Intrathecal Morphine Pump in Cancer Pain Management

Abstract

Intrathecal morphine pump is a medical device used to
deliver morphine directly into the cerebrospinal fluid for pain
management. It is primarily used for patients with severe
pain, particularly due to cancer or chronic pain conditions,
who do not respond adequately to oral or systemic opioids.
It a programmable device placed under the skin , usually
in the abdomen. A thin catheter connects the pump to the
intrathecal space around the spinal cord allowing the
morphine to be delivered directly [1]. Opioids work in the three areas of central nervous system: the
periaqueductal -periventricular gray matter, ventromedial
medulla and spinal cord. Morphineinteracts with the mu
receptor sites of the brain with higher concentration seen
in posterior amygdala,hypothalamus,thalamus, caudate
nucleus, putamina region, cortex and also in the terminal
axons of primary afferents in the substantia gelatinosa of the
spinal cord. on patient age, weight, overall health status, opioid tolerant
or opioid naïve patient, previous history of side effects and
physician variance. Initial dosing of intrathecal pump is 1 to
5mg per day depending on pain intensity and opioid naïve/
opioid tolerant patient. Doses can be adjusted based on
patient needs and gradually increased to achieve optimal
pain control. Maintenance dose can range from 5 to 15mg per
day, few patients may require higher doses especially if they
are opioid tolerant. Intrathecal pump can have dual delivery
mechanism like continuous and intermittent depending on
the machine instructions, physician recommendations and
individualized patient needs [2].