Assessment of intra‐operative cell salvage haemolysis in the obstetric and orthopaedic clinical setting, in comparison with allogeneic blood

OBJECTIVES/BACKGROUND: Haemolysis is still a re-occurring theme in intra-operative cell salvage (ICS) with further haemolysis possibly caused by suction pressure, washing/centrifuging process and aspiration method. Previous investigations, along with manufacturer's reports, state that between 75 and 95% of free haemoglobin (Hb) is removed by the washing and centrifugation process; however, if these results are above the expected levels, excess free Hb may remain after washing. The aim of this article was to quantify haemolysis levels whilst employing different aspiration methods from skimmed (orthopaedics) and pooled (obstetrics) surgery types and comparing this to allogeneic blood. METHODS/MATERIALS: Samples obtained from 50 allogeneic units and 50 ICS cases (25 obstetric and 25 orthopaedic) were tested for plasma free Hb levels. RESULTS: Free Hb testing as a marker of haemolysis was greatest in orthopaedic 17·2 g L(-1) (range: 1·7-57·0 g L(-1) ), obstetric 2·8 g L(-1) (range: 1·0-13·5 g L(-1) ) and allogeneic 0·95 g L(-1) (range: 0·2-4·8 g L(-1) ) cases. CONCLUSION: ICS involving skimming collection techniques (orthopaedics) had significantly more haemolysis than pooled collections (obstetrics) (P < 0·001). Further analysis of orthopaedic data highlighted a difference between the three machines used with the Haemonetics OrthoPat (Haemonetics Ltd., Watford, UK) significantly higher with a free Hb of 29·8 g L(-1) compared with the other two machines 6·7 g L(-1) (P < 0·001). On comparison of ICS blood to allogeneic blood, free Hb levels obtained from ICS were significantly higher (P < 0·001).