451that alter splice variant expression could predispose patients to differences in
disease progression. Genetically defi ned variations might account for differences of
the intensity of infl ammatory disease progression.
Mechanism-Specifi c Management of Pain
The is a need for the development of diagnostic tools that will allow us to identify
the mechanisms of pain in an individual patient and pharmacologic tools that act
specifi cally on these mechanisms. This strategy will enable a rational rather than an
empirical trial-and-error approach to controlling pain. Treatment with antiinfl am-
matory drugs would be helpful in pain associated with infl ammatory conditions but
these drugs may not benefi t patients whose pain is due mainly due to excitability
caused by abnormal sodium channel activity after nerve injury as in painful diabetic
peripheral neuropathy.
Preoperative Testing to Tailor Postoperative Analgesic
Requirements
Patients vary a great deal in requirement for analgesics after surgery. Determining
the best dose for each patient can be diffi cult because of individual differences in
pain tolerance. If patients are undertreated and have severe pain, it can lead to ongo-
ing, chronic pain. On the other hand, over treatment with pain medicine is associ-
ated with bothersome side effects.
Research at Wake Forest University Baptist Medical Center (Winston-Salem,
NC) shows that having patients complete a series of simple tests before surgery may
help predict the intensity of their post-surgical pain and how much pain medication
they will need. They conducted a study on women undergoing elective cesarean
sections. About 2 weeks before surgery, the women answered questionnaires to
measure anxiety, their expectations about pain and the levels of pain they were hav-
ing during pregnancy. In addition, a small heat element was applied to their arms
and backs and the women were asked to rate the intensity and unpleasantness. The
heat was not applied long enough to cause skin damage and could be stopped by the
patient at any time. After surgery, the women reported on their pain severity levels
and researchers measured their requirements for pain medication. The researchers
found that six groups of predictive factors accounted for 90 % of the total variances
in patients’ postsurgical pain severity and medication requirements. The best pre-
dictor of the total amount of pain medication required was a validated questionnaire
that measured anxiety. The best predictors of overall postsurgical pain were blood
pressure readings shortly before surgery and patients’ responses to the heat element
that was performed before surgery. The model was also useful in identifying patients
in the top 20 % of pain severity and amount of pain medication required after sur-
gery. This study shows that it is possible to identify patients at risk for high pain
levels after surgery to allow tailored treatments to improve their quality of care.
Personalized Management of Pain