Review for 10.1186/s12876-025-03782-6 (2025)

Title: Preoperative quantitative quadriceps muscle ultrasound to predict POD for
gastrointestinal surgery in older patients
Version: 0 Date: 06 Feb 2025
Reviewer:  Anwar Ashraf Abouelnasr
Reviewer's report:
Dear Authors, please address the following points below
-The study is conducted at a single center, and it would be helpful to mention whether the
findings are likely to apply to different healthcare settings, particularly those with varying
levels of healthcare resources. External validation in a multicenter cohort would enhance the
generalizability of the findings.
-While ultrasound imaging is an attractive non-invasive tool, it is still operator-dependent.
Despite training the anesthesiologist to perform the ultrasound measurements, this could
introduce some degree of variability. The inclusion of more than one trained operator or inter-
observer reliability testing could further strengthen the study’s methodology.
-While the study has a strong focus on clinical and demographic data, other potential
confounders influencing POD (such as medication use, postoperative mobility, and patient
engagement) are not addressed in great detail. These could be considered in the analysis or
mentioned as limitations.
-The introduction briefly mentions frailty as a risk factor for POD but does not provide much
detail on how frailty is assessed in this cohort (beyond referencing Fried et al.). A more detailed
description of the frailty assessment method would help clarify the rigor of this assessment.
Using an established frailty scale or more objective measurement tools would strengthen this
part of the study.
-The diagnosis of POD is based on the Confusion Assessment Method (CAM), but the
introduction does not explain how frequently these assessments were conducted or what criteria
were used to detect changes in mental status. More detail on the timing and frequency of
assessments could enhance the clarity of how POD was detected and reduce the risk of missed
diagnoses.
-While the authors mention that quadriceps degeneration involves both muscle mass loss and
increased fat infiltration, they could delve deeper into the biological mechanisms that connect
these changes to POD. For instance, explaining how muscle atrophy may affect neurological
function or interact with inflammatory pathways could strengthen the discussion. This would
help readers better understand the underlying physiology driving the association between muscle
quality and POD.
-The authors mention that the results cannot be generalized to patients undergoing other types
of surgery, but they could further explore the potential limitations of applying these findings to
broader populations. For example, how might these findings translate to patients with different
comorbidities or younger age groups? A brief exploration of this could help address concerns
about the external validity of the study’s conclusions.
-The authors focus on six main risk factors, but it might be useful to discuss additional factors
that could influence the occurrence of POD but were not included in this study. For instance,
medications or pre-existing cognitive disorders (e.g., dementia) could play a role in POD risk.
Expanding on these factors could provide a more comprehensive view of the complex nature
of POD in older patients.