Comparison of three PET methods to assess peritoneal membrane transport

Abstract

The peritoneal equilibration test (PET) is the most widespread method for assessing water and solute transport across the peritoneal membrane. This study compared three methods: traditional PET (t-PET), mini-PET, and modified PET (mod-PET). Non-diabetic adults (n=21) who had been on peritoneal dialysis (PD) for at least three months underwent t-PET (glucose 2.5%-4 h), mini-PET (glucose 3.86%-1 h), and mod-PET (glucose 3.86%-4 h) to determine dialysate-to-plasma concentration ratio (D/P) for creatinine and dialysate-to-baseline dialysate concentration ratio (D/D0) for glucose. Agreement between methods regarding D/P creatinine and D/D0 glucose was assessed using analysis of variance (ANOVA), Pearson's correlation coefficient, and Bland-Altman analysis. D/P creatinine differed between t-PET and mini-PET (P<0.001) and between mod-PET and mini-PET (P<0.01) but not between t-PET and mod-PET (P=0.746). The correlation of D/P creatinine with t-PET vs mod-PET was significant (r=0.387, P=0.009) but not that of t-PET vs mini-PET (r=0.088, P=0.241). Estimated bias was −0.029 (P=0.201) between t-PET and mod-PET, and 0.206 (P<0.001) between t-PET and mini-PET. D/D0 glucose differed between t-PET and mod-PET (P=0.003) and between mod-PET and mini-PET (P=0.002) but not between t-PET and mini-PET (P=0.885). The correlations of D/D0 glucose in t-PET vs mod-PET (r=−0.017, P=0.421) or t-PET vs mini-PET (r=0.152, P=0.609) were not significant. Estimated bias was 0.122 (P=0.026) between t-PET and mod-PET, and 0.122 (P=0.026) between t-PET and mini-PET. The significant correlation of D/P creatinine between t-PET and mod-PET suggested that the latter is a good alternative to t-PET. There was no such correlation between t-PET and mini-PET.

The role of segmental bioelectrical impedance technique in the assessment of intraperitoneal ultrafiltration volume with peritoneal dialysis patients

“…It may also provide information on total ultrafiltration and solute transport [ 17 ]. Although the peritoneal equilibrium test has been used to elucidate the properties of the peritoneum [ 18 ], however, it cannot adequately predict the dynamics of the peritoneal fluid or the optimal retention time because the total ultrafiltration of peritoneal dialysis depends not only on the removal of peritoneal fluid but also on the absorption of peritoneal fluid [ 19 ]. So it is difficult to predict the time to reach the maximum ultrafiltration volume (UFVmax) and the maximum ultrafiltration volume.…”

Peritoneal equilibration testing: Your questions answered

“…40,[47][48][49][50] In a study comparing traditional PET, modified PET and mini-PET, Romani et al used the dialysate-to-plasma concentration ratio for creatinine (D/P creatinine) and the dialysate-to-baseline dialysate concentration ratio for glucose (D/D0 glucose) to assess and compare the small-solute transfer profile of 21 patients undergoing PD. 51 The authors found D/P creatinine measurements among patients undergoing modified PET and traditional PET to be comparable, suggesting that modified PET is a method of PET that provides additional evaluation of UF and free water transfer without compromising on the evaluation of small solute transfer. On the other hand, mini-PET was observed to lack equivalence to traditional PET in its evaluation of small solute transfer.…”