Topics:

A 15-Year-Old Boy With Primitive Neurectodermal Tumor

A 15-Year-Old Boy With Primitive Neurectodermal Tumor

ABSTRACT: Case Presentation Dr. Peter Staats presented the case of a 15-year-old, 40-kg boy with a primitive neurectodermal tumor located in his right hemipelvis, invading the lumbar plexus. No invasion in the spinal cord was noted. The boy’s pain score was 8 out of 10 on the visual-analog scale (VAS). He had a history of anxiety and fear of procedures, and he was sedated on a regimen of Neurontin (gabapentin), nortriptyline, and oxycodone at relatively low doses (5 mg q4h). He had previously received maximal radiation therapy and high doses of systemic steroids. The patient’s pain was out of control, and sedation was a major problem. Several therapeutic options included (1) working with medications, eg, decreasing nortriptyline, switching or rotating opioids, adding psychostimulants, and adding anxiolytic agents; (2) placing an epidural catheter for infusions of a local anesthetic; (3) performing a cordotomy; and (4) considering further chemotherapy and palliative therapy. Dr. Staats and his pain management team sought to gain control as quickly as possible because of their knowledge that over time this patient’s tumor would be very difficult to manage. An intrathecal catheter was placed under general anesthesia. The patient received a 1-mg bolus followed by a 1-mg infusion of morphine. Complete relief of pain was achieved and persisted the next day. A pediatric pump was implanted, and the catheter was placed at T10 where the substantia gelatinosa was processing much of his pain. All systemic opioids and anticonvulsants were stopped; tricyclic antidepressants were continued to help the boy sleep. The patient’s course after starting on oral opioids is depicted in Figure 1. Intrathecal opioids initially relieved the patient’s pain. The boy chose not to increase his intrathecal opioids until his pain reached about 3 on the VAS scale. At that point, his dose of intrathecal morphine was doubled to 2 mg/d, and his pain decreased. A burning pain in the patient’s right leg and hip developed at which time intrathecal morphine was increased to 3 mg/d and bupivacaine at 2.5 mg/d was added; his pain decreased. The boy’s pain again intensified and morphine was increased to 3 mg/d and bupivacaine to 3.5 mg/d. The patient was pain-free for approximately 1 month before he developed facial V3 pain, for which the dose of intrathecal morphine was increased to 4 mg/d and bupivacaine was increased to 5 mg/d. The oncology team started the patient on intravenous Dilaudid (hydromorphone), but he became extremely nauseated. Intrathecal morphine and bupivacaine doses were increased, and the patient’s pain decreased. He was pain-free at death 9 months later.

Discussion


Peter S. Staats, MD:
This was a case where we had poor control
to begin with and many options. The pain management team elected to
implant an intrathecal pump in this child for several reasons,
including the patient’s lumbar plexus problem. We believed he
would develop significant problems and that we ought to implant the
pump early. I felt that we could better manage this patient long term
with bupivacaine and morphine delivered by this neuraxial route.

Russell K. Portenoy, MD: How was the boy doing
psychologically, and what were some of the issues concerning his parents?

Dr. Staats: The boy’s parents were very supportive of
him. The child wanted nothing more than to go back to school. He did
have a lot pain, and he was anxious about procedures and needles. I
had seen the boy previously because his pain was out of control, and
when I explained his options, he said he really didn’t hurt that
bad. The patient waited 1 to 2 months before returning to see us, at
which time we discussed his concerns about the implanted devices.

Dr. Portenoy: What was the patient’s level of function
when systemic opioid therapy with oxycodone was failing because of somnolence?

Dr. Staats: His function was very poor at the time because of
sedation, which was really his problem. Once we placed an
externalized intrathecal catheter, the sedation improved rapidly and
he returned to school. One might question why we chose not to switch
opioids since the boy was on a relatively low dose of opioids.
Although we thought about this option, we wanted an alternative route
of therapy for the local anesthetics that we knew would eventually be
needed because the tumor was invading the lumbar plexus.

Decision-Making

Dr. Portenoy: The major decision point in managing this
patient appears to be between providing more aggressive
pharmacotherapy and undergoing a trial of intraspinal therapy. From
the point of view of more aggressive pharmacotherapy, I probably
would have tried an opioid switch to methadone first, and then
certainly would have added a psychostimulant before opting for
intraspinal therapy. This difference in selection of therapy raises
important issues about how much that decision-making in pain
management is based on who is available to manage a patient’s therapy.

Dr. Staats: That is a very good point, and something that
I’ve struggled with over time. How aggressively does one work to
manage a patient medically to get the same level of function? I am
not convinced that this was the absolute way to go. There are two
viable approaches in this case: 1) opioid switch and 2) intraspinal
therapy. I believe that you would have worked a lot harder and that
the patient would have been taking a lot more pills by opting for the
opioid switch than by intervening very early with intraspinal therapy
as we did. But, there are no randomized trials to confirm this, which
is one of the reasons we’re having this discussion.

Michael H. Levy, MD, PhD: At Fox Chase Cancer Center we
don’t see patients younger than 18 years, so for the sake of
discussion, I would like to assume that the patient was 20 years old.
We probably would have opted to try different opioids, as Dr.
Portenoy discussed. Other than first trying different opioids, our
management would not have differed much from that of Dr. Staats in
this patient. Even in our hypothetical 20-year-old patient,
implanting a pump and administering medications intrathecally to
manage most of the pain so that he was not taking multiple drugs (eg,
laxatives, coanalgesics, stimulants, opioids) could be in the
patient’s best interest and could improve his quality of life.

Anticipating the Course Of Pain

Stuart Du Pen, MD: With severe neuropathic pain in a young
patient, I support neuraxial analgesia through a temporary device.
Once pain is under control, then other options may be evaluated.

Dr. Staats: This case is very unusual, which is one reason I
chose to present it for discussion. My belief was that some of you
might disagree with implanting a device in a patient who was
receiving only 5 mg of oxycodone q4h. However, my thought process in
selecting intraspinal therapy included anticipation of what was
foreseeable over the life of this patient.

In a much more typical case at Johns Hopkins, we would have tried two
or three opioid rotations. This case, however, demonstrated some
principles worth discussing. One principle is to think through what
you anticipate the problem is going to be, for example, the issue of
neuropathic pain vs nociceptive pain, and the addition of local
anesthetics. This is not a static disease, and the oncologist or pain
specialist needs to work with the patient and the course of his or
her pain. You cannot just implant a device and hope that 1 mg/d of
intrathecal morphine will effectively relieve the patient’s pain
until he or she dies.

Dr. Portenoy: After the pump was implanted, why did you add
bupivacaine when the patient was actually still taking very low doses
of intrathecal morphine?

Dr. Staats: The quality of the pain was changing to more of a
burning pain that was neuropathic. The additional local anesthetic
was what I believed to be in the child’s best interest. Clearly,
another option could have been to increase the intrathecal morphine.

Dr. Portenoy: It seems like that decision was similar to what
we noninterventionists do when we’re choosing adjuvant
analgesics. The decision is completely idiosyncratic. Some clinicians
will choose to increase the morphine to some arbitrary ceiling based
on the fear of hyperalgesia syndrome, whereas others will increase
the morphine until patients get side effects; still others will add
bupivacaine early. Do you feel the decision is basically
clinician-specific without any justification?

Elliot S. Krames, MD: This is the art of medicine. We do not
have randomized controlled studies to guide us to the appropriate
time to add bupivacaine. My art of medicine would be to increase the
dose of morphine. I basically give the opioid the benefit of the
doubt. When I approach, in my art, 20 mg/day, then I add bupivacaine
and/or clonidine.

Dr. Portenoy: There seems to be a general feeling among you
that a painful lumbosacral plexopathy would not be as responsive to
opioids as would, for example, a somatic pain. I only bring up this
point for the oncologists who may be reading this because it does
vary with the guideline for systemic opioid therapy discussed in my
article on page 25. If you accept the concept that you select an
opioid drug, and then you individualize the dose by escalating until
you get to treatment-limiting toxicity, which defines the
responsiveness to that drug by that route, then the appropriate
intervention would always be opioid dose titration first, before
addition of another drug.

Dr. Staats: If a patient presented with a lumbar plexopathy
with tumor invading the right hip and you believed that this lumbar
plexopathy neuropathic component might respond well to Neurontin or
to carbamazepine (Tegretol), or to something else if there was a
shooting or lancinating component, you might start that agent. And if
the tumor was invading the spine, I might use opioids or steroids or
something else to manage this nociceptive component. Conceptually,
that’s what I believed I was doing in this case.

Systemic Pharmacologic Approach

Dr. Portenoy: A problem with very early use of combination
therapy is the possibility of additive side effects. If a person has
a painful lumbosacral plexopathy, our teaching about systemic therapy
would be to increase the systemic opioid first, and to do so very
quickly. Once the patient starts to become somnolent without adequate
pain relief, you could reduce the opioid dose and quickly administer
adjuvant analgesics. There is just no evidence behind the rationale
for adding adjuvant analgesics when the opioid dose is very low and
is not associated with any toxicity because you assume that the
efficacy of the opioid won’t be adequate to treat that pain.

Dr. Levy: In a systemic pharmacologic approach, it is much
like what Dr. Staats did in this case. Our experience indicates that
it is uncommon for a patient’s burning pain to go away; the
typical response to opioids is that the pain is reduced in intensity,
but the burning sensation is not gone. And if you choose to use a
tricyclic antidepressant, it will take weeks to reach a therapeutic
dose with minimal side effects. We do a lot of anticipatory use of
coanalgesics, particularly of the neuropathic drugs, to perhaps
prevent or minimize the side effects of increasing doses of opioids.
We use combination chemotherapy in oncology in the same way. Moderate
doses of several agents with different mechanisms of action work
better and with less toxicity than high doses of just one agent. We
don’t have the data, but I believe our experience, particularly
with neuropathic pain, is that it’s the rare patient in whom
most symptoms can be controlled with just opioids. And because it
takes some titration to reach the full effect (even Neurontin can
take days, or weeks), we do that same kind of anticipatory approach
that Dr. Staats used in this case.

Dr. Krames: Many patients with neuropathic pain do not respond
to intrathecal morphine at 1 mg/d but may respond to 2.5 mg/d or even
higher. Once you’ve started therapy, unless you’ve titrated
to either efficacy or side effects, you’re not really giving
that therapy an adequate trial. In some patients we’ll add
Neurontin or desipramine. With intrathecal therapy, however, there is
evidence that higher doses of opioids are better in neuropathic pain
states, and I believe you should titrate until efficacy is achieved
or side effects occur. In a patient with severe neuropathic pain,
I’ll increase the dosage by 50%, and if the patient is still in
pain, will increase another 50% a day or two later, and still again
until toxicity occurs or efficacy is achieved. I’ll stop once
dosage has reached 20 mg/d and then consider the addition of a
nonopioid such as clonidine or bupivacaine.

Dr. DuPen: In my practice, we strongly support the use of
opioids and adjuvant drugs through an algorithm. However, this is a
15-year-old child with out-of-control pain who is not responding to
opioids. My therapeutic choice is intravenous sedation, with a
temporary epidural catheter with bupivacaine to get pain control,
then a progressive effort to use drug trials and adjuvant therapy to
determine the role for long-term intrathecal therapy.

Pages

 
Loading comments...
Please Wait 20 seconds or click here to close