British journal of anaesthesia
-
Unresolved surgical inflammation might induce chronic cognitive decline in older adults. Although inflammatory biomarkers have been correlated with perioperative cognitive impairment and delirium, the effects of prolonged inflammation on cognition are not well studied. This prospective cohort study investigated 1-yr dynamics in plasma interleukin-6 levels and executive function. ⋯ NCT01980511, NCT03124303.
-
Sensory disconnection is a key feature of sleep and anaesthesia. We have proposed that predictive coding offers a framework for understanding the mechanisms of disconnection. Low doses of ketamine that do not induce disconnection should thus diminish predictive coding, but not abolish it. ⋯ NCT03284307.
-
Cortical excitability is higher in unconsciousness than in wakefulness, but it is unclear how this relates to anaesthesia. We investigated cortical excitability in response to dexmedetomidine, the effects of which are not fully known. ⋯ Transcranial magnetic stimulation-evoked potential amplitude changes non-linearly as a function of depth of sedation by dexmedetomidine, with a region-specific paradoxical increase. Future research should investigate other anaesthetics to elucidate the link between cortical excitability and depth of sedation.
-
Anaemic cardiac surgery patients are at greater risk of intraoperative red blood cell transfusion. This study questions the application of the World Health Organization population-based anaemia thresholds (haemoglobin <120 g L-1 in non-pregnant females and <130 g L-1 in males) as appropriate preoperative optimisation targets for cardiac surgery. ⋯ The World Health Organization female anaemia threshold of haemoglobin <120 g L-1 disproportionately disadvantages female cardiac surgery patients. A preoperative haemoglobin concentration ≥130 g L-1 in adult cardiac surgery patients would minimise their overall probability of intraoperative red blood cell transfusion to <15%.
-
Editorial Comment
The art of chasing numbers in titration of anaesthetic dose.
There is no difference in between-patient variability of concentrations when comparing propofol and sevoflurane titrated to a bispectral index of 40-60. There is about a 300% variation in hypnotic concentration between the bottom 5% and top 5% of the population. Anaesthesia titration cannot be based solely on measured or estimated drug concentrations.