Intrathecal catheter tip inflammatory mass: a failure of clonidine to protect.

Regional Anesthesia for presumed recurrence of her meralgia pares- thetica. In contrast to the pain she reported with her previous episodes of meralgia paresthetica, this pain was bilateral and was located more anteriorly on the thighs. She also reported bilateral leg weakness and increased pain with hip ﬂexion. Physical examination at this time revealed no changes in her strength, sensation, or reﬂexes. However, given these new symptoms, lumbar and thoracic magnetic resonance imaging studies were completed. These magnetic resonance imaging studies revealed a contrast-en-hancing mass at the tip of the intrathecal catheter, consistent with intrathecal granuloma (ﬁgs. 1 and 2). The mass was located anterior to the spinal cord at the T11 level. It compressed the spinal cord and caused cord deformity. A neurosurgical evaluation was completed; given the absence of neurologic deﬁcit and the anterior location of the lesion in relation to the cord (which would have made surgical resection of the mass difﬁcult), conservative management was elected. During the course of 15 days, the intrathecal morphine–clonidine dose was progressively reduced, and then the morphine–clonidine solution in the pump was replaced with preservative-free normal saline. Concurrent with the reduction in intrathecal analgesics, oral analgesic medications were increased. The lumbar and thoracic magnetic resonance imaging studies were repeated approximately 4 weeks after initiation of intrathecal saline infusion and revealed near complete resolution of the mass with restoration of the spinal cord to normal dimensions (ﬁgs. 3 and 4). At this time, the patient reported complete resolution of her leg weakness and leg pain. Retrospectively, the patient reported a history of intermittent urinary urgency and incon- tinence in the 6 months before discovery of the intrathecal mass that resolved entirely. inspiration developed immediately, suggestive of diaphragmatic paralysis. Electromyography and nerve conduction studies excluded a sen- sorimotor polyneuropathy, neuromuscular junction dysfunction, and a spinal cord lesion. To conﬁrm our clinical diagnosis of diaphragmatic paralysis, we placed two balloon-tipped catheters (SmartCath ® Esophageal Catheter; VIASYS Healthcare, Palm Springs, CA) during local anesthesia from the nose into the esophagus and stomach to evaluate changes in intrathoracic and intraabdominal pressure during unsupported breathing. 5 A pneumotachometer (Novametrix Medical Systems, Wallingford, CT) was attached to the tracheostomy tube. Flow and pressures signals were recorded with a VenTrak Respiratory Mechanics Monitoring System (Novametrix Medical Systems) using waveform acquisition soft-ware (Analysis-Plus; Novametrix Medical Systems). As shown in ﬁgure 1, during unsupported breathing, both esophageal and gastric pressures had a negative deﬂection during inspiration, a ﬁnding suggestive of diaphragmatic paralysis. 6–8 of the patient’s wish to avoid prolonged respiratory and renal support, mechanical ventilation and hemodialysis were eventu-ally withdrawn, and she died on the 53rd postoperative day. A post- mortem examination was denied by the family.