Monitoring of Intraperitoneal Fluid Volume during Peritoneal Equilibration Testing using Segmental Bioimpedance.

BACKGROUND: Ultrafiltration failure and fluid overload are common in peritoneal dialysis (PD) patients. Knowledge of intraperitoneal volume (IPV) and time to peak IPV during a dwell would permit improved PD prescription. This study aimed to utilize trunk segmental bioimpedance analysis (SBIA) to quasi-continuously monitor IPV (IPVSBIA) during the peritoneal dwell. METHODS: IPVSBIA was measured every minute using lower-trunk SBIA (Hydra 4200; Xitron Technologies Inc., CA, USA) in 10 PD patients during a standard 240-min peritoneal equilibration test (PET). The known dialysate volume (2 L) rendered IPVSBIA calibration and calculation of instantaneous ultrafiltration volume (UFVSBIA) possible. UFVSBIA was defined as IPVSBIA - 2 L. RESULTS: Based on dialysate-to-plasma creatinine ratio, 2 patients were high, 7 high-average, and 1 low-average transporters. Technically sound IPVSBIA measurements were obtained in 9 patients (age 59.0 ± 8.8 years, 7 females, 5 African Americans). Drained ultrafiltration volume (UFVdrain) was 0.47 ± 0.21 L and correlated (r = 0.74; p < 0.05) with end-dwell UFVSBIA (0.55 ± 0.17 L). Peak UFVSBIA was 1.04 ± 0.32 L, it was reached 177 ± 61 min into the dwell and exceeded end-dwell UFVSBIA by 0.49 ± 0.28 L (95% CI: 0.27-0.7) and UFVdrain by 0.52 ± 0.31 L (95% CI: 0.29-0.76), respectively. CONCLUSION: This pilot study demonstrates the feasibility of trunk segmental bioimpedance to quasi-continuously monitor IPVSBIA and identify the time to peak UFVSBIA during a standard PET. Such new insights into the dynamics of intraperitoneal fluid volume during the dwell may advance our understanding of the underlying transport physiology and eventually assist in improving PD treatment prescriptions.

Deceased-donor kidney transplantation: improvement in long-term survival.

BACKGROUND: Despite marked improvement in short-term renal allograft survival rates (GSR) in recent years, improvement in long-term GSR remained elusive. METHODS: We analysed the kidney transplant experience at our centre accrued over four decades to evaluate how short-term and long-term GSR had changed and to identify risk factors affecting graft survival. The study included 1476 adult recipients of a deceased-donor kidney transplant who were transplanted between 1963 and 2006 and who had received one of five distinct immunosuppressive protocols. RESULTS: Five-year actual GSR steadily improved over the years as immunosuppressive therapy evolved (22-86%, P < 0.001) in spite of an increasing trend in the transplantation of higher-risk donor-recipient pairings. For those whose grafts functioned for the first year, subsequent 4-year GSR (5-year conditional GSR) also improved significantly (63-92%, P < 0.001). Acute rejection and delayed graft function (DGF) were the most significant risk factors for actual graft survival, while acute rejection was the only significant risk factor for conditional GSR. Use of kidneys from expanded-criteria donors (ECD) was not a risk factor, compared to the use of standard-criteria donor kidneys for either 5-year actual or conditional GSR. There was an impressive decline in the incidence of acute rejection events (77.4-5.8%, P < 0.001). While the DGF rate had decreased, it still remained high (68.7-38.5%, P < 0.001). CONCLUSIONS: We found a significant improvement in both short-term and long-term GSR of deceased-donor kidney transplants over the last four decades. These improvements are most likely related to the decreased incidence of acute rejection episodes. Minimizing acute rejection events and preventing DGF could result in further improvement in the GSR. Our experience in the judicious use of ECD kidneys suggests that this source of kidneys could be expanded further.