Related Experiment Video
Updated: Aug 16, 2026
Continuous Venous-Arterial Doppler Ultrasound During a Preload Challenge
Published on: January 20, 2023
Volume status and blood pressure in continuous ambulatory peritoneal dialysis patients
Xin Wang1, Jonas Axelsson, Bengt Lindholm
1Institute of Nephrology, Peking University, Beijing, China.
Insights
Hypertension in peritoneal dialysis patients is linked to excess fluid. Uncontrolled high blood pressure in these patients suggests volume overload, requiring stricter dietary salt and fluid restriction for better management.
Area of Science:
- Nephrology
- Hypertension Research
- Fluid Balance Studies
Background:
- Hypertension pathophysiology in dialysis patients is often due to sodium balance and volume expansion.
- The link between fluid status and blood pressure is established in hemodialysis but less studied in peritoneal dialysis.
Purpose of the Study:
- To investigate the relationship between fluid status and blood pressure control in continuous ambulatory peritoneal dialysis (CAPD) patients.
- To compare fluid parameters in normotensive, controlled hypertensive, and uncontrolled hypertensive CAPD patients.
Main Methods:
- Cross-sectional study of 100 CAPD patients and 60 healthy controls.
- Categorized CAPD patients into normotensive, controlled hypertensive, and uncontrolled hypertensive groups.
- Measured extracellular water (ECW) and intracellular water (ICW) using bioimpedance spectroscopy; assessed dialysis adequacy and transport.
Main Results:
- Dialysis patients showed higher ECW/ICW ratios compared to controls.
- Uncontrolled hypertensive patients (Group 3) had higher normalized ECW (nECW) than normotensive patients (Group 1).
- Male CAPD patients in Group 3 had higher urinary volume and fluid removal than Group 1; sodium removal was also higher.
Conclusions:
- Peritoneal dialysis patients with uncontrolled hypertension exhibit volume overload, making blood pressure control challenging with antihypertensive medication alone.
- Intensified volume control through dietary salt and fluid restriction is recommended for hypertensive CAPD patients.
Unlabelled:
The pathophysiology of hypertension in dialysis patients is largely attributed to positive sodium balance and volume expansion. Whereas the relationship between fluid status and blood pressure control in hemodialysis patients is well established, this relationship is not well studied in peritoneal dialysis patients.
Methods:
100 stable CAPD patients who had been dialyzed for more than 3 months, as well as 60 healthy controls, were studied cross-sectionally. CAPD patients were divided into three groups according to their blood pressure level: group 1 (normotension), group 2 (controlled hypertension with antihypertensive medication (AHM)) and group 3 (uncontrolled hypertension with AHM). Extracellular water (ECW) and intracellular water (ICW) were measured using bioimpedance spectroscopy in all subjects. Dialysis adequacy and transport test was conducted in each patient.
Results:
Height normalized ICW (nICW) was much lower, and ECW/ICW was higher in both male and female dialysis patients as compared to healthy controls. nECW was also significantly higher in group 3 when compared to group 1. The dose of AHM was similar in group 2 and group 3. In female CAPD patients, there were no differences in urinary volume (UV) and the total fluid removal among the three patient groups. However, in male CAPD patients, UV and total fluid removal were significantly higher in group 3 than in group 1. Renal and total removal of sodium was also significantly higher in group 3 male patients than group 1.
Conclusions:
Peritoneal dialysis patients with uncontrolled hypertension are more volume overloaded and their blood pressure may be difficult to control by AHM alone. These findings indicate that volume control preferably by dietary salt and fluid restriction should be intensified in hypertensive CAPD patients.
Related Concept Videos
01:25Peritoneal Dialysis II: Peritoneal Dialysis Systems and Complications
01:25Peritoneal Dialysis III: Nursing Management
01:25Hemodialysis III: Nursing Management
01:30Peritoneal Dialysis I: Introduction and Procedure
01:30Continuous Renal Replacement Therapy
01:28Special considerations while measuring blood pressure
Monitoring Both Arms:
Monitoring BP in both arms during the initial assessment is advisable, as the systolic value may differ by five to ten mm Hg between arms. For subsequent BP assessments, use the arm with the higher reading.