Relationship between Filtration Coefficients of Microvasculature and Levels of Atrial Natriuretic Peptide or Echocardiographic Measurements

Abstract

Background/Aims: Assessing the volume status of hemodialysis (HD) patients and determining their adequate dry weight (DW) present great challenges for physicians involved in HD. In this study the relationship between standardized filtration coefficients of microvasculature (Lpst) and the plasma atrial natriuretic peptide (ANP) levels or echocardiographic measurements (UCGm) were clarified. The aim of this study was to evaluate the possibility of utilizing Lpst as one of the tools for assessing volume status of patients undergoing HD. Methods: 52 patients on maintenance HD were examined. Lpst was calculated by utilizing continuous measurements of blood volume during HD by means of monitoring changes of hematocrit with CRIT-LINE^TM. Plasma ANP levels were measured shortly after HD. Plasma ANP levels were elevated beyond the normal limit in 32 patients (Hi group) and were within the normal range in the remaining 20 patients (Lo group). UCGm were performed within 1 month prior to the study. Inferior vena cava diameters in quiet expiration (IVCe) were dilated in 21 patients (Hivc group) and were within the normal range in the remaining 31 patients (Livc group). Lpst was compared with plasma ANP level and UCGm. Results: Lpst in Lo group were significantly lower than those in the Hi group (0.83 ± 0.19 vs. 2.64 ± 2.73 ml/mm Hg/min; p < 0.001). Lpst correlated significantly with plasma ANP levels (r = 0.613; p < 0.001). Lpst in the Livc group were significantly lower than those in the Hivc group (1.33± 1.61 vs. 2.85 ± 2.88 ml/mm Hg/min; p < 0.001). Lpst also correlated with IVCe (r = 0.630; p < 0.001). The receiver operating characteristic (ROC) curves for high plasma ANP level and for dilated IVCe were significant for Lpst. Area under the ROC curve for elevated ANP was 0.909 (95% confidence interval (CI) 0.834–0.985) and for dilated IVCe was 0.833 (95% CI 0.724–0.941). Conclusion: We conclude that there exists a significant association between Lpst and plasma ANP levels at the end of a dialysis session. There is a possibility that high plasma ANP levels cause elevation of Lpst. Besides ANP, Lpst significantly correlated with IVCe. These results suggested that Lpst can be utilized as one of the tools for assessing volume status of patients undergoing HD.

How Does Higher Ultrafiltration within the Conventional Clinical Range Impact the Volume Status of Hemodialysis Patients?

“…The ratio of post-HD blood volume to pre-HD (BVpost/BVpre) was calculated using the hematocrit (Ht) of pre-HD and post-HD as follows: unchanged from the start of UF. Lp was calculated according to our previous report [15] . The initial circulating blood volume was assumed to be 7.7% of the initial body weight [15,18] .…”

“…Standardized Lp (Lpst) in the vicinity of PDW was previously reported to be associated with volume status in HD patients [15] .…”

Comparison of Bioimpedance Techniques to Detect Changes in Fluid Status in Hemodialysis Patients

“…However, none of them satisfactorily combines specificity, sensitivity, practicality, and accuracy [17,18,19,20,21]. …”

Atrial Natriuretic Peptide: A Regulator of Transvascular Fluid Transport in Dialysis?

“…In this journal, Yashiro et al [7] describe the relationship between atrial natriuretic peptide (ANP), ICVD and Lp. They demonstrate a highly signifi cant relationship between ANP levels and Lp values.…”

“…Due to its design, the study of Yashiro et al [7] cannot answer the question on the physiological importance of the extrarenal actions of ANP in dialysis patients. It does however raise an important question that merits further investigation.…”