Intra-operative hyperoxia and the risk of delirium in elderly patients after cardiac surgery

Abstract

Delirium is a common complication after cardiac surgery. The aim of our study was to determine the impact of hyperoxia episodes occurring during cardiopulmonary bypass (CBP) on the rate of delirium episodes in the postoperative period. 93 patients, aged ≥ 65, who underwent elective cardiac surgery (CBP <90 minutes) were enrolled. The occurrence of delirium episodes was examined every 12 hours for three days after surgery. Eleven patients (11.8%) developed postoperative delirium (POD (+)) and 83 did not (POD (-)). More incidences of severe hyperoxia (PaO2 ≥ 26.6kPa) during CBP were observed in the POD (+) group: 64% had ≥ 2 episodes of hyperoxia, 27% ≥ 3, and 18% ≥ 4, while in the POD (-) group: 42%, 13% and 1%, respectively (P=0.02). Patients in the POD (+) group had a higher maximum PaO2 during CBP than the POD (-) group (37 ± 5.8 vs 31.6 ± 6.6 kPa; P=0.01) and a higher mean PaO2 (30.1 ± 4.5 vs 26.1 ± 5.6 kPa; P=0.01). The optimal maximum PaO2 cutoff point for the occurrence of delirium was 33.2 kPa (AUC 0.72, P=0.001, sensitivity 75%, specificity 38%). We conclude that CBP hyperoxia episodes may be a risk factor associated with the occurrence of postoperative delirium.

Intraoperative hyperoxygenation may negatively affect postoperative cognitive functions in coronary artery bypass graft operations: A randomized controlled study

“…20 In their study, Marcos et al reported an association between intraoperative hyperoxic cerebral reperfusion and adverse effects, such as increased early POCD and delirium. 21,22 In contrast to the results of our study, a randomized trial demonstrated no difference between their NG and HG concerning postoperative cognitive functions. 23 We think that the difference between the studies could be attributed to the facts that the number of patients was lower in our study than in the compared study, our patients were younger, and the education level, which is one of the parameters affecting delirium, was not examined in that study or the possible difference in pump and cross-clamp times.…”

Exploring Hyperoxia Effects in Cancer—From Perioperative Clinical Data to Potential Molecular Mechanisms

“…Hyperoxia effects on cancer biology were explored following multiple pathways, using both in vitro cancer cell cultures and in vivo tumoral animal models. Experimental data support clinical evidences demonstrating that hyperoxia, mainly if prolonged, can induce lung injury and cerebral damage [ 56 , 57 , 58 , 59 , 60 , 61 , 62 ], and this can be counteracted by down-modulation of Akt [ 63 ] or by low-dose vitamin D [ 64 ] or aspirin [ 65 ]. Moreover, hyperoxia diminishes protein synthesis [ 66 ], and high levels of reactive oxygen species trigger expression of several microRNAs in cardiac and pulmonary diseases, as recently reviewed [ 67 , 68 , 69 ].…”

Elevated Procalcitonin as a Risk Factor for Postoperative Delirium in the Elderly after Cardiac Surgery—A Prospective Observational Study

“…Perioperative factors and the type of cardiac surgery are associated with postoperative delirium. In our previously published study, it was shown that cardiopulmonary hyperoxia episodes might be a risk factor associated with the occurrence of postoperative delirium [4]. Three subtypes of delirium have been differentiated: hypoactive, hyperactive, and mixed [5].…”