BLOOD LOSS CLINICAL PEARLS AND PITFALLS In acute hemorrhage, measured hemoglobin changes may lag behind blood loss, and normal values should not provide reassurance against clinically significant blood loss Clinical Considerations Clinical Recognition Anemia due to blood loss occurs from a variety of causes ( Fig 93.1 ) Overall, these conditions are divided into traumatic or atraumatic bleeding The possibility of occult nonaccidental trauma must always be considered, particularly in younger children Gastrointestinal hemorrhage is the most common cause of atraumatic blood loss, but postsurgical (e.g., posttonsillectomy hemorrhage), renal, gynecologic, and other etiologies may also present In some cases, an anatomic lesion or process may combine with a congenital or acquired coagulopathy to precipitate significant anemia For example, adolescent girls with unrecognized von Willebrand disease (VWD) may present with anemia due to both acute and chronic blood loss during menses Assessment for anemia should be considered in any patient with pallor, jaundice, or unexplained tachycardia Asymptomatic chronic anemia may be detected as an incidental finding that requires further evaluation Triage Known or suspected anemia due to blood loss, hypotension, hypoxia, or evidence of end-organ dysfunction is a medical emergency and warrants immediate intervention to prevent progression to cardiopulmonary collapse Patients with both acute and chronic blood loss may become unstable The chronicity of symptoms should not reassure the clinician, as it may be the exhaustion of physiologic compensatory mechanisms that prompts the patient to present to medical attention Initial Assessment Initial assessment of a patient presenting with anemia secondary to blood loss includes a focused history targeted at symptoms of compromise related to anemia/hypoxia as well as potential etiologies In suspected blood loss, the clinician must assess for evidence of trauma including nonaccidental injury, postprocedure bleeding, symptoms of upper or lower gastrointestinal bleeding, medication use that could precipitate gastrointestinal bleeding, reports of epistaxis, hematuria or menorrhagia, and any concern for complications of pregnancy or hemorrhagic ovarian cyst Inquiries in the history related to symptomatic anemia should include fatigue, exercise intolerance, syncope,