1. Opioid-induced hyperalgesia in patients after surgery: a systematic review and a meta- analysis 
D. Fletcher, V. Martinez 
British Journal of Anaesthesia 
Volume 112, Issue 6, Pages (June 2014)
DOI: /bja/aeu137
Copyright © 2014 The Author(s) Terms and Conditions

2. Fig 1
PRISMA flow chart detailing retrieved, excluded, assessed, and included trials.
British Journal of Anaesthesia  , DOI: ( /bja/aeu137)
Copyright © 2014 The Author(s) Terms and Conditions

3. Fig 2
Forest plot for pain scores at rest at 1, 4 and 24 h. Pooled data analysis of the pain at rest in adults receiving intraoperative opioid vs control. CI, confidence interval.
British Journal of Anaesthesia  , DOI: ( /bja/aeu137)
Copyright © 2014 The Author(s) Terms and Conditions

4. Fig 3
Forest plots of morphine titration and morphine consumption at 24 h. Pooled data analysis of the cumulative opioid consumption in adults receiving intraoperative opioid vs control. CI, confidence interval.
British Journal of Anaesthesia  , DOI: ( /bja/aeu137)
Copyright © 2014 The Author(s) Terms and Conditions

5. Fig 4
Forest plot of primary (a) and secondary hyperalgesia (b). Pooled data analysis of the primary hyperalgesia (pain threshold near the wound) or secondary hyperalgesia (area around the wound) in adults receiving intraoperative opioid vs control. CI, confidence interval.
British Journal of Anaesthesia  , DOI: ( /bja/aeu137)
Copyright © 2014 The Author(s) Terms and Conditions

6. Fig 5
Funnel plot for pain at rest (a) and for morphine consumption at 24 h (b). Funnel plot to assess for publication bias.
British Journal of Anaesthesia  , DOI: ( /bja/aeu137)
Copyright © 2014 The Author(s) Terms and Conditions

7. Fig 6
Funnel plot for pain at rest (a) and for morphine consumption at 24 h (b).
British Journal of Anaesthesia  , DOI: ( /bja/aeu137)
Copyright © 2014 The Author(s) Terms and Conditions