Correction to: J Anesth (2016) 30:187–192 https://doi.org/10.1007/s00540-015-2088-7

In the original publication of the article, figure caption of Fig. 5 was published incorrectly. The correct caption should read as below,

Fig. 5 The relationship between lengths (A) (B), and (C) and the predicted optimal length (D). Gray triangles Maximum optimal length (A) on the Y-axis, black open circles minimum optimal length (B) on the Y-axis. The predicted optimal lengths (D) calculated by Eqs. (1–3) are plotted on the X-axis in a, b, and c, respectively. Dotted black linesY = X’, meaning that the measured optimal length (C) equals the predicted optimal length (D). Gray triangles below the dotted line or black hollow circles above the dotted line means the cases where the predicted optimal length (D) were outside of the measured optimal length range [from (A) to (B)]