Acute cauda equina syndrome after total knee arthroplasty as a result of epidural anesthesia and spinal stenosis

Subdural Spinal Haematoma after Epidural Anaesthesia in a Patient with Spinal Canal Stenosis

A 60-year-old male with a past history of T12 fracture had epidural analgesia for a radical prostatectomy. It was unknown prior to epidural insertion that the patient had a canal stenosis at T12 from the previous injury. The patient developed severe bilateral buttock pain after epidural catheter removal. Magnetic resonance imaging demonstrated a spinal subdural haematoma from T10 to L2 with mild cord compression. The patient made a successful recovery with conservative management. Neuraxial blockade should be approached with caution in patients with previous back injury, and only after a thorough assessment has been obtained to exclude spinal canal stenosis.

Acute cauda equina syndrome following orthopedic procedures as a result of epidural anesthesia

Background:

Cauda equina syndrome (CES) is a rare complication of spinal or epidural anesthesia. It is attributed to direct mechanical injury to the spinal roots of the cauda equina that may result in saddle anesthesia and paraplegia with bowel and bladder dysfunction.

Case Description:

The first patient underwent a hip replacement and received 5 mL of 1% lidocaine epidural anesthesia. Postoperatively, when the patient developed an acute CES, the lumbar magnetic resonance imaging (MRI) scan demonstrated clumping/posterior displacement of nerve roots of the cauda equina consistent with adhesive arachnoiditis attributed to the patient's previous L4-L5 lumbar decompression/fusion. The second patient underwent spinal anesthesia (injection of 10 mg of isobaric bupivacaine for an epidural block) for a total knee replacement. When the patient developed an acute CES following surgery, the lumbar MRI scan showed an abnormal T2 signal in the conus and lower thoracic spinal cord over 4.3 cm.

Conclusions:

Acute CES should be considered in patients undergoing spinal or epidural anesthesia for joint replacement surgery. Prompt evaluation with MRI studies may lead to appropriate medical/surgical measures to reverse the deficit.

Meralgia paresthetica-like symptoms following epidural analgesia after total knee arthroplasty

Meralgia paresthetica (MP) is generally caused by entrapment of the lateral femoral cutaneous nerve (LFCN), and presents with pain and paresthesia in the anterolateral thigh. This paper describes a patient who had MP-like symptoms as a result of continuous epidural analgesia after total knee arthroplasty. The patient with pre-existing left foraminal stenosis at L3-L4 and disc herniations at L4-5 did not complain of paresthesia or pain during the combined spinal-epidural anesthetic procedure. However, during epidural analgesia on the second post-operative day, he complained of paresthesia and pain in the anterolateral thigh of the contralateral leg. Electromyography showed a neurogenic lesion at the level of L3. Although an ultrasound-guided diagnostic block of the LFCN was performed twice post-operatively, the patient's symptoms persisted. The symptoms gradually resolved 12 months after the surgery. In our case, we suggest that the continuous epidural infusate caused neural ischemia of the L3 nerve root by a compressive effect.

Cauda equina syndrome after spinal anaesthesia in a patient with asymptomatic tubercular arachnoiditis

A 14-year-old boy underwent emergency debridement surgery of right foot under spinal anaesthesia. Four hours after the surgery, the patient developed symptoms of cauda equina syndrome (CES). Postoperative magnetic resonance imaging of the patient's spine suggested underlying tubercular arachnoiditis. The boy was started on intravenous methylprednisolone and antitubercular therapy. He responded to the therapy and recovered completely in 2 weeks without any residual neurological deficits. We suggest that underlying pathological changes in the subarachnoid space due to tubercular arachnoiditis contributed to maldistribution of the local anaesthetic drug leading to CES.

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.

[Regional anesthesia and neurological diseases]

Modern anesthesia is handling an increasing number of patients with neurological diseases who require narcosis. Regional anesthesia techniques offer qualities which might be advantageous for this group particularly for childbirth. The number of pregnant women with neurological diseases has increased significantly in the recent years due to improved diagnostics and therapy. A more careful approach to regional anesthesia in patients with neurological diseases is necessary as the drugs themselves possess neurotoxic effects and the procedure might worsen the underlying neurological diseases. Additionally, performing regional anesthesia might be more complicated and the resulting blockade might be different from the expected neuronal block. Published data concerning regional anesthesia in this patient group are limited and mainly restricted to case reports. In this review general considerations regarding regional anesthesia, techniques, drugs and methods in these patient groups will be discussed. In the second part the practical approach to regional anesthesia for some of the most important neurological diseases is highlighted.

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.