Reviewer ’s report  
 
Title:  Is Discard Better than Return Gastric Residual Aspirates: A Systematic Review and M eta-
analysis  
 
Version: 1 Date: 13 Mar 2019 
 
Reviewer:  Thangaraj  Abiramalatha  
 
Reviewer’s report:  
 
I thank the authors for  attempting to revise. I am sorry to state that the revision is grossly 
inadequate. The authors have not done many of the major changes suggested.  
 
 
Major comments  
 
1. Title: The primary outcome has to be included in the title. 'gastric residual volume' can not 
be the primary outcome, because it is not a clinical outcome.  
 
2. The outcomes (primary and secondary) are still not clearly stated and defined. I cannot 
find the outcomes in the methods section.  
 
3. Methods ln 123: "The source of heterogeneity was also assessed with subgroup analyses 
according to patients' characteristics, intervention difference among trials, as well as the 
sensitivity analyses for each study" - is vague. Subgroup analyses need to be pre -defined 
specifically.  
 
4. Eligibility criteria for  inclusion in the review need to be clearly defined.  
 
a. Participants - age groups (since the neonatal study was not included),  
 
c. Timing of starting and ending of the intervention  
 
- Not clearly defined still.  
 
5. Risk of bias assessment in individual studies (for included trials) - Table could be 
included. If there is space constraint, the table can be made as 'online only' file  
 
- Is not done. The pictures give only whether its low, high or unclear risk. 
The details for each component have to be presented as a table for each 
trial. The authors can see any Cochrane review for reference.  
 
6. Information on 'allocation concealment' is very important. Bcoz, without it, the 
randomization is not valid. The authors shou ld try to contact the trial authors to get the 
information in each included trial.  
7. Behairy 2014 - method of randomization is not clear. The study is called as a 'quasi -
experimental study'. Booker 2000 - method of randomization is not clear.  
 
- If the au thors cannot get the information, then they cannot be graded as 
'low risk' for randomization like how they have done.  
 
8. Gastric emptying delay: The numbers in the meta -analysis differ from those reported in 
the original studies. Are the authors looking at  'number of episodes of gastric emptying 
delay' or 'number of patients with episodes of gastric emptying delay'? It is confusing. 
This is the reason why each outcome needs to be pre -defined.  
 
- I cannot see the definitions for any outcome in the methods par t. 
 
9. GRADE SoF (Summary of Findings) table to be included. It will give the level of 
evidence for each outcome. Conclusion has to be written based on the GRADE level of 
evidence for each outcome  
 
- Is not done. Table 2 is not acceptable. The authors need t o grade the level 
of evidence for each outcome.  
 
10. The discussion reads very vague and all mixed up. Many points are getting repeated. 
Needs a major revision.  
 
 
Minor comments  
 
1. Abstract ln 28: 'The management of gastric residual aspirates is essential t o the prognosis 
of critically ill patients with enteral nutrition' - is too declarative. Needs to be changed or 
modified.  
 
2. Background ln 52: 'nasal tube' can be rephrased as 'nasogastric or orogastric tube'  
 
3. Background ln 59 - 'et al' should be removed  
 
4. Many spelling errors such as: 'focused' collaborationon'  
 
5. Methods ln 87: The search strategy for each database was adapted from the search 
strategies used in Pubmed and the instructions and rules of each database - sentence 
needs to be rephrased  
 
6. Methods ln 97: 'The case reports, series, qualitative studies and review articles were 
excluded' - This sentence can be removed, as there is no need for it.  
 
7. Methods ln 81, 98 -100, 104, 108, 117: Two review authors, third author - Which authors? 
The initi als of the author can be written in brackets  
 
8. Methods ln 99 - 'consensus' can be used instead of 'consents'  
 
9. Methods ln 116: the reference for 'Revman 5' has to be added as a citation  
 
10. Methods lines 123 -126: The sentences can be modified as 'planned  to assess' rather than 
'assessed' for subgroup analyses and funnel plot, since these were only planned and not 
done.  
 
11. Results ln 143: "For the results, three RCTs[15, 17, 18] favored the return of gastric 
residual aspirates, and one RCT[16] found no su periority of discard or return of gastric 
residual  aspirates on critical ill patients" - this line needs to be removed. Bcoz this 
paragraph is to summarize only the methods of the included studies, not the results.  
 
12. Results ln 150: "none of the include d RCTs reported allocation blinding, one RCT 
reported significant exposure of allocation, the rest three RCTs[16 -18] remained unclear" 
- sentence is vague, needs to be rephrased. Use 'allocation concealment' instead of 
'allocation blinding'  
 
13. Figures 2 &  3 - any one figure is adequate. Since both the figures convey the same 
information.  
 
Are the methods appropriate and well described?  
If not, please specify what is required in your comments to the authors.  
 
No 
 
Does the work include the necessary controls?  
If not, please specify which controls are required in your comments to the authors.  
 
Yes 
 
Are the conclusions drawn adequately supported by the data shown?  
If not, please explain in your comments to the authors.  
 
Yes 
 
Are you able to assess any statistics in the manuscript or would yo u recommend an 
additional statistical review?  
If an additional statistical review is recommended, please specify what aspects require further 
assessment in your comments to the editors.  
 
I recommend additional statistical review  
 
Quality of written English  
Please in dicate the quality of language in the manuscript:  
 
Not suitable for publication unless extensively edited  
 
Declaration of competing interests  
Please complete a declaration of competing interests, considering the following questions:  
 
1. Have you in the past five years received reimbursements, fees, funding, or salary from an 
organisation that may in any way gain or lose financially from the publication of this 
manuscript, either now or in the future?  
 
2. Do you hold any stocks or shares in an organisation that may in any way gain or lose 
financially from the publication of this manuscript, either now or in the future?  
 
3. Do you hold or are you currently applying for any patents relating to the content of the 
manuscript?  
 
4. Have you received reimbursements, fees, funding, or salary from an organization tha t 
holds or has applied for patents relating to the content of the manuscript?  
 
5. Do you have any other financial competing interests?  
 
6. Do you have any non -financial competing interests in relation to this paper?  
 
If you can answer no to all of the above, wri te 'I declare that I have no competing interests' 
below. If your reply is yes to any, please give details below.  
 
I declare that I have no competing interests  
 
I agree to the open peer review policy of the journal. I understand that my name will be include d 
on my report to the authors and, if the manuscript is accepted for publication, my named report 
including any attachments I upload will be posted on the website along with the authors' 
responses. I agree for my report to be made available under an Open A ccess Creative Commons 
CC-BY license ( http://creativecommons.org/licenses/by/4.0/ ). I understand that any comments 
which I do not wish to be included in my named report can be included as confidential comments 
to the editors, which will not be published.  
 
I agree to the open peer review policy of the journal  
Reviewer ’s report  
 
Title:  Is Discard Better than Return Gastric Residual Aspirates: A Systematic Review and M eta-
analysis  
 
Version: 1 Date: 13 Mar 2019 
 
Reviewer:  Thangaraj  Abiramalatha  
 
Reviewer’s report:  
 
I thank the authors for  attempting to revise. I am sorry to state that the revision is grossly 
inadequate. The authors have not done many of the major changes suggested.  
 
 
Major comments  
 
1. Title: The primary outcome has to be included in the title. 'gastric residual volume' can not 
be the primary outcome, because it is not a clinical outcome.  
 
2. The outcomes (primary and secondary) are still not clearly stated and defined. I cannot 
find the outcomes in the methods section.  
 
3. Methods ln 123: "The source of heterogeneity was also assessed with subgroup analyses 
according to patients' characteristics, intervention difference among trials, as well as the 
sensitivity analyses for each study" - is vague. Subgroup analyses need to be pre -defined 
specifically.  
 
4. Eligibility criteria for  inclusion in the review need to be clearly defined.  
 
a. Participants - age groups (since the neonatal study was not included),  
 
c. Timing of starting and ending of the intervention  
 
- Not clearly defined still.  
 
5. Risk of bias assessment in individual studies (for included trials) - Table could be 
included. If there is space constraint, the table can be made as 'online only' file  
 
- Is not done. The pictures give only whether its low, high or unclear risk. 
The details for each component have to be presented as a table for each 
trial. The authors can see any Cochrane review for reference.  
 
6. Information on 'allocation concealment' is very important. Bcoz, without it, the 
randomization is not valid. The authors shou ld try to contact the trial authors to get the 
information in each included trial.  
7. Behairy 2014 - method of randomization is not clear. The study is called as a 'quasi -
experimental study'. Booker 2000 - method of randomization is not clear.  
 
- If the au thors cannot get the information, then they cannot be graded as 
'low risk' for randomization like how they have done.  
 
8. Gastric emptying delay: The numbers in the meta -analysis differ from those reported in 
the original studies. Are the authors looking at  'number of episodes of gastric emptying 
delay' or 'number of patients with episodes of gastric emptying delay'? It is confusing. 
This is the reason why each outcome needs to be pre -defined.  
 
- I cannot see the definitions for any outcome in the methods par t. 
 
9. GRADE SoF (Summary of Findings) table to be included. It will give the level of 
evidence for each outcome. Conclusion has to be written based on the GRADE level of 
evidence for each outcome  
 
- Is not done. Table 2 is not acceptable. The authors need t o grade the level 
of evidence for each outcome.  
 
10. The discussion reads very vague and all mixed up. Many points are getting repeated. 
Needs a major revision.  
 
 
Minor comments  
 
1. Abstract ln 28: 'The management of gastric residual aspirates is essential t o the prognosis 
of critically ill patients with enteral nutrition' - is too declarative. Needs to be changed or 
modified.  
 
2. Background ln 52: 'nasal tube' can be rephrased as 'nasogastric or orogastric tube'  
 
3. Background ln 59 - 'et al' should be removed  
 
4. Many spelling errors such as: 'focused' collaborationon'  
 
5. Methods ln 87: The search strategy for each database was adapted from the search 
strategies used in Pubmed and the instructions and rules of each database - sentence 
needs to be rephrased  
 
6. Methods ln 97: 'The case reports, series, qualitative studies and review articles were 
excluded' - This sentence can be removed, as there is no need for it.  
 
7. Methods ln 81, 98 -100, 104, 108, 117: Two review authors, third author - Which authors? 
The initi als of the author can be written in brackets  
 
8. Methods ln 99 - 'consensus' can be used instead of 'consents'  
 
9. Methods ln 116: the reference for 'Revman 5' has to be added as a citation  
 
10. Methods lines 123 -126: The sentences can be modified as 'planned  to assess' rather than 
'assessed' for subgroup analyses and funnel plot, since these were only planned and not 
done.  
 
11. Results ln 143: "For the results, three RCTs[15, 17, 18] favored the return of gastric 
residual aspirates, and one RCT[16] found no su periority of discard or return of gastric 
residual  aspirates on critical ill patients" - this line needs to be removed. Bcoz this 
paragraph is to summarize only the methods of the included studies, not the results.  
 
12. Results ln 150: "none of the include d RCTs reported allocation blinding, one RCT 
reported significant exposure of allocation, the rest three RCTs[16 -18] remained unclear" 
- sentence is vague, needs to be rephrased. Use 'allocation concealment' instead of 
'allocation blinding'  
 
13. Figures 2 &  3 - any one figure is adequate. Since both the figures convey the same 
information.  
 
Are the methods appropriate and well described?  
If not, please specify what is required in your comments to the authors.  
 
No 
 
Does the work include the necessary controls?  
If not, please specify which controls are required in your comments to the authors.  
 
Yes 
 
Are the conclusions drawn adequately supported by the data shown?  
If not, please explain in your comments to the authors.  
 
Yes 
 
Are you able to assess any statistics in the manuscript or would yo u recommend an 
additional statistical review?  
If an additional statistical review is recommended, please specify what aspects require further 
assessment in your comments to the editors.  
 
I recommend additional statistical review  
 
Quality of written English  
Please in dicate the quality of language in the manuscript:  
 
Not suitable for publication unless extensively edited  
 
Declaration of competing interests  
Please complete a declaration of competing interests, considering the following questions:  
 
1. Have you in the past five years received reimbursements, fees, funding, or salary from an 
organisation that may in any way gain or lose financially from the publication of this 
manuscript, either now or in the future?  
 
2. Do you hold any stocks or shares in an organisation that may in any way gain or lose 
financially from the publication of this manuscript, either now or in the future?  
 
3. Do you hold or are you currently applying for any patents relating to the content of the 
manuscript?  
 
4. Have you received reimbursements, fees, funding, or salary from an organization tha t 
holds or has applied for patents relating to the content of the manuscript?  
 
5. Do you have any other financial competing interests?  
 
6. Do you have any non -financial competing interests in relation to this paper?  
 
If you can answer no to all of the above, wri te 'I declare that I have no competing interests' 
below. If your reply is yes to any, please give details below.  
 
I declare that I have no competing interests  
 
I agree to the open peer review policy of the journal. I understand that my name will be include d 
on my report to the authors and, if the manuscript is accepted for publication, my named report 
including any attachments I upload will be posted on the website along with the authors' 
responses. I agree for my report to be made available under an Open A ccess Creative Commons 
CC-BY license ( http://creativecommons.org/licenses/by/4.0/ ). I understand that any comments 
which I do not wish to be included in my named report can be included as confidential comments 
to the editors, which will not be published.  
 
I agree to the open peer review policy of the journal  
Please review this paper.
user
Reviewer ’s report  
 
Title:  Is Discard Better than Return Gastric Residual Aspirates: A Systematic Review and M eta-
analysis  
 
Version: 1 Date: 13 Mar 2019 
 
Reviewer:  Thangaraj  Abiramalatha  
 
Reviewer’s report:  
 
I thank the authors for  attempting to revise. I am sorry to state that the revision is grossly 
inadequate. The authors have not done many of the major changes suggested.  
 
 
Major comments  
 
1. Title: The primary outcome has to be included in the title. 'gastric residual volume' can not 
be the primary outcome, because it is not a clinical outcome.  
 
2. The outcomes (primary and secondary) are still not clearly stated and defined. I cannot 
find the outcomes in the methods section.  
 
3. Methods ln 123: "The source of heterogeneity was also assessed with subgroup analyses 
according to patients' characteristics, intervention difference among trials, as well as the 
sensitivity analyses for each study" - is vague. Subgroup analyses need to be pre -defined 
specifically.  
 
4. Eligibility criteria for  inclusion in the review need to be clearly defined.  
 
a. Participants - age groups (since the neonatal study was not included),  
 
c. Timing of starting and ending of the intervention  
 
- Not clearly defined still.  
 
5. Risk of bias assessment in individual studies (for included trials) - Table could be 
included. If there is space constraint, the table can be made as 'online only' file  
 
- Is not done. The pictures give only whether its low, high or unclear risk. 
The details for each component have to be presented as a table for each 
trial. The authors can see any Cochrane review for reference.  
 
6. Information on 'allocation concealment' is very important. Bcoz, without it, the 
randomization is not valid. The authors shou ld try to contact the trial authors to get the 
information in each included trial.  
7. Behairy 2014 - method of randomization is not clear. The study is called as a 'quasi -
experimental study'. Booker 2000 - method of randomization is not clear.  
 
- If the au thors cannot get the information, then they cannot be graded as 
'low risk' for randomization like how they have done.  
 
8. Gastric emptying delay: The numbers in the meta -analysis differ from those reported in 
the original studies. Are the authors looking at  'number of episodes of gastric emptying 
delay' or 'number of patients with episodes of gastric emptying delay'? It is confusing. 
This is the reason why each outcome needs to be pre -defined.  
 
- I cannot see the definitions for any outcome in the methods par t. 
 
9. GRADE SoF (Summary of Findings) table to be included. It will give the level of 
evidence for each outcome. Conclusion has to be written based on the GRADE level of 
evidence for each outcome  
 
- Is not done. Table 2 is not acceptable. The authors need t o grade the level 
of evidence for each outcome.  
 
10. The discussion reads very vague and all mixed up. Many points are getting repeated. 
Needs a major revision.  
 
 
Minor comments  
 
1. Abstract ln 28: 'The management of gastric residual aspirates is essential t o the prognosis 
of critically ill patients with enteral nutrition' - is too declarative. Needs to be changed or 
modified.  
 
2. Background ln 52: 'nasal tube' can be rephrased as 'nasogastric or orogastric tube'  
 
3. Background ln 59 - 'et al' should be removed  
 
4. Many spelling errors such as: 'focused' collaborationon'  
 
5. Methods ln 87: The search strategy for each database was adapted from the search 
strategies used in Pubmed and the instructions and rules of each database - sentence 
needs to be rephrased  
 
6. Methods ln 97: 'The case reports, series, qualitative studies and review articles were 
excluded' - This sentence can be removed, as there is no need for it.  
 
7. Methods ln 81, 98 -100, 104, 108, 117: Two review authors, third author - Which authors? 
The initi als of the author can be written in brackets  
 
8. Methods ln 99 - 'consensus' can be used instead of 'consents'  
 
9. Methods ln 116: the reference for 'Revman 5' has to be added as a citation  
 
10. Methods lines 123 -126: The sentences can be modified as 'planned  to assess' rather than 
'assessed' for subgroup analyses and funnel plot, since these were only planned and not 
done.  
 
11. Results ln 143: "For the results, three RCTs[15, 17, 18] favored the return of gastric 
residual aspirates, and one RCT[16] found no su periority of discard or return of gastric 
residual  aspirates on critical ill patients" - this line needs to be removed. Bcoz this 
paragraph is to summarize only the methods of the included studies, not the results.  
 
12. Results ln 150: "none of the include d RCTs reported allocation blinding, one RCT 
reported significant exposure of allocation, the rest three RCTs[16 -18] remained unclear" 
- sentence is vague, needs to be rephrased. Use 'allocation concealment' instead of 
'allocation blinding'  
 
13. Figures 2 &  3 - any one figure is adequate. Since both the figures convey the same 
information.  
 
Are the methods appropriate and well described?  
If not, please specify what is required in your comments to the authors.  
 
No 
 
Does the work include the necessary controls?  
If not, please specify which controls are required in your comments to the authors.  
 
Yes 
 
Are the conclusions drawn adequately supported by the data shown?  
If not, please explain in your comments to the authors.  
 
Yes 
 
Are you able to assess any statistics in the manuscript or would yo u recommend an 
additional statistical review?  
If an additional statistical review is recommended, please specify what aspects require further 
assessment in your comments to the editors.  
 
I recommend additional statistical review  
 
Quality of written English  
Please in dicate the quality of language in the manuscript:  
 
Not suitable for publication unless extensively edited  
 
Declaration of competing interests  
Please complete a declaration of competing interests, considering the following questions:  
 
1. Have you in the past five years received reimbursements, fees, funding, or salary from an 
organisation that may in any way gain or lose financially from the publication of this 
manuscript, either now or in the future?  
 
2. Do you hold any stocks or shares in an organisation that may in any way gain or lose 
financially from the publication of this manuscript, either now or in the future?  
 
3. Do you hold or are you currently applying for any patents relating to the content of the 
manuscript?  
 
4. Have you received reimbursements, fees, funding, or salary from an organization tha t 
holds or has applied for patents relating to the content of the manuscript?  
 
5. Do you have any other financial competing interests?  
 
6. Do you have any non -financial competing interests in relation to this paper?  
 
If you can answer no to all of the above, wri te 'I declare that I have no competing interests' 
below. If your reply is yes to any, please give details below.  
 
I declare that I have no competing interests  
 
I agree to the open peer review policy of the journal. I understand that my name will be include d 
on my report to the authors and, if the manuscript is accepted for publication, my named report 
including any attachments I upload will be posted on the website along with the authors' 
responses. I agree for my report to be made available under an Open A ccess Creative Commons 
CC-BY license ( http://creativecommons.org/licenses/by/4.0/ ). I understand that any comments 
which I do not wish to be included in my named report can be included as confidential comments 
to the editors, which will not be published.  
 
I agree to the open peer review policy of the journal  
assistant