Difference between true functional haemoglobin and pre-dialysis haemoglobin is associated with plasma volume variation: a multicentre study.

Autor: Siga, Esteban, Fernandez, Miguel, Galarza, Mario, Mesina, Vito, Palma, Hugo, Coste, Raul
Zdroj: International Urology & Nephrology; Dec2014, Vol. 46 Issue 12, p2379-2384, 6p
Abstrakt: Purpose: Due to the well-known intradialytic haemoglobin (Hb) change, it has been suggested that true functional Hb differs from pre-dialysis Hb. However, mechanisms of this change are not understood properly. We aimed at studying the role of plasma volume variation. Methods: This is a multicentre study with two consecutive phases. First, true functional Hb was predicted by Krisper's formula that estimates time-averaged haemoglobin concentration (TAC-Hb) and by the average (Avg-Hb) of Pre-Hb and Post-Hb ( n = 346). Erythropoiesis-stimulating agent (ESA) doses were estimated according to the FDA instructions. Second, we investigated the correlations between Hb changes (ΔHb), body weight loss (ΔBW) and relative plasma volume changes (%ΔPV) in subjects with a weight gain higher than 1 kg ( n = 208). Results: First: Avg-Hb and TAC-Hb were similar to each other and higher than midweek Pre-Hb ( p < 0. 002). Odds of having an Hb change >1 g/dL were 0.415. Odds were similar in both women and men [odds ratio (OR) 0.923; 95 % confidence interval (CI) 0.591-1.441]. If ESA doses were estimated by TAC-Hb or Avg-Hb instead of Pre-Hb, they should be lower in 40 % of the 346 patients. Second: Mean %ΔPV was −12.1 % (95 % CI −10.72/−13.48), and mean ΔHb was 1.1 g/dL (95 % CI 0.97/1.25). Correlation between ΔHb and %ΔPV was −0.92 ( r 0.84) whereas that of ΔHb/ΔBW was just −0.45 ( r 0.21; p < 0.000). Prevalence of ΔHb >1 g/dL was independent of ΔBW from 1.4 to 6.3 kg. By contrast, prevalence of ΔHb >1 g/dL in %ΔPV quartiles was clearly linear: 0, 52, 90 and 100 %, respectively. Conclusions: Plasma volume variations play a major role in intradialytic Hb change. True functional Hb should be estimated in all patients with a weight gain higher than 1 kg. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
Externí odkaz: