Figure 1 - The Hillingdon Hospitals NHS Foundation Trust Pre-operative anaemia optimisation protocol for elective total hip and total knee arthroplasties. THR: Total Hip Replacement; TKR: Total Knee Replacement; Hb: Haemoglobin; RBC: Red Blood Cells; GP: General Practitioner; FBC: Full Blood Count; IV: Intravenous.
Upon the decision to proceed for surgery, patients are referred to the pre-operative assessment clinic, where they undergo routine investigations (full blood count, urea and electrolytes, group and save, ECG) and an assessment of their medical co-morbidities. A protocol, based on the NATA guidelines previously discussed, was created specifically for patients undergoing elective primary hip or knee replacement surgery. This would be initiated at the pre-operative assessment clinic.
The haemoglobin and ferritin levels were evaluated, and patients who were identified as anaemic (as defined by the WHO criteria of Hb <12g/dL in non-pregnant women and Hb<13g/dL in men) and have a serum ferritin level of <100ng/ml receive oral iron therapy for four weeks through their GP. Where there is less than four weeks before the date of surgery, patients received intravenous iron, ferric carboxymaltose, instead.
These patients are then re-assessed to see if their anaemia has been optimised. If there has been no response to oral therapy, patients are then given intravenous iron therapy, provided that there are no contra-indications. In patients with a serum ferritin level of more than 100 ng/mL and a Haemoglobin of less than 12 g/dL, discussion with the haematology team is recommended to further investigate and address the cause of anaemia.
We conducted a retrospective audit of patients who had undergone elective primary total hip or total knee arthroplasty in 2016. A patient database was obtained from the clinical coding department. We initially analysed all patients’ blood results using the Trust’s electronic blood test reporting system. Once the anaemic patients were identified from their initial pre-operative assessment bloods, we used their inpatient clinical notes, electronic discharge summaries and electronic GP records to determine which patients received pre-operative anaemia correction treatment.
683 patients were included in the audit from the database that had undergone surgery between January 1st 2016 and December 31st 2016. From the same database, 21 patients were excluded for a variety of reasons - 18 patients had revision arthroplasty surgeries, 1 patient had bilateral joint replacement surgery, 1 patient was receiving blood transfusions on a regular basis prior to surgery for a complex haematological condition, and 1 patient had no discharge summary. From this, we established that 138 patients were identified as being anaemic at pre-operative assessment clinic (20.2% of the cohort population).
Only 25 of the 138 anaemic patients were correctly identified and managed with regards to their anaemia and the pre-operative assessment protocol (18.1%).
Following on from the results of the audit, we decided to examine what impact anaemia and the subsequent management protocol had on hospital length of stay and blood transfusion requirement. This was done by 2 methods: For hospital length of stay we obtained the information from patients’ electronic discharge summaries. For blood transfusions, we used the Trust’s electronic blood test and investigation reporting system to determine how many units of blood were issued for each patient (if any) and cross referenced with their electronic discharge summaries. The length of stay and blood transfusion rates were calculated for both anaemic and non-anaemic patients.