A pilot study of cerebral tissue oxygenation and postoperative cognitive dysfunction among patients undergoing coronary artery bypass grafting randomised to surgery with or without cardiopulmonary bypass*

Abstract

SummaryCoronary artery bypass surgery, performed with or without cardiopulmonary bypass, is frequently followed by postoperative cognitive decline. Near-infrared spectroscopy is commonly used to assess cerebral tissue oxygenation, especially during cardiac surgery. Recent studies have suggested an association between cerebral desaturation and postoperative cognitive dysfunction. We therefore studied cerebral oxygen desaturation, defined as area under the cerebral oxygenation curve < 40% of > 10 min.%, with respect to cognitive performance at 4 days (early) and 3 months (late) postoperatively, compared with baseline, using a computerised cognitive test battery. We included 60 patients, of mean (SD) age 62.8 (9.4) years, scheduled for elective coronary artery bypass grafting, who were randomly allocated to surgery with or without cardiopulmonary bypass. Cerebral desaturation occurred in only three patients and there was no difference in cerebral oxygenation between the two groups at any time. Among patients who received cardiopulmonary bypass, 18 (62%) had early cognitive decline, compared with 16 (53%) in the group without cardiopulmonary bypass (p = 0.50). Three months after surgery, 11 patients (39%) in the cardiopulmonary bypass group displayed cognitive dysfunction, compared with four (14%) in the non-cardiopulmonary bypass group (p = 0.03). The use of cardiopulmonary bypass was identified as an independent risk factor for the development of late cognitive dysfunction (OR 6.4 (95% CI 1.2-33.0) p = 0.027. In conclusion, although cerebral oxygen desaturation was rare in our population, postoperative cognitive decline was common in both groups, suggesting that factors other than hypoxic neuronal injury are responsible.

Intraoperative cerebral oximetry-based management for optimizing perioperative outcomes: a meta-analysis of randomized controlled trials

“…23,24 An additional nine RCTs were excluded as they did not involve the target intervention comparison. [25][26][27][28][29][30][31][32][33][34] Two additional RCTs were excluded because they were published as an abstract 35,36 and one RCT was excluded because although it correlated anesthetic depth with cerebral oximetry, it did not detail the associated intervention. 37 Finally, three additional trials were identified from reference lists of the articles included.…”

Neuronal damage biomarkers in the identification of patients at risk of long-term postoperative cognitive dysfunction after cardiac surgery

“…We undertook a secondary analysis of data from a published randomised clinical trial that investigated the differences in the incidence and severity of cerebral oxygen desaturation during coronary artery bypass surgery with or without bypass . Study patients underwent coronary artery bypass surgery at the University Medical Centre Groningen, the Netherlands, between June 2011 and May 2012.…”

The correlation between brain near-infrared spectroscopy and cerebral blood flow in piglets with intracranial hypertension

“…Clinically, brain NIRS has been used as a marker for cerebral oxygenation during the intraoperative management of cardiopulmonary bypass and carotid endarterectomy (8,10,11,18). It has also been investigated for use in the management of adult and neonatal ischemic brain injury (1,3,6,14) and traumatic brain injury (22).…”