Lactate dehydrogenase and Haemolysis Index as quality control markers of haemolysis in intra-operative cell salvage

The aim of this investigation was to explore the potential use of the tests lactate dehydrogenase (LDH) and Haemolysis Index as haemolysis markers in intra-operative cell salvage (ICS) blood in comparison to plasma free haemoglobin levels.

Quality control (QC) should be seen as a fundamental part of any ICS blood conservation programme, however, due to lack of available knowledge, familiarity and experience, QC is still a comparatively new subject. A QC pilot scheme is currently being undertaken by the Royal Cornwall Hospital in association with the UK Cell Salvage Action Group to explore potential markers that can be used to assess the quality of blood obtained from ICS. This test list should be available to all ICS users and achievable within financial budgets. Currently this proposed test list includes a full blood count, a protein marker such as urine albumin/microalbumin and heparin monitoring. Haemolysis testing is another key marker.

Samples were collected from ICS processed blood and allogeneic SAGM leucodepleted red cell units and processed for plasma free haemoglobin, LDH and Haemolysis Index.

There was a very strong correlation between plasma free haemoglobin and LDH (0.960), and plasma free haemoglobin and the Haemolysis Index (0.944).

We have shown that the LDH and Haemolysis Index tests are suitable and reliable alternatives for measuring haemolysis from samples obtained from ICS or allogeneic blood. We have incorporated the LDH test into our Hospital's ICS QC package and recommend that this test is considered for all ICS QC samples.