery

This report highlights transient Horner's syndrome and trigeminal nerve palsy following labor epidural analgesia. A 29-year-old primigravida had a lumbar epidural catheter placed for analgesia in labor. The analgesia was maintained by infusion of a dilute local anesthetic/opioid mixture and turned off after achieving complete cervical dilation. Approximately 1 hour after delivery she complained of heaviness in her left eyelid, and was noted to have left-sided ptosis and paresthesia within the distribution of the ophthalmic and maxillary divisions of the trigeminal nerve, which resolved over the next 2 hours. There were no other neurologic changes. Horner's syndrome and cranial nerve palsies can occur as a consequence of epidural analgesia for labor.

Neurological long-term sequelae after spinal anaesthesia in a tropical setting: a case control study

Spinal anaesthesia (SA) is an important form of anaesthesia in tropical countries. It is considered to have few long-term complications or sequelae, although this hypothesis has not been proven in a rural tropical setting. In a case control study we found SA to he a significant risk factor for lower back pain, reflex abnormalities and muscular atrophy and mild impairment of muscle power in patients examined between 3 months and 4 years after SA. These long-term sequelae need to be confirmed in a larger prospective study employing all possible neurophysiological and neuroimaging techniques.

Complications of Regional Anaesthesia

The complications of failure, neural injury and local anaesthetic toxicity are common to all regional anaesthesia techniques, and individual techniques are associated with specific complications. All potential candidates for regional anaesthesia should be thoroughly evaluated and informed of potential complications. If there is significant risk of injury, then these techniques should be avoided. Central neural blockade (CNB) still accounts for more than 70% of regional anaesthesia procedures. Permanent neurological injury is rare (0.02 to 0.07%); however, transient injuries do occur and are more common (0.01 to 0.8%). Pain on injection and paraesthesiae while performing regional anaesthesia are danger signals of potential injury and must not be ignored. The incidence of systemic toxicity to local anaesthetics has significantly reduced in the past 30 years, from 0.2 to 0.01%. Peripheral nerve blocks are associated with the highest incidence of systemic toxicity (7.5 per 10000) and the lowest incidence of serious neural injury (1.9 per 10000). Intravenous regional anaesthesia is one of the safest and most reliable forms of regional anaesthesia for short procedures on the upper extremity. Brachial plexus anaesthesia is one of the most challenging procedures. Axillary blocks are performed most frequently and are safer than supraclavicular approaches. Ophthalmic surgery is particularly suited to regional anaesthesia. Serious risks include retrobulbar haemorrhage, brain stem anaesthesia and globe perforation, but are uncommon with skilled practitioners. Postdural puncture headache remains a common complication of epidural and spinal anaesthesia; however, the incidence has decreased significantly in the past 2 to 3 decades from 37 to approximately 1%, largely because of advances in needle design. Backache is frequently linked with CNB; however, other causes should also be considered. Duration of surgery, irrespective of the anaesthetic technique, seems to be the most important factor. The syndrome of transient neurological symptoms is a form of backache that is associated with patient position and use of lidocaine (lignocaine). Disturbances of micturition are a common accompaniment of CNB, especially in elderly males. Hypotension is the most common cardiovascular disturbance associated with CNB. Severe bradycardia and even cardiac arrest have been reported in healthy patients following neuraxial anaesthesia, with a reported incidence of cardiac arrest of 6.4 per 10 000 associated with spinal anaesthesia. Prompt diagnosis, immediate cardiopulmonary resuscitation and aggressive vasopressor therapy with epinephrine (adrenaline) are required. New complications of regional anaesthesia emerge occasionally, e.g. cauda equina syndrome with chloroprocaine, microspinal catheters and 5% hyperbaric lidocaine, and epidural haematoma formation in association with low molecular weight heparin. Even so, after 100 years of experience, most discerning physicians appreciate the benefits of regional anaesthesia.

Potential neurotoxicity of spinal anesthesia with lidocaine

Spinal (intrathecal) anesthesia has evolved into a safe, widely accepted method of anesthesia with many advantages. However, the past decade has seen a large number of case reports and incidence studies that implicate the local anesthetic (LA) lidocaine as being more neurotoxic than other commonly used LAs such as bupivacaine and tetracaine, based on patterns of clinical use current at the time of those reports. Available studies suggest a risk of persistent lumbosacral neuropathy after spinal lidocaine by single injection in about 1 in 1300 procedures and a risk as high as about 1 in 200 after continuous spinal anesthesia with lidocaine. While uncommon, this risk is probably an order of magnitude higher than the risk reported for other commonly used LAs or for general anesthesia. Spinal lidocaine is also implicated in the syndrome of transient neurologic symptoms (previously referred to as transient radicular irritation), manifest by pain or dysesthesia in the buttocks or legs after recovery from anesthesia. Although the pain typically resolves within 1 week without lasting sequelae, it can be severe in up to one third of patients with the syndrome. In addition to clinical studies, both whole animal and in vitro studies have shown that lidocaine can be neurotoxic at clinically available concentrations and that lidocaine is more neurotoxic than equipotent concentrations of other commonly used LAs. The mechanism of this neurotoxicity may involve changes in cytoplasmic calcium homeostasis and mitochondrial membrane potential.

Major neurological sequelae of lumbar epidural anesthesia. Report of three cases

We here report the major permanent neurological complications that developed in three patients after epidural anesthesia. MR clearly showed that paraplegia, which arose one and nine days after anesthesia, was due to epi-subdural haematoma in the first case and epidural abscess in the second. The sudden left lower limb palsy in the third patient was caused by a paracentral ischemic lesion all along the conus-epiconus following a probable trauma of the cord during the insertion of the needle. Despite the fact that this was reported to have been performed at L1-L2, an erroneous introduction into the upper interspace must be postulated since the spinal cord of this patient terminated at mid-L1. Our report is useful insofar as it may remind anesthesiologists and neurologists to pay attention to the unusual complications of spinal anesthesia that may require urgent intervention.