Preoperative Transfusion Practices and Outcomes in Sickle Cell Patients Admitted to California Hospitals,
Authors: Claster Susan , Schrager Sheree M , Guzman Vanessa , Wolfson Julie , Iverson Ellen 
Published: October 2019

Abstract
Abstract 4189

Introduction:
Surgery in patients with Sickle Cell Disease (SCD) is associated with a high rate of postoperative complications, including acute chest syndrome (ACS). Some early reports have suggested that the overall complication rate may be as high as 50% and the mortality rate 10%. In 1995, a large multicenter trial conducted at SCD centers in the U.S. showed that preoperative transfusion reduced complications related to sickling. Despite transfusions, 10% of the patients in this study developed ACS. Recently, smaller studies in the US and other countries have suggested that not all SCD patients who undergo surgery need a transfusion. Practices may vary depending on surgical risk and the clinical history of the patient. For example, while most SCD centers use preoperative transfusions, practices outside of centers (where the majority of patients are being followed) are not well understood. To describe the transfusion practices in our state as well some of the outcomes of SCD patients who undergo surgery, we queried California's statewide hospital discharge database to describe the frequency of preoperative transfusions for SCD patients as well as the frequency of ACS following surgery.

Methods:
This was a retrospective cohort study using 2005–2008 public data from the California Office of Statewide Health Planning and Development (OSHPD). Data included all inpatient discharges from all non-federal California hospitals. Inclusion criteria included the presence of a sickle cell disease ICD-9 code in the primary or a secondary diagnosis (282.60–282.69, 282.41–282.42) and the presence of ICD-9 codes for one of the six most common surgical procedures performed in SCD: tonsillectomy, cholecystectomy, splenectomy, hysterectomy, therapeutic abortion, and hip arthroplasty. A variable summarizing the temporal sequence of transfusion and surgery was created by comparing the number of days to surgery with the number of days to transfusion. Cases were coded for the presence of ACS (517.3) or respiratory diagnoses (including pneumonia, pulmonary edema, acute respiratory distress syndrome, hypoxia and respiratory failure) in any primary or secondary diagnosis. Transfusion, ACS diagnosis, and mortality frequencies were described, and differences in outcome between patients treated with or without transfusion were assessed with chi-square tests.

Results:
Between 2005 and 2008, 468 visits to California hospitals by patients with SCD were associated with one of the six targeted surgical procedures. Of these visits, 222 cases (47.4%) were associated with a transfusion. Of the 179 cases in which the timing of transfusion could be determined, 145 visits (81%) were associated with a preoperative transfusion, and 34 visits (19%) were associated with a transfusion given after surgery. ACS was documented in 59 (12.6%) surgical patients. Forty three cases of ACS occurred in the transfused patients(19%). Sixteen cases(6.5%) occurred in the non transfused group. The timing of transfusion was available in 32 of the ACS cases, of which 21 had a transfusion either before or on the same day of surgery and 11 were transfused after surgery. There were four deaths in the cohort: three patients had been transfused and developed ACS.The fourth patient was never transfused and did not develop ACS.

Conclusions:
Over half of the SCD patients in California are not transfused in association with a surgical procedure. The majority of transfused patients received preoperative transfusions and were more likely to develop ACS or a related pulmonary complication following surgery, whereas the frequency of ACS was lower in the nontransfused group. This latter finding could be consistent with a group of patients with less severe disease. Similarly, the increased frequency of death in transfused patients likely reflects the clinical severity of this group. Although we were unable to determine if preoperative transfusions were administered prior to hospital admission, the data suggests that many patients are not being given what many sickle cell providers in the US consider standard preoperative treatment. Finally, the frequency of ACS in transfused patients was nearly twice that of the study performed in academic sickle cell centers in 1995. This finding is consistent with the notion that many California patients do not receive care at a sickle cell center and thus may have poorer outcomes

Disclosures:
No relevant conflicts of interest to declare.