Review for 10.1186/s12876-025-04198-y (2025)

Title: Application of continuous renal replacement therapy (CRRT) in patients with severe acute
pancreatitis: an analytical study
Version: 2 Date: 20 Jun 2025
Reviewer's report:
This retrospective cohort study investigates the role of Continuous Renal Replacement Therapy
(CRRT) in the management of Severe Acute Pancreatitis (SAP), with a particular focus on CRRT
timing and prognostic outcomes. The authors further stratify patients based on the presence
or absence of strong CRRT indications and develop a nomogram for predicting treatment
efficacy in borderline cases. The study is comprehensive, utilizes robust statistical methods, and
addresses a clinically relevant topic, though several methodological, interpretive, and reporting
issues must be addressed to meet publication standards.
Major Concerns:
1. Study Design and Patient Selection Bias:
• The retrospective nature of the study inherently limits causal inference. The authors
acknowledge this but do not discuss how confounding was minimized. While multivariate
analysis is conducted, details regarding missing data handling, selection bias control, or any
propensity score matching approach are not mentioned.
• The definition of “strong CRRT indication” appears rigid and dichotomized based on KDIGO-
like criteria. However, borderline patients may have dynamic indications over time. This
oversimplification could affect generalizability.
2. Predictive Modeling and Nomogram Validation:
• While the AUC of 0.912 in the training set and 0.844 in the test set suggest high discriminatory
power, the small sample size of the validation cohort (n=23) undermines the external validity and
robustness of the model. The authors should consider k-fold cross-validation or bootstrapping.
• Key variables such as treatment duration, anticoagulation strategy, and specific CRRT
modality (CVVH, CVVHD, etc.) were not included in the model despite their known clinical
relevance.
3. Interpretation of CRRT Timing Effect:
• The manuscript presents CRRT initiation before 36 hours as a key predictor of better prognosis.
However, no sensitivity analysis or instrumental variable analysis was performed to account for
confounding by indication (e.g., sicker patients might receive earlier intervention).
• The biological rationale for the 36-hour cutoff needs clearer mechanistic justification beyond
statistical optimization via Youden index.
4. Heterogeneity of SAP Etiologies and Subgroup Analysis:
• While etiology is included as a variable, the analysis does not adequately explore whether
CRRT’s efficacy differs between biliary, hyperlipidemic, or alcoholic pancreatitis. Given
distinct pathophysiologies, subgroup analyses would provide valuable insight.
Minor Concerns:
1. Language and Grammar:
• The manuscript requires careful English language editing. Phrases like “no statistically
significant differences in other indicators between the groups” could be more precise.
• Avoid redundancy (e.g., “voluntary discharge or death” is mentioned multiple times without
redefinition).
2. Tables and Figures:
• Figures (e.g., nomogram, ROC curves) should include more descriptive captions and axis
labeling.
• Table 1 and 7 have overlapping data—streamlining or consolidating tables would improve
readability.
3. Reference Formatting:
• Some references lack proper formatting (e.g., inconsistent citation of DOI, journal names).
• Ensure all cited guidelines (e.g., KDIGO, IAP) are referenced with their exact publication year
and edition.
Unacknowledged Limitations:
• The study does not account for the impact of ICU staffing levels, fluid management protocols,
or concomitant therapies such as antibiotics and nutritional support, all of which can influence
prognosis in SAP.
• There is no discussion on potential variability in CRRT technical application (e.g., membrane
type, session length) which may introduce center-specific bias.
• Lack of data on long-term outcomes (e.g., renal recovery, readmission) limits the full
assessment of CRRT efficacy.
Language and Reference Revisions:
• Examples of revision needed:
• Replace: “The results are statistically significant.”
With: “These findings reached statistical significance (p<0.05), suggesting…”
• Replace: “No statistical difference in indicators was observed.”
With: “No significant intergroup differences were observed in the remaining outcome indicators
(p>0.05).”
• Reference issues: Some references include Chinese-language journals or lack full citation
formatting. Ensure uniformity and adhere to BMC referencing style.
• The manuscript generally aligns with BMC Gastroenterology scope but should improve
transparency in methods and modeling per STROBE and TRIPOD guidelines.