Home›Rheumatology› Inflammaging may explain heightened anaesthetic sensitivity in older adults, but clinical evidence is limited
Inflammaging may explain heightened anaesthetic sensitivity in older adults, but clinical evidence is limitedOlder adults show higher sensitivity to anesthesia during surgery
Frontiers in MedicinePublished November 3, 2026DOI ↗Editorial oversight: Dr. Amelia Tan, PhD · Internal Medicine & Chronic Disease
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Key Takeaway
Consider heightened anaesthetic sensitivity in older adults, but note limited direct evidence.
This narrative review explores the relationship between ageing, immune dysregulation, and anaesthetic sensitivity in older adults. The authors synthesize evidence suggesting that older adults exhibit increased vulnerability to anaesthetic agents, heightened sensitivity, reduced drug requirements, and delayed emergence. They propose that inflammaging and neuroimmune alterations, such as peripheral macrophage activation, blood-brain barrier dysfunction, and immune-to-brain signalling, may modulate anaesthetic response.
The review discusses potential mechanisms including changes in neuronal excitability, synaptic function, and electroencephalographic markers of anaesthetic depth. It also considers postoperative delirium and haemodynamic instability as secondary outcomes that may be influenced by these age-related changes.
However, the authors acknowledge important limitations: direct clinical evidence is limited, and many mechanistic links rely on extrapolation from preclinical models. The review notes a biologically plausible link between age-related immune dysregulation and altered anaesthetic sensitivity, potentially contributing to perioperative brain vulnerability, but does not establish causality.
No specific effect sizes, sample sizes, or adverse event rates are reported. The certainty of the evidence is not reported. The review suggests that clinicians should be aware of the potential for altered anaesthetic sensitivity in older adults, but the lack of direct clinical evidence means that practice implications remain speculative.
How this fits prior evidence
This review extends prior coverage of ageing biology by focusing on anaesthetic sensitivity rather than combination therapy. Where the computational model review predicted dual optima for combination therapy in ageing, this review proposes that inflammaging and neuroimmune alterations may underlie heightened anaesthetic sensitivity in older adults. Both sources emphasize the complexity of ageing mechanisms, but this review highlights a specific clinical implication (anaesthetic response) while acknowledging that direct clinical evidence is limited and mechanistic links rely on extrapolation from preclinical models.
When an older adult goes into surgery, their body may react differently to anesthesia than a younger person's. Research shows that older adults can be more sensitive to these drugs. This means they might need smaller doses to feel the effects, but they may also take longer to wake up after the procedure is finished.
Scientists believe this happens because of changes in the immune system and the brain's environment. Specifically, a process called inflammaging and changes in how the brain's barrier functions might change how the body handles anesthetic drugs. These factors could make the brain more vulnerable during surgery.
While these findings suggest a clear biological link between aging and anesthesia, it is important to note that direct clinical evidence is still limited. Some of the reasons why this happens are based on models rather than direct human trials. Talk to your doctor about how these factors might affect your specific care.
What this means for you:
Older adults may be more sensitive to anesthesia and take longer to wake up due to age-related immune changes.
Common questions
Why are older adults more sensitive to anesthesia?
Older adults may have increased sensitivity and a delayed recovery from anesthesia. This is likely linked to inflammaging and changes in the immune system. These factors can change how the body responds to drugs and may make the brain more vulnerable during surgery.
Does this mean anesthesia is less safe for older adults?
The research suggests that older adults may have a higher vulnerability to anesthesia. Because they may require lower doses and take longer to wake up, it is important to discuss these specific risks and your medical history with your doctor before any procedure.
Ageing surgical patients demonstrate increased vulnerability to anaesthetic agents, including heightened sensitivity, reduced drug requirements, and delayed emergence, and they are also at increased risk of postoperative complications such as delirium and haemodynamic instability. These phenomena are only partially understood and have traditionally been attributed to the global functional decline associated with ageing. However, emerging preclinical and clinical evidence suggests that inflammaging and related neuroimmune alterations, including peripheral macrophage activation, blood-brain barrier dysfunction, and immune-to-brain signalling, may also modulate anaesthetic response. This narrative review examines current evidence on anaesthetic sensitivity in older adults, the role of macrophage phenotypes in ageing, and the mechanisms by which neuroinflammation may alter neuronal excitability, synaptic function, and electroencephalographic markers of anaesthetic depth. It also reviews methodological approaches ranging from rodent models to biomarkers such as the cerebrospinal fluid to plasma albumin ratio and EEG-derived indices. Overall, the available literature supports a biologically plausible link between age-related immune dysregulation and altered anaesthetic sensitivity, while also suggesting that these same pathways may contribute to broader perioperative brain vulnerability, including postoperative delirium. Direct clinical evidence remains limited, however, and many mechanistic links continue to rely on extrapolation from preclinical models. Further integrative perioperative studies combining immunological profiling, neurophysiological monitoring, and pharmacodynamic modelling are needed to clarify how neuroimmune ageing influences anaesthetic brain sensitivity in older adults.
