Review for 10.1186/s12876-023-02801-8 (2023)

Title: Albumin infusion may decrease the mortality of hypoalbuminemia patients with severe
acute pancreatitis: a retrospective cohort study
Version: 2 Date: 28 Dec 2022
Reviewer's report:
This is a well written manuscript analyzing hypoalbuminemia as a prognostic marker for
mortality in severe acute pancreatitis (SAP) patients and evaluating the association between
albumin infusion and outcome in a propensity score matched cohort. The topic as well as results
are of interest.
Comments:
In general-as this is a retrospective study general conclusions on causality cannot be done. Please
revise the manuscript for errors indicating causality f ex in aim “the effectiveness of human
serum albumin infusions” and in discussion “we observed that albumin infusions lead to obvious
benefits, significantly reducing mortality in hypoalbuminemia patients with SAP.”
Methods
Diagnosis and definitions of acute pancreatitis and SAP- are in accordance with the Revised
Atlanta classification which is well known. Please shorten the text this section and keep the
reference (to Revised Atlanta)
The definition of cohort and sampling of S- albumin could be more clear. The authors describe a
prospectively collected database of SAP. Should this be a prospectively collected database of all
patients with acute pancreatitis where the authors extracted SAP patients? Or, if only SAP- did
all patients fulfill criteria for SAP within 1 week from admission when s- albumin was mesured?
Please also describe accurate time from admission to sampling of the lowest s- albumin level
during the first week (median and IQR).
If possible, include CRP levels at admission and also highest CRP during first week and
calculate its association to albumin levels. Include this result also in discussion (any correlation
inflammation and hypoalbuminemia)
Definition of sepsis is theoretically correct but cannot be used in the clinical setting. How was
sepsis defined for this specific study? Was a positive culture necessary? Was this a clinical based
decision retracted from medical records?
How did the authors handle the quite high numbers of in-hospital mortality when calculating
hospital stay, hospital stay in ICU and hospital costs? Early deaths might lead to lower hospital
stays and costs and thus the given values must be interpreted with caution.
Results
Overall: please do not repeat all information from tables in text, the text could be reduced.
Figure 1- please indicate n for excluded patients according to exclusion criteria 1-5.
Exclusion criteria 5 (lack of lab data or medical records)- describe this group and in discussion
discuss if this group can introduce a bias in the study.
Table 1-are all laboratory values, SIRS score and APACHE score from admission? If so please
indicate this in the table text. If not please give only admission values in this table.  IQR for
creatinine is very wide- is this value correct?
For supplementary results- it is not clear if a new PSM was calculated. The numbers in
Supplementary table 1 does not match table 4.
Discussion
Overall discussion is well written. Some limitations need to be discussed more. In the last section
limitations numbered 1-4 should be more thoroughly included in discussion and not just listed.
Especially number 4: other parameters known to be of importance for outcome in SAP such as
initial fluid resuscitation, enteral nutrition were not included in the study and not adjusted for.
Discuss the impact of these parameters.
Please also discuss that no morbidity scale was included in the study (only hypertension and
diabetes) and patients with chronic hypoalbuminemia due to comorbidity or frailty could have
biased the results since it is a retrospective study.
For the Propensity score matching- patients were matched according to 16 variables and then
differences calculated for outcomes. Please discuss the possibilities of a type II error.