The Role of Intravenous Lidocaine in Preventing Chronic Post-Operative Pain

Luís M. F. Ramos*

The Role of Intravenous Lidocaine in Preventing Chronic Post-Operative Pain.

There is no standardized definition of chronic post-operative pain but it is usually described as persistent pain 2 or more months after a surgical procedure, not explainable by any other cause.

The incidence of CPOP can be as high as 75%, depending on the surgical procedure and other factors, which makes it an
increasing public health issue considering its impact on patients quality of life and its associated costs for the healthcare system. CPOP is a dysfunction of the nociceptive system and the mechanisms that lead to its development are multifactorial and often poorly understood.

The wind-up phenomenon seems to be fundamental to the development of central sensitization and chronic pain. Stimulation of C fibers leads to the synaptic release of glutamate that
activates α-amino-3-hydroxyl-5-methyl-4-isoxazolepropionate receptors, allowing sodium to leak in the cell and thus propagating the action potential.

The intense stimulation of C fibers, for instance after surgery, will result in greater postsynaptic depolarization, which can remove the magnesium ion that normally blocks N-methyl-d-aspartate receptors.

Then these also can be activated by glutamate, allowing calcium ions to enter the post-synaptic
neuron, increasing the likelihood for this cell to reach threshold for firing an action. This
increased status of susceptibility for neuron membrane
depolarization is called central sensitization.

Several risk factors for the development of CPOP are
known.  Among the most important risk factors
for the development of CPOP is acute post-operative pain.

Res Pract Anesthesiol Open J. 2021; 5(1): 1-4. doi: 10.17140/RPAOJ-5-127