Predictors of chronic neuropathic pain after scoliosis surgery in children.

BACKGROUND

Numerous publications describe chronic pain following surgery in both adults and children. However, data in the paediatric population are still sparse and both prevalence of chronic pain after surgery and risk factors of this complication still undetermined.

METHODS

We prospectively evaluated the prevalence of chronic pain and its neuropathic pain component at 1 year following correction of idiopathic scoliosis in children less than 18 years of age. Pain was defined as the presence of pain (numerical rating scale - NRS≥4), the presence of signs of neurologic damage within the area of surgery and the presence of the neuropathic symptoms as a DN4 (Douleur Neuropathique 4) questionnaire ≥4. Factors investigated as potentially associated with the presence of a persistent neuropathic pain were: age, weight, the presence of continuous preoperative pain over the 3 months before surgery, surgical characteristics, pain scores during the first five postoperative days, and DN4 at day 3. Statistical analysis employed univariate analysis and a multivariate logistic regression model.

RESULTS

Thirty six patients were included in the study. Nineteen (52.8%) had pain at one year after surgery. Among them 17 (48.2%) had neuropathic pain. Logistic regression found continuous pain over the 3 months preceding surgery and day 1 morphine consumption ≥0.5mgkg as independent predictors of persistent chronic pain with a neuropathic component. The overall model accuracy was 80.6 and the area under the curve of the model was 0.89 (95% confidence interval 0.78-0.99).

CONCLUSIONS

The present study found a high proportion of paediatric patients developing chronic persistent pain after surgical correction of scoliosis diformity. It allows identifying two factors associated with the occurrence of persistent chronic pain with a neuropathic component: the presence of persistent preoperative pain during the 3 months preceeding surgery and postoperative opioid consumption at day 1 ≥0.5mgkg.

IMPLICATION

Patients scheduled for spine surgery and presenting with preoperative pain should be considered at risk of chronic pain after surgery and managed accordingly by the chronic and/or acute pain team. Postoperative opioid consumption should be lowered as possible by using multimodal analgesia and regional analgesia such as postoperative epidural analgesia.