Transfusion-related mortality after primary hip arthroplasty--an analysis of mechanisms and confounders

Bleeding and postoperative anaemia after total hip arthroplasty (THA) may trigger transfusion of red blood cells (RBC). However, large observational studies have reported associations between RBC transfusion and increased postoperative morbidity and mortality. As major bleeding or severe postoperative anaemia is intrinsically linked with RBC transfusion, direct causality between transfusion and adverse outcomes remains unclear. This study aimed to identify possible relations between RBC transfusion, severe bleeding or anaemia and mortality in all patients who died <90 days after THA in Denmark in 2008.

Nationwide review of patient records. Cases of adverse transfusion events, infections following transfusion, severe perioperative bleeding or anaemia and possible causal relations to mortality were identified by two independent reviewers.

Of 6932 THA patients, 45 (0·6%) were transfused within 30 days and died <90 days from surgery. Three patients (7%) died from causes possibly related to either severe anaemia, major bleeding alone or major bleeding with transfusion-related acute lung injury, while five (11%) died from infections occurring after RBC transfusion. Mortality in the remaining 37 patients (82%) was of unknown cause (nine patients) or related to patient or surgical factors (28 patients).

Transfusion-related mortality after THA included cases of major perioperative bleeding or severe postoperative anaemia with delayed RBC transfusion in addition to possible complications to RBC transfusion per se. Future studies should account for pretransfusion haemoglobin and perioperative blood loss when evaluating RBC transfusion-associated outcomes after surgery.