Red blood cell transfusion and skeletal muscle tissue oxygenation in anaemic haematologic outpatients

Abstract

Background: Stored red blood cells (RBCs) accumulate biochemical and biophysical changes, known as storage lesion. The aim of this study was to re-challenge current data that anaemia in chronically anaemic haematology patients is not associated with low skeletal muscle tissue oxygen (StO₂), and that RBC storage age does not influence the tissue response after ischaemic provocation, using near-infrared spectroscopy.

Patients and methods: Twenty-four chronic anaemic haematology patients were included. Thenar skeletal muscle StO₂ was measured at rest (basal StO₂), with vascular occlusion testing (upslope StO₂, maximum StO₂) before and after transfusion.

Results: Basal StO₂ was low (53% ± 7%). Average RBC storage time was 10.5 ± 3.9 days. Effects of RBC transfusions were as follows: basal StO₂ and upslope StO₂ did not change significantly; maximum StO₂ increased compared to baseline (64 ± 14% vs. 59 ± 10%, p = 0.049). Change of basal StO₂, upslope StO₂ and maximum StO₂ was negatively related to age of RBCs. The decrease of maximum StO₂ was predicted (sensitivity 70%, specificity 100%), after receiving RBCs ≥ 10days old.

Discussion: Resting skeletal muscle StO₂ in chronic anaemic patients is low. RBC storage time affects skeletal muscle StO₂ in the resting period and after ischaemic provocation.

Keywords: red blood cells; skeletal muscle; storage lesion; tissue oxygenation; transfusion.

Figure 1

Schematic presentation of thenar skeletal muscle StO₂ before, during and after the vascular occlusion tests. Before the vascular occlusion, the StO₂ is measured in the resting period (1, basal StO₂). During the vascular occlusion, the StO₂ gradually decreases. The rate of this decrease is determined from the curve as the downslope StO₂ (2; %/min), as a surrogate of the tissue oxygen consumption. After reaching the predetermined minimum StO₂, present here as 40% StO₂ (3), the vascular occlusion is released, and the StO₂ begins to rise again. The rate of this increase is determined from the curve as the upslope StO₂ (4; %/min), as a surrogate marker of the microcirculatory reactivity. After the release of the occlusion, the StO₂ increases to higher values compared to the basal StO₂ due to post-ischaemic vasodilatation (5, maximum StO₂). The StO₂ then slowly returns to the basal StO₂.

Figure 2

Effects of the age of the RBCs for the transfusions on the basal StO₂. (A) Regression/analysis of variance. (B) Roc analysis, interactive dot diagram for optimal effect separation. Prediction line (solid lines); 95% confidence line (dashed lines)

Figure 3

Effects of the age of the RBCs for the transfusions on the upslope StO₂. (A) Regression/analysis of variance. (B) ROC analysis, interactive dot diagram for optimal effect separation. Prediction line (solid lines); 95% confidence line (dashed lines

Figure 4

Effects of the age of the RBCs for the transfusions on the maximum StO₂. (A) Regression/analysis of variance. (B) ROC analysis, interactive dot diagram for optimal effect separation Prediction line (solid lines); 95% confidence line (dashed lines)