Non-invasive Identification of Preoperative Anaemia

Approximately 20% of patients undergoing elective orthopaedic surgery are anaemic. When not identified and treated before surgery, this can lead to requiring blood transfusions, which brings additional expenses, time and inconvenience to the patient.It is recommended that preoperative assessment involves investigation and where possible, treatment of anaemia.

The timescale between assessment and surgery makes it difficult to comply with guidelines without postponing surgery.

This study will investigate adult patients scheduled for elective orthopaedic surgery, where a full blood count is to be taken as part of routine care. A paired non-invasive reading of their blood will be taken. It will be conducted at The Royal Infirmary, Edinburgh. This device is not in use within the department currently but has been given free of charge for the study. There are no restrictions placed on the device except that it is not accurate for measuring haemoglobin <8g.dL. Participant care will only be determined by results from the laboratory assay as per routine care, not the noninvasive device.

The device is CE marked for haemoglobin determination. Masimo (manufacturer) have released results in the accuracy of their monitor but with very little other information, for example, study population or precision. This study aims to answer how accurate and precise non-invasive measurements are in patients scheduled for orthopaedic surgery (there are no studies with these results) and whether anaemia can be identified earlier in the patient pathway i.e. an anaemia screen at time of surgical listing, therefore leaving ample time for treatment and optimisation of care.

The data from the study will not be shared with Masimo. There is ongoing work towards introducing and piloting a new pre-operative triage system where optimisable conditions e.g. anaemia are identified at the time of listing. This study would aid this work.