Current strategies of cerebral oxygenation monitoring in general intensive care units: a narrative review

Abstract

Introduction:
Cerebral hypoxia  reflects failure of cerebral autoregulation and exhaustion of compensatory mechanisms. Continuous monitoring of cerebral oxygenation is therefore a cornerstone of neurocritical care, particularly in neuro–intensive care unit (ICU), but provides insight into systemic disturbances such as shock, sepsis, and severe respiratory failure. In perioperative practice, its use is expanding in high-risk procedures, including cardiac, carotid, and neurosurgical surgery, as well as during deliberate hypotension.

Aim of the study:
This narrative review summarizes the physiological basis, available monitoring technologies, and clinical applications of cerebral oxygenation monitoring across neurocritical care, general intensive care, and perioperative settings. Emphasis is placed on practical bedside interpretation, multimodal integration within multimodal neuromonitoring, and current gaps and controversies.

Material and Methods:
A literature search of PubMed and Scopus was conducted for the period January 2010 to January 2025 using MeSH terms and keywords related to cerebral oxygenation and neurocritical care. Fifty-eight English-language peer-reviewed articles, including reviews, randomized controlled trials, observational studies, and editorials, were included. Animal studies, conference abstracts, non-English papers, and unavailable full texts were excluded.

Results:
Brain tissue oxygen tension, jugular bulb oximetry, and near-infrared spectroscopy provide complementary information. Brain tissue oxygen tension is invasive and regional, while jugular bulb oximetry reflects global cerebral oxygen extraction. Near-infrared spectroscopy allows non-invasive monitoring of regional trends. Integration with intracranial pressure monitoring, transcranial Doppler ultrasonography, and electroencephalography enhances detection and management of secondary ischemia. In neurocritical care, invasive modalities are used, whereas in general ICU and perioperative settings, near-infrared spectroscopy is practical.

Conclusions:
Multimodal neuromonitoring, combining invasive and non-invasive techniques, enables individualized optimization of cerebral perfusion. Near-infrared spectroscopy is well suited for general ICU and perioperative use, while invasive methods remain essential in high-risk neurocritical patients. The absence of standardized thresholds highlights the need for consensus guidelines and further research.