Laboratory tests that may be useful include Complete blood count to establish a baseline Serial hemoglobin levels to assess for bleeding Blood gas determination for partial pressure of oxygen, partial pressure of carbon dioxide, and base deficit Urine examination for blood Glucose to evaluate for hypoglycemia Type and crossmatch for possible blood transfusion Coagulation studies Measures of perfusion (serum lactate, base deficit on arterial blood gas measurement, and, in patients with a catheterized central vein, central venous oxygen saturation) are indicated to help identify early or partially treated shock.