Peritoneal Dialysis in the ICU: A Comprehensive Overview

Current Role and Practice Patterns

The American Society of Nephrology notes that peritoneal dialysis (PD) is rarely used for critically ill adult patients in Western ICUs, where extracorporeal kidney replacement therapy (KRT) represents the gold standard, but it remains a viable and underutilized option that offers distinct advantages in specific clinical scenarios 1
In Western countries and the United States, PD is not routinely utilized for critically ill adult patients in the ICU setting, according to the Clinical Nutrition journal 1
The modality is more commonly continued in hospitalized patients previously on continuous ambulatory peritoneal dialysis (CAPD) or automated peritoneal dialysis (APD), as stated in the Clinical Nutrition journal 1

The peritoneum serves as a natural semipermeable membrane, with blood flow provided by peritoneal microcirculation rather than an artificial extracorporeal circuit, as described in Praxis Medical Insights 2
Dialysate solution instilled into the peritoneal cavity removes uremic toxins through diffusion and convection, while ultrafiltration is achieved by creating an osmotic gradient using hypertonic glucose or icodextrin solutions, according to Praxis Medical Insights 2
Diffusion is the primary mechanism for small molecule clearance (creatinine, urea, electrolytes), where solutes move from high to low concentration across the peritoneal membrane, as explained in Praxis Medical Insights 2

For patients with left ventricular assist devices (LVADs), peritoneal dialysis represents an attractive alternative to hemodialysis given smaller hemodynamic shifts, lack of need for venous catheters, more patient-centric approach, and potentially better chance at renal recovery, as stated in the Circulation journal 3

PD achieves only 10-20% of normal kidney clearance for index substances like urea and creatinine, with even lower clearance for higher molecular weight solutes, according to Praxis Medical Insights 2
Critical kidney functions not replaced by PD include tubular secretive and reabsorptive function, and endocrine function, as described in Praxis Medical Insights 2
Continuous protein loss can contribute to malnutrition, and nutrient losses occur during treatment, including low molecular weight macronutrients and micronutrients, as explained in Praxis Medical Insights 2

Regular assessment of residual renal function is crucial, as stated in Praxis Medical Insights 4

More prolonged KRT modalities like PD offer better hemodynamic stability, slower and reduced solute shifts, and better tolerance of fluid removal compared to intermittent hemodialysis, according to the Clinical Nutrition journal 1