Volume control and peritoneal dialysis

The very nature of peritoneal dialysis (PD) avoids many of the complications inherent in thrice-weekly in-center hemodialysis (IHD),1 including allowing for gentle ultrafiltration during all hours—day and night.2 Volume overload, however, is common with PD and should be addressed.3

Avoiding interdialytic symptoms associated with IHD

High rates of ultrafiltration during hemodialysis sessions are associated with higher rates of cardiovascular death and hospitalization, as well as increased incidence of intradialytic hypotension and longer post-dialysis recovery time.4–9

  • The concept of an interdialytic gap, along with all its associated complications, is often eliminated because the majority of PD is performed daily.2
  • PD may be a more effective therapy for patients who exhibit intolerability to the intermittency of hemodialysis due to heart failure comorbidities, whether in the facility or at home.10

PD and associated volume overload

Volume overload is one of the most common complications of PD.3 Appropriate PD prescription and continuous assessment of hydration status are critically important.3 Dialytic and nutritional management of salt and water is as important as weekly clearance of urea.2

  • In a prospective cohort study of more than 1,000 PD patients across Europe, the prevalence of relative volume overload was 57% at PD initiation and persisted for the duration of the 3-year study.11
  • In a small, randomized clinical study comparing a volume management educational intervention to conventional care, patients in the intervention group had improved volume status and fewer volume-related hospitalizations.12

Achieving euvolemia through PD prescriptions

High-quality PD prescriptions should aim to achieve euvolemia.An important component of this is maximizing ultrafiltration to the end of targeting “dry” weight.13 In the U.S., dry weight assessment in PD patients is often limited to monitoring edema and blood pressure (BP) without medication.14

  • Dietary approaches to managing fluid include restriction of salt and water intake, and glycemic control.2
  • Dialytic approaches to managing fluid include applying results of peritoneal equilibration testing, increasing adherence to the PD prescription, adjusting dwell time and fill volume, increasing the number of exchanges during each 24-hour interval, and use of icodextrin during a long-day dwell in high transporters.1,15
  • Both traditional measurements (body weight, pedal edema, and BP3) and newer assessment techniques (bioimpedance spectroscopy, N-terminal pro-brain natriuretic peptide (NT-proBNP), and lung water ultrasound) may be useful to assess volume status.16–20
    • A changing trend in the ratio of extracellular water to total body water may be indicative of worsening hydration status, but the trend may also reflect worsening inflammation or hypoalbuminemia.19

Prescribing diuretics to achieve euvolemia

Pharmacologic interventions should be applied in addition to making attempts to maximize adherence to the PD prescription.21

  • Loop diuretics, unlike thiazide diuretics, are a class of medications that can be effectively used in advanced chronic kidney disease and end-stage kidney disease to increase urine production.21
  • Once-daily furosemide (e.g., at 250 mg per day) can be an especially useful tactic in PD patients who possess residual kidney function (RKF), but have trouble achieving euvolemia.22
    • In a trial of 62 patients on continuous ambulatory PD, use of furosemide increased 24-hour urine volume by approximately 350 mL and 24-hour urinary sodium excretion by more than 3 mmol after one year.22
  • In a trial of 51 patients on continuous ambulatory PD, a “triple diuretic” regimen of furosemide (1000 mg/day), hydrochlorothiazide (100 mg/day), and spironolactone (50 mg/day) increased 24-hour urine volume by over 400 mL after 6 months, relative to a regimen of furosemide (1000 mg/day) alone.23
    • The “triple diuretic” regimen also improved hydration status, as measured by bioimpedance spectroscopy.23

BP control as a core parameter in assessing volume control 

With a conventional definition of >140/90 mmHg, over 90% of patients initiating PD were hypertensive.24Improvements in BP control were observed up to one year after initiating PD, however, these deteriorated over time.24

  • The optimal level of BP in PD patients is unknown—partly because of the absence of randomized clinical trials of BP targets in PD patients, and partly because of inconsistent findings in observational studies.25
    • Some studies have suggested intuitive associations of BP and increased cardiovascular and mortality risk.25,26
    • Others have reported that systolic BP below 110 mmHg is associated with increased risk of morbidity, likely as a result of confounding by cardiac function.25

Conclusion

PD is inherently customizable as a home therapy, providing many opportunities for the care team and patient to achieve volume control. However, the mechanics of PD partially depend on the transport status of the peritoneum, not an extracorporeal machine. Each patient presents unique challenges and conditions that may change due to complications and/or duration on PD, increasing the need for routine and thoughtful management of hydration status. PD on “autopilot” may result in poor outcomes in the long run, but PD with active monitoring can improve clinical outcomes.1,15

References

  1. François K, Bargman JM. Evaluating the benefits of home-based peritoneal dialysis. Int J Nephrol Renovasc Dis. 2014;7:447-455. doi:10.2147/IJNRD.S50527
  2. Raimann JG. Handbook of Dialysis Fifth Edition by John T. Daugirdas, Peter G. Blake and Todd S. Ing. Philadelphia, PA: Lippincott Williams & Wilkins, 2014, 900 pp. (ISBN-13: 978-1451144291). Daugirdas JT, Blake PG, Ing TS, eds. Hemodial Int. 2015;19(4):609-610. doi:10.1111/hdi.12322
  3. Wang AYM, Dong J, Xu X, Davies S. Volume management as a key dimension of a high-quality PD prescription. Perit Dial Int. 2020;40(3):282-292. doi:10.1177/0896860819895365
  4. Foley RN, Gilbertson DT, Murray T, Collins AJ. Long Interdialytic Interval and Mortality among Patients Receiving Hemodialysis. N Engl J Med. 2011;365(12):1099-1107. doi:10.1056/NEJMoa1103313
  5. Assimon MM, Wenger JB, Wang L, Flythe JE. Ultrafiltration Rate and Mortality in Maintenance Hemodialysis Patients. Am J Kidney Dis. 2016;68(6):911-922. doi:10.1053/j.ajkd.2016.06.020
  6. Jefferies HJ, Virk B, Schiller B, Moran J, Mcintyre CW. Frequent hemodialysis schedules are associated with reduced levels of dialysis-induced cardiac injury (myocardial stunning). Clin J Am Soc Nephrol. 2011;6(6):1326-1332. doi:10.2215/CJN.05200610
  7. Flythe JE, Kimmel SE, Brunelli SM. Rapid fluid removal during dialysis is associated with cardiovascular morbidity and mortality. Kidney Int. 2011;79(2):250-257. doi:10.1038/ki.2010.383
  8. Selby NM, Kazmi I. Peritoneal dialysis has optimal intradialytic hemodynamics and preserves residual renal function: Why isn’t it better than hemodialysis? Semin Dial. 2019;32(1):3-8. doi:10.1111/sdi.12752
  9. Garg AX, Suri RS, Eggers P, et al. Patients receiving frequent hemodialysis have better health-related quality of life compared to patients receiving conventional hemodialysis. Kidney Int. 2017;91(3):746-754. doi:10.1016/j.kint.2016.10.033
  10. Roehm B, Gulati G, Weiner DE. Heart failure management in dialysis patients: Many treatment options with no clear evidence.Semin Dial. 2020;33(3):198-208. doi:10.1111/sdi.12878
  11. Van Biesen W, Verger C, Heaf J, et al. Evolution over time of volume status and PD-related practice patterns in an incident peritoneal dialysis cohort. Clin J Am Soc Nephrol. 2019;14(6):882-893. doi:10.2215/CJN.11590918
  12. Xu Y, Yang S-M, Wang X, et al. Impact of Volume Management on Volume Overload and Rehospitalization in CAPD Patients. West J Nurs Res. 2018;40(5):725-737. doi:10.1177/0193945916683652
  13. Brown EA, Blake PG, Boudville N, et al. International Society for Peritoneal Dialysis practice recommendations: Prescribing high-quality goal-directed peritoneal dialysis. Perit Dial Int. 2020;40(3):244-253. doi:10.1177/0896860819895364
  14. Ronco C, Verger C, Crepaldi C, et al. Baseline hydration status in incident peritoneal dialysis patients: The initiative of patient outcomes in dialysis (IPOD-PD study). Nephrol Dial Transplant. 2015;30(5):849-858. doi:10.1093/ndt/gfv013
  15. Mehrotra R, Devuyst O, Davies SJ, Johnson DW. The current state of peritoneal dialysis. J Am Soc Nephrol. 2016;27(11):3238-3252. doi:10.1681/ASN.2016010112
  16. Kang SH, Choi EW, Park JW, Cho KH, Do JY. Clinical significance of the edema index in incident peritoneal dialysis patients. PLoS One. 2016;11(1):1-15. doi:10.1371/journal.pone.0147070
  17. Harrison TG, Shukalek CB, Hemmelgarn BR, et al. Association of NT-proBNP and BNP With Future Clinical Outcomes in Patients With ESKD: A Systematic Review and Meta-analysis. Am J Kidney Dis. 2020;76(2):233-247. doi:10.1053/j.ajkd.2019.12.017
  18. Van Biesen W, Claes K, Covic A, et al. A multicentric, international matched pair analysis of body composition in peritoneal dialysis versus haemodialysis patients. Nephrol Dial Transplant. 2013;28(10):2620-2628. doi:10.1093/ndt/gft296
  19. Lai S, Molfino A, Russo GE, et al. Cardiac, inflammatory and metabolic parameters: Hemodialysis versus peritoneal dialysis.CardioRenal Med. 2015;5(1):20-30. doi:10.1159/000369588
  20. Loutradis C, Sarafidis PA, Ekart R, et al. The effect of dry-weight reduction guided by lung ultrasound on ambulatory blood pressure in hemodialysis patients: a randomized controlled trial. Kidney Int. 2019;95(6):1505-1513. doi:10.1016/j.kint.2019.02.018
  21. Kumra R, Bargman JM. A review of diuretic use in dialysis patients. Adv Perit Dial. 2014;30(1):115-119.
  22. Medcalf JF, Harris KPG, Walls J. Role of diuretics in the preservation of residual renal function in patients on continuous ambulatory peritoneal dialysis. Kidney Int. 2001;59(3):1128-1133. doi:10.1046/j.1523-1755.2001.0590031128.x
  23. Witoon R, Yongsiri S, Buranaburidej P, Nanna P. Efficacy of triple diuretic treatment in continuous ambulatory peritoneal dialysis patients: A randomized controlled trial. Kidney Res Clin Pract. 2019;38(1):108-115. doi:10.23876/j.krcp.18.0115
  24. Menon MK, Naimark DM, Bargman JM, Vas SI, Oreopoulos DG. Long-term blood pressure control in a cohort of peritoneal dialysis patients and its association with residual renal function. Nephrol Dial Transplant. 2001;16(11):2207-2213. doi:10.1093/ndt/16.11.2207
  25. Jhee JH, Park J, Kim H, et al. The Optimal Blood Pressure Target in Different Dialysis Populations. Sci Rep. 2018;8(1):1-10. doi:10.1038/s41598-018-32281-w
  26. Udayaraj UP, Steenkamp R, Caskey FJ, et al. Blood Pressure and Mortality Risk on Peritoneal Dialysis. Am J Kidney Dis. 2009;53(1):70-78. doi:10.1053/j.ajkd.2008.08.030