Reticulocyte counts and their relation to hemoglobin levels in trauma patients

Increased production of red blood cells (RBCs) should be reflected by increased reticulocyte counts (RC). With the introduction of modern fully automated measurements of RC, the recovery of hemoglobin (Hb) after blood loss might be assessed earlier. We investigated the temporal relation of Hb and RC in trauma patients.

Over a 10-month period, all patients with trauma admitted to our University Medical Center were analyzed. Both Hb (reference values: males, 14.0-17.1 g/dL; females, 12.1-15.9 g/dL) and RC (8-26 promille) were determined with a Sysmex XE-2100 analyzer. RBC transfusions were administered in otherwise healthy patients below an Hb threshold of 6.9 g/dL. Hb and RC were analyzed for a maximum of 30 days posttrauma and related in multivariate analysis to age, sex, and comorbidity.

Two hundred and forty-one patients (age 52 years +/- 21 years) were studied. In 28 patients (12%), one or more RBCs were administered with a mean of 2.2 RBCs (range, 1-4). Hb decreased to 10.9 g/dL +/- 2.1 g/dL on day 3. RC rose from 16 +/- 11 at admission to 38 promille +/- 21 promille on day 13 (p < 0.0001). Nadir Hb values and maximum RC values were inversely related according to univariate analysis (Pearson R = -0.62, p < 0.001). In multivariate analysis, Hb remained the only significant determinant of RC (R = 0.64, p < 0.001).

Hb and RC are clearly related in trauma patients. Measuring RC may be helpful in predicting the rise of Hb after acute blood loss.