Anesthesia Research

Background: Postoperative cognitive dysfunction (POCD) is a significant complication following thoracic surgery. One-lung ventilation (OLV) during these procedures can lead to cerebral desaturation, potentially contributing to POCD. This study investigated the correlation between intraoperative cerebral oximetry, measured by near-infrared spectroscopy (NIRS), and neurocognitive function changes in patients undergoing thoracic surgery. Methods: In this prospective, observational pilot study, 54 adult patients undergoing OLV for thoracic surgery were enrolled. Cerebral oxygen saturation (rScO₂) was monitored continuously using NIRS. Patients were categorized into two groups: Group N (normal NIRS values) and Group D (decreased NIRS values, defined as a drop of ≥20% from baseline or an absolute value <50%). Neurocognitive function was assessed preoperatively, on the 3rd postoperative day, and at 3 months using the Addenbrooke’s Cognitive Examination-Revised (ACE-R) battery. The correlation between intraoperative rScO₂ values, postoperative complications, and neurocognitive outcomes was analyzed. Results: A significant association was found between intraoperative cerebral desaturation and a decline in ACE-R scores. Group D showed a significant decrease in ACE-R scores on the 3rd postoperative day and at 3 months compared to their baseline, while Group N showed no significant change. The most pronounced decline in Group D was observed in the “Fluency” cognitive domain. Interestingly, there was a significant difference in ICU admission rates (p = 0.004) between the two groups, with more admissions in Group D, despite no significant difference in intraoperative hypotension or peripheral desaturation. Patients with pre-existing hypertension were more likely to experience cerebral desaturation. Conclusion: Intraoperative cerebral desaturation, as detected by NIRS, is a strong predictor of both early and late postoperative neurocognitive decline and increased postoperative morbidity in thoracic surgery patients. This underscores the value of NIRS as a sensitive monitoring tool to identify patients at risk and guide timely interventions. These findings suggest a need for further research, including larger randomized controlled trials, to confirm these associations and evaluate the impact of a protocol-driven NIRS intervention strategy on patient outcomes.

Damage-associated molecular patterns (DAMPs) are endogenous molecules released during cellular stress or injury that trigger sterile inflammation. In perioperative settings, common triggers include surgical trauma, ischemia–reperfusion injury, cardiopulmonary bypass, blood transfusion, and mechanical ventilation. When released extracellularly, DAMPs activate innate immune receptors such as Toll-like receptors (TLRs) and the receptor for advanced glycation end products (RAGE), initiating signaling cascades that amplify inflammation, disrupt endothelial integrity, and promote coagulation and metabolic imbalance. This sterile inflammatory response may extend local tissue injury into systemic organ dysfunction, manifesting clinically as acute lung injury, acute kidney injury, myocardial dysfunction, disseminated intravascular coagulation, and perioperative neurocognitive disorders. Recognizing the central role of DAMPs reframes these complications as predictable consequences of endogenous danger signaling rather than solely as results of infection or hemodynamic instability. This understanding supports the use of established strategies such as protective ventilation and restrictive transfusion to minimize DAMP release. Emerging evidence also suggests that anesthetic agents may influence DAMP-mediated inflammation: propofol and dexmedetomidine appear to exert anti-inflammatory effects, whereas volatile anesthetics show variable results. Although clinical data remain limited, anesthetic choice and perioperative management may significantly affect systemic inflammatory burden and recovery. Future research validating DAMPs as biomarkers and therapeutic targets may inform precision anesthetic strategies aimed at modulating sterile inflammation, ultimately enhancing perioperative outcome.

The assessment of a conduction block following regional anaesthesia involves the clinical examination of motor and sensory neural pathways. Motor assessment includes the subjective evaluation of power, while sensory function is assessed using subjective perceptions of touch, cold and pain. There are considerable subjectivities and variabilities in the assessment of regional anaesthesia. Regional anaesthesia results in a blockade of not only somatosensory and motor nerve fibres but also sympathetic fibres. This results in vasodilation and an increase in blood flow, which leads to an increase in skin temperature. Multiple studies have demonstrated a high correlation between conduction block success and skin temperature changes at 10 min, detected using infrared thermography with a higher sensitivity and specificity and positive and negative predictive values up to 100%. Infrared thermography (IRT) is a non-invasive imaging tool which measures surface temperature. The role of IRT in assessing conduction blocks has been evaluated. We reviewed the literature to characterise the role of IRT in determining the onset of a conduction block following regional anaesthesia. This narrative review article synthesises the current evidence on the application of IRT in the evaluation of conduction block onset. In conclusion, IRT is a reliable tool to assess early block success as compared to routine assessment methods (touch, cold and pain perception). However, the limited studies and effects of environmental factors highlight the need for standardised protocols and multicentre studies to integrate into routine clinical practice. With further validation and integration into clinical practice, it has the potential to improve both patient safety and the reliability of block assessment.