Point-of-care ultrasound (POCUS) has become an essential tool in managing critically ill patients in the ICU, including those requiring extracorporeal membrane oxygenation (ECMO). Complications such as cannula malposition can lead to significant adverse outcomes, including vessel or cardiac trauma, recirculation, and organ congestion, which may result in cerebral hypoperfusion, hemodynamic instability, or death. Despite the routine use of radiography to assess ECMO cannula positioning, its limitations in detecting malposition are evident. This retrospective review highlights four cases where POCUS identified cannula malposition that was missed on standard radiographic imaging. In all cases, the malposition was corrected under ultrasound guidance, demonstrating immediate clinical improvement in three patients. For example, in one case, a patient with refractory hypoxemia showed improved oxygenation and ECMO flow after ultrasound-guided cannula adjustment. Another case demonstrated the normalization of liver enzymes after correcting malposition using POCUS.
POCUS offers several advantages over radiography for ECMO monitoring, including real-time imaging, visualization of blood flow with color Doppler, and the ability to guide immediate cannula repositioning. Radiographs can be limited by factors like pulmonary edema or ARDS, which obscure mediastinal landmarks, and poor patient positioning. This case series is the first to suggest that POCUS may be superior to radiographic imaging for identifying clinically significant ECMO cannula malpositions. The findings underscore the need for standardized guidelines on POCUS utilization in ECMO patients and further comparative studies to validate these observations. Training ECMO teams in vascular and cardiac ultrasonography could significantly improve patient outcomes by enabling rapid, accurate identification and management of complications like cannula malposition.
