Hydration Status Does Not Influence Peritoneal Equilibration Test Ultrafiltration Volumes

University College London Center for Nephrology, University College London Medical School, London, UK.
Clinical Journal of the American Society of Nephrology (Impact Factor: 4.61). 06/2009; 4(7):1207-12. DOI: 10.2215/CJN.01060209
Source: PubMed


The peritoneal equilibration test (PET) was developed some 25 yr ago and has been used to help prescribe peritoneal dialysis. However, PET is affected by several factors, including diabetes and inflammation. It was speculated that extracellular fluid overload would increase PET ultrafiltration volumes, and therefore the usefulness of the PET in routine clinical practice was audited.
Data from 211 consecutive patients attending a university teaching hospital for a standard PET who had multifrequency bioimpedance performance were analyzed to determine which factors affected net PET ultrafiltration volumes.
Net PET ultrafiltration volume was independent of gender, age, diabetes, residual renal function, peritoneal dialysis prescriptions (modes and dialysates), extracellular fluid volume, or C-reactive protein (CRP). There was an inverse regression with serum albumin and sodium on multiple logistical regression analysis (F = 13.4, P < 0.001 and F = 10.1, P = 0.001, respectively) and a positive regression with 24-h net peritoneal ultrafiltration volumes (F = 15.5, P < 0.001). As expected, there was a strong correlation with net sodium losses (r = 0.99, P < 0001).
It was found that PET test ultrafiltration volume in routine clinical practice was not affected by CRP, hyperglycemia, or extracellular fluid volume overload. Ultrafiltration volumes were increased in those patients with reduced serum sodium and albumin, most likely because of inflammation and protein malnutrition.

8 Reads
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Encapsulating peritoneal sclerosis (EPS) is an uncommon but potentially devastating complication of peritoneal dialysis. We have observed an increased incidence in our centre over the last few years. To look at potential risk factors for developing EPS, we reviewed 39 cases diagnosed between 2000 and 2009 and compared these with a control group of 71 patients who had been treated by peritoneal dialysis for a minimum of 4 years. Both groups extensively used icodextrin, >80% of patients. Both groups had been treated by peritoneal dialysis for a similar time: EPS median 54 months (46-87.5), compared to controls 70 (54-79.5). However, more of the EPS group were treated with peritoneal cyclers (75% vs 46%, X(2) = 6.86, P = 0.009) and prescribed more peritoneal dialysate 14.2 l/day +/- 0.7 vs 10.8 +/- 0.5, P < 0.0001. Although both groups were fast transporters, those with EPS had higher D/P creatinine ratios on peritoneal equilibration testing, 0.84 +/- 0.1 vs 0.77 +/- 0.1, P < 0.05, and lower peritoneal test ultrafiltration volumes, 193 +/- 26 ml vs 283 +/- 21 ml, P < 0.05. Discussion. The patients in the EPS group were faster transporters, with lower peritoneal equilibration and 24-h ultrafiltration volumes, and were exposed to greater volumes of peritoneal dialysates compared to peritoneal dialysis vintage controls.
    Nephrology Dialysis Transplantation 05/2010; 25(5):1633-8. DOI:10.1093/ndt/gfp677 · 3.58 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: N-terminal probrain type natriuretic peptide (NTproBNP) has been proven to be a valuable biomarker for predicting cardiac events and mortality in the hemodialysis population. However recent reports have suggested that NTproBNP is a marker of volume overload rather than one of cardiac dysfunction. Therefore this study investigated the effect of fluid volume status on NTproBNP. Volume status was determined pre- and postdialysis in 72 stable hemodialysis outpatients by multifrequency bioimpedance, and the relationship to NTproBNP values was examined. The mean and median NTproBNP values were 931.9 +/- 230 and 242 (90 to 688) pmol/L, respectively. On simple correlation, NTproBNP was associated with markers of volume overload and cardiac dysfunction. However, on logistical regression analysis, the strongest association was with the predialysis ratio of extracellular water/total body water (beta 26.6, F29.6, P = 0.000), followed by postdialysis mean arterial blood pressure (beta 0.14, F17.1, P = 0.000), dialysate calcium concentration (beta -1.19, F14.1, P = 0.002), and change in extracellular fluid volume with dialysis (beta 0.27, F7.4, P = 0.009) In this study, NTproBNP was not associated with cardiac dysfunction as assessed by transthoracic echo or nuclear medicine scintigraphy but was dependent on factors associated with volume overload. However, because bioimpedance results can also be affected by malnutrition with loss of cell mass, NTproBNP may be elevated not only in patients with volume overload, but also those with malnutrition.
    Clinical Journal of the American Society of Nephrology 06/2010; 5(6):1036-40. DOI:10.2215/CJN.09001209 · 4.61 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Intradialytic hypotension remains the commonest complication of routine outpatient haemodialysis treatments. Multifrequency bioimpedance allows assessment of body fluid volumes. Multifrequency bioimpedance can potentially monitor changes in extracellular volume during dialysis and may therefore help to reduce intradialytic hypotension. Hypotension-prone patients have been reported to start dialysis with relatively more fluid distributed in the trunk than the arms. However, as arterio-venous fistulae are the preferred form of vascular access and fistulae could potentially affect fluid retention in the arm, we investigated whether multifrequency bioimpedance could detect differences in fluid distribution in the arms with haemodialysis in patients with different vascular access modalities. We audited the change in extracellular water (ECW) and total body water (TBW) in the arms following haemodialysis in 100 patients attending for routine outpatient haemodialysis at a university centre by multifrequency bioimpedance using an eight-electrode contact technique. Patients with fistulae had greater ECW/TBW % in the fistula arm both prior to and post dialysis compared with central venous catheter (CVC) (pre 38.9 ± 0.1 vs 38.3 ± 0.1 and post 38.4 ± 0.1 vs 37.8 ± 0.1, P < 0.01), with a greater absolute difference between arms (0.53 ± 0.01 vs 0.05 ± 0.01, P < 0.01) and greater arm ECW/TBW % compared with total body ECW/TBW % predialysis (forearm fistula 99.4 ± 0.4 vs CVC 97.2 ± 0.3, P < 0.01). Absolute and also relative extracellular fluid volumes are increased in the fistula arm of haemodialysis patients. Thus, if algorithms are to be developed to monitor relative segmental changes in extracellular volumes to help prevent intradialytic hypotension using bioimpedance, then the dialysis vascular access and site will have to be considered, particularly if using relative changes in the upper limbs. Thus, alterative sites which are not so affected by vascular access, such as the calf, may prove advantageous.
    Nephrology Dialysis Transplantation 01/2011; 26(1):227-31. DOI:10.1093/ndt/gfq331 · 3.58 Impact Factor
Show more