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Chronic pain is a complex condition characterized by changes in the nervous system. Implantable intrathecal drug delivery systems are typically employed in patients with chronic noncancer pain, cancer-related pain, or spasticity who do not achieve therapeutic goals with conservative management. Intrathecal drug delivery can achieve effective analgesia and spasticity reduction with significantly lower medication dosages than traditional oral or parenteral administrative routes. Although implanting an intrathecal drug delivery system is an invasive procedure, complication rates are low. The safety and efficacy of intrathecal drug delivery for controlling spasticity and cancer-related and noncancer pain have been widely demonstrated. This activity for healthcare professionals reviews the indications, contraindications, necessary equipment, procedural techniques, pharmacological therapies, and common complications of implanting an intrathecal drug delivery system. The activity also highlights the critical role of the interprofessional team in improving analgesic and procedural outcomes for patients undergoing this procedure to treat their pain or spasticity. Objectives: Identify patients who may benefit from the implantation of an intrathecal drug delivery system based on their clinical history. Apply best practices when implanting an intrathecal drug delivery system. Identify and manage the common complications of intrathecal drug delivery system implantation. Develop and implement effective interprofessional team strategies to improve outcomes for patients with chronic pain or spasticity who undergo implantation of an intrathecal drug delivery system. Access free multiple choice questions on this topic.

Chronic pain is a complex condition characterized by changes in the nervous system and clinical manifestations influenced by psychosocial and potentially iatrogenic factors.[1] Repeated activation of the nociceptive system abnormally sensitizes the peripheral and central neural pathways that typically convert noxious environmental stimuli into perceived pain in the brain.[2] These abnormal pathways can present clinically as severe, persistent, and functionally disabling pain, which is often challenging to manage despite individualized care with oral medications and psychosocial treatments. Attaining good outcomes for patients with severe chronic pain has recently become even more difficult because of the critical safety concerns and public health issues associated with prescription opioids.[3] Advanced pain management options should be considered when patients cannot reach their analgesic and functional goals with more conventional therapies. One advanced interventional modality involves delivering analgesics directly into the cerebrospinal fluid (CSF) via pump and catheter. The first pump providing low-dose morphine in a patient with cancer-related pain was implanted in 1981. Since then, several systematic reviews have demonstrated intrathecal drug delivery systems to be effective and safe for cancer-related and chronic noncancer pain.[4]

Procedure-Related Complications Bleeding Abdominal incision: Careful attention to intraoperative hemostasis can avoid the formation of a hematoma within the abdominal pocket. Using an abdominal binder in the early postoperative period may also reduce the formation of hematoma or seroma in the abdominal wound. Epidural or intrathecal bleed: Preoperative anticoagulation reversal and cessation of corticosteroid or anti-inflammatory medications will reduce the risk of this complication. Signs of a developing epidural or intrathecal hematoma include an abrupt increase in back pain, progressive numbness, weakness in the lower extremities, and loss of bowel and bladder control. This clinical presentation justifies immediate myelography with MRI or computed tomography (CT); neurologic deterioration warrants emergent surgical decompression. Infection Wound infection: Prophylactic antibiotics and intraoperative antibiotic wound irrigation are usually sufficient to prevent wound infection when combined with appropriate adherence to sterile technique. Superficial wound infection may be managed conservatively. Deeper wound infections require device explantation; infection can track along the intrathecal catheter and can cause either meningitis or an epidural abscess.[28] Injury to surrounding tissue Nerve root injury: Needle placement, even when performed with fluoroscopic guidance, may injure the nerve roots. However, placing the catheter under conscious sedation can decrease this risk. Patients under conscious sedation can report a shock-like or burning sensation in the distribution of the involved nerve root; if this occurs, the needle should be promptly withdrawn and placed at a different level. Spinal cord injury: Catheters are designed with some stiffness to facilitate steering through the intrathecal space. The catheter must not be forced through the spinal canal because the tip may end up in an intramedullary position. Penetration of the spinal cord often results in dysesthesias or burning, stinging pain below the lesion, and neurological signs are usually observable immediately. Intramedullary infusion of the drug may result in developing signs of a spinal cord lesion and should be immediately evaluated with MRI or CT myelography and followed by a neurosurgical consultation. Cerebral Spinal Fluid Leak

Spinal cord injury: Catheters are designed with some stiffness to facilitate steering through the intrathecal space. The catheter must not be forced through the spinal canal because the tip may end up in an intramedullary position. Penetration of the spinal cord often results in dysesthesias or burning, stinging pain below the lesion, and neurological signs are usually observable immediately. Intramedullary infusion of the drug may result in developing signs of a spinal cord lesion and should be immediately evaluated with MRI or CT myelography and followed by a neurosurgical consultation. Cerebral Spinal Fluid Leak CSF leaks can occur either due to failure of the dura to close over time after insertion of the catheter or several causes of catheter injury. CSF leakage can evolve into a postdural puncture headache. The initial management of a postdural puncture headache is conservative, comprising intravenous fluid administration, supine positioning, increased caffeine intake, and utilization of nonopioid analgesics such as acetaminophen. If the headache is refractory to conservative management, a blood patch of 10 to 20 mL of autologous venous blood injected one level above the catheter entry point under fluoroscopic guidance should treat the headache effectively.[29] Sometimes, the CSF may leak into the pump pocket, creating a noticeable swelling in the abdomen. To confirm the origin of the fluid, it should be aspirated and sent for detection of beta-2-transferrin. A serious sequela of CSF leak is intracranial hypovolemia; this should be considered a medical emergency, as it can result in subdural hematoma. The treatment of CSF leaks necessitates the identification of the underlying cause. As described above, blood patches can be performed if the culprit is an opening in the dura. In cases of device-related issues, surgical intervention may be required. Device-Related Complications Device-related complications typically involve either the catheter system or the pump. Catheter-related complications are more frequent than pump complications.[30] Catheter malfunction

Sometimes, the CSF may leak into the pump pocket, creating a noticeable swelling in the abdomen. To confirm the origin of the fluid, it should be aspirated and sent for detection of beta-2-transferrin. A serious sequela of CSF leak is intracranial hypovolemia; this should be considered a medical emergency, as it can result in subdural hematoma. The treatment of CSF leaks necessitates the identification of the underlying cause. As described above, blood patches can be performed if the culprit is an opening in the dura. In cases of device-related issues, surgical intervention may be required. Device-Related Complications Device-related complications typically involve either the catheter system or the pump. Catheter-related complications are more frequent than pump complications.[30] Catheter malfunction Catheter malfunction is frequently suspected when the expected and measured residual infusion volumes differ by more than 20%, or the patient reports a fluctuation in analgesic effectiveness. A comprehensive evaluation of the catheter is necessary if kinking, obstruction, or separation is suspected. This evaluation is performed with basic imaging or a catheter study; catheter studies require injecting contrast dye via the pump side port. Injecting contrast can display the point of kinking, obstruction, or leakage. The catheter should be aspirated before injecting contrast dye to avoid delivering a large dose of medication into the intrathecal space, which can lead to overdosage. Intrathecal granuloma formation In addition to catheter tip obstruction, intrathecal granulomas may increase pain and neurologic deficits. The risk of granuloma progression seems to correlate directly with the daily opioid dose, the rate of drug titration, and the duration of intrathecal therapy. This is most commonly seen when using morphine, which is postulated to induce a cascade reaction involving mast cells that leads to increased cytokine formation and inflammatory response. If a granuloma is suspected, the diagnosis should be confirmed with an MRI, preferably with contrast.[31] Reducing the medication dose, switching to another medication, or relocating the catheter will typically lead to the resolution of the granuloma. In patients with progressive neurologic deficits, however, surgical intervention should be considered.

Recognizing that an integrated healthcare team approach should be utilized to manage chronic pain in which intrathecal drug delivery is indicated is vital. Intrathecal therapy and management can substantially lower healthcare costs compared with conventional pain management, especially when systemic opioids are discontinued.[33] To attain beneficial patient-centric care, the supervising clinician should oversee pump refills and medication adjustments after patient evaluation. The PACC guidelines contain algorithms intended to guide intrathecal medication choices for localized or diffuse nociceptive or neuropathic pain for patients with cancer, terminal illness, and noncancer pain. These guidelines emphasize the necessity for clinical education across healthcare settings and specialties to address the expanding evidence related to intrathecal drug delivery for chronic pain. Protocols for patients with an implantable intrathecal drug delivery system should be assembled around a collaborative team-based care model that provides ongoing education for patients and caregivers and properly uses psychosocial support services. A patient-centered approach can lend to encouraging outcomes among patients with refractory chronic pain.[34] All nurses caring for patients with an intrathecal pump should have an orientation and a seminar to ensure they are fully aware of the potential therapeutic complications.