Management of Harlequin syndrome in veno-arterial extracorporeal membrane oxygenation

Veno-arterial extracorporeal membrane oxygenation (VA ECMO) provides temporary mechanical circulatory support, primarily for patients with compromised cardiac function. In individuals supported on femoral VA ECMO with concurrent pulmonary dysfunction, poorly oxygenated blood may be ejected from the left ventricle resulting in differential hypoxia to the upper body, or Harlequin syndrome.

A retrospective, observational review of our institutional experience in managing patients who developed Harlequin syndrome from March 2016 to May 2021 was conducted. We evaluated interventions to correct Harlequin syndrome, pre-cannulation laboratory values, clinical outcomes, and overall survival to discharged.

Forty-four patients developed Harlequin syndrome during the study period. Eleven (25%) patients underwent ECMO revision, while 33 (75%) patients did not. The ECMO revision group had a Survival after Veno-Arterial ECMO (SAVE) score of -15 (interquartile range (IQR) -17, -11), while the non-revision group had a SAVE score of -6.0 (IQR -10, -1). The median time to resolution of Harlequin syndrome for the entire cohort was 4.5 h (IQR 1.4, 7.80). Hospital length of stay was similar between groups. There were eight (73%) patients in the ECMO revision group who survived to decannulation, compared to 23 (70%) patients in the non-revision group.

Our findings underscore Harlequin syndrome as a serious complication of femoral VA ECMO. Our observed findings also suggest that physiological interventions can effectively resolve Harlequin syndrome and should be considered as a key strategy before considering ECMO revision.

The online version contains supplementary material available at 10.1007/s12055-026-02185-w.