My name is Jon Raphael,
I'm a specialist in pain medicine and
I'm going to be talking about
spinal analgesia for cancer pain.
The place of spinal analgesia in cancer
pain management is following the more
conservative measures as outlined in
the World Health Organization's well
known ladder, thus following strong
opioids together with adjuvants if pain
relief cannot be controlled,
then advanced strategies come into play.
Of course the majority of patients' pain
can be controlled by the more conservative
nonetheless there's a significant number
who require more advanced strategies.
Spinal analgesia is generally preferred
above the destructive procedures,
either neurologic or neurosurgical.
The story of spinal analgesia
in management of pain and
cancer pain goes back some years now
to seminal work in the mid seventies,
in which it was demonstrated
that opioids would inhibit,
nociceptive transmission level of
the dorsal horn of the spinal chord.
The rationale for delivering drugs
to this area is based on a number of
which will be outlined.
It mainly relies upon a fortuitous
difference in the capillaries of
the central nervous system, compared with
almost all other tissues of the body.
To look to the left of this slide,
we see that drugs can pass from
the capillaries into the tissues,
either across the membranes of the
endothelial cells, but also their passage
is aided by the ability to go through
clefts between cells and fenestrations.
However, in the central nervous
system as shown on the right,
there are no such intercellular clefts or
fenestrations, and therefore the passage
of drugs into central nervous system
tissue from the capillaries is impeded.
This is, of course, a technological
effect that protects us from toxins.
But it can be used as we will demonstrate
to the benefit of analgesia in patients
by spinal drug delivery.