In older patients with chronic kidney‑related metabolic syndrome and limited cardiovascular reserve, is peritoneal dialysis preferred over hemodialysis?

Peritoneal Dialysis is Preferred Over Hemodialysis in CKM Syndrome Patients with Limited Cardiovascular Reserve

In older patients with chronic kidney-related metabolic syndrome and limited cardiovascular reserve, peritoneal dialysis should be the preferred initial dialysis modality due to superior hemodynamic stability, better preservation of residual kidney function, and avoidance of acute electrolyte shifts that can precipitate arrhythmias. 1, 2

Primary Rationale for PD Preference in CKM Syndrome

Hemodynamic Advantages

• PD provides superior hemodynamic control compared to HD, which is critical in patients with limited cardiovascular reserve. 1, 2
• HD causes rapid changes in solute transport and volume shifts between compartments that many patients with severe cardiac disease cannot tolerate 1
• Continuous renal replacement therapy (CRRT) or peritoneal dialysis should be prioritized over intermittent HD in patients with cardiogenic shock or severe hemodynamic instability, despite inferior solute clearance, because these modalities provide superior hemodynamic stability and avoid large fluid shifts 2
• PD avoids the acute hypokalemia and electrolyte shifts characteristic of HD that can result in arrhythmias—particularly dangerous in patients with coronary artery disease 1

Preservation of Residual Kidney Function

• Every effort must be made to preserve residual kidney function (RKF) in cardiorenal patients, especially when daily urine volume exceeds 100 mL, as RKF contributes significantly to total solute clearance and is strongly associated with improved survival 2
• The continuous nature of RKF contrasts with the intermittent schedule of HD, whereas for PD patients, both are nearly continuous, making continuous clearance more efficient than intermittent clearance 1
• PD preserves renal function better than HD, which is particularly valuable in CKM syndrome where maintaining any residual function provides continuous clearance and improves survival 1, 3
• Biocompatible membranes and ultrapure dialysate in HD have improved RKF preservation, but PD still maintains an advantage in this regard 1

Cardiovascular-Specific Benefits

• Better control of anemia (important in patients with coronary artery disease) is achieved with PD 1
• Fluid management is more gradual and better tolerated in hemodynamically unstable patients 1
• Prevention of arrhythmias is superior with PD due to avoidance of rapid electrolyte shifts 1

Survival Considerations

Early Survival Advantage

• Most studies show that the relative risk of death in patients on in-center HD versus PD changes over time with a lower risk on PD, especially in the first 3 months of dialysis 4
• The survival advantage of PD continues for 1.5-2 years, making it ideal as initial therapy in CKM syndrome 4, 5
• In RCT analysis, PD may reduce the risk of all-cause death (RR 0.53,95% CI 0.32 to 0.86) 6

Long-Term Strategy

• An integrated care approach with "healthy start" and PD as the initial renal replacement therapy, followed by timely transfer to HD once complications arise, may improve the long-term survival 5
• After 1.5-2 years, monitor closely for signs of under-dialysis as the reduction in Kt/V with declining RRF can give PD a potential risk 3

Critical Management Principles When Using PD

Ultrafiltration Strategy

• Implement a slow, gradual approach to achieving dry weight in most patients, while reserving more aggressive ultrafiltration for those with cardiac failure or severe hypertension 2

Adjunctive Medical Management

• Continue loop diuretics in patients with preserved RKF (urine output >100 mL/day) to enhance urinary sodium and water removal between dialysis sessions 2
• Maintain ACE inhibitors or ARBs when tolerated, as these may help preserve residual kidney function 2
• Restrict dietary sodium intake to <2g/day to reduce interdialytic weight gain 2

When to Consider Switching from PD to HD

Absolute Indications for Transition

• Documented loss of peritoneal function or extensive abdominal adhesions that limit dialysate flow 1
• Inadequate solute transport documented by measures of Kt/Vurea and creatinine clearance when maximum PD prescription has been reached 1
• Inadequate ultrafiltration that is usually secondary to high transport characteristics or mechanical defects 1
• Unacceptably frequent peritonitis 1
• Severe malnutrition resistant to aggressive management (due to continuous protein loss associated with PD) 1
• Development of irreparable technical or mechanical problems such as catheter malposition 1

Monitoring for Transition Timing

• After a few years of PD treatment, maintain sharp vigilance to detect signs of under-dialysis promptly and shift the patient to HD when indicated 3
• In patients without RRF, it becomes more difficult to control hypertension with PD and they are more prone to hyperhydration, which may necessitate transition 3

Common Pitfalls to Avoid

• Do not initiate HD in hemodynamically unstable CKM patients simply because it is more familiar or available—this can precipitate cardiovascular collapse 2
• Avoid intradialytic hypotension through extended treatment times and lower ultrafiltration rates if HD must be used, as hypotensive episodes accelerate loss of RKF 2
• Do not assume that all older patients or those with cardiovascular disease cannot perform PD—patient education and proper selection are key 4
• Avoid nephrotoxic medications when possible to preserve any residual kidney function 7