부산대학교 도서관

ABSTRACT: Anemia is a common worldwide problem that is associated with nonspecific complaints. The initial focus for the emergency evaluation of anemia is to determine whether the problem is acute or chronic. Acute anemia is most commonly associated with blood loss, and the patient is usually symptomatic. Chronic anemia is usually well tolerated and is often discovered coincidentally. Once diagnosed, the etiology of anemia can often be determined by applying a systematic approach to its evaluation. The severity of the anemia impacts clinical outcomes, particularly in critically ill patients; however, the specific threshold to transfuse is uncertain. Evaluation of the current literature and clinical guidelines does not settle this controversy, but it does help clarify that a restrictive transfusion strategy (ie, for patients with a hemoglobin < 6-8 g/dL) is associated with better outcomes than a more liberal transfusion strategy. Certain anemias may have well-defined treatment options (eg, sickle cell disease), but empiric use of nutritional supplements to treat anemia of uncertain etiology is discouraged. CASE PRESENTATIONS: A 54-year-old Hispanic male presents to the ED with the complaints of fatigue and weakness. The weakness is described as generalized, and the symptoms have been present and constant for the last 2 days. The patient denies hematemesis, hematochezia, dark-colored stools, hematuria, or other evidence of bleeding. He also denies chest or abdominal pain, dyspnea, diaphoresis, fever, or chills. The patient has not seen a doctor in the last 15 years and does not think he has any medical conditions. The only medication he has been taking is over-the-counter ibuprofen, which he has been taking daily since he injured his back at work 2 weeks ago. The patient works as a construction laborer and denies past surgeries or allergies. His vital signs are: blood pressure, 110/50 mm Hg; heart rate, 127 beats/min; respirations, 22 breaths/min; and SpO2, 97% on room air. The patient is afebrile. His skin is warm and dry but, despite being dark-skinned, he appears a little pale. On eye examination, the sclerae appear to have a yellow hue. Cardiovascular examination reveals bounding pulses, a hyperdynamic precordium, and a grade II over VI soft, systolic murmur. The remainder of the examination is unremarkable, including a rectal examination, which is negative for occult blood. An ECG shows a sinus tachycardia but is otherwise normal. A basic chemistry panel is within normal limits; however, the CBC reveals a hemoglobin of 5.4 g/dL, hematocrit of 16%, WBC of 8000, and platelet count of 154,000. Based on the presenting symptoms and signs, the patient is likely to need RBC transfusions. An IV catheter is placed, and a normal saline infusion is initiated. A 500-mL bolus of normal saline reduces the heart rate to 105 beats/min. As you write the order for the transfusion, your nurse asks, “What is the goal for the transfusion and what is the cause of the anemia?” You think, “Good questions!”