Ann Earles

A Comparison of Conservative and Aggressive Transfusion Regimens in the Perioperative Management of Sickle Cell Disease

BACKGROUND Preoperative transfusions are frequently given to prevent perioperative morbidity in patients with sickle cell anemia. There is no consensus, however, on the best regimen of transfusions for this purpose. METHODS We conducted a multicenter study to compare the rates of perioperative complications among patients randomly assigned to receive either an aggressive transfusion regimen designed to decrease the hemoglobin S level to less than 30 percent (group 1) or a conservative regimen designed to increase the hemoglobin level to 10 g per deciliter (group 2). RESULTS Patients undergoing a total of 604 operations were randomly assigned to group 1 or group 2. The severity of the disease, compliance with the protocol, and the types of operations were similar in the two groups. The preoperative hemoglobin level was 11 g per deciliter in group 1 and 10.6 g per deciliter in group 2. The preoperative value for hemoglobin S was 31 percent in group 1 and 59 percent in group 2. The most frequent operations were cholecystectomies (232), head and neck surgery (156), and orthopedic surgery (72). With the exception of transfusion-related complications, which occurred in 14 percent of the operations in group 1 and in 7 percent of those in group 2, the frequency of serious complications was similar in the two groups (31 percent in group 1 and 35 percent in group 2). The acute chest syndrome developed in 10 percent of both groups and resulted in two deaths in group 1. A history of pulmonary disease and a higher risk associated with surgery were significant predictors of the acute chest syndrome. CONCLUSIONS A conservative transfusion regimen was as effective as an aggressive regimen in preventing perioperative complications in patients with sickle cell anemia, and the conservative approach resulted in only half as many transfusion-associated complications.

Alloimmunization in Sickle Cell Anemia and Transfusion of Racially Unmatched Blood

Transfusion therapy for sickle cell anemia is limited by the development of antibodies to foreign red cells. To evaluate the frequency and risk factors associated with such alloimmunization, we determined the transfusion history, red-cell phenotype, and development of alloantibodies in 107 black patients with sickle cell anemia who received transfusions. We compared the results with those from similar studies in 51 black patients with sickle cell disease who had not received transfusions and in 19 nonblack patients who received transfusions for other forms of chronic anemia. We assessed the effect that racial differences might have on the frequency of alloimmunization by comparing the red-cell phenotypes of patients and blood-bank donors (n = 200, 90 percent white). Although they received transfusions less frequently, 30 percent of the patients with sickle cell anemia became alloimmunized, in contrast to 5 percent of the comparison-group patients with other forms of anemia (P less than 0.001). Of the 32 alloimmunized patients with sickle cell anemia, 17 had multiple antibodies and 14 had delayed transfusion reactions. Antibodies against the K, E, C, and Jkb antigens accounted for 82 percent of the alloantibodies. Comparison of red-cell phenotypes in the three study groups (the patients with sickle cell anemia, the patients with other forms of anemia, and the blood donors) revealed statistically significant differences between the patients with sickle cell anemia and the donors but not between the patients with other forms of anemia and the donors. These differences are most likely racial. We conclude that alloimmunization is a common, clinically serious problem in sickle cell anemia and that it is partly due to racial differences between the blood-donor and recipient populations.

The perioperative complication rate of orthopedic surgery in sickle cell disease: Report of the national sickle cell surgery study group

Orthopedic disease affects the majority of sickle cell anemia patients of which aseptic necrosis of the hip is the most common, occurring in up to 50% of patients. We conducted a multicentered study to determine the perioperative complications among sickle cell patients assigned to different transfusion regimens prior to orthopedic procedures: 118 patients underwent 138 surgeries. The overall serious complication rate was 67%. The most common of these were excessive intraoperative blood loss, defined as in excess of 10% of blood volume. The next most common complication was sickle cell‐related events (acute chest syndrome or vaso‐occlusive crisis), which occurred in 17% of cases. While preoperative transfusion group assignment did not predict overall complication rates, higher risk procedures were associated with significantly higher rates of overall complications. Transfusion complications were experienced by 12% of the patients. Two patients died following surgery. Both deaths were associated with an acute pulmonary event. The 52 patients undergoing hip replacements experienced the highest rate of complications with excessive intraoperative blood loss occurring in the majority of patients. Sickle cell‐related events occurred in 19% of patients, and surgical complications occurred after 15% of hip replacements and included postoperative hemorrhage, dislocated prosthesis, wound abscess, and rupture of the femoral prosthesis. There were twenty‐two hip coring procedures. Acute chest syndrome occurred in 14% of the patients. Overall, decompression coring was a safer, shorter operation. A randomized prospective trial to determine the perioperative and long‐term efficacy of core decompression for avascular necrosis of the hip in sickle cell disease is needed. In conclusion, this study demonstrates a high rate of perioperative complications despite compliance with sickle cell perioperative care guidelines. Pulmonary complications and transfusion reactions were common. This study supports the results previously published by the National Preoperative Transfusion in Sickle Cell Disease Group. These results stated that a conservative preoperative transfusion regimen to bring hemoglobin concentration to between 9 and 11 g/dl was as effective as an aggressive transfusion regimen in which the hemoglobin S level was lowered to 30%. Am. J. Hematol. 62:129–138, 1999.

Cost-effectiveness of hydroxyurea in sickle cell anemia

The Multicenter Study of Hydroxyurea in Sickle Cell Anemia (MSH) demonstrated the efficacy of hydroxyurea in reducing the rate of painful crises compared to placebo. We used resource utilization data collected in the MSH to determine the cost‐effectiveness of hydroxyurea. The MSH was a randomized, placebo‐controlled double‐blind clinical trial involving 299 patients at 21 sites. The primary outcome, visit to a medical facility, was one of the criteria to define occurrence of painful crisis. Cost estimates were applied to all outpatient and emergency department visits and inpatient hospital stays that were classified as a crisis. Other resources for which cost estimates were applied included hospitalization for chest syndrome, analgesics received, hydroxyurea dosing, laboratory testing, and clinic visits for management of patient care. Annualized differential costs were calculated between hydroxyurea‐ and placebo‐receiving patients. Hospitalization for painful crisis accounted for the majority of costs in both arms of the study, with an annual mean of

Physical therapy alone compared with core decompression and physical therapy for femoral head osteonecrosis in sickle cell disease: Results of a multicenter study at a mean of three years after treatment

12,160 (95% CI:

Tonsillectomy, Adenoidectomy, and Myringotomy in Sickle Cell Disease: Perioperative Morbidity

9,440,

Newborn Screening for Sickle Cell Disease: Effect on Mortality

14,880) for hydroxyurea and

Pulmonary fat embolism : a distinct cause of severe acute chest syndrome in sickle cell anemia

17,290 (95% CI:

Cholecystectomy in Sickle Cell Anemia Patients: Perioperative Outcome of 364 Cases From the National Preoperative Transfusion Study

13,010,

Cholecystectomy in sickle cell anemia patients: perioperative outcome of 364 cases from the National Preoperative Transfusion Study. Preoperative Transfusion in Sickle Cell Disease Study Group.

21,570) for placebo. The difference in means was