Figure 3. Pain scores as described by the visual analog scale, numeric rating scale, number of words chosen, and total pain rating index [31] in patients receiving interpleural morphine (group 4, squares), saline (group 5, circles), or bupivacaine (group 6, triangles). Mean plus/minus SEM are given. Asterisks indicate significant differences (P < 0.05, Kruskal-Wallis and Dunn test) between group 6 and the other two groups.