Paraplegia after accidental continuous subdural analgesia.

Almost all reported cases of unintentional subdural block have described a reversible disorder. We report a patient who developed an incomplete mixed sensory and motor neurological deficit after accidental continuous subdural infusion of 0.1% levobupivacaine given to provide postoperative analgesia after cesarean section. Our report shows that accidental continuous subdural injection can cause permanent neurological sequelae. In the event of suspected compressive neural damage, subdural fluid accumulation, although very rare, should be considered.

Inyección subdural: informe de dos casos / Subdural injection: report of two cases / Injeção subdural: reporte de dois casos

Se presentan dos casos de inyección subdural accidental durante procedimientos epidurales para control del dolor. El primero fue un hombre con dolor lumbar crónico quien sufrió dicha complicación durante la inyección epidural de esteroides por vía interlaminar; el segundo, una mujer con síndrome de hipotensión endocraneana que requirió la aplicación de un parche hemático epidural para controlar múltiples fístulas de LCR, que debió ser abortada en dos ocasiones debido al patrón subdural que se evidenció luego de la administración del medio de contraste. El bloqueo subdural accidental es una complicación rara de la inyección epidural con fines analgésicos o anestésicos. Es de suma importancia la identificación temprana del patrón de distribución subdural y epidural del medio de contraste con el fin de disminuir el riesgo y aumentar la seguridad de los procedimientos en el espacio epidural.

Two cases are reported of accidental subdural injection during epidural procedures for pain control. The first one was a man with chronic lumbar pain who suffered such complication during an epidural injection of steroids using the interlaminar approach. The second one was a woman with intracranial hypotension syndrome who required the application of an epidural blood patch in order to control multiple CSF fistulae. The procedure had to be aborted twice due to the subdural pattern observed after injection of the contrast medium. Accidental subdural block is a rare complication of epidural injection for analgesic or anesthetic procedures.

Se apresentam dois casos ocorridos durante a execução de procedimentos da prática diária do especialista de dor. O primeiro, um doente com diagnóstico de dor lombar crónico quem apresenta uma injeção subdural acidental durante uma injeção epidural de esteroides por via interlaminar; o segundo uma doentecom síndrome de hipotensão endocraniana quem precisou da colocação de um curativo hemático epidural o qual teve que ser abortado em 2 ocasiões devido ao padrão subdural que se evidenciou logo da administração de meio de contraste. O bloqueio subdural acidental é uma rara complicação da injeção epidural com fins analgésicos ou anestésicos. Por tanto, resulta de suma importância a precoce identificação do padrão de distribuição do meio de contraste subdural e epidural com o fim de diminuir o risco e aumentar a segurança dos procedimentos no espaço epidural.

Subdural block and the anaesthetist.

There are a number of case reports describing accidental subdural block during the performance of subarachnoid or epidural anaesthesia. However it appears that subdural drug deposition remains a poorly understood complication of neuraxial anaesthesia. The clinical presentation may often be attributed to other causes. Subdural injection of local anaesthetic can present as high sensory block, sometimes even involving the cranial nerves due to extension of the subdural space into the cranium. The block is disproportionate to the amount of drug injected, often with sparing of sympathetic and motor fibres. On the other hand, the subdural deposition can also lead to failure of the intended block. The variable presentation can be explained by the anatomy of this space. High suspicion in the presence of predisposing factors and early detection could prevent further complications. This review aims at increasing awareness amongst anaesthetists about inadvertent subdural block. It reviews the relevant anatomy, incidence, predisposing factors, presentation, diagnosis and management of unintentional subdural block during the performance of neuraxial anaesthesia.

Unintentional subdural catheter placement during labor analgesia shows typical radiological pattern but atypical response to the Tsui test.

Subdural injection may be associated with abnormally extensive or limited spread of local anesthetics during neuraxial anesthesia. This complication is difficult to diagnose clinically. Radiological imaging is the gold standard for confirming the location of subdural catheter, but electrical stimulation of the catheter has also been described as a useful diagnostic tool. We present the case of an obstetric patient with unintentional subdural catheter placement that presented as a failed epidural block associated with severe upper back and scapular pain on catheter injection. Electrical stimulation of the catheter did not elicit muscle contractions until a current of 4 mAmp was attained, which is the response pattern of epidural placement. Subdural location of the catheter was subsequently confirmed by contrast radiography. This case adds to the evidence that subdural catheters are difficult to identify clinically, and that electrical stimulation may not differentiate them from epidural catheters.

Peridural scar and its relation to clinical outcome: a randomised study on surgically treated lumbar disc herniation patients.

A prospective randomised 2-year follow-up study on patients undergoing lumbar disc herniation surgery. The objective was to investigate the relationship between peridural scarring and clinical outcome, the scar development 6 and 24 months postoperatively by using MRI, and if ADCON-L (a bioresorbable carbohydrate polymer gel) has an effect on scar size and/or improve patients' outcome after lumbar disc herniation surgery. The association between peridural scarring and recurrent pain after lumbar disc herniation surgery is debated. Numerous materials have been used in attempts to prevent or reduce postoperative peridural scarring; however, there are conflicting data regarding the clinical effects. The study included 119 patients whose mean age was 39 years (18-66); 51 (47%) were women. Sixty patients (56%) were perioperatively randomised to receive ADCON-L, and 48 (44%) served as controls. All patients underwent MRI at 6 and 24 months postoperatively, and an independent radiologist graded the size, location and development of the scar, by using a previously described scoring system. Pre- and 2-year postoperatively patients graded their leg pain on a visual analogue scale (VAS). At the 2-year follow-up patients rated their satisfaction with treatment (subjective outcome) and were evaluated by an independent neurologist (objective outcome), using MacNab score. There was no relationship between size or localisation of the scar and any of the clinical outcomes (VAS, subjective and objective outcome). The scar size decreased between 6 and 24 months in 49%, was unchanged in 42% and increased in 9% of the patients. Patients treated with ADCON-L did not demonstrate any adverse effects, nor did they demonstrate less scarring or better clinical outcome than control patients. No significant association between the presence of extensive peridural scar or localisation of scar formation and clinical outcome could be detected in the present study. Further, no positive or negative effects of ADCON-L used in disc herniation surgery could be seen.

Intradural migration of broken IDET catheter causing a radiculopathy.

This case report describes the migration of a broken intradiscal electrothermal therapy catheter tip from the disc space into the thecal sac, leading to a radiculopathy that improved after removing the catheter.

Subdural and intraventricular traumatic tension pneumocephalus: case report.

Simple pneumocephalus most frequently arises as a complication of a head injury in which a compound basal skull fracture with tearing of the meninges allows entry of air into the cranial cavity. It can also follow a neurosurgical operation. Tension traumatic pneumocephalus with intraventricular extension is an extremely rare, potentially lethal condition that requires prompt diagnosis and treatment. We report the case of subdural and intraventricular accidental tension pneumocephalus occurring in a 26-year-old man as a result of skull fracture. This case is combined with rhinorrhea and meningitis that suggest some difficulties to treat. The operative procedure associated with medical treatment was performed and a good result was obtained.

Origin of chronic subdural haematoma and relation to traumatic subdural lesions.

The origin of chronic subdural haematoma (CSDH) and the pathogenesis of subdural hygroma (SDG) are still controversial issues. These issues and relationships between these traumatic subdural lesions are discussed. The origin of CSDH is usually a SDG, although a few cases are caused by acute subdural haematomas (ASDH). Subdural hygroma is produced by separation of the dura-arachnoid interface, when there is sufficient subdural space. When the brain remains shrunken, the SDG remains unresolved. Any pathologic condition inducing cleavage of tissue within the dural border layer at the dura-arachnoid interface can induce proliferation of dural border cells with production of neomembrane. In-growth of new vessels will follow, especially along the outer membrane, then bleeding from these vessels occurs. These unresolved SDGs become CSDHs by repeated microhaemorrhage from the neomembrane. Although most victims with ASDH underwent surgery or died, some patients could be managed conservatively. Since the ASDH is usually absorbed within a few weeks, only a very few ASDHs become CSDHs, when there is a sufficient potential subdural space. Chronic subdural haematoma can arise from ASDH, but more commonly from SDG. Such transformation, or development of a new subdural lesion, is a function of the premorbid status and the dynamics of absorption and expansion.

[Subdural catheterization uncovered by severe hypotension during epidural plus general anesthesia].

We experienced three cases of accidental subdural catheterization during epidural combined with general anesthesia. In each case, epidural catheterization was performed before induction of general anesthesia. Aspiration through the catheter and a response to a test dose were negative. Then anesthesia was induced with thiamylal IV and the trachea was intubated with vecuronium IV. Hypotension, which was not easily treated by vasopressors and volume load, occurred after administration of 3 to 8 ml mepivacaine with 1: 200,000 epinephrine through the catheter. We examined position of the catheter by injecting iohexol 240 and confirmed subdural catheterization after surgery. It is often difficult to identify subdural placement of an epidural catheter under general anesthesia since signs of massive sensory blockade are masked by general anesthesia. In each case, we suspected malpositioning of the catheter by severe hypotension due to sympatholysis which was difficult to treat. Subdural catheterization is a complication of epidural anesthesia that probably occurs more frequently than previously recognized and is usually unpredictable during general anesthesia.

[Accidental subdural extra-arachnoid catheterization during epidural analgesia in obstetrics]. / Cathétérisation accidentelle de l'espace sous-dural extra-arachnoïdien lors d'une analgésie péridurale en obstétrique.

The authors describe a case of accidental catheterization of the subdural extra-arachnoid space during epidural analgesia for labour. The epidural catheter had been inserted at the L3-L4 interspace without any problem. A severe hypotension occurred 90 min after the onset of analgesia. A T4 upper sensory level was associated with a complete motor blockade. Total spinal anaesthesia was suspected but ruled out because of delayed onset of analgesia. Extensive epidural anaesthesia was also eliminated as the local anaesthetic dose (15 mL of bupivacaine 0.125%) was not excessive for this patient. After delivery, a water-soluble contrast medium (10 mL of Omnipaque 180) was injected through the catheter and subsequent radiograph of spine showed subdural spread of the contrast medium. This complication might occur more frequently than usually thought and may be life-threatening. Anaesthetic management is discussed in the case of Caesarean section during labour.

Accidental subdural catheterization: radiological evidence of a possible mechanism for spinal cord damage.

We describe the inadvertent subdural insertion of a lumbar extradural catheter in a primiparous woman in labour. A small quantity of local anaesthetic resulted in extensive motor and sensory block. Computed tomography performed after contrast injection demonstrated unequivocally that the catheter was in the subdural space. The catheter and injected fluid produced considerable displacement of the arachnoid within the thecal sac. We postulate that this could result in arterial compression or direct damage to the spinal nerve roots. Such a mechanism might explain some of the cases of permanent neurological damage associated with extradural analgesia.

[Accidental catheterization of the subdural space. Description of 2 cases]. / Cateterizzazione accidentale dello spazio subdurale. Descrizione di due casi.

Two cases of accidental subdural catheterisation, occurred in cancer patients during pain treatment, are presented and radiographically confirmed. The possible mechanisms that can cause such malposition, the X-ray picture and the effect of subdurally injected morphine are discussed.