Thank you for your thoughtful and insightful comments1 regarding our study on the incidence of concurrent cerebral desaturation and electroencephalographic burst suppression in cardiac surgery patients. We deeply appreciate your engagement with our research, and we welcome the opportunity to address the points raised.
- Hypothermia: We acknowledge the importance of hypothermia as a potential confounding factor in the study. As you noted, intraoperative temperature was not explicitly highlighted in the manuscript.2 However, we did adjust for this factor in our analysis. Specifically, we found that burst suppression was more frequently associated with cerebral desaturation (1.52, [1.11–2.07], P =.009) even after adjusting for several covariates, which includes temperature. That said, we agree that physical function status and other related variables are crucial to fully understanding the relationship between cerebral desaturation, burst suppression, and neurological outcomes.3 In our ongoing analysis, we plan to further refine our models to adjust for additional factors such as patient physical function status, which should provide a more comprehensive understanding.
- Autoregulation: The issue of cerebral blood flow (CBF) autoregulation, particularly during cardiopulmonary bypass (CPB), is indeed important and warrants further investigation. As you correctly pointed out, disruption of CBF autoregulation may increase the risk of stroke and be strongly correlated with cerebral desaturation. Calculation of cerebral autoregulation4 requires additional computations and we are currently exploring this aspect in our next analyses and hope to incorporate these findings into future iterations of our research.
- Postoperative delirium (POD): Regarding the association between burst suppression and postoperative delirium (POD), we appreciate your reference to the ENGAGES (Electroencephalography-Guided Anesthesia and Delirium in Older Adults After Cardiac Surgery) trial,5 which highlights the complexity of POD’s pathophysiology. Unfortunately, as the study is still ongoing, we are unable to access or analyze the final results related to POD at this time. We intend to explore this aspect once the study is completed, and we look forward to sharing our findings on this topic in due course.
Once again, we thank you for your valuable feedback. We believe these considerations will help refine and expand on the initial findings of our study, and we look forward to continuing this important dialogue as we proceed with our research.
Siddhartha Reddy Janga, MD
Sadhguru Center for a Conscious Planet
Department of Anesthesiology
Beth Israel Deaconess Medical Center
Boston, Massachusetts
Balachundhar Subramaniam, MD, MPH, FASA
Harvard Medical School
Sadhguru Center for a Conscious Planet
Department of Anesthesiology
Beth Israel Deaconess Medical Center
Boston, Massachusetts