Original Investigations: Dialysis Therapies
Influence of the cyclic variation of hydration status on hemoglobin levels in hemodialysis patients*,**

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Abstract

Background: Maintenance hemodialysis (HD) patients were studied to assess the effect on hemoglobin (Hb) concentration induced by the cyclic variation in hydration status. Methods: Forty-nine HD patients were examined in three consecutive HD sessions in a 1-week treatment period. In a subgroup of 23 patients, Hb levels also were investigated during the long interdialytic interval. Results: Hb levels at the end of the long interdialytic interval were significantly lower by 0.5 to 0.6 g/dL (5 to 6 g/L) than those at the end of short intervals. Among all pre-HD and post-HD Hb values, levels measured at the end of short intervals were closest to the mean Hb value of the week, derived from calculation of the area under the curve (12.0 ± 0.2 g/dL [120 ± 2 g/L]). Intradialytic Hb increments were different in the three sessions (+1.6 ± 0.1 g/dL [+16 ± 1 g/L] after the long interval, +1.1 ± 0.1 g/dL [+11 ± 1 g/L] and +1.1 ± 0.1 g/dL [+11 ± 1 g/L] after short intervals [P < 0.001] and proportionate to weight loss [−3.4 ± 0.1, −2.7 ± 0.1, and −2.6 ± 0.1 kg, respectively; P < 0.001]). Hb level increment and weight loss correlated directly (r = 0.527; P < 0.0001); each 1 L of ultrafiltration (UF) led to an increase in Hb level of approximately 0.4 g/dL (4 g/L). Plasma refilling accounted for an approximately 45% decrement in the intradialytic increase in Hb level 2 hours post-HD. Conclusion: This study suggests that: (1) the end of the short interdialytic period is the most appropriate timing for anemia assessment, and (2) the remarkable hemodiluting effect of post-HD plasma refilling protects against excessive increments in Hb levels induced by UF. © 2002 by the National Kidney Foundation, Inc.

Section snippets

Study A

This study aims to evaluate the impact on Hb levels of different degrees of fluid retention after the long and short interdialytic periods. Anuric (ie, urinary output < 200 mL in the long interval) HD patients were studied in the three consecutive HD sessions during 1 week of treatment (HD-1, session of the week performed after the long interdialytic interval; HD-2 and HD-3, subsequent sessions performed after the two short intervals). We selected patients treated for at least 1 year with

Study A

The study was performed in 49 patients (21 men, 28 women) with a mean age of 60.6 ± 2.2 years and a body mass index of 23.2 ± 0.5 kg/m2. Achievement of dry weight, suggested on a clinical basis, was testified by inferior vena cava diameter values (8.9 ± 0.7 mm/m2) and BIA-derived percent total body water (%TBW; 53.3% ± 1.2%) obtained at the end of the last HD session before the study week.

Delivered Kt/V dose in HD-1 was 1.35 ± 0.03; this value did not change during the study week. The duration

Discussion

This prospective study documents the effects of variations in hydration status and plasma refilling on variability in Hb levels in maintenance HD patients. Results constitute novel information because no previous work has monitored changes in Hb values in relation to different amounts of fluid removed in the three consecutive HD sessions of the week. Similarly, no investigator has estimated the effect on Hb concentration of post-HD plasma refilling.

In study A, the comparison between the mean Hb

References (27)

  • M Guthrie et al.

    Effects of erythropoietin on strength and functional status of patients on hemodialysis

    Clin Nephrol

    (1993)
  • H Xia et al.

    Hematocrit levels and hospitalization risks in hemodialysis patients

    J Am Soc Nephrol

    (1999)
  • A Besarab et al.

    The effects of normal as compared with low hematocrit values in patients with cardiac disease who are receiving hemodialysis and epoetin

    N Engl J Med

    (1998)
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      The recommendation to evaluate anemia in hemodialysis-chronic kidney disease patients using predialysis hemoglobin levels is based on two considerations. First, postdialysis hemoglobin levels vary depending on the amount of fluid removed during a hemodialysis session, with an average increase in hemoglobin of 3–4 g for every liter of volume ultrafiltered.24,25 Second, there is no evidence providing associations between postdialysis hemoglobin levels and clinical outcomes.

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    *

    Address reprint requests to Biagio R. Di Iorio, MD, Contrada S. Tommaso 286, 83100 Avellino, Italy. E-mail: [email protected]

    **

    0272-6386/02/4003-0015$35.00/0

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