Neutrophil vacuolization in peripheral blood smear assessed with May Grnwald-Giemsa stain has direct correlation with the severity of hemorrhagic shock and serum lactate in trauma patients

Tissue trauma induces migration and activation of neutrophils through specific mediators. Vacuolated neutrophils in peripheral blood smear of septic patients correlated with mortality. However, scarce data exist with respect to findings in hemorrhagic shock (HS) trauma patients. The aim of this work was to evaluate the number and size of cytoplasmic and nuclear vacuoles in polymorphonuclear neutrophil (PMN) obtained from a peripheral blood smear stained with the May-Grunwald-Giemsa method in trauma patients with hemorrhagic shock. Seven sequential blood samples were taken from 20 patients with severe hemorrhagic shock and 20 patients who sustained mild thoracic trauma (control group). The first sample was obtained shortly after admission to the hospital followed by new samples taken at 6, 12, 18, 24, 48 and 72 h. Blood smears from both groups were processed to assess vacuolization and vacuole morphology in one hundred PMNs at each time point. The number and the area of vacuoles in the nucleus and the cytoplasm were determined using the program Image-Pro Express version 4.0 for Windows (Media Cybernetics, Bethesda, MD, USA). The number and the area of vacuoles in the cytoplasm and nucleus were significantly different (p <0.05) between shock and control groups. Moreover, serum lactate and heart rate correlated directly with the number (r=0.634) and the area (r=0.624) of cytoplasmic vacuoles as shown by multivariate analysis (p<0.05). Severe hemorrhagic shock induces greater vacuolization of PMNs as compared to mild trauma. PMN vacuolization has direct correlation with serum lactate, a known marker of severe shock.   Key words: Hemorrhagic shock, trauma, lactate, inflammatory response, blood smear, neutrophils, vacuolization, apoptosis.