Editorial: "Detrimental EƯects of Hypoxia on Brain and Cognitive Functions"

Alberto Zani^1*Stephanie Otto²Terry McMorris^3*

• ¹School of Psychology of Vita Salute San Raffaele University, Milan, Italy
• ²Naval Medical Research Unit Dayton, Dayton, OH, USA, Dayton, United States
• ³Department of Sport and Exercise Sciences, University of Chichester, Chichester, United Kingdom, UK., Chichester, United Kingdom

Reinforcing the importance of preventing hypoxia, Chen et al. (2025) studied how permissive hypercapnia (PH) a ects cerebral oxygenation and early cognitive function in elderly laparoscopic surgery patients. Analyzing data from 450 patients, they found that PH significantly increased intraoperative cerebral oxygen saturation (rSO2), particularly after pneumoperitoneum was established. Patients receiving PH showed less cognitive decline on the first postoperative day, with scores returning to baseline by day 14, outperforming those on conventional ventilation. Importantly, secondary outcomes like recovery time and vital signs showed no adverse di erences, indicating that PH is safe. The study suggests moderate hypercapnia may serve as a neuroprotective strategy during surgery by improving cerebral blood flow and oxygenation, thereby reducing early postoperative cognitive impairments. However, given its retrospective focus on early outcomes, further research is needed to confirm benefits and assess long-term e ects. Furthermore, Schnaubelt et al. ( 2025) conducted a prospective study on the prognostic value of near-infrared spectroscopy (NIRS) monitoring of cerebral oxygen saturation (rSO2) in out-of-hospital cardiac arrest (OHCA) patients. Measurements taken pre-hospital and inhospital over up to 72 hours showed that higher initial rSO2 levels and increasing trends within the first 10 minutes post-ROSC (i.e., return of spontaneous circulation) were strongly linked to favorable neurological outcomes. An initial rSO2 cuto of around 62% demonstrated good predictive accuracy. The study suggests that early NIRS measurements and dynamic changes may outperform extended Intensive Care Unit (ICU) monitoring for prognosis. These results support NIRS as a valuable, non-invasive bedside tool in post-resuscitation care. Nonetheless, larger studies are still needed to establish standard cuto values and support clinical adoption.Shabani and Proverbio (2025) report a review of the literature into the e ects of Neonatal Hypoxic-Ischemic Encephalopathy (NHIE), the reduced blood and oxygen flow to the brain during pregnancy or birth, which often results in significant brain damage. It is one of the most common complications during childbirth and, as the authors point out, it can have negative lifelong e ects on the child. These may include complications such as cerebral palsy, cognitive and learning impairment and emotional di iculties. Structural anomalies, such as reduced corpus callosum volume, reduced white matter integrity, decreased brainstem volume and increased ventricular size are also found. Furthermore, it can result in autism, and other disorders. The standard treatment, therapeutic hypothermia (TH) can have positive e ects even when NHIE is severe.Nevertheless, NHIE survivors face life with increased risk of cognitive impairments, including deficits in processing speed, problem-solving, and attention. They also often show poor psychomotor skills. Common psychiatric deficits include mood and personality disorders, aggressiveness, anxiety, expression, autism, attention deficit hyperactivity disorder and schizophrenia. Zani et al. (2024) present a comprehensive review of the literature covering neurocognitive e ects of hypoxia in various environmental conditions. Moreover, they examine similarities and di erences concerning e ects of normobaric hypoxia and hypobaric hypoxia. The authors review e ects on neuroimaging markers, such as electroencephalogram (EEG), event related potentials (ERPs), positron emission tomography (PET) and functional magnetic resonance imaging (fMRI). The types of tasks examined are cognitive and motor functions related to short-term memory, attention and executive control. Amplitudes of ERPs P3b, ADAN, and CNV increased with cognitive demands in hypoxia, indicating a compensatory response. Furthermore, integrations of sensory and cognitive functions are examined using measures of delta, gamma, theta, and alpha oscillatory systems. Despite this, the authors conclude that the tasks most a ected are executive functions and short-term memory recall. Additionally, they highlight that visual and audio-spatial skills are also negatively impacted.The research paper by Borden et al. (2024) provides valuable insights into the e ects of hypoxia on cognitive and neural functions relevant to tactical aviation. The study extends previous work by using a more ecologically valid hypoxia simulation device, the ODHT, or "On-Demand Hypoxia Trainer", which closely mimics in-flight conditions. Results demonstrate that physiological responses such as SpO2 decline and increased heart rate occur rapidly within minutes of exposure, while subjective symptom reporting is delayed, highlighting limitations of self-awareness for hypoxia detection. Importantly, cognitive performance deteriorates notably in complex tasks involving visual search, working memory, and inhibitory control, especially at higher altitudes. Neural markers, specifically the MMN/P3a ERP complex, show reductions in amplitude associated with sensory processing deficits, aligning with physiological and behavioral impairments. The findings underscore the potential for EEGbased neural markers to serve as objective indicators of hypoxia-induced impairment, advancing the development of real-time monitoring systems to enhance pilot safety.