Using Near-Infrared Spectroscopy to Monitor Lower Extremities in Patients on Venoarterial Extracorporeal Membrane Oxygenation

Patients on peripheral extracorporeal membrane oxygenation (ECMO) are at risk for lower extremity ischemia. Effective monitoring is needed to identify complications quickly and allow timely correction. Near-infrared spectroscopy has been used extensively in cerebral monitoring during cardiac surgery. We present its use in monitoring lower extremity perfusion in patients on ECMO. Five patients on ECMO had near-infrared spectroscopy monitors placed on the calf of both lower extremities. Continuous real-time tissue oxygen saturation data (stO₂) was displayed and recorded. Two patients had lower extremity complications in the leg with the arterial cannula. The patients with complications had lower stO₂ in the cannulated leg at the time of ECMO insertion, larger differences in stO₂ between the legs at the time of insertion, lower nadir stO₂s, and larger peak differences in stO₂ between the legs than patients without limb complications. The use of near-infrared spectroscopy for continuous monitoring of tissue oxygenation in the lower extremities in patients on ECMO may allow early identification of patients with lower extremity complications.