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RSD PUZZLE #17
Use Of The Infusion Pump, Why And Why Not
"I don't want infusion pump because I am afraid of addiction."
Infusion pump (in the form of Morphine, Dilaulid, Marcaine, or Baclofen) works on the
principle of the application of a very small dose of medication infused in a continuous
fashion ("drip irrigation") providing relief. The medication bypasses other
organs such as liver, kidney, etc., and has direct access to the spinal cord and brain. It
should be applied to the patients who have documented objective cause of chronic pain that
has failed every other form of treatment.
The daily dosage of the treatment is 1-6mg Morphine Sulfate given in a continuous drip
irrigation. This dosage is on the average 1/20 the dose of the same pain medication given
in other forms (by mouth, MS Contin, skin patch, IM, or IV).
There is an optimal dosage for control of the pain which usually is somewhere around 3-7
mg per day for Dilaudid and 5-18 mg per day for Morphine. Once the optimal analgesic dose
is established, then there is no need to increase the dosage. This is because of the fact
that the continuous drip irrigation prevents withdrawal effect, and the amount of
analgesic is so small that it does not cause tolerance to the medication.
Interestingly, if the patient tries to additionally use alcohol or narcotic pills, then
the pain becomes worse. Once the optimal dosage is increased by additional narcotic pain
medication, the patient experiences more severe pain, and excessive drowsiness, and edema
(swelling) of ankles. These phenomena and symptoms of abuse safeguard repetition of
further abuse of the medications.
The fact that the pain becomes worse (if the optimal dose is exceeded), is suggestive of
the large dose of narcotic blocking the formation of natural endorphines.
Addiction has three main principles:
1. Tampering with the brain's natural essential hormones and biogenic amines (in the case
of pain blocking the formation of endorphine).
2. Withdrawal effect. Even a normal person using narcotics for anxiety or temporary
tension headache develops severe pain 4-5 hours after the use of a strong narcotic.
3. Tolerance. This is the case of addiction with Lortab, Heroin, Alcohol, Chocolate, or
Cocaine. In such addictions the brain requires more and more dosage of the drug to achieve
the same pleasure.
The infusion pump bypasses all the three principles and pillars of habituation and
dependence:
1. Infusion pump provides such a small dose of medication that does not effectively block
the brain formation of endorphine. The best proof of it is when too much of analgesic is
applied through the infusion pump, then the pain becomes worse rather than better
suggesting the blockade of the cerebral endrophine.
2. In the infusion pump the medication is continuously administered so there is no
tendency for withdrawal.
3. The infusion pump, in optimal dose, provides pain relief without the patient realizing
that he or she needs to takes any medication. The patient cannot self inflict tolerance
because he has no control over the adjustment of the dosage of the infusate (the medicine
given in the pump).
In our nine years experience of application of infusion pump in late advanced stages of
RSD, the success rate of two years and longer has been around 80%. The other 20% failure
rates have been due to the following factors:
1. Simultaneous oral intake of opioids, resulting in high levels of
opioids (such as Oxycontin or Methadone) in plasma and saturation of opioid receptors. As
the result, the brain stops the formation of endorphines. This phenomenon results in lack
of formation of endorphine, leading to withdrawal pain and dependence (tolerance) to
strong narcotics.
2. In advanced (stage IV) stages of CRPS/RSD, the immune system is so dysfunctional that
the patient has a tendency towards intolerance of the foreign body leading to development
of inflamation, scar formation and infection around the pump.
3. In rare cases, the patient cannot tolerate any type of infusate applied directly into
the spinal fluid.
4. The patient's poor judgment and dependence on alcohol is apt to mess up the function of
the infusion pump. The alcoholism is incompatible with any form of CRPS/RSD treatment
including infusion pump If the patient has any tendency for alcohol abuse, then the pump
should not be considered for that matter no treatment will do any good.
Fortunately, it takes a few weeks for the surgeon or anesthesiologist to decide if the
patient is tolerating the pump. Usually a few weeks trial of the pump is done which weeds
out most of the ones that are not candidates for it. One such example is the patient who
has hysterical pain. Unbeknownst to the patient, the patient gets relief from pain with
even normal saline or sugar and water inserted into the spinal fluid. This also sorts out
the patients who are not the candidates. However, this specific placebo test should be
done on every infusion pump patient as long as one takes into consideration that if the
patient has been given narcotic in the infusion pump, it cannot be immediately
discontinued and placebo tried because of the fact that the narcotic effect in the spinal
fluid can last even 4-5 days after infusion of the medication.
H. Hooshmand, M.D.
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