A High Preoperative Pain and Symptom Profile Predicts Worse Pain Outcomes for Children After Spine Fusion Surgery
Authors: Voepel-Lewis Terri , Caird Michelle S. , Tait Alan R. , Malviya Shobha , Farley Frances A. , Li Ying , Abbott Matthew D. , van Veen Tara , Hassett Afton L. , Clauw Daniel J. 
Published: March 2017

BACKGROUND:
Preoperative pain predicts persistent pain after spine fusion, yet little is understood about the nature of that pain, related symptoms, and how these symptoms relate to postoperative pain outcomes. This prospective study examined children’s baseline pain and symptom profiles and the association between a high symptom profile and postoperative outcomes.

METHODS:
Seventy children (aged 10–17 years) scheduled for correction of idiopathic scoliosis completed pain and symptom surveys during their preoperative visit (ie, pain intensity [0–10 numeric rating scores], a pediatric version of the 2011 fibromyalgia survey criteria [including pain locations and symptom severity scale], neuropathic pain symptoms [painDETECT], and Patient-Reported Outcome Measurement System measures of fatigue, depression, function, pain interference, and pain catastrophizing). Pain intensity and total analgesic use were recorded daily postoperatively and for 2 weeks after discharge. A 2-step cluster analysis differentiated a high and low pain and symptom profile at baseline, and a multivariate main effects regression model examined the association between pain profile and posthospital discharge pain and analgesic outcomes.

RESULTS:
The cluster analysis differentiated 2 groups of children well characterized by their baseline symptom reporting. Thirty percent (95% confidence interval [CI], 20.2%–41.8%) had a high symptom profile with higher depression, fatigue, pain interference, a pediatric version of the fibromyalgia survey criteria symptoms, neuropathic pain, and catastrophizing. Girls were more likely than boys to be clustered in the high symptom profile (odds ratio [OR], 5.76 [95% CI, 1.20–27.58]; P = .022) as were those with preoperative pain lasting >3 months (OR, 3.42 [95% CI, 1.21–9.70]; P = .018). Adjusting for sex, age, and total in-hospital opioid consumption, high cluster membership was independently associated with higher self-reported pain after discharge (mean difference +1.13 point [97.5% CI, 0.09–2.17]; P = .015). Children in the high symptom cluster were more likely to report ongoing opioid use at 2 weeks compared with the low symptom group (87% vs 50%; OR, 6.5 [95% CI, 1.30–33.03]; P = .015). At 6 months, high symptom cluster membership was associated with higher pain intensity, higher pain interference, and ongoing analgesic use (P ≤ .018).

CONCLUSIONS:
A behavioral pain vulnerable profile was present preoperatively in 30% of children with idiopathic scoliosis and was independently associated with poorer and potentially long-lasting pain outcomes after spine fusion in this setting. This high symptom profile is similar to that described in children and adults with chronic and centralized pain disorders and was more prevalent in girls and those with long-standing pain. Further study is needed to elucidate the potential mechanisms behind our observations.