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· DOS Abstracts
Iron deficiency and causes of preoperative anemia
in patients scheduled for elective hip- and knee
arthroplasty – an observational study
Øivind Jans , Khan Nissa , Christian Skovgaard Nielsen , Kirill Gromow, Anders
Trolsen, Henrik Husted
Section for Surgical Pathophysiology 4074, Rigshospitalet, Copenhagen
University, Copenhagen, Denmark; Department of Orthopaedic surgery,
Copenhagen University Hospital Hvidovre, Copenhagen, Denmark
Background:
Preoperative anemia is prevalent in elderly patients undergo-
ing major orthopaedic surgery and has been associated with increased risk of
blood transfusion and postoperative morbidity. Current guidelines recommend
correcting anemia and iron deficiency prior to surgery. However, the causes of
preoperative anemia in hip- (THA) and knee (TKA) arthroplasty are sparsely
studied.
Purpose / Aim of Study:
Investigating the causes for preoperative anemia
prior to THA and TKA.
Materials and Methods:
Preoperative hemoglobin and biochemical markers of
anemia and iron status were prospectively collected from 900 patients sched-
uled for elective fast-track THA and TKA. Anemia was defined using WHO cri-
teria (Hb < 12 g/dl in females or < 13 g/dl in males). Iron deficiency (ID) and
other possible anemia causes were classified using ferritin, transferrin saturation
(TSAT), P-Cobalamine,, P- Folate, C-reactive-protein and creatinine. ID was
defined as absolute (ferritin < 30 ng/ml) or functional (ferritin 30-100 ng/ml
& TSAT < 20%).
Findings / Results:
96 (10.7%) patients were anemic preoperatively. 329
(37%) had absolute or functional iron deficiency, 44 % vs. 34 % in anemic and
non- anemic patients, respectively (p = 0.09). Anemic patients were transfused
more frequently, 42 vs. 12 %; p < 0.001). 90 day readmission rate was 24 vs.
17 % in anemic vs. non-anemic patients (p = 0.14). Among anemic patients, 43
(44.8%) had ID; 22 (22.9%) had ID alone and 21 (21.9%) patients had mixed
anemia (ID + chronic inflammation or possible nephrogenic anemia). In a further
25 (26.0%) patients without ID, anemia was possibly due to inflammation, renal
failure or both. In the remaining 28 (29.2%) patients, the anemia was of inde-
terminate origin.
Conclusions:
Anemia is prevalent prior to THA or TKA with potentially revers-
ible iron deficiency as a possible cause in 45% of anemic patients.
No conflicts of interest reported
65.