THE VALUE OF RETICULOCYTE HEMOGLOBIN IN THE PERI-OPERATIVE EVALUATION
OF ERYTHROPOIESIS
Eloisa Urrechaga1, Monica Fernandez2, Manuel Quintana3, and Jose Antonio García-Erce4
(1)Hospital galdakao usansolo, Galdakao, Spain
(2)Hematology, Hospital Universitario de Alava, Vitoria, Spain
(3)ICU, Hospital Universitario La Paz, Madrid, Spain
(4)Banco de sangre y Tejidos, Pamplona, Spain
Background: Although anemia is a recognized risk factor in surgery iron deficiency without
anemia can allow a timely intervention and is thus of high importance. It is a common practice
for patients to have pre-operative laboratory testing, drawn around the time that their
surgery is scheduled, including measuring CBC, but usually biochemical tests for iron status
assessment are not requested.
Non-anemic iron deficiency is called latent iron deficiency (LID). The process entails decrease
of the storage iron, with serum Ferritin values below reference range eventually leading to
iron deficient erythropoiesis. Recognizing this issue in time is crucial as part of patient blood
management
Consequence of an imbalance between iron requirements for erythropoiesis and the low
supply is a reduction of Hb production by reticulocytes (iron deficient erythropoiesis).
We study the potential utility of mean reticulocyte hemoglobin Ret He reported by Sysmex
XN 20 analyzer in the detection of LID in non-anemic patients undergoing surgery.
Patients and methods: Patients were recruited in the course of their preoperative controls.
Inclusion criteria: Hb>120g/L (women), >130 g/L (men) ; CRP <5.mg/L and or /ESR > 10 mm/h.
Exclusion criteria: hemoglobinopathy, transfusion in the previous month.
S-Ferritin and Hemograms were run in the analyzer within 6 hours of collection.
Independent samples t test was applied in order to detect statistical deviations between the
groups, patients with normal iron stores and those with LID with; statistical significance P<
0.05. Receiver operating characteristic (ROC) curve analysis was utilized to illustrate the
diagnostic performance of RetHe in the detection of LID,. using s-Ferritin< 30 μg/L as gold
standard
Results: 142 patients were analyzed (63.2 % women 56.8 % men , mean age 55.5 years); 39.8
% of them had s-ferritin lower than the reference range 50 μg/L and 31.4 % bellow threshold
value of iron deficiency 30 μg/L; in this group 81 % of them had RetHe <30 pg.
Mean Ret He in the LID group was 25.9 pg, statistically different from the group with adequate
iron stores, 30.1 pg (P< 0.001).
RetHe had the best performance AUC 0.821 (95% CI 0.740-0.891) at cut off 30.0 pg sensitivity
82.1 % and specificity 70.1 %; Hb , MCV and MCH rendered 0,539, 0,774 and 0.734
respectively.
Conclusions: Preoperative iron deficiency is independently associated with increased
mortality and prolonged hospital stay after surgery. LID screening, not only anemia, is
important in the context of a comprehensive patient blood management
Ret He can reflect the negative balance in iron supply for erythropoiesis; due to their short life
span reticulocytes and derived parameters reflect the current erythropoiesis status before Hb
and mature red cell indices start to decrease.