Purpose

Patients undergoing cardiothoracic surgery are at risk of developing perioperative stroke, but residual effects of anesthesia may hamper timely detection. This study aims to determine if there is an association between intraoperative regional cerebral oxygenation (ScO₂) monitoring using near-infrared spectroscopy (NIRS) and the occurrence of early perioperative stroke within three days after cardiothoracic surgery.

Methods

We performed a single-center retrospective observational cohort study including all consecutive cardiothoracic surgery patients with routinely perioperative ScO₂ monitoring admitted postoperatively to the Intensive Care Unit (ICU) between 2008 and 2017. Patients with a confirmed stroke in the anterior cerebral circulation on brain imaging were included in the analysis. Intraoperative area under the curve (AUC), duration, and total ScO₂ excursions below predefined thresholds (< 50% ScO₂ or > 20% reduction below baseline) were calculated for each hemisphere. Stroke-affected and non-affected hemispheres were compared using logistic regression analyses to investigate a potential association between ScO₂ values and stroke.

Results

Of the 2454 cardiothoracic surgery patients with perioperative ScO₂ monitoring, 39 had a anterior stroke on brain imaging. ScO₂ readings of 44 affected hemispheres were compared to 34 non-affected hemispheres. Only the duration of ScO₂ < 50% or a > 20% drop from baseline were significantly associated with global ischemia (OR 1.30 (0.95%CI; 1.09–2.30)) when comparing affected (72 [5 to 33] min.) versus non-affected (28 [4 to 44] min.) hemispheres.

Conclusion

The duration of ScO₂ values < 50% or a drop > 20% from baseline were associated with the occurrence of early perioperative global cerebral ischemia within three days after cardiothoracic surgery.