Manual Immature Reticulocyte Fraction: a reliable marker to assess post traumatic blood loss.
Abstract
Abstract. Hemorrhage is a common stress
condition following acute trauma that needs
prompt medical attention as it can be fatal.
Traumatic haemorrhage be classified into
three categories; mild, moderate and severe
based on clinical manifestations and
outcomes expected with each. However,
some instances, clinical features may not
reflect exact degree of blood loss due to other
comorbid factors etc. Rapid marrow
response to haemorrhage includes release of
more immature red cells; reticulocytes and
normoblasts depending on haemopoietic
stimulus. Therefore, the presence of red cell
precursors in peripheral blood is an expected
marker following acute hemorrhage. Among
reticulocyte parameters, Immature
Reticulocyte Fraction (IRF) is widely used to
indicate the erythropoietic activity of the
bone marrow in stress conditions. Even
though the manual reticulocyte count is
performed in laboratories, calculation of
manual IRF is not routinely practiced. Based
on morphology, reticulocytes can be
classified in to immature and mature sub
types. Although automated method is
available, it is costly to use. Therefore this
study was performed to evaluate the
relationship of manual IRF with degree of
hemorrhage in acute trauma. In this
analytical cross-sectional study, 38 blood
samples of acute trauma patients admitted to
emergency trauma care at a tertiary care
hospital were analyzed. The IRF values were
significantly higher in study subjects with
severe hemorrhage than mild and moderate.
When the time duration from trauma to
admission was considered, subjects with
clinically severe hemorrhage showed high IRF
values within one hour. Appearance of the most
immature (stage I) reticulocytes were noted
after two hours of trauma in study subjects.
Therefore, this study supports us ability of
manual IRF in objective assessment of early
marrow response to hemorrhage thus
assessment of severity of acute trauma. Thus
the manual IRF in peripheral blood can be
considered an important, reliable and cheap
laboratory indicator in acute trauma care in the
diagnosis and management acute blood loss.