An Early Warning Marker in Acute Respiratory Failure: The Prognostic Significance of the PaCO₂–ETCO₂ Gap During Noninvasive Ventilation

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Thank you for permitting me to review this manuscript 

In this prospective study the authors assessed the impact of the increase in the paco2 and ETCO2  in respiratory prognosis , they sugest an increse in this difference may predict further deterioration and  need for respiraory support 

The authors should clearly describe their local criteria , for ventilation , icu admission and intubation 

 for such a little ppopulation it is difficult to conclude as other values which can be more easily obtained could show similar results 

Please expose the ventilation values for each group of patients especially how we can assume the absence of leak for etco2 ? please provide the difference betwenn volume inspired and expired (to confirm the absence of leak) especcially in the NON invasive ventilation setting 

It appears that hco3 measurement was significanly different between groups from the first measurement hy this value cannot be considered also ? 

 

 

 

 

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Dear authors,

I find this article interesting because the ability to detect respiratory failure early in patients treated with non-invasive mechanical ventilation who will require invasive mechanical ventilation will allow us to perform it early and under the best possible conditions for the patient, improving their survival.

My comments or suggestions regarding the article are as follows:

References 5 and 6 are very outdated; it would be advisable to update them if possible.

The type of sampling used in the study should be indicated: non-probability convenience sampling.

It would be advisable to clarify the inclusion criterion "suitable for non-invasive mechanical ventilation." The authors are referring to patients who required non-invasive mechanical ventilation due to their respiratory condition.

In the results, the authors state that "patients were classified into two groups according to the need for intubation." The methodology should specify the clinical or analytical criteria used to determine intubation and connection to mechanical ventilation in these patients.

In Table 2, what do the authors mean by the word "fire"? Are they referring to temperature?

Table 2 should specify which variables were compared using the Student's t-test and which were compared using the Mann-Whitney U test. The same applies to Table 6.

Considering the study's limitations due to the number of patients and the sampling method, do the authors believe that a delta difference greater than 2.9 indicates a failure of non-invasive mechanical ventilation and that these patients should be intubated and placed on invasive mechanical ventilation? What implications might using such a small difference to guide intubation have for clinical practice? These aspects should be addressed in more detail in the discussion.

Kind regards.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have adequately improved the manuscript 

Reviewer 2 Report

Comments and Suggestions for Authors

Dear authors,

The manuscript has been sufficiently improved, and I have no further comments or suggestions.

Kind regards.