(1226) Determining potentially avoidable blood transfusion after cesarean delivery: a retrospective cohort

Objective: Prior work shows that actual blood loss is similar between vaginal (VD) and cesarean deliveries (CD). Yet, 12-hour complete blood counts (12hCBCs) are only routinely performed after CD, possibly contributing to a higher blood transfusion rate after CD as compared to VD. We sought to determine the proportion of blood transfusions after CD performed secondary to the routine post-CD 12hCBC alone, thus potentially avoidable.

Study Design: This retrospective cohort evaluated indications for packed red blood cell (pRBC) transfusion after CD in the postpartum (PP) period at a single institution from 2017-2022. Patients were evaluated for: pRBC transfusion before or after 12hCBC, high risk clinical criteria for PP anemia warranting a CBC (defined as ≥1 of the following: EBL≥1L, ≥3 CD, placental abnormalities, severe preeclampsia, multiple gestation, bleeding/clotting disorder, antepartum pRBC transfusion, admission Hb< 9.5g/dL, and surgical injury), and documented symptomatology (lightheadedness and/or fatigue) or abnormal vital signs (VS, defined as ≥1 of the following HR≥100; BP< 90/50; O2 sat < 95%) prior to transfusion. Those transfusions that occurred post-12hCBC, without high-risk clinical criteria, symptoms, or abnormal VS, were deemed potentially avoidable without a routine 12hCBC. Descriptive statistics were utilized.

Results: 421 patients were included; demographics are shown in the Table. Of those 421, 244 (58.0%) of post-CD transfusions occurred after the 12hCBC. Among those 244, 216 had at least one of the high-risk clinical criteria. Of the remaining 28 (6.6% of the initial cohort), 17 had either documented symptoms or abnormal VS. Thus, of 421 patients receiving pRBC transfusions post-CD after the 12hCBC, only 11 (2.6%), encompassing 19 pRBC units out of 984 transfused in the cohort (1.9%), were deemed potentially avoidable (Figure).

Conclusion: This study highlights that the majority ( >97%) of patients who received pRBCs post CD would not have avoided the transfusion even in the absence of a routine 12hCBC. Alternative interventions to reduce unnecessary post-CD transfusion should be pursued.