Correct!
5. All of the above
All of these are reasonable to lower the FiO2 with proning and increasing PEEP being the simplest maneuvers. Increasing PEEP can result in barotrauma and usually levels above 15 cm H2O result in no further FiO2 improvement. Proning may help if the lung is not evenly affected which can result in better ventilation-perfusion matching. Unfortunately, both failed to increase the FiO2. There are a variety of other maneuvers such as increasing the expiratory time (which essentially results in increasing the PEEP) which was also unsuccessful.
Although initial trials were unimpressive, more recent trials suggest a possible mortality benefit with ECMO (1,2). ECMO is done in specialized centers that have experience with this therapy. Given that this patient was young and functional a trial of ECMO seemed reasonable.
The patient was begun on venous to venous ECMO where venous blood is taken from a vein, oxygenated and returned to the venous system. This resulted in an improvement in the pO2 but also resulted in a depressed cardiac output and hypotension. The patient suffered a cardiac arrest but recovered spontaneous circulation. The ECMO was switched to venous-arterial (VA) ECMO where blood was removed from the femoral vein, oxygenated and returned to the arterial circulation through a catheter placed in the descending aorta through the femoral artery.
The patient developed an unusual appearance where the lower extremities were pink but the upper extremities and head were cyanotic.
What should be done next? (Click on the correct answer to proceed to the fifth and final panel)