Delirium outcomes in a randomized trial of blood transfusion thresholds in hospitalized older adults with hip fracture

Abstract

Objectives: To determine whether a higher blood transfusion threshold would prevent new or worsening delirium symptoms in the hospital after hip fracture surgery.

Design: Ancillary study to a randomized clinical trial.

Setting: Thirteen hospitals in the United States and Canada.

Participants: One hundred thirty-nine individuals hospitalized with hip fracture aged 50 and older (mean age 81.5 ± 9.1) with cardiovascular disease or risk factors and hemoglobin concentrations of less than 10 g/dL within 3 days of surgery recruited in an ancillary study of the Transfusion Trigger Trial for Functional Outcomes in Cardiovascular Patients Undergoing Surgical Hip Fracture Repair.

Intervention: Individuals in the liberal treatment group received one unit of packed red blood cells and as much blood as needed to maintain hemoglobin concentrations at greater than 10 g/dL; those in the restrictive treatment group received transfusions if they developed symptoms of anemia or their hemoglobin fell below 8 g/dL.

Measurements: Delirium assessments were performed before randomization and up to three times after randomization. The primary outcome was severity of delirium according to the Memorial Delirium Assessment Scale (MDAS). The secondary outcome was the presence or absence of delirium defined according to the Confusion Assessment Method (CAM).

Results: The liberal group received a median two units of blood and the restrictive group zero units of blood. Hemoglobin concentration on Day 1 after randomization was 1.4 g/dL higher in the liberal group. Treatment groups did not differ significantly at any time point or over time on MDAS delirium severity (P = .28) or CAM delirium presence (P = .83).

Conclusion: Blood transfusion to maintain hemoglobin concentrations greater than 10 g/dL alone is unlikely to influence delirium severity or rate in individuals with hip fracture after surgery with a hemoglobin concentration less than 10 g/dL.

Keywords: blood transfusion; delirium; hip fracture.