Preoperative Anemia Screening for Elective Hip Arthroplasty
The most appropriate next test is iron studies (Option A), as this patient requires hemoglobin measurement and evaluation for iron deficiency anemia given her heavy menstrual periods and upcoming elective hip arthroplasty.
Rationale for Preoperative Anemia Screening
All elective orthopaedic surgical patients should have hemoglobin determination 28 days before scheduled surgery to allow adequate time for detection and treatment of anemia 1. This patient has multiple risk factors for iron deficiency anemia:
- Heavy menstrual bleeding is a leading cause of iron deficiency in women of reproductive age, with up to one-third of women with heavy menstrual bleeding developing iron deficiency or iron-deficiency anemia 2
- Chronic NSAID use (ibuprofen) can cause occult gastrointestinal blood loss, further depleting iron stores 1
- Type 2 diabetes is associated with increased prevalence of preoperative anemia in surgical patients 1
Clinical Impact of Untreated Preoperative Anemia
Preoperative anemia in elective orthopaedic surgery is associated with:
- Increased perioperative morbidity and mortality 1
- Higher likelihood of allogeneic blood transfusion 1
- Impaired postoperative functional recovery, particularly in hip surgery patients 1
- Reduced quality of life after total hip arthroplasty 1
In elective orthopaedic surgery patients, 35% have hemoglobin levels <13 g/dL at preadmission testing, with approximately one-third due to iron deficiency 1. The prevalence of haematinic deficiencies includes 33% for iron, 12.3% for vitamin B12, and 3% for folate 1.
Recommended Diagnostic Workup
When anemia is detected, further laboratory testing should evaluate for nutritional deficiencies (iron, B12, folate), chronic renal insufficiency, and chronic inflammatory disease 1. The initial workup should include:
- Complete blood count with hemoglobin measurement 1
- Iron studies (serum iron, ferritin, transferrin saturation, total iron-binding capacity) to identify iron deficiency 1
- Additional testing for B12 and folate if iron deficiency is not present or only partially explains the anemia 1
Why Other Options Are Inappropriate
- Vitamin B12 level alone (Option B) would miss the most likely diagnosis of iron deficiency anemia in a woman with heavy menstrual bleeding 2
- No further evaluation (Option C) contradicts established guidelines requiring preoperative hemoglobin screening and anemia workup before elective orthopaedic surgery 1
- Hemoglobin electrophoresis (Option D) is not indicated without evidence suggesting hemoglobinopathy; iron deficiency is far more likely given her clinical presentation 1
Treatment Implications
Nutritional deficiencies identified preoperatively should be treated before elective surgery 1. The target hemoglobin should be within the normal range according to WHO criteria before proceeding with elective surgery 1. This approach improves patient outcomes and reduces transfusion requirements 1.
Important Clinical Caveat
While metformin can cause changes in menstrual bleeding patterns in some women, any woman with heavy menstrual bleeding should be evaluated for iron deficiency regardless of medication use 2, 3. The heavy menstrual periods described warrant investigation independent of her diabetes management.