Acute neuropathic pain following surgery

Chronic neuropathic pain occurring after an operation is a common problem,
however little data is available describing the nature or prevalence of acute
neuropathic pain following surgery. In this thesis, I explore the measurement
scale properties of a commonly used neuropathic pain screening tool, and use
this tool to describe the prevalence of acute and chronic neuropathic pain
following thoracic surgery. I also explore how best to diagnose acute
neuropathic pain with a Delphi survey of expert opinion and confirmatory
observational cohort study. The results show that the Leeds Assessment of
Neuropathic Symptoms and Signs (LANSS) neuropathic pain screening tool
demonstrates acceptable fit to the Rasch measurement model in the chronic
postoperative pain population, but only has reliability consistent with use at a
group level. Using this tool, I demonstrate that 8% of thoracic surgery patients
experience acute neuropathic pain an average of 3 days after surgery, with
22% developing neuropathic pain by 3 months. Experiencing acute neuropathic
pain significantly increased the odds of developing chronic neuropathic pain
(odds ratio 7.7 [95% confidence interval 1.5-39.7]). A Delphi survey of
specialists identified 9 items considered important in the diagnosis of acute
neuropathic pain, and suggests that unlike diagnosis in the chronic pain
population, a poor response to opioid medications was an important indicator of
neuropathic pain. Preliminary results from a matched cohort study confirm this,
by demonstrating that verbal descriptors of neuropathic pain are significantly
more common in patients with poorly controlled postoperative pain despite
strong opioid use.