Peritoneal Volume Influence on POCUS Volume Assessment in Patients Undergoing Peritoneal Dialysis.

Objective: This study aimed to investigate variations in fluid overload using point of care ultrasound (POCUS). We assessed patients undergoing peritoneal dialysis (PD) with full and drained peritoneum and their correlation with clinical parameters. Methods: POCUS examination and intra-abdominal pressure (IAP) measurements were conducted in patients undergoing PD with a full peritoneum. Subsequently, after drainage, a new POCUS and bioimpedance analysis (BIA) were performed. Results: Seventeen patients were included in the study: 70.6% male, mean age 66+/-9.5 years. Of these, 65% had fluid overload >1 L and 23% had overhydration (OH) adjusted for extracellular water (ECW) exceeding 15%, as assessed by BIA. B-lines with full peritoneum had a median of 1 (0-2.5), and with drained peritoneum 0 (0-0). This difference was not statistically significant (p=0.063). In the correlation analysis of variables, IAP and PD fluid volume per m2 of body surface did not correlate with the diameters or collapsibility of the inferior vena cava (IVC) with full or drained peritoneum. The degree of OH in liters correlated with IVC collapsibility with drained peritoneum (Spearman ρ=-0.43; p=0.08), as did the OH adjusted for ECW (Spearman ρ=-0.61; p=0.02). These correlations disappeared with full peritoneum (p>0.05). Conclusions: There were no significant differences in ultrasound volume overload parameters in patients undergoing PD with full vs. drained peritoneum. However, there are indications of lower POCUS sensitivity to fluid overload with a full peritoneum.