To the Editor:

We read with great interest the article of Nishida et al. [1] in a recent issue of the journal. The authors evaluated patients < 18 years of age who underwent pediatric ambulatory surgery under general anesthesia and concluded that increased time spent in a hospital was affected by the type of regional block, surgery, and intraoperative fluid volume. The authors should be congratulated for performing a well-designed trial in an important topic in pediatric patients [2]. Moreover, current emphasis on fluid management and regional blocks as a part of enhanced recovery protocols makes the topic more relevant [3].

There are some questions that need to be clarified to determine the validity of the results. First, the authors arbitrarily defined prolonged stay as within 8 h at the end of anesthesia. It would be important to perform a sensitivity analysis to demonstrate if their results differ when other time cutoffs are utilized (e.g., 6 and 4 h). Second, it is unclear how frequent patients were assessed using the PADSS instrument and if the results can be affected by bias on unstandardized discharge evaluations. Last, most studies examining discharge times demonstrate < 3 h. One could argue that the discharge time in this study is driven by practice characteristics and therefore, poor generalizability to other centers.