Complications after Thoracocentesis and Chest Drain Insertion: A Single Centre Study from the North East of England
Round 1
Reviewer 1 Report
Lines 51-53 - Im a huge fan of checklists, but nothing in your study seeks to test the usefulness of its application here and this should probably be removed.
Line 75 - this is not a complete sentence.
Line 83 - I suspect that your rate of hematomas in this retrospective study is underestimated, similar to your risk of PTX in the absence of prospectively monitoring for them. I would imagine you would find the clinically significant bleeds, but hard to make an estimation of the final denominator
Line 104 - After reading this a few times, I assume you mean the 92 patients who under went ICD placement for a pleural effusion and had air seen on CXR, but the preceding paragraph is too long to quickly make that connection - this should be expanded.
Line 136 - There is nothing in annex 2 that describes limiting drainage to 1L. If >1500mL, it suggests clamping for an hour. Annex 2 specific to ICDs, no mention of thoracentesis guidelines.
Line 143 - You really can't make any connections to check lists with the available data. Hard to imagine it would have any effect on hematomas.
Line 159 - I suspect your PTX rate is also lower in the setting of limiting drainage to 1L. With less drainage, less likely to cause significantly negative intrapleural pressure and shearing (as you described in your discussion of tears for large effusions and ICD placement).
Line 165 - There is also no data that I have seen to support the use of routine antibiotics in tunneled pleural catheter placement. The citation listed is a description of your local practice where you give them, but does not by itself justify antibiotics.
Line 180 - Your discussion of checklists makes me uncomfortable. If uptake is variable (and unreportable) then how can we make anything from the discussion that the 93 patients without a complication did not have a checklist?
Author Response
Lines 51-53 - Im a huge fan of checklists, but nothing in your study seeks to test the usefulness of its application here and this should probably be removed.
We agree with this comment, and this has been removed
Line 75 - this is not a complete sentence.
We agree with this and this has been re-written.
Line 83 - I suspect that your rate of hematomas in this retrospective study is underestimated, similar to your risk of PTX in the absence of prospectively monitoring for them. I would imagine you would find the clinically significant bleeds, but hard to make an estimation of the final denominator
We agree with this and make a note of it in the limitations. (final paragraph of article)
Line 104 - After reading this a few times, I assume you mean the 92 patients who under went ICD placement for a pleural effusion and had air seen on CXR, but the preceding paragraph is too long to quickly make that connection - this should be expanded.
We agree and have modified line 94 to make it more succint. I have also made the paragraph starting with line 104 more succint by shortening the sentences and adding some details.
Line 136 - There is nothing in annex 2 that describes limiting drainage to 1L. If >1500mL, it suggests clamping for an hour. Annex 2 specific to ICDs, no mention of thoracentesis guidelines.
We made an error with this and this has been rectified. I have re-worded it as such: No re-expansion pulmonary edema is attributable to adherence to local guidance (annex 1) of close observation and limitation of rate of drainage
Line 143 - You really can't make any connections to check lists with the available data. Hard to imagine it would have any effect on hematomas.
We agree and have deleted the sentence.
Line 159 - I suspect your PTX rate is also lower in the setting of limiting drainage to 1L. With less drainage, less likely to cause significantly negative intrapleural pressure and shearing (as you described in your discussion of tears for large effusions and ICD placement).
We agree and have put a line to that effect.
Line 165 - There is also no data that I have seen to support the use of routine antibiotics in tunneled pleural catheter placement. The citation listed is a description of your local practice where you give them, but does not by itself justify antibiotics.
That's true, and thus, I have removed the sentence and reference 12 and 13.
Line 180 - Your discussion of checklists makes me uncomfortable. If uptake is variable (and unreportable) then how can we make anything from the discussion that the 93 patients without a complication did not have a checklist?
We agree to this, and make a note of the suturing of chest drains. Adhering to the checklist and suturing the drains in might have prevented the drain fall out.
Reviewer 2 Report
Dear Authors, Dear Editor,
Thank you for the possibility of revision of the manuscript entitled ”Complications after thoracocentesis and chest drain insertion: A single centre study from the North East of England”. It is a retrospective study that analysed inpatient records in 5-year time to estimate the type and percentage of complication after thoracentesis and chest drain insertion. I found the study simple, but interesting and adding to current knowledge about pleural procedures.
However, I have a few comments and suggestions, that I present below:
-The study has 2 aims. The first one is clear, however, the second seems incorrect for me (line 55-57) or it is my misunderstanding. Is it possible to retrospectively “test the usefulness of the application of the local invasive checklists (annex 1 and 52) and the drainage observation proforma (annex 3) to prevent complications” if it was a new, proposed checklist and observation proforma? If the documents were previously prepared, before study beginning it should be described in the Method section of the manuscript.
-Please explain how you assessed the usefulness of the checklists – did you compare it with any other tools, in how many cases it was fulfilled, was there any relation between use of checklists and presence of AEs?
- Based on the text the manuscript seems to be analysis of retrospective data, while the title inform it’s “study protocol”. It is not clear for me
-I would propose to present in the Methods section inclusion and exclusion criteria as age, size of drain etc. Why were patients with the large bore chest drains and tunneled catheters excluded? (line 71).
-According to the data presented in the Results section patients younger than 18 years were excluded (line 72), while in patients characteristics range of age was 17-97 (line 18 and 74). It is inconsistent.
-please check if percentages in line 75 are correct (in my opinion 199/1159=17.2% and 960/1159=82.8%)
-line 76 and 77 – is it percentage of whole procedures or percentage of ICDs?
-Please check if numbers are correct (line 76), if there were 960 patients with pleural effusion, and there were 280 thoracocenteses (all for pleural effusion) and 672 ICDs for pleural effusion, we miss 8 patients (280+672 =952).
- I would consider to present definitions of different complications in methods section not in results (line 83)
-line 93 – have all patients with pleural effusion chest X-ray performed after the procedure (you mentioned in methods section that “CXRs after thoracenteses are at the discretion of the physician”.In how many cases it was performed? I think it is crucial information to assess the percentage of pneumothorax after the procedure, and percentage of pneumothorax ex vacuo.
-How to understand difference in pneumothorax rate presented in line 93 (102 chest x-ray presented air in pleural space) and line 113 – there was rate of 9 pneumothoraces? The presentation of the results is not always clear for me
- line 119. Is the structure of the sentence correct? :”They both presented within with 2 weeks…”
-surprising but interesting for me is fall out percentage of sutured drains. (24 cases?) – what was the reason for that in your study? maybe it is worth consideration if there are any predisposing factors as cachexia? You discuss it with other study results, but maybe its worth to hypothesize some factors/possible causes?
- I do really miss presentation of your results on graphs or in tables, I think it would give even more information and make your results more interesting and easier to read
-I’m sorry to say, that I do not understand the problem of checklists – your aim is to implement them and assess their usefulness (how?), or they had been already used and you planned to assessed if they are helpful in reducing number of complications? (how was it assessed)? There is no data about this subject in Result section.
I wish the Authors all the best!
Author Response
The study has 2 aims. The first one is clear, however, the second seems incorrect for me (line 55-57) or it is my misunderstanding. Is it possible to retrospectively “test the usefulness of the application of the local invasive checklists (annex 1 and 52) and the drainage observation proforma (annex 3) to prevent complications” if it was a new, proposed checklist and observation proforma? If the documents were previously prepared, before study beginning it should be described in the Method section of the manuscript.
We agree with this, and as per the other reviewers' comments, we have removed this inference about the checklists and not discussing this anymore. The safety aspect is concentrated on.
-Please explain how you assessed the usefulness of the checklists – did you compare it with any other tools, in how many cases it was fulfilled, was there any relation between use of checklists and presence of AEs?
See above point. Upon further review, we have agreed that we cannot test the usefulness of checklists and have thus removed the inferences from our paper.
- Based on the text the manuscript seems to be analysis of retrospective data, while the title inform it’s “study protocol”. It is not clear for me
I have removed this and written research paper at the top.
-I would propose to present in the Methods section inclusion and exclusion criteria as age, size of drain etc. Why were patients with the large bore chest drains and tunneled catheters excluded? (line 71).
I have expanded on this. Anyone above the age of 18 was included and dran size was 12french only. We only do large bore drains and tunnelled catheters in theatre and they have been part of other work that has already been published. thus we could not include them as well. Indwelling pleural catheters for malignancy related pleural effusions (europeanreview.org) and A review of the outcomes of rigid medical thoracoscopy in a large UK district general hospital. - Abstract - Europe PMC. we do not perform large bore drains in respiratory patients and transfer them to our local cardiothoracic centre.
-According to the data presented in the Results section patients younger than 18 years were excluded (line 72), while in patients characteristics range of age was 17-97 (line 18 and 74). It is inconsistent.
this is an error and i have rectified it to 18.
-please check if percentages in line 75 are correct (in my opinion 199/1159=17.2% and 960/1159=82.8%)
this is an error and i have rectified to the correct % as you stated
-line 76 and 77 – is it percentage of whole procedures or percentage of ICDs?
we agree that this paragraph was ambiguous and we have re-worded it and made it more succint.
-Please check if numbers are correct (line 76), if there were 960 patients with pleural effusion, and there were 280 thoracocenteses (all for pleural effusion) and 672 ICDs for pleural effusion, we miss 8 patients (280+672 =952).
we agree that this is confusing and have re-written it. 1159 procedures were done in total. 199 for pneumothorax and 960 for pleural effusions, the total is 1159.
280 thoracocenteses and 879 drains were done in total, so total is still 1159
of the 879 drains, 672 were done for effusions and 207 for pneumothorax. total is 879
8 patients were missing in the thoracentesis group. this has been added
- I would consider to present definitions of different complications in methods section not in results (line 83)
i think this is tricky, as then the methods section will be very long. i am happy to go with an editorial decision about it? let me know?
-line 93 – have all patients with pleural effusion chest X-ray performed after the procedure (you mentioned in methods section that “CXRs after thoracenteses are at the discretion of the physician”.In how many cases it was performed? I think it is crucial information to assess the percentage of pneumothorax after the procedure, and percentage of pneumothorax ex vacuo.
we did 960 procedures for pleural effusion, and only 702 post procedural x-rays were done. 102 of those showed air. as described, there were 9 pneumothoraces described. and yes we agree, that a small pneumothorax might have not been picked up by not doing an xray. so we have modified line 112 that the % rate of pneumothorax is probably 1.2% (9 out out 702). this is also mentioned in the limitations section.
-How to understand difference in pneumothorax rate presented in line 93 (102 chest x-ray presented air in pleural space) and line 113 – there was rate of 9 pneumothoraces? The presentation of the results is not always clear for me
we have re-written these few paragraphs and explained how that only true pneumthoraces were seen. all the others were pneumothoraces ex-vacuo/trapped lung/non-expandable lung.
- line 119. Is the structure of the sentence correct? :”They both presented within with 2 weeks…”
we have removed 'with' and hope that the sentence makes more sense now.
-surprising but interesting for me is fall out percentage of sutured drains. (24 cases?) – what was the reason for that in your study? maybe it is worth consideration if there are any predisposing factors as cachexia? You discuss it with other study results, but maybe its worth to hypothesize some factors/possible causes?
Fall out rate is 35 cases, 3%. this is not the whole reason for the study, but this is an important finding. 9 of the 35 cases were not sutured, and thus 24 happened for other reasons (patient tripping over drains, pulling them etc). i am not sure we can easily hypothesize. i am not sure there is any evidence for reasons for drain fall out such as cachexia and as such, i am reluctant to hypothesize.
Suturing is important (Asciak R, Addala D, Karimjee J et al. Chest Drain Fall-Out Rate According to Suturing Practices: A Retrospective Direct Comparison. Respiration. 2018;96(1):48-51. doi: 10.1159/000489230.)
- I do really miss presentation of your results on graphs or in tables, I think it would give even more information and make your results more interesting and easier to read
we agree, and have done a table. thanks
-I’m sorry to say, that I do not understand the problem of checklists – your aim is to implement them and assess their usefulness (how?), or they had been already used and you planned to assessed if they are helpful in reducing number of complications? (how was it assessed)? There is no data about this subject in Result section.
We agree with this and have removed most of the sections relating to checklists. Only this remains Our local pleural procedure invasive checklist is annexed (Annex 2). Uptake is variable (local unpublished data) and suturing is mandated. This would have perhaps prevented 9 of the non-sutured ICDs from not falling out, but this cannot be reliably inferred. An electronic system mandating the use of the checklist is currently being developed
Reviewer 3 Report
The article entitled ‘Complications after thoracocentesis and chest drain insertion: a single-center study from North East of England’
is a retrospective single-center study on complication rate after thoracocentesis and ICD insertion, a topic with a very lack of data.
Although this is a retrospective study with consequent limitations, I believe the number of cases examined (1159 procedures) and the methodology applied are two elements in favor of the publication of this article.
Author Response
Thank you, no response is required to this
Round 2
Reviewer 2 Report
Dear Authors,
Thank you for your answers and comments and changes made in the text. I do not have any additional comments.
I wish you good luck
Magdalena Grabczak
