Intrathecal Drug Delivery

There are many factors crucial to the success of Intrathecal drug delivery. One of the most important is careful patient selection.

Who Can Benefit?

Who Can Benefit from Intrathecal Drug Delivery for Chronic Pain?

Patients suffering from chronic pain such as failed low back surgery syndrome (FBSS), Complex Regional Pain Syndrome (CRPS), Peripheral Causalgia and pain due to cancer may be candidates for intrathecal drug delivery.

Goal for Patient Selection

The overall goal for patient selection is to choose those patients most likely to experience therapeutic success and who would not be at risk for complications and adverse events.

A careful assessment and discussion of the patient's expectations and goals will help identify appropriate candidates for the therapy.

Key Tasks of Patient Selection and Trials

  • Reviewing patient selection criteria
  • Qualifying the patient
  • Facilitating patient education
  • Conducting the trial

Patient Assessment

When assessing a patient with chronic pain for intrathecal drug delivery, there are 4 primary areas on which to focus:

  • Pain assessment
  • Functional assessment
  • Psychological assessment
  • Medical assessment

Refer to the table below for a checklist of tasks associated with assessment and patient selection.

 

Pain Assessment
  • Complete baseline pain assessment
    Assessment of pain is difficult to standardize. As the pain state changes, the patient's baseline usually changes as well.
  • Review patient's current situation
    For example, is the patient receiving oral, intravenenous, or intramuscular opioids without adequate pain relief at reasonable doses? Does the patient have pain relief but with side effects that limit the desired activity level?
  • Obtain supplemental opiate and non-opiate history
  • Assess signs and symptoms, Consider the intensity, distribution and impact of pain

Functional Assessment
  • Obtain patient functional history
    Consider using a questionnaire that inquires into personal care, sleeping, sex life, social life and mobility

Psychological Assessment
  • Complete psychological evaluation
  • Establish diagnosis

Medical Assessment
  • Evaluate for medical contraindications to surgery
  • Conduct physical examination
  • Evaluate radiographically for patient spinal canal, if indicated

Patient Selection Criteria

General Patient Selection Criteria

Managing a patient's pain requires a complete evaluation of the pain and the patient's medications.

Selection Criteria for Patients with Chronic Pain

  • Patient experiences inadequate pain relief and/or intolerable side effects from systemic opioid therapy
  • Patient has objective evidence of pathology
  • Patient obtains psychological clearance
  • Patient has no untreated substance abuse
  • Patient has sufficient body size to accept the bulk and weight of the pump.
  • Patient has no evidence of infection

A psychological evaluation is indicated to examine factors such as patient expectations, psychosomatic components of the pain, and secondary gain motivation. The value of a multidisciplinary approach to assess chronic pain cannot be overstated.

Selection Criteria for Patients with Chronic Pain due to Cancer

Patient selection for treatment of chronic pain due to cancer or its therapies is usually guided by the severity of the pain, the nature of the pain, life expectancy, and the location of the pain.

  • Patient experiences inadequate pain relief and/or intolerable side effects from systemic opioid therapy
  • Patient's life expectancy is greater than 3 months
  • Patient's body size is sufficient enough to accept the bulk and weight of the pump
  • Patient has no evidence of infection

Trialing

The objective of the trial is to determine the patient's response to the intervention.

A trial can be performed:1

  • Using epidural or intrathecal administration
  • With or without an intraspinal catheter
  • Single bolus injection, multiple bolus injections, or continuous infusion

Existing clinical research data do not clearly indicate that one protocol is associated with a better outcome than others. Therefore, the benefits and risks of each possible choice must be weighed.1

For more information regarding patient selection criteria and how to perform the trial, please see the Programmable Infusion System Clinical Reference Guide.

References

  1. Follett KA, Doleys DM. Minneapolis, MN; Selection of Candidates for Intrathecal Drug Administration to Treat Chronic Pain: Considerations in Pre-Implantation Trials. Medtronic, Inc: 2002.