Monday, August 1, 2016


An adult patient develops severe hypoxemia from a pneumonia and goes into cardiac arrest. He is successfully resuscitated with the machine shown above. The following day, it is noted that a sat probe on his right forefinger and a sat probe on his ear reads 75% whereas a sat probe on the toe reads 98%. He does have a right femoral arterial cannula and an ABG drawn there reads a PaO2 of 150mmHg. However, when you do a fresh ABG stick from the right radial artery, the PaO2 is 40mmHg.

Challenge: What machine is he on?

Image is in the public domain.


RaH said...


Craig Chen said...

yes - definitely related to ECLS, and specifically a complication associated with VA ECMO

There are several harlequin syndromes, and this is one related to venoarterial extracoroporeal membrane oxygenation (VA ECMO). In adults, most VA ECMO involves venous cannula draining the superior and inferior vena cava and a femoral arterial cannula delivering oxygenated blood. However, if native cardiac function returns, poorly oxygenated blood may be ejected into the aortic arch leading to hypoxemia of the upper body at the same time as optimal oxygenation of the lower body.

Source: Miller’s Anesthesia; Wikipedia.