Commentary: Measurement of real-time cerebral blood flow during cardiac surgery—A useful tool?

Abstract

In this article from Boston, Zavriyev and colleagues 1 look to demonstrate the benefits and use of real-time noninvasive monitoring of cerebral blood flow during cardiac surgery requiring hypothermic circulatory arrest in adult cardiac surgical patients. The authors monitored cerebral blood flow during different brain-protection techniques using diffuse correlation spectroscopy in 12 patients undergoing cardiac surgery with hypothermic circulatory arrest. Diffuse correlation spectroscopy differs from the widely used NIRS (near-infrared spectroscopy) by providing an index of cerebral blood flow.Using this technique, the authors were able to measure cerebral oxygen saturation, cerebral blood flow, and cerebral metabolic rate of oxygen consumption (CMRO 2 ) during cardiac surgery with hypothermic circulatory arrest. Measurements revealed that negligible amounts of blood were delivered to the brain during circulatory arrest with retrograde cerebral perfusion or circulatory arrest alone. Cerebral blood flow was significantly greater during the use of antegrade cerebral perfusion, however. The authors concluded that this technique could be a powerful tool to optimize cerebral perfusion and that retrograde cerebral perfusion needs to be further examined to confirm its efficacy.The article demonstrates a new technique for noninvasive, real-time measurement of cerebral blood flow. With the concurrent use of NIRS, this also gives the ability to