Transfusion
Hébert P, Wells G, Blajchmann M, et al. A multicenter randomized controlled clinical trial of transfusion requirements in critical care. N Engl J Med 1999;340:409-17. Landmark study found equal mortality using transfusion thresholds of 7 gm/dl and 10gm/dl and higher mortality with liberal transfusion among younger and less ill patients.
Villanueva C, Colomo A, Bosch A, et al. Transfusion strategies for acute upper gastrointestinal bleeding. N Engl J Med. 2013; 368:11-21. A large multi-center trial that found a hemoglobin goal of 7 mg/dL during acute upper gastrointestinal bleed resulted in a lower risk of re-bleeding, adverse events, and a decreased hazard ratio for death at 6 weeks when compared with a 9 mg/dL target. Patients with rapid exsanguination were excluded. The mortality benefit appears greatest in patients with Child-Pugh class A or B cirrhosis.
Sickle Cell Anemia
Novelli EM and Gladwin MT. Crises in sickle cell disease. Chest. 2016; 149:1082-93. A review that includes discussion of acute chest syndrome, acute anemia, stroke, and infectious complications.