PRE-OPERATIVE ANAEMIA IN ELECTIVE TOTAL KNEE ARTHROPLASTY PATIENTS

Abstract

Study Objective: To determine the proportion of patients proceeding to elective total knee arthroplasty with pre-operative anaemia.

Background: Over 60,000 primary total knee replacements are performed in England and Wales each year. Blood transfusion can be associated with serious complications. A pre-operative haemoglobin of less than 12 g/dl increases the likelihood of blood transfusion in the peri-operative period by threefold [1]. Published BOA guidelines recommend patients with pre-operative haemoglobins of 12 g/dl or below in males or 11 g/dl or below in females should have their anaemia investigated and treated prior to total knee arthroplasty.

Methods: Patients having elective total knee arthroplasty at our hospital over three-months formed the study population. Data were collected on age, sex, pre- and postoperative haemoglobin, transfusion requirements in the peri-operative period, and whether the patient had inflammatory arthritis. Patients were classified according to the recommended BOA guidelines for deferring elective surgery using pre-operative haemoglobin levels. Post-operative haemoglobin drop was also calculated.

Results: Fifteen patients (7%) out of 212 had pre-operative haemoglobins below guideline thresholds. The age range of these patients was 59–84 yr. Nine patients were female. Pre-operative haemoglobin ranged from 9.2–12.0 g/dl. Post-operative haemoglobin drop ranged from 0.5–4.3 g/dl. Six patients received blood transfusion in the peri-operative period (maximum of three units). One patient had a diagnosis of inflammatory arthritis.

Discussion: Pre-operative anaemia is common in patients having elective total knee arthroplasty. In this study most anaemic patients did not have anaemias attributable to inflammatory arthritis. Using cell salvage techniques did not prevent peri-operative blood transfusion in anaemic patients.

Conclusion: Anaemic patients wanting arthroplasty in favour of surgical deferral and treatment of their anaemia must be made fully aware of the serious complications associated with blood transfusions.