Delirium Outcomes in a Randomized Trial of Blood Transfusion Thresholds in Hospitalized Older Adults with Hip Fracture

Abstract

Objectives To determine if 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 United States and Canada. Participants One-hundred-thirty-nine hospitalized hip fracture patients, age ≥50, with cardiovascular disease or risk factors, and hemoglobin<10 g/dL within 3 days of surgery, recruited in an ancillary study of “Transfusion Trigger Trial for Functional Outcomes in Cardiovascular Patients Undergoing Surgical Hip Fracture Repair (FOCUS) trial.” Intervention Treatment groups: 1) Liberal: received one unit of packed red blood cells and as much blood as needed to maintain hemoglobin >10 g/dL; 2) Restrictive: received transfusions if developed symptoms of anemia or hemoglobin fell below 8 g/dL. Measurements Delirium assessments performed pre-randomization and up to three times post-randomization. Primary outcome: Severity of delirium using Memorial Delirium Assessment Scale (MDAS) scale. Secondary outcome: presence or absence of delirium defined by Confusion Assessment Method Diagnostic Algorithm (CAM). Results Mean age was 81.5 (SD=9.1). Liberal group received a median 2 units and Restrictive group 0 units of blood. Hemoglobin concentration on day 1 post randomization was 1.4 g/dL higher in the Liberal group. Treatment groups did not significantly differ at any time point or over time on either MDAS delirium severity (p=0.28) or CAM delirium presence (p=0.83). Conclusion Blood transfusion to maintain hemoglobin >10 g/dL alone is unlikely to influence delirium severity or rate in postoperative hip fracture patients with hemoglobin concentration <10 g/dL. Trial Registration ClinicalTrials.gov identifier: NCT00071032 http://clinicaltrials.gov/ct2/show/NCT00071032

Daily Lowest Hemoglobin and Risk of Organ Dysfunctions in Critically Ill Patients

“…While the pathogenesis of delirium is not known, it is plausible that the degree of anemia in our patient population did not impact cerebral oxygen delivery and any potential for brain organ dysfunction. Our findings corroborate studies where red blood cell transfusions have shown to have no impact on delirium rates (36) (37) (38). While anemia and red blood cell transfusions have both been implicated in acute kidney injury (39), a degree of anemia may be protective for the kidney due to decreased viscosity and rheology, and there is evidence that correcting anemia with either erythropoietin or transfusion, does not improve renal function (28) (29) (39).…”

A Guide to Improving the Care of Patients with Fragility Fractures, Edition 2

“…42 Another study has shown that there was no reduction in incidence or severity of delirium in individuals after hip fracture surgery when hemoglobin levels were less than 10 g/dL. 167 Hydrate patients to achieve urine output of 30 to 35 mL/h using isotonic saline Based on current best evidence, the red cell transfusion threshold should be hemoglobin <8 g/dL. 42 …”

The Effect of Treatment of Anemia with Blood Transfusion on Delirium: A Systematic Review

“…The quality of Gruber‐Baldini's and Fan's studies was additionally assessed with a form from the Dutch Cochrane Institute for RCTs. In the study of Gruber‐Baldini, the intervention was randomized by central telephone randomization system. Patients, physicians and study personnel were not blinded.…”