Title : Pre-operative anaemia hb 30g is associated with an extended inpatient stay following elective primary hip and knee replacements
Introduction: NICE guidelines recommend that pre-operative haemoglobin (Hb) should be ≥130g/L in patients undergoing elective surgery. At our centre the preoperative Hb cut-off, for patients undergoing elective joint replacement, is ≥110g/L. We aimed to compare the post-operative length of stay in anaemic (Hb<130g/L) and non-anaemic (Hb ≥130g/L) patients, undergoing elective primary knee or hip replacement.
Methods: A retrospective review of all patients who had undergone an elective primary knee or hip replacement, over a 6 week period, was carried out. Pre-operative Hb, day 1 post-operative Hb and inpatient length of stay data were all recorded. Patients with no pre-operative Hb available to review were excluded.
Results: A total of 99 patients (35 males, 64 females) were included in this study. 36 patients (3 males, 33 females; median age 70 years (32-89)) were found to be anaemic (Hb <130g/L pre-operatively). 63 patients (32 males, 31 females; median age 69 years (22-93)) were not anaemic pre-operatively. In the anaemic group, 13 patients underwent primary knee and 23 patients primary hip replacement. The median preoperative Hb was 120g/L (95-129g/L). The median day 1 post-operative Hb was 104g/L (72-143g/L). No day 1 postoperative Hb was available in 4 patients. In the non-anaemic group, 26 patients underwent primary knee and 37 primary hip replacement. The median preoperative Hb was 139g/L (130-169g/L). The median day 1 post-operative Hb was 104g/dL (86-123g/L). Median inpatient stay was longer in the anaemic group when compared to the non-anaemic group 3 days (1-74) vs. 5.5 days (1-103) (p= 0.08).
Conclusion: Although statistical significance has not been reached in this small study, there is a tendency towards a longer inpatient stay in patients undergoing elective lower limb arthroplasty who have preoperative anaemia (Hb <130g/L). Preoperative optimisation of the patient in general, and haemoglobin in particular, may reduce post-operative inpatient stay