1. Benefit and risk of intrathecal morphine without local anaesthetic in patients undergoing major surgery: meta-analysis of randomized trials 
N. Meylan, N. Elia, C. Lysakowski, M.R. Tramèr 
British Journal of Anaesthesia 
Volume 102, Issue 2, Pages (February 2009)
DOI: /bja/aen368
Copyright © 2009 British Journal of Anaesthesia Terms and Conditions

2. Fig 1
Flow chart of retrieved, excluded, and analysed trials. RCT, randomized, controlled trial. Relevant trials tested intrathecal morphine alone (without a local anaesthetic) in patients undergoing a general anaesthetic for major surgery.
British Journal of Anaesthesia  , DOI: ( /bja/aen368)
Copyright © 2009 British Journal of Anaesthesia Terms and Conditions

3. Fig 2
Relationship between the year of publication of the trials and the doses of intrathecal morphine that were investigated in the trials. Data are from 27 placebo-controlled randomized trials. Each symbol represents one trial arm that tested intrathecal morphine; number of symbols does not add up since some trials tested more than one morphine dose.
British Journal of Anaesthesia  , DOI: ( /bja/aen368)
Copyright © 2009 British Journal of Anaesthesia Terms and Conditions

4. Fig 3
Cumulative 24 h consumption of i.v. morphine (in milligrams) for break-through pain after operation. IT, intrathecal; WMD, weighted mean difference; CI, confidence interval. On the bubble graph, each bubble represents one trial; sizes of the bubbles are proportional to sizes of the trials.
British Journal of Anaesthesia  , DOI: ( /bja/aen368)
Copyright © 2009 British Journal of Anaesthesia Terms and Conditions

5. Fig 4
Pain intensity (0–10-point scale, ranging from 0, no pain, to 10, maximum pain) at rest at 2, 4, 12, and 24 h after operation. IT, intrathecal; WMD, weighted mean difference; CI, confidence interval. On the bubble graphs, axes are pain intensities (0–10-point scale). Each bubble represents one trial; sizes of the bubbles are proportional to sizes of the trials.
British Journal of Anaesthesia  , DOI: ( /bja/aen368)
Copyright © 2009 British Journal of Anaesthesia Terms and Conditions