Reply to the comment by Dr. Rubulotta et al.

Excerpt

We are pleased that readers have shown interest in our recent contribution to Intensive Care Medicine [1]. We are also disappointed, however, that certain aspects of our study seem to have misled some readers in the interpretation of our findings. We are therefore thankful to have this opportunity to discuss our contribution again and hopefully to correct the misunderstandings. While we referred to the “afferent muscle spindle theory” [2, 3] in our article, we did not intend to verify this theory based on our study results. We would like readers to know that arousal status can be, at least partially, affected by muscular activity status. This was the fundamental rationale for the study hypothesis. During the process of a power analysis for the hypothesis we used a BIS score of 70 for Ramsay score 4 or 5. The power analysis for sample size calculation requires a standard deviation of the mean value. Regarding this statistical procedure, one may think that we set a BIS score at 70 ± 25 for moderate sedation during the study, and that some patients showed a high BIS score up to 95, which indicates almost awake status. Actually, we used the Ramsay score to determine sedation status but not a BIS score. As a result no patients who were maintained at Ramsay score 4 or 5 demonstrated a BIS score higher than 90 without muscular relaxation. No patients reported unpleasantness or obvious awareness during moderate sedative status of the study period. …