Multiple studies of patients scheduled for major, elective orthopaedic surgical procedures have demonstrated that the prevalence of preoperative anaemia ranges from 25 to 35%.1 Preoperative anaemia, defined by the World Health Organization as haemoglobin < 130g/L in men and < 120g/L in women, has been identified as an independent predictor of allogeneic blood transfusion in this patient population.2,3 If left untreated, preoperative anaemia has been associated with significant adverse clinical events specifically, increased infection rates, hospital length of stay and mortality^.4^ Management of preoperative anaemia reduces perioperative risk and leads to improved patient outcomes.5, 6
Anaemia is not a diagnosis but rather a symptom of underlying disease. Identification of the causative underlying disease can become an extremely complex and laborious process. Frequently, particular investigations are carried out to rule out specific disease processes, such as laboratory tests to refute iron or vitamin B12 deficiency or hypothyroidism and colonoscopy to exclude bowel cancer. In some cases, a precise disease is not readily identified and anaemia is categorized as multifactorial or as anaemia of chronic disease.
In our elective orthopaedic surgery patient population, the surgeon initiates perioperative blood management discussion and orders screening complete blood count and ferritin tests once the decision to proceed with surgery is confirmed. The surgeon reviews the laboratory investigations and refers patients with haemoglobin < 135 g/L or ferritin < 100 ug/L to the blood conservation program. The nurse then assesses the current and previous haemoglobin, mean corpuscular volume, and ferritin values as well as the patient’s health history. The blood conservation program hematology consultant provides guidance regarding the need for immediate further investigations.
The focus of preoperative anaemia assessment and management at our institution is not identification of the causative pathology. In patients with new and severe anaemia (in our blood conservation program defined as haemoglobin < 100 g/L), elective surgery is deferred. These patients are referred to their family physician or an internal medicine consultant for complete investigation. Haemoglobin optimization strategies are implemented for patients with chronic or mild anaemia (in our blood conservation program defined as haemoglobin > 100 and < 130 g/L). Patients with mild anaemia but identified as iron deficient (ferritin < 35 ug/L) are advised to follow up with their family physician postoperatively (laboratory report and a recommendation for postoperative review is faxed to the family physician).
Chronic or mild anaemia patients are contacted by the blood conservation program nurse to discuss blood conservation and preoperative haemoglobin optimization. Patients are counseled to initiate oral iron supplements and are provided with the nurse’s contact information if they encounter any challenges with their iron therapy. The time frame for preoperative haemoglobin assessment is of pivotal significance. In our experience, haemoglobin optimization can often be achieved with simply oral iron supplementation. However, this requires a treatment period of 6-12 weeks.
All elective orthopaedic surgery patients attend preadmission clinic for preoperative history and physical assessment, preparation instructions, and education regarding their surgery and recovery. This appointment is scheduled approximately 4 weeks prior to the surgery date. Complete blood count and ferritin are re-assessed to ensure that the preoperative haemoglobin is optimized. The blood conservation nurse reviews the response to oral iron supplements previously implemented. Intravenous iron and/or erythropoiesis-stimulating agents may also be considered to optimize patients with preoperative haemoglobin < 130 g/L. Patients with haemoglobin > 130g/L but < 150 g/L are counseled to initiate oral iron supplements at this time point. The preoperative haemoglobin optimization approach for our patients is summarized in Figure 1.
Timely assessment and treatment of preoperative anaemia is the cornerstone of blood conservation. Optimal preoperative haemoglobin enhances intraoperative blood conservation strategies (cell salvage, antifibrinolytics, and acute normovolemic hemodilution) and minimizes postoperative anaemia. Treatment of anaemia in elective orthopaedic surgery does improve patient outcomes and serves to reinforce a culture of patient safety.
- Bierbaum B.E., Callaghan J.J., Galante J.O. et al. An analysis of blood management in patients having a total hip or knee arthroplasty. J Bone Joint Surg Am 1999;81:2-10
- Nuttal G.A., Santrach P.J., Oliver W.C. Jr. et al. The predictors of red cell transfusion in total hip arthroplasty. Transfusion 1996;36:144-4
- Spahn D.R. Anemia and patient blood management in hip and knee surgery. A systematic review of the literature. Anesthesiology 2010;113:482-95
- Myers E., O’Grady P., Dolan A.M. et al. The influence of preclinical anaemia on outcome following total hip arthroplasty. Arch Orthop Trauma Surg 2004;124:699-701
- Saleh E., McClelland D.B.L, Hay A. et al. Prevalence of anaemia before major joint arthroplasty and the potential impact of preoperative investigation and correction on perioperative blood transfusion. Br J Anaesth 2007;99:801-8
- Goodnough L.T., Maniatis A., Earnshaw P. et al. Detection, evaluation, and management of preoperative anaemia in the elective orthopaedic surgical patient: NATA guidelines. Br J Anesth 2011;106 (1):13-22
Reprinted with permission from the Summer 2011 issue of COA Bulletin