The brain at risk

Fragile brain undergoing non-neurological surgeries

The brain, even in the absence of direct neurological injury, remains highly vulnerable during non-neurological surgeries, particularly in elderly patients, those with cerebrovascular disease, or patients with pre-existing cognitive impairment. Anaesthetists play a crucial role in safeguarding cerebral integrity through careful monitoring, tailored anaesthetic techniques, and the prevention of perioperative complications. As evidence grows around postoperative neurocognitive disorders and silent brain injury, it becomes imperative to recognise the “fragile brain” and adapt perioperative strategies accordingly. 

During this session, “The brain at risk – Fragile brain undergoing non-neurological surgeries,” participants will learn more about how to provide anaesthesia in cases with special neurological considerations. 

Although therapeutic hypothermia is the current standard for treating neonatal encephalopathy in term infants, many still experience poor outcomes. Research into adjunct therapies, like erythropoietin, stem cells, and melatonin, is ongoing. Meanwhile, concerns persist about the neurodevelopmental risks of anaesthesia in neonates, particularly with repeated or prolonged exposure, though the clinical impact remains uncertain and under investigation.  

Professor Arash Afari, a senior consultant from the University of Copenhagen, Rigshospitalet, Denmark, emphasises that general anaesthesia is often a necessary medical intervention, not a casual choice. The important question is: how do we make sure that we provide the best conditions during the perioperative course to ensure the safety of the brain? While it is important to acknowledge concerns about potential neurotoxicity, he stresses that avoiding anaesthesia is not a viable option when surgery or painful procedures are required. Untreated pain in neonates can itself have long-term neurodevelopmental consequences. Current clinical evidence does not conclusively prove anaesthesia is harmful at typical clinical doses and durations. 

At the other end of the age spectrum, elderly surgical patients are at increased risk for postoperative cognitive complications, and traditional tools like the Montreal Cognitive Assessment (MoCA) often fail to detect hidden vulnerabilities. Dr. Dana Baron Shahaf, Head of Neuroanaesthesia at Rambam Health Care Campus, Israel, will show us how predicting postoperative cognitive risk in geriatric patients can be more complex than we might realise.  

In a recent study, Dr Shahaf and colleagues explored the use of two EEG-based markers during MoCA testing: the Cognitive Effort Index (CEI) which reflects how much attentional effort a patient invests during the task, and the Tension Index (TensI), which reflects stress-related arousal or alertness during the assessment. They recorded these indices during MoCA testing both before and after surgery, in a cohort of elderly patients undergoing cardiac procedures.  

The study showed that High CEI and TensI, especially in patients with intermediate MoCA scores, were linked to greater risk of postoperative cognitive decline. High preoperative TensI also emerged as a potential predictor of lasting cognitive deterioration, even beyond the immediate postoperative period. This may reflect task-related anxiety, where cognitively vulnerable patients perceive cognitive testing itself as threatening. These findings underscore a key concept: identical MoCA scores can mask very different neurophysiological profiles. By integrating these EEG-based indices into routine preoperative screening, we gain a deeper, more individualised understanding of brain function, one that reveals hidden cognitive vulnerability and enables more precise risk stratification.  

Another important area of vulnerability is traumatic brain injury (TBI). When a patient with TBI requires non-neurological surgery, secondary brain injury is a very real risk. In his presentation “Fragile brain undergoing non-neurological surgeries -The patient with traumatic brain injury” Prof. Özlem Korkmaz Dilmen, from the Department of Anaesthesiology & Intensive Care at the Istanbul University-Cerrahpasa, Turkey, will highlight how the main goal in the treatment of traumatic brain injury (TBI) is to prevent secondary brain injury by reducing intracranial pressure (ICP) and optimising cerebral perfusion pressure (CPP).  

During non-neurosurgical procedures, elevated ICP poses a risk if not monitored or managed. ICP can be tracked non-invasively (e.g. optic nerve sheath diameter, transcranial Doppler) or invasively, with intraventricular catheters as the gold standard. CPP targets are generally 60–70 mmHg but should be adjusted based on cerebral autoregulation (CA), which can be assessed by observing ICP response to vasopressors. Normoxia, normocapnia, normothermia, and careful PEEP titration are crucial, especially in TBI with ARDS. Traditionally, ketamine was avoided to prevent elevated ICP, but the current evidence supports that ketamine can be beneficial in TBI patients by reducing cortical spreading depolarisations.  

The brain at risk – Fragile brain undergoing non-neurological surgeries will take place on Sunday, 25 May, at 10:30 – 11:30 WEST in room Évora.