The aim of the study is to further understand whether the use of non-invasive monitoring NIRS (Near Infrared Spectroscopy) is useful in reducing postoperative complications in high-risk patients undergoing elective surgery.
hypertensive patients with American Society of Anesthesiologists (ASA) score≥ 2 with either Age ≥ 65 years or frailty score ≥5
presence of an arterial catheter during anesthesia
planned high-risk surgery (abdominal, vascular, urologic, thoracic one-lung ventilation (OLV) procedures), longer than 60 minutes, in general anesthesia
ability to give informed consent according to International Conference on Harmonization ICH/ Good Clinical Practice (GCP), and national/local regulations
Unable to consent to study inclusion
Language barrier
Severe neurological or psychiatric disease
End-stage dementia