The meaning of a high plasma free haemoglobin: retrospective review of the prevalence of haemolysis and circuit XXXX in an adult ECMO centre over 5 years.

@entity1 @entity715
AIMS: In adults requiring extracorporeal membrane oxygenation (ECMO), we wanted to determine; i) the frequency of elevated plasma free haemoglobin (PFHb), ii) the reasons for circuit changes and iii) whether elevated PFHb was associated with higher in-hospital mortality. MATERIALS AND METHODS: @entity1 requiring ECMO between January 2010 and August 2014 were identified from a prospectively collected ECMO database. Their scanned medical records and pathology results were reviewed. Relevant @entity1 , biochemical and circuit data were collected on an Excel spreadsheet and analysed using Stata 13 (StataCorp, College Station, TX). The @entity1 were analysed in three groups, depending on their peak PFHb during ECMO: 'Normal PFHb' (<0.1 g/L), 'Low level PFHb' (0.1 - 0.5 g/L), 'High level PFHb' (>0.5 g/L). MAIN RESULTS: There were 184 ECMO runs (56 VV, 128 VA) - 61 'Normal PFHb', 99 'Low level PFHb', 24 'High level PFHb'. Circuit @entity715 (pump, oxygenator) or haemolysis requiring exchanges were significantly more common in VV ECMO compared to VA ECMO - 23.21% (13/56) vs. 0.78% (1/128), p<0.001. Elevated PFHb was associated with a longer duration of haemofiltration (p<0.001) and ECMO support (p<0.001). In-hospital mortality rates for the 'Normal PFHb', 'Low level PFHb' and 'High level PFHb' groups were 16.39% (10/61), 30.30% (30/99) and 37.50% (9/24), respectively, p=0.067. CONCLUSION: Elevated PFHb values during adult ECMO were common. Severe haemolysis or @entity715 requiring circuit changes were uncommon and occurred almost exclusively on VV ECMO. There was a non-statistically significant increase in in-hospital mortality with elevated PFHb and studies of larger registry data may clarify the prognostic value of PFHb in adult @entity1 .
