Neuropathic Evaluation of Postoperative Pain

Preoperative assessment will consist on collecting demographic data as well as the presence preoperative chronic pain and its localization, preoperative opioid, gabapentin or pregabalin consumption. In postoperative, we will collect the following data: type of anesthesia, intra operative ketamine administration, type and total dose of opioid administered during surgery. Pain will be evaluated at least 2 hours after the surgery within the same day (D0) and then at day 2 (D2), 1 (M1) and 2 months (M2) after the surgery. Pain will be assessed using a 10-point NPS. If NPS \>0, neuropathic pain will be diagnosed on the basis of DN4 questionnaire. NCPSP is defined by NPS \>0 and positive DN4 (DN4 ≥ 4 /10) (11). APSNP and CPSNP are defined by D0/D2 DN4≥ 4/10 and M1/M2 DN4≥ 4/10, respectively.