Indications for transfusions

Prophylactic Perioperative Transfusion

Background
Transfusions are commonly used in the perioperative period to prevent the development of vaso-occlusive crises (VOCs), stroke, or ACS after surgery. Surgical procedures are associated with significant morbidity for individuals with SCD. In the Cooperative Study of Sickle Cell Disease (CSSCD), sickle-related complications (e.g., VOC, ACS, and stroke) occurred in 0-18.6 percent of patients with SCA (depending on the surgical procedure) and non-sickle cell-related complications (defined as fever, infection, bleeding, thrombosis, embolism, and death) occurred in 5.7 to 26.2 percent of patients. There were 12 deaths in 1,079 surgical cases.

The Transfusion Alternatives Preoperatively in Sickle Cell Disease (TAPS) study was published in 2013 and thus was not included in the evidence review. However, the expert panel did want to acknowledge this important study. TAPS was a multicenter trial in Europe and Canada401 that randomized individuals with SCA to either no preoperative transfusion or preoperative transfusion. The study enrolled patients undergoing low­ risk (e.g., adenoidectomy, inguinal hernia repair) and medium-risk (e.g., cholecystectomy, joint replacement) procedures. The goal of transfusion was to raise the hemoglobin to 10.0 g/dL. In patients with preoperative hemoglobin levels of 9.0 g/dL or higher, a partial exchange transfusion was done. The study was closed early due to significantly more complications in the medium-risk, no preoperative transfusion arm than in the medium-risk transfusion arm (10/33 vs. 1/34). The unadjusted odds ratio of clinically important complications was 3.8. As the study was closed early, the estimate observed may be overestimated. There were too few patients enrolled in the low-risk procedure arms to draw any conclusions.

Key Question

i An updated search was performed to span the time from June 1, 2010 through July 11, 2014. One additional RCT was identified, for a total of 300 studies, and a supplemental table reflecting this addition was added to the evidence table document.

Summary of the Evidence
One RCT, four observational studies, and six case series evaluated perioperative transfusion outcomes in SCD. Overall, the quality of evidence was low due to severe imprecision (small number of events) and lack of controlled comparisons; therefore, the results are inconclusive.

A single randomized trial has been done examining the use of transfusion in the perioperative period. This study compared the use of simple transfusion with a hemoglobin (Hb) goal of 10 g/dL preoperatively to the use of exchange transfusion to bring the HbS :30 percent. No statistically significant reduction in the incidence of perioperative complications was seen between the two arms of the study, although complication rates in both arms were high (31 percent in the exchange group and 35 percent in the simple transfusion group), and 10 percent of patients in both arms developed ACS.

The four observational studies and six case series reported on various outcomes of transfusion in the perioperative period. In patients with SCA undergoing surgical procedures in the CSSCD, the combined incidence of all sickle cell-related complications postoperatively was significantly lower in those who had preoperative transfusion compared to those who did not have transfusion.Similar results were demonstrated in individuals with sickle hemoglobin C (HbSC) disease. Al-Samak et al. described 46 patients who underwent simple transfusion, exchange transfusion, and no transfusion. The incidence of sickle cell crisis and ACS was similar in all three groups. Wali et al. studied 14 patients and reported similar perioperative outcomes of conservative versus aggressive transfusion (Hb >10 g/dL and HbS <30 percent). The remaining seven studies were uncontrolled case series and did not provide additional conclusions. Recommendations In adults and children with SCA, transfuseRBCs to bring thehemoglobin level to10 g/dl prior to undergoing a surgical procedure involving general anesthesia. {Strong Recommendation, Moderate-Quality Evidence) In patients with HbSS disease who require surgery and who already have a hemoglobin level higher than 8.5g/dl without transfusion,are on chronic hydroxyureatherapy, or who requirehigh-risksurgery(e.g., neurosurgery, prolonged anesthesia, cardiac bypass), consult a sickle cell expert for guidance as to the appropriate transfusion method. {Strong Recommendation, Low-Quality Evidence) In adults and children with HbSC or HbSB•-thalassemia consult a sickle cell expert to determine if full or partial exchange transfusion is indicated before a surgical procedure involving general anesthesia. (Moderate Recommendation, Low-Quality Evidence)