A patient admitted with tarry stool and fatigue presents with a hemoglobin of 6.8 g/dl and platelet count of 180,000/μL. What is the best immediate treatment?

The best immediate treatment for a patient presenting with a hemoglobin level of 6.8 g/dL and exhibiting symptoms such as tarry stools and fatigue is the administration of red blood cells (RBCs). In this scenario, the patient's low hemoglobin indicates significant anemia, which could be life-threatening and suggests that the patient may not be oxygenating their tissues effectively. Immediate treatment aims to restore adequate hemoglobin levels and improve oxygen delivery to the body's organs.

Red blood cells provide the necessary hemoglobin needed to carry oxygen throughout the body. This is particularly critical in patients with such low hemoglobin levels who may be at risk of severe hypoxia and other complications if left untreated.

Other treatments like fresh whole blood would provide both red blood cells and plasma components, which might not be necessary in this specific case where the primary issue is red blood cell deficiency rather than coagulopathy or volume depletion. Erythropoietin is a hormone that stimulates red blood cell production, but it takes time to work and is not suitable for an acute situation where immediate transfusion is needed. Desmopressin is used primarily to treat bleeding disorders and would not address the urgent need for red blood cells in this patient.

Therefore, the