Urgent-Start Peritoneal Dialysis: Current State and Future Directions

Round 1

Reviewer 1 Report

To the Editor of Kidney and Dialysis,

I thank you for the possibility to collaborate with your journal by reviewing Vogt and Shah’s manuscript “Urgent start peritoneal dialysis (USPD): current state and future directions”.

USPD is defined as peritoneal dialysis (PD) initiated within 14 days of catheter insertion. In this review, the authors describe the most recent data on USPD, including outcomes, complications, barriers to implementation, and areas for future research.

The manuscript is well written by experienced nephrologists who seem to know very well the topic and address an aspect that is not new, but has recently become relevant with the aim of implementing the diffusion of PD.

A broad examination of the various aspects of PD treatment is provided and emphasis is placed on the importance of distinguishing between emergent start PD within 72 hours and early start PD between 72 hours and 14 days.

Some comments:

1- the focus should be put by the authors into distinguishing various types of USPD: in the acute patient with AKI and in the one with chronic kidney disease (CKD). While in the case of AKI the indication to use PD has been widely used since the 1970s, the advent of central venous catheterization has effectively shifted the attention to emergency hemodialysis. In the second case, what are the real advantages of starting USPD early? this should be further expanded by the authors.

2- Another point that should be expanded is how the authors think that USPD can broaden the spread of PD, given that the training period, once the peritoneal catheter has been positioned, is generally 2-3 weeks in most Centers.

3- The mechanical complications are reported to be more frequent, 15-37% within two weeks of peritoneal catheter placement (Yang Y et al. PDI 2011) with USPD than with conventional start, while other authors did not found comparable differences in infectious and mechanical complications between break-in period of less or more than 24 hours (Xiaoqing Hu, et al. Front Endocrinol 2022).

However, little is reported on the type of PD after break-in in USPD: automated PD with reduced infusion volume or continuos ambulatory CAPD? The authors have to clarify because the first choice seems to be related to reduced incidence of ernias or mechanical complications.

LINE 32: many countries are creating incentives to increase PD: in several countries, however, economic incentives paradoxically have not led to a greater diffusion of PD either in the USA or in Europe. Please briefly expand this aspect.

LINE 64: “the most important aspects of patient selection criteria is patient preference”: I fully agree and I believe that an expansion of the theme of a pre-dialysis educational program contributes greatly to the larger diffusion of PD, perhaps limiting the need to start treatment urgently but planning it promptly and in the best possible way.

LINE 161: the authors report the study of Kim et al in 103 patients who started PD within 48 hours versus patients within 2-13 days. Mechanical complications occurred more frequently in the first group (28,2% versus 10,2%) with the need of repositioning the catheter in 14,6% versus 3,4% with a increase in discomfort for the patient and higher costs. Also other authors (Chin Phang C. Int Urol Nephrol 2021) report significantly higher dialysate leak (7.6% versus 0.8%), catheter malfunction (4.5% vs. 3.3%) and peritonitis (IRR) 3.10, 95% CI 1.29-7.44)  among 66/187 PD patients starting USPD compared with conventional-start PD. The possible side effects of USPD has to be remarked.

Moreover, is the surgical technique different in the placement of the peritoneal catheter in USPD versus conventional PD?

LINE 179, Infectious complications: analyzing various studies, although not RCTs, the authors concluded that no significant differences in peritonitis risk between USPD and conventional. These results seem also to be those of the Cochrane review (Htay H. Cochrane Database Syst Rev. 2021):“compared with HD initiated using a CVC, urgent-start PD may reduce the risk of bacteraemia and had uncertain effects on other complications of dialysis and technique and patient survival. In summary, there are very few studies directly comparing the outcomes of USPD and HD initiated using a CVC for patients with CKD who need to commence dialysis urgently. This evidence gap needs to be addressed in future studies”.

LINE 213: Interesting data about reduced costs of USPD versus urgent HD with CVC, but more attention had to be considered among different organization models: CVC positioning and/or peritoneal catheter by nephrologists and consequent permanent HD access creation. The costs differ if the placement of the peritoneal catheter occurs via percutaneously by a nephrologist, or if operating room or need of anesthetist are requested.

LINE 225: Barriers and strategies to optimize USPD.

A multidisciplinary approach is fundamental, because a team composed by nurses, doctors, psychologists, dietists, is an obligatory path for an efficient PD program and without it PD program will wreck and expanding the knowledge of the PD method also among medical and nursing staff, because those who don't know don't offer it to the patient: I agree with the authors when at LINE 285 said “patients may choose PD at higher rates when fully educated”.

LINE 312: Remote monitoring in PD may be important, a something more to help PD home technique diffusion but this paragraph seems to be not relevant for this topic.

Finally an interesting aspect that could be taken into consideration by the authors is the possible use of USPD during the recent covid-19 pandemic in reducing the surgical need for AVF setup, and in favoring home treatments, away from the risks of in-Center hospitalization.

Author Response

We greatly appreciate the thorough and important comments from the reviewer. Please see attached document for our specific responses.

Author Response File: Author Response.pdf

Reviewer 2 Report

The manuscript provides a comprehensive analysis of urgent start peritoneal dialysis (USPD), addressing clinical aspects, effectiveness, challenges, and future research prospects. While the chosen topic may not be considered highly novel and lacks a unique data perspective, its significance is evident. The core content is generally well-presented; nevertheless, certain areas could benefit from additional attention and improvement to meet publication standards.

1)  The introduction section should be more focused. It presently contains an abundance of statistics and data but lacks a clear structure.

2)  The review lacks a critical analysis of the referenced studies. Rather than simply outlining their findings, it would be more informative to discuss the strengths and limitations of these studies and their impact on the field. A more in-depth analysis of research gaps and areas necessitating further investigation would be valuable.

3) The paper addresses the problem of inconsistent terminology within the USPD field and suggests specific timing intervals for introducing the terms "emergent start peritoneal dialysis" and "early start peritoneal dialysis." However, the authors should provide further justification and clarify their stance to promote the adoption of these terms in the field.

4)   To prevent reader ambiguity, ensure that all abbreviations are introduced and defined upon their initial usage. For example, in the manuscript, both "peritoneal dialysis" and its abbreviation "PD" are frequently employed, potentially confusing the audience.

5)    As a reader, I strongly recommend incorporating high-quality figures into the paper. Doing so has the potential to substantially elevate the paper's overall quality and make it more comprehensible to the audience.

6) The manuscript is missing essential declarations, including Author Contributions, Conflict of Interest Statements, and funding information.

Author Response

We appreciate the important feedback by the reviewer that have helped improve our manuscript. Please see attached file for our specific responses.

Author Response File: Author Response.pdf

Reviewer 3 Report

This is an up-to-date and comprehensive review of the literature on urgent start peritoneal dialysis, a theme that deserves more attention from the nephrology community.  All major challenges and pertinent topics are addressed appropriately by the authors. The review contributes to the claim for uniform terminology and the need for a statement from peritoneal dialysis leaders on this important subject.     

Author Response

We thank the reviewer for their kind words.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

I appreciate the authors' reply and their attention to the suggestions proposed. Thank you now the manuscript seems to flow better

Author Response

We appreciate the reviewers efforts in improving our manuscript.

Reviewer 2 Report

Dear authors,

Thank you for resolving the previous issues and making the necessary corrections. The manuscript has improved greatly, and I appreciate your efforts.

I have just one additional suggestion: consider adding a title to Figure 1 rather than just a description. Additionally, it would be helpful to place text boxes next to each icon in Figure 1 for better understanding.

Author Response

We appreciate the additional suggestions by the reviewer. Descriptors have been added below each icon. Additionally, the figure is now called, "Rethinking Dialysis in the Urgent Start Patient."