Table 4.

Details of indications for transfusion from recent guidelines

	NHLBI (2014)22	BSH (2017)7 and BJH (2018)37	ASH (2020)21
Perioperative transfusion	• In HbSS disease, goal Hb 10  g/dL prior to undergoing a surgical procedure with general anesthesia. • In HbSS patients who require surgery and have an Hb >8.5  g/dL without transfusion, are on hydroxyurea, or need high-risk surgery (eg, neurosurgery, prolonged anesthesia, cardiac bypass), consult a sickle cell expert. • In HbSC or HbSβ +-thalassemia disease that requires a surgical procedure with general anesthesia, consult a sickle cell expert.	• In HbSS disease, goal Hb 10  g/dL prior to undergoing a surgical procedure with general anesthesia for low- or moderate-risk surgery. • In HbSS disease, full exchange transfusion, with a target HbS of <30%, for high-risk surgery (major neurosurgery, cardiothoracic) and for those with a high risk of perioperative complications (eg, severe organ damage or a history of complications). • In HbSC disease, give preoperative transfusion prior to moderate- and high-risk surgery. • All other patients undergoing surgery should be individually assessed. • Consider simple transfusion for patients with Hb <9 g/dL. • If Hb >9 g/dL and exchange transfusion would delay the surgery, it may be appropriate to proceed with surgery but to plan a postoperative transfusion if needed.	• For all SCD, recommend preoperative transfusion over no preoperative transfusion in patients undergoing surgeries requiring general anesthesia and lasting more than 1 hour.
Symptomatic ACS with Hb 1 g/dL below baseline	• Exchange or simple transfusion	• Exchange or simple transfusion	• Automated RCE, manual RCE, or simple transfusion
Symptomatic severe ACS (i.e., O2 saturation <90% with supplemental oxygen)	• Exchange transfusion	• Exchange transfusion	• Automated RCE or manual RCE over simple transfusion

BJH, British Journal of Haematology; BSH, British Society of Haematology; NHLBI, National Heart, Lung, and Blood Institute; RCE, red cell exchange.