Title: Ketamine's impact on mood after day-case surgery and its relation to obesity: a
randomised controlled trial in women undergoing fractional curettage
Version: 2 Date: 02 Jun 2024
Reviewer's report:
PEER REVIEWER ASSESSMENTS:
OBJECTIVE - Full research articles: is there a clear objective that addresses a testable research
question(s) (brief or other article types: is there a clear objective)?
No - there are minor issues
DESIGN - Is the current approach (including controls and analysis protocols) appropriate for
the objective?
No - there are minor issues
EXECUTION - Are the experiments and analyses performed with technical rigor to allow
confidence in the results?
No - there are minor issues
STATISTICS - Is the use of statistics in the manuscript appropriate?
No - there are issues with the statistics in the study
INTERPRETATION - Is the current interpretation/discussion of the results reasonable and not
overstated?
No - there are minor issues
OVERALL MANUSCRIPT POTENTIAL - Is the current version of this work technically
sound? If not, can revisions be made to make the work technically sound?
Probably - with minor revisions
PEER REVIEWER COMMENTS:
GENERAL COMMENTS: The study attempts to study mood changes in patients receiving
ketamine for day care surgery. The authors have studied a topic that is very clinically relevant
and the methodology is fairly robust. However, the association that the authors are describing,
that of obesity with postoperative mood scores seems to be an afterthought based on the
multiple regression analysis data, which the authors have included as something which they were
specifically looking for in the "Background" section. More over some parts of the methodology
section and statistics need to be described in greater detail and / or clarifications provided.
REQUESTED REVISIONS:
1. Lines 75 & 76: “With 64.4% of adults being overweight or obese, Turkey ranks among the
top ten OECD countries in this regard, where women are more likely to be obese…..” This
statement in the “Background” section seems to be an afterthought. The initial intention of the
authors seemed to be like to check the association of mood symptoms and ketamine use with
a lot of variables, of which obesity was one. Hence, it is better that this statement be shifted
to the” Discussion” section, since specifically checking the association of obesity in particular,
with mood symptoms in the ketamine groups does not seem to be a stated ad hoc objective of
the study.
2. Were there any age limits in the inclusion criteria? Considering that mood disorders are often
influenced by age, would the authors not deem it reasonable to use a homogenous sample of
women of a pre-specified age group?
3. The exclusion criteria mention ASA III and IV. What about ASA V?
4. By “language impairment” do the authors mean patients who could not understand a particular
language like Turkish, or are they referring to a linguistic disability? They may please clarify.
5. How were the patients assigned into groups? How was randomization done? How was
allocation concealment achieved? The authors need to mention all of these in some detail. It is
mentioned in the protocol, but not in the final manuscript.
6. When exactly in the perioperative sequence were the study drugs given? Were they given as
a bolus or as an infusion over several minutes?
7. Was this written or online version of POMS? Who filled it? The patient herself or the clinician
quizzing the patient?
8. There are several versions of the POMS. Which one was used in this study?
9. Line 144: “a sample size of 70 cases per group was calculated after recruiting 60 patients into
the study”. This does not make sense. Wasn’t the sample size calculated a priori? How was the
sample size of 70 calculated only AFTER recruiting 60 patients?
10. Line 174: No such thing as “almost statistically significant”. It’s apparent that in this case
there was no statistical significance demonstrable in the comparison between the TMS values
before and after surgery in group C.
11. How do the authors explain higher sedation scores in Group C?
12. Line 186: “Group”, not “Grup”. Typographical error to be corrected.
ADDITIONAL REQUESTS/SUGGESTIONS:
I have mentioned the specific areas of the manuscript which require the authors' attention in my
comments to the same earlier.