Perioperative Near Infrared Spectroscopy Measurements of Cerebral Regional Oxygen Desaturations Are Not Associated With Delirium After Cardiac Surgery.

OBJECTIVE

Postoperative delirium remains a common complication after cardiac surgery in high-risk patients and has been associated with prolonged intensive care unit length of stay, overall morbidity, and mortality. It has been proposed that cerebral hypoperfusion is an important etiological component. In the present study, we retrospectively queried intraoperative near-infrared spectroscopy measurements of regional cerebral oxygen saturations (rSO2) during adult cardiac surgical procedures to examine the association between rSO2 desaturations and postoperative delirium.

DESIGN

Retrospective observational cross-sectional study.

SETTING

Single tertiary care institution.

PARTICIPANTS

Patients aged 18 and older undergoing cardiac or open ascending thoracic aortic surgery from January 2016 through April 2023 were eligible; 3,696 patients were included in the analysis.

MEASUREMENTS AND MAIN

RESULTS

As per departmental protocol, bilateral rSO2 probes were applied to the patients' forehead before induction of anesthesia. The first 5 minutes of rSO2 measurements were averaged and used as their baseline measurements. The total intraoperative duration of rSO2 measurements that were either 20% below baseline or below an absolute value of 50% and the total time in either category were determined. Postoperative delirium was assessed using the Confusion Assessment Method for Intensive Care Unit during the postoperative period. Age, cerebral vascular disease, preoperative cognitive impairment, dexmedetomidine use, and durations of cardiopulmonary bypass and bispectral index values less than 40 were associated with delirium. Neither baseline rSO2 nor any of the perioperative rSO2 desaturation incidences or durations were associated with postoperative delirium.

CONCLUSIONS

Neither baseline nor intraoperative near-infrared spectroscopy-measured cerebral rSO2 parameters were associated with postoperative delirium. Additional future studies are necessary to further define the value of perioperative cerebral rSO2 monitoring for the prevention of delirium after cardiac surgery.