Variability in Anesthesia Models of Care in Cardiac Surgery
Round 1
Reviewer 1 Report
The authors present an article looking at the variability in Anesthesia models of care during cardiac surgery
General Comments:
To look at which practitioners provide anesthesia during cardiac surgery is an interesting and important topic. However, I am not sure this study gives us full insight or can tell us anything about outcome.
Specific Comments:
“The authors hypothesize that there exists a large variability in the composition, structure and functioning of the anesthesia providing team in cardiac surgery across programs”.
Surveys are always difficult to evaluate because of the low voluntary respond rate.
40 programs from across the world answered. What’s the respond rate? How many surveys were sent?
What were the questions asked? (I don’t see an appendix with the originally questionnaire)
It is very hard to draw any conclusions from this survey when most countries only have 1 response. When CRNAs provide anesthesia are they working by themselves or are they supervised by an attending anesthesiologist?
Dedicated cardiothoracic anesthesiologist does that mean they are fellowship trained? That would be interesting to know
What do we know about outcome and providers? Does it matter who provides anesthesia for these complex patients? How will you evaluate outcome by providers?
In several places in the manuscript it is referred to outcome and handover, that this might be different when different providers are responsible for the care of patients. But we don’t know that. This survey does not answer that question.
An interesting question on the survey would be, how is handover given, is there a protocolized handover system used? Like “a formula one” sign out? This can decrease errors and improve outcome.
Also in the conclusion the authors assume the anesthesia providers change during a case. We don’t know that. That would be a question to have on the survey: do the providers normally finish the cases they start or will another provider take over the case?
Table 2 is a nice table demonstrating what kind of services each program performs but it doesn’t really give any extra insight to the providers or the anesthesia model.
Since most of this data is in the STS database, why not use that data or use the data to compare with the survey results?
Author Response
please see attached overall response summary.
thank you for your time reviewing our manuscript
-michael
Author Response File: 
Author Response.pdf
Reviewer 2 Report
McCallister et al. provide a small survey of the composition of anaesthesia teams in the delivery of cardiac surgery. The response rate to the survey was very low, which is a major limitation, but the results are important for the improvement of patient care. The survey shows that there is substantial heterogeneity in the composition of anaesthesia teams in cardiac surgery with regards to roles (doctors, nurses) and training (fellow, no fellow). Unfortunately, no outcome data is provided, but this should be investigated in future studies. There are the following comments.:
Introduction
- Page 1, line 29-31: Provide reference(s), if any.
Methods
- More information about the “listserv” communication forum is needed. How are/were hospitals recruited? What is the aim of this forum? Who is in charge of this forum? Is there any member fee or are there any direct benefits from participation? How many of countries hospitals with cardiac surgery are reflected by this forum? Who (doctors, nurses, head of departments?) represents the sites in this forum? Who fills in the data? How did you present the survey? Who answered the survey (nurses, doctors)? Were there any reminders if sites did not answer? If yes, how many?
- Add as supplementary data the provided questionnaire.
- Provide a rationale and detailed description on how the survey was created (which variables and why).
Results
- Line 42-45: this belongs to the methods section
- Table 1: provide the total number of programmes asked for participation
- Table 2: define multiple training programmes
- A table showing surgical programme size(s) according to country would be helpful
Discussion
- Line 91-93: this sentence is not clear, please explain better
- Line 94-95: provide references
- Line 98: elaborate further how the finding of your survey relate to this statement
- Line 107: provide the reference
- Line 114: team experience with one another? In which variable is this represented?
- Line 116: correct this statement, you have not provided any outcome data
- Line 118-119: what is the idea of this link here?
- Please discuss your findings in the context of the following references: 1) Sun EC, Anesthesia Care Team Composition and Surgical Outcomes. Anaesthesiology 2018;129:700-709. 2) Liu TC, Survey of 11-year anesthesia-related mortality and analysis of its associated factors in Taiwan. Acta Anaesthesiol Taiwan. 2010;48:56-61. 3) Posner KL, Trends in quality of anesthesia care associated with changing staffing patterns, productivity, and concurrency of case supervision in a teaching hospital. Anesthesiology. 1999;91:839-4
- Please perform an extensive literature search to ensure you have integrated all important studies related to your work.
Limitations
- Generally move most of this section to the discussion, as you are not only mentioning limitations here.
Conclusions
- Too long section with too many discussion points. Move all points not being a true and sole conclusion to the discussion section.
Author Response
please see attached overall response summary.
thank you for your time reviewing our manuscript
-michael
Author Response File: Author Response.pdf
Reviewer 3 Report
I have read and enjoyed your manuscript very much.
The manuscript, even if it has some limitations (eg the limited number of centers and answers), nevertheless focuses on a question of primary importance: the skill of the team and the volume of interventions as a condition associated with an improvement in the outcome.
The heart surgery environment, even when made up of staff with little previous experiences, however, for the particularity of the patient, selects highly specialized personnel, so that integration with the expertise of the elderly team is very rapid.
From the literature it emerges that the incidence of the anesthesiology team on the outcame of the cardiac surgery patient is really unimportant.
However, instead, I believe that only a harmonization of the anesthesiology-surgical-perfusionist teams can lead to an excellent outcome in cardiac surgery.
Furthermore, if the other components of the team rotate (hours, rests, changes, etc.) without negatively affecting the progress of the intervention, perhaps it depends on the fact that they follow planned strategies and EBM, while the surgeons have skills related to the number of procedures performed, and they are not easily interchangeable, in fact there is no evidence based surgery.
Author Response
please see attached overall response summary.
thank you for your time reviewing our manuscript
-michael
Author Response File: Author Response.pdf
Reviewer 4 Report
The topic you explored is new and interesting,
however the community you involved in your analysis is not well defined (line 42,43,44...) and maybe represent only a small group . Pleas clarify this point and add more information and underline this aspect in Title as well in Introduction and Materials and Methods
no others comment
Thank you
Author Response
please see attached overall response summary.
thank you for your time reviewing our manuscript
-michael
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
I am still confused with the comments about handover and practitioners in the introduction and the entire manuscript. The survey is about different practitioners and not handover and outcome. This survey does not answer that.
Author Response
please see attached
-michael
Author Response File: Author Response.pdf
Reviewer 2 Report
Thank you for the revisions, your manuscript has undergone substantial improvement. However, there are still improvements needed, particularly in the methods section.
Methods
- Provide the number of participants in the forum at the date of survey distribution, not at the time of manuscript submission. Is 524 corresponding to hospitals or individual members (i.e. can a hospital have several members)?
- How many countries were represented in the forum and the timepoint of survey distribution?
- How did the participants “express interest” in the survey? Why did you send it only to those? This way, you have introduced relevant selection bias. If done so, please describe in detail in the methods and mention as limitation.
- Table 1: the comment is not answered!
Results
- The grouping of the program sizes is inconsistent. In the text, you group into <200, 201-749 and >750/cases per year. In Table 1 and 3 the grouping is 51-200, 201-750 and >750. Please be consistent.
- Please indicate your response rate to the survey and discuss whether this is sufficient compared to other large scale surveys (e.g. the ACC, STS surveys you mention in the answer to comment 1 of reviewer 1).
Discussion
- “Studies specifically exploring the role of anesthesia and various models of care in cardiac surgical cases, suggest that patient factors have the greatest impact on outcomes, followed by surgeon variables. However, these studies do acknowledge the potential role that anesthesia related variables – such as team composition, models of care, volume of cases, and overall experience – might have on outcomes (refences already).” -> Please provide the references here.
- What were the results of your additional literature review (as requested by the previous comments)? For which terms and in which database(s) did you search? This reviewer found 3 important additional references at first attempt in Pubmed, this raises the suspicion that your literature search was not extensive enough. Please describe (not in the manuscript, but as answer) how you improved this.
Limitations
- Delete “(and potentially significant – depending on how defined)”.
- Delete the quotation mark from “anaesthesia”. It is anaesthesia itself.
Conclusions
- Simplify the last sentence, too long and not straight to the point.
Author Response
please see attached
-michael
Author Response File: Author Response.pdf
Reviewer 4 Report
No comments after revision
Thank you
Author Response
please see attached
-michael
Author Response File: Author Response.pdf
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
Round 1
Reviewer 1 Report
The question of team work in cardiac surgery and mortality is quite repeated in the literature and has few or poor results.
The volume of each center affects mortality more than the individual operator. However, if we wanted to study the impact of operators on mortality, then the literature tells us that surgeons have a greater impact, even if the percentage of impact is very low, compared to anesthetists who have a relevance close to zero. This is mainly because surgeons contribute directly to any damage to the myocardium during surgery and in the immediate postoperative period. But anesthetists can determine, with their anesthesiologic behaviors, problems of another nature such as AKI or delirium that certainly impact on the outcome.
The turnover in the operating room and the changes that the anesthesiologists have on the same surgery compared to the surgeon can affect the correct management of the patient's hemodynamic stability, but we could hardly measure the performance of this activity.
The survey must be taken with great caution and cannot give us absolutely any information on the matter.
It is necessary to find the team's performance indices and not to discriminate the intervention of the individual protagonists on morbidity and mortality.
Author Response
The comments by the Reviewer illustrate the very importance of doing this type of study. Specifically, and we added additional comments on this in a new "limitations" paragraph (including some references) that help better understand that while the surgeon clearly has an impact on the outcome of the patient, that there is growing interest in studying the role of the anesthesia team. This is particularly important - since, as the Reviewer comments (and we do not discuss the details since it is a little out of the focus of this paper) that anesthesia can have a role in AKI and delirium - both are topics that have clearly been linked to difficult and potentially poor outcomes in cardiac surgery. Hence, the need to better understand and study the roles of different models of care, as we suggest - and are currently being explored by major CV professional societies (as mentioned and references).
Hopefully, the addition of our limitations section help to address and clarify this point
Reviewer 2 Report
Dear Authors,
I miss an important differentiation between the "dedicated cardiothoracic anesthesiologist" and "the anesthesiologist that gives once and a while anesthesia for cardiac surgery". The first will be much more involved in the whole perioperative proces than the later. In Europe and many other countries in the world CRNA does not exist or are certainly not allowed to give anesthesia by them self.
Second: since the low response it is hardly to call an international study, or if so, it is not representative.
27 or 67.5% of the responders are USA + 1 Canadien. The other 12 responders are divided over Asia, South-America, Europe, Australia and Africa, since the number is so small you cannot generalize or conclude anything. Maybe you should focus on North-America.
Kind regards
Author Response
We appreciate the comments by this Reviewer and, as such, have made a few changes to the manuscript. Firstly, in the table legend, we better define what a "dedicated cardiothoracic anesthesiologist" is. We also have added a limitations section to this manuscript to address some of the concerns regarding the limited number of responses - and the limited number from programs outside of the USA. Clearly, we acknowledge the difficulties in drawing definitive conclusions other than suggesting that such variabilities exists and that we need to better study them to understand their impact on patient outcomes - a concept that is also the foundation for work (as mentioned and referenced) by key major professional societies (STS and SCA).
Hopefully our responses in the manuscript are appropriate and that it is now acceptable for publication.
Round 2
Reviewer 2 Report
none
