Peripheral venoarterial extracorporeal membrane oxygenation for severe hyperlactataemia after cardiac surgery: a pilot study

BACKGROUND: Severe hyperlactataemia in patients after cardiac surgery is associated with poor prognosis and implies possible splanchnic hypoperfusion. Peripheral venoarterial extracorporeal membrane oxygenation (splanchnic ECMO) may be more effective at reducing lactic acidosis for these patients. OBJECTIVE: To investigate whether splanchnic ECMO attenuates hyperlactataemia and liver enzyme release in these patients, despite them having a cardiac index > 2 L/min/m2 and a mixed venous oxygen saturation > 55%. DESIGN AND PARTICIPANTS: Retrospective matched case- control study of patients treated with splanchnic ECMO for hyperlactataemia. Seven patients who had had cardiac surgery were treated with splanchnic ECMO compared with seven matched control patients. RESULTS: We observed a mean decrease in lactate levels from 9.9 mmol/L (SD, 2.9 mmol/L) to 1.4 mmol/L (SD, 0.6 mmol/L) in patients receiving 48 hours of splanchnic ECMO, compared with a mean of 10.4 mmol/L (SD, 2.8 mmol/L) to 4.4 mmol/L (SD, 5 mmol/L) during 48 hours in control patients (P < 0.0001). Normalisation of lactate levels (to < 2 mmol/L) was achieved within a mean of 16.3 hours (SD, 14.6 hours) with splanchnic ECMO, compared with 38.3 hours (SD, 23.8 hours) in the control group (P = 0.029). The median increase in alanine aminotransferase level with splanchnic ECMO was 68% (range, -84% to 2015%) compared with 158% (range: 0%-6024%) (not significant) in control patients. CONCLUSION: In a selected cohort of patients who had had cardiac surgery with severe post-operative hyperlactataemia, despite an acceptable cardiac index and a mixed venous oxygen saturation, splanchnic ECMO appeared to reduce overall lactate levels and time to normalisation of lactataemia.