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Background and Aims The evaluation of the postoperative acute pain (PAP) is sometimes difficult in children more than six-years old, such as the visual analogue scale (VAS). The objective of this study is to assess the existence or not of a difference in the scores obtained by two evaluation scales at the same time.

Methods This is a prospective study which includes children who had limbs surgery. In order to identify patients ‘difficult to be evaluated’ during the first 24 hours of the post-operative phase at: H0, H4, H8, H12, H18, H24. self-assessment of pain combined with the behavioral pain assessment scale were proposed at the same time to patients (VAS and FLACC ¬[Face Legs Activity Cry Consolability]). The data was analyzed by the SPSS ‘20’ software program. The threshold of significance was 5% (P < 0,05). An intra-category correlation test was realized between the two above-mentioned scales.

Results 355 patients were included in this study. The average age was 9,29 ± 4,13 years.The average of the postoperative pain scores were 1,03 ± 1,61 for the VAS and 0,48 ± 1,23 for the FLACC. We also found that the intra-category coefficients were stated between r = 0,79 and 0,81 with a very good reproducibility of the two scales.

Conclusions These results sustain the possibility of using the FLACC scale as reliable instrument in case of doubt regarding the VAS obtained score in more-than-6-years-old children.