Author: Naveed Saleh, MD, MS
There is a current lack of standardized neuroprotective strategies during cardiac surgery, and this could affect postoperative neurologic outcomes.
In research presented at the 2019 annual meeting of the Society of Cardiovascular Anesthesiologists (SCA), investigators cited high rates of neurologic injury and cognitive dysfunction as the impetus for their study of neuroprotective practices during heart surgery.
In the new study, a 15-item survey was developed by three members of the SCA Clinical Practice Improvement Committee on Cerebral Protection, which assessed the SCA membership regarding high-yield perioperative neuroprotective challenges, including the assessment of aortic atheroma and management of intraoperative blood pressure, as well as cerebral monitoring.
The survey was emailed to 3,645 SCA members, with 526 responses (14.4%). Each SCA member received a unique survey link, eliminating the possibility of redundant answers, and two reminder emails were sent to nonresponders before the survey closed.
More than half of the respondents noted no standardized neuroprotective strategies during cardiac surgery at their respective institutions. Only 15% reported such measures where they practice. Furthermore, 20% of respondents reported practice standardization only for selected patient populations at higher risk for perioperative cerebral injury.
In other findings, 70% of respondents always used transesophageal echocardiography (TEE) to investigate the atheromatous burden of the aorta, 35% always monitored cerebral oxygen saturation, and just 10% performed epiaortic scanning in all cases. Lastly, 52% reported that there were no standardized strategies in place at their institutions to target the management of blood pressure during surgery.
“Intraoperative TEE is a monitoring device that is well established for the evaluation of cardiac structures and function during cardiac surgery. Investigating issues with primary relevance for neuroprotection, such as atheromatous burden in the ascending aorta, can easily be embedded in a comprehensive TEE examination. So TEE serves multiple purposes,” Dr. Bartels said.
Based on study findings, Dr. Bartels made one suggestion: “From an operations standpoint, blood pressure management during cardiopulmonary bypass can be standardized as part of a goal-directed perfusion algorithm.”
Care Needed in Standardizing
However, Dr. Bartels pointed out that it is hard to make any further recommendations without more research. “We do not yet know if standardization of neuroprotective practices during cardiac surgery will improve outcomes, and if so, at what price. While ‘standardization’ is an appealing buzzword, this needs to be carefully investigated. In perioperative medicine, in particular, we had to learn this the hard way. For example, past nondiscriminant perioperative beta-blockade standardization efforts probably harmed patients,” he said.
Dr. Bartels noted some limitations of the study, including the low survey response rate, which he said is par for the course with this type of online survey. In contrast, strengths of the study included its “closed design, meaning that participants received a unique survey invitation as opposed to blast email, where multiple responses by the same individual are possible.”
In a separate interview with Anesthesiology News, Emily Methangkool, MD, MPH, a cardiac anesthesiologist at UCLA Health, reflected on the study results. “Cognitive dysfunction after cardiac surgery is a major source of postoperative morbidity; strategies for neuroprotection are essential. Unfortunately, physicians do not take the time to fill out surveys that may provide useful information to improve our collective practice. This study had a low survey response rate at 14.4%.”
Dr. Methangkool added, “From those that did reply, it seems as though TEE assessment of the aortic atheromatous burden is the most widely used practice, so perhaps interventions to promote this readily accepted technique would yield high implementation results. Conversely, campaigns to encourage less employed techniques, such as cerebral oxygen saturation monitoring and epiaortic scanning, are necessary but may be hindered by the equipment available to the practicing cardiac anesthesiologist. This study is a good example of how we can all improve as members of our subspecialties and fill out surveys aimed at refining our shared knowledge.”