 |
| | Patient selection
| Many patients with chronic pain will respond
to a combination of physiotherapy, oral medication and other conservative
therapies. However, when non-interventional therapies lack effectiveness,
oral analgesics cause intolerable side effects and further corrective surgeries
fail to give adequate pain relief, intrathecal drug delivery (IDD) is an
effective alternative. |
|
General selection criteria
for intrathecal drug delivery
As with neurostimulation, for IDD to be considered as a treatment option,
patients should meet
the following general selection criteria:
- There is an objective basis for the patient's
pain complaint
- The patient is psychologically competent and
has no psychological contraindications
- Further corrective surgeries are likely to produce
complications or poor outcomes
- More conservative therapies have failed to relieve
pain or have caused intolerable
adverse events
- No contraindications to surgery exist (e.g.
sepsis, coagulopathy)
- No untreated chemical dependency exists
- Neurostimulation and IDD are not contraindicated
IDD has proven efficacy in patients with intractable
nociceptive pain where other therapies have failed, for example, when
oral analgesics have not been effective or cause intolerable side-effects.
IDD has been used to successfully treat FBS patients where pain is predominantly
in the lower back, in multiple sites, or of a dominant nociceptive nature.
IDD has also been used in cases where neurostimulation or a neurostimulation
trial was unsuccessful and in difficult cancer pain and visceral pain
cases.
|
Patient
selection for intrathecal drug delivery
As with neurostimulation, before a patient becomes a candidate for IDD,
the patient should undergo a thorough evaluation, which should include both
physical and psychological elements.
In addition, all patients should undergo a trial procedure. |
|
Physical evaluation
A comprehensive history and physical examination of the patient should
be completed to ensure that there is an objective basis for the pain.
A complete pain history includes a general medical history with emphasis
on the chronology and symptomatology of the pain. These data should include
information about the onset, quality, intensity, distribution, duration,
course and affective components of the pain, and details about exacerbating
and relieving factors.
The physical examination should also include an
appropriate neurological and musculoskeletal evaluation. The effects of
pain, as well as the causes of pain, should be evaluated and recorded.
In addition, the physician should determine the pain type, pain pattern,
and sources of pain. Determination of such pain characteristics allows
the physician to select the appropriate therapy.
|
|
Psychological evaluation
Most physicians agree that before considering a neuromodulation procedure,
the patient should be assessed by a psychiatrist or a psychologist to
rule out any psychological issues that may effect the therapeutic outcome.
This psychological evaluation should take place
in the early phase of the patient selection procedure. A carefully performed
psychological evaluation will have several benefits including, identifying
those patients most likely to benefit from neuromodulation and better
preparing
the patient for the procedure. It can also aid in preventing unsuitable
candidates from undergoing an invasive and costly procedure and in redirecting
rejected candidates to more appropriate treatment programs.
|
Intrathecal drug delivery
trial procedure
The IDD trial period consists of an initial titration period, followed by
an evaluation period in the patient's home environment. Dose titration must
be carried out in hospital. For this, small intrathecal doses of medication
are administered in a patient-controlled manner by the use of
a patient-controlled analgesia pump. The patient can increase the dose until
an acceptable level
of pain relief is achieved. The aim of the titration period is to find an
optimal balance between pain relief and prevention of the occurrence of
side effects. Once an optimal dose is established, the patient is further
tested on an outpatient basis. This permits the assessment of the efficacy
of IDD in the patient's home, and provides important information on improvements
in quality of life and daily functioning. Ideally, the trial period should
last between 3 to 4 weeks. |
|
|
|
