Reduced cerebral oxygen–carbohydrate index during endotracheal intubation in vascular surgical patients

Abstract

Brain activation reduces balance between cerebral consumption of oxygen versus carbohydrate as expressed by the so-called cerebral oxygen-carbohydrate-index (OCI). We evaluated whether preparation for surgery, anaesthesia including tracheal intubation and surgery affect OCI. In patients undergoing aortic surgery, arterial to internal jugular venous (a-v) concentration differences for oxygen versus lactate and glucose were determined from before anaesthesia to when the patient left the recovery room. Intravenous anaesthesia was supplemented with thoracic epidural anaesthesia for open aortic surgery (n = 5) and infiltration with bupivacaine for endovascular procedures (n = 14). The a-v difference for O2 decreased throughout anaesthesia and in the recovery room (1.6 ± 1.9 versus 3.2 ± 0.8 mmol l(-1), mean ± SD), and while a-v glucose decreased during surgery and into the recovery (0.4 ± 0.2 versus 0.7 ± 0.2 mmol l(-1) , P<0.05), a-v lactate did not change significantly (0.03 ± 0.16 versus -0.03 ± 0.09 mmol l(-1)). Thus, OCI decreased from 5.2 ± 1.8 before induction of anaesthesia to 3.2 ± 1.0 following tracheal intubation (P<0.05) because of the decrease in a-v O2 with a recovery for OCI to 4.6 ± 1.4 during surgery and to 5.6 ± 1.7 in the recovery room. In conclusion, preparation for surgery and tracheal intubation decrease OCI that recovers during surgery under the influence of sensory blockade.

Effects of vasodilator and esmolol-induced hemodynamic stability on early post-operative cognitive dysfunction in elderly patients: a randomized trial

“…Brain activation reduces the balance between cerebral consumption of oxygen and carbohydrate in terms of the cerebral oxygen-carbohydrate index (OCI) 9 , which is a ratio determined by the cerebral uptake of oxygen compared with that of carbohydrate [10][11][12][13] . Surgery and anesthesia can cause a strong stress response, leading to the secretion of many hormones such as adrenaline, noradrenaline, and cortisol 14,15 .…”

“…An increase in the sympathetic nervous activity increases the OCI 16 . Imbalance in cerebral metabolism during anesthesia leads to the development of clinical symptoms, including postoperative fatigue and cognitive dysfunction 9,17 . Early POCD, which occurs within a week of the triggering event, is associated with the induction of anesthesia…”