eComment. Negative effect of delirium beyond the immediate postoperative period

In this interesting publication, Otomo et al. [1] highlights the relationship between pre-existing silent cerebral infarcts assessed by magnetic resonance imaging and postoperative delirium. They clearly demonstrated that pre-existing multiple cerebral infarctions are an independent predictor of postoperative delirium after cardiac surgery.

Postoperative delirium is an acute confusional state with fluctuating consciousness and is very common after cardiac surgery. This transit mental syndrome is associated with many negative short-term consequences such as prolonged hospital stay, readmission to the hospital, poorer cognitive and functional recovery yielding an increase in economic and social costs [2-3]. Although delirium may resolve during hospital stay, it may have long-term functional and cognitive consequences, up to two years after the index hospitalization. Recently, Saczynski et al. [4] demonstrated in a prospective study of 225 patients undergoing cardiac surgery that postoperative delirium was a significant risk factor for a decline in cognitive function followed by a prolonged period of impairment up to one year after the cardiac procedure. The authors of the above-mentioned study concluded that postoperative delirium should be added to the list of risk factors of prolonged impairment after cardiac surgery, which include de novo atrial fibrillation, pre-existing cerebral disease, a low level of education and a history of major depression. Of note, Martin et al. [5] found that development of delirium after coronary artery bypass grafting increased the risk of stroke up to five years after the surgery. We fully agree with Otomo et al. that delirium is a marker of impaired cerebral microcirculation and that patients developing delirium have a more vulnerable central nervous system.

Postoperative delirium negatively affects early and long-term outcomes. Every efforts to prevent, early detect and rapidly treat delirium are of utmost importance. Postoperative delirium should not be considered as only an inconvenient complication of cardiac surgery.

Conflict of interest: none declared

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