The influence of oxygen delivery during cardiopulmonary bypass on the incidence of delirium in CABG patients; a retrospective study

Abstract

Introduction:Postoperative delirium is the most common neurological complication of cardiac surgery. Hypoxia has been shown to increase the risk of postoperative delirium. The possibility to continuously monitor oxygen delivery (DO2) during cardiopulmonary bypass (CPB) offers an adequate approximation of the oxygen status in a patient. This study investigates the role of oxygen delivery during cardiopulmonary bypass in the incidence of postoperative delirium.Methods:Three hundred and fifty-seven adult patients who underwent normothermic coronary artery bypass grafting (CABG) surgery were included in this retrospective study. The nadir indexed DO2 (DO2i) value on bypass, the total time under the critical DO2i level and the area under the curve (AUC) for critical DO2i were determined. Delirium was identified by the postoperative administration of haloperidol.Results:The mean nadir DO2i significantly differed, comparing the group of patients with postoperative delirium to the group without. Multivariate analysis only identified age, pre-existing cognitive impairment, preoperative kidney dysfunction and cross-clamp time as independent risk factors for delirium. The results also indicated that patients of older age were more sensitive to a declined DO2i.Conclusion:A low DO2i during cardiopulmonary bypass is significantly associated with the incidence of postoperative delirium in CABG patients. However, the role of DO2 as an independent predictor of delirium could not be proven.

Risk factors for postoperative delirium on oxygen delivery-guided perfusion

“…However, unlike DO 2 parameters, the evaluation of hemodilution was performed only at specific points in these studies. The lowest Hb on CPB just failed to reach significance but tended to be lower in patients with delirium (9.29 ± 1.27 vs. 8.89 ± 1.27; p = 0.053) [ 12 ]. It is likely that the hemodilution was not correctly assessed, and the results may have been different if a comprehensive method for assessing hemodilution, such as AUC, was used.…”

“…Our preliminary results suggest the importance of optimizing DO 2 management during CPB. A recent study reported that although DO 2 parameters, such as AUC of DO 2 i, were clearly associated with delirium, DO 2 could not be identified as an independent predictor of postoperative delirium [ 12 ]. However, unlike DO 2 parameters, the evaluation of hemodilution was performed only at specific points in these studies.…”

“…Recently, many studies have directly examined the relationship between oxygen delivery (DO 2 ) during cardiopulmonary bypass (CPB) and postoperative acute kidney injury (AKI) [5][6][7][8][9][10][11]. Moreover, the relationship between low DO 2 during CPB and postoperative delirium has also been reported [12], and CPB management using DO 2 as an index of perfusion flow has received increased attention as a new concept regarding optimal perfusion flow. In a previous study, we reported that oxygen delivery-guided perfusion (ODGP), preventing a DO 2 index (DO 2 i) of < 300 mL/min/m 2 during CPB, reduced the incidence of postoperative AKI.…”

Delirium in Older Adults: What a Surgeon Needs to Know

“…It is crucial to assess CAM fluctuations during the day, and the presence of relatives or next of kin of the patients could also be a resource in delirium prevention [56]. To summarize, actions to avoid or reduce delirium incidence can be divided into three categories: preoperative, intraoperative, and postoperative strategies (Table 2) [57][58][59][60][61][62][63][64][65][66]. Due to the paucity of evidence, the actual guidelines suggest avoiding pharmacological approaches as first-line therapy both in non-intensive and intensive care settings [67][68][69].…”

Lower surgical Apgar score is predictive on delirium in patients following off-pump coronary artery bypass grafting

“…Delirium is a common neuropsychiatric syndrome in the patients following OPCABG surgery. 6,8,9 The hallmark of delirium is acute cognitive disturbance with fluctuation in the level of consciousness and attention. The incidence of delirium in critically ill patients is high.…”