Intraoperative hypotension and its organ-related consequences in hypertensive subjects undergoing abdominal surgery: a cohort study

Purpose. Intraoperative hypotension is associated with organ hypoperfusion, which is deleterious to vital organs. Little is known about the prevalence and consequences of intraoperative hypotension in subjects with arterial hypertension (AH). The primary goal of this study was to investigate the prevalence and determinants of hypoperfusion-related clinical consequences of intraoperative hypotension, taking into account the role of AH, in a homogeneous cohort of patients undergoing abdominal surgery. Materials and methods. We enrolled 508 patients (219 males, median age 62 years). Intraoperative hypotension was defined as systolic blood pressure (SBP) <90 mmHg for at least 10 min or mean arterial pressure (MAP) <65 mmHg for at least 10 min or a need for noradrenaline infusion of at least 0.05 mu g/kg/min for >= 10 min or intraoperative MAP drop of at least 30% from the baseline value for at least 10 min, regardless of the time of surgery. Acute kidney injury, stroke or transient ischaemic attack, delirium, and myocardial infarction were considered as the outcome. Results. AH concerned 234 (46%) individuals. The prevalence of intraoperative hypotension varied from 19.9 to 59.4%. Patients with AH were more likely to experience MAP drop of >30% than non-hypertensive patients (OR = 1.53; 95%CI 1.07-2.19; p = 0.02). The outcome was diagnosed in 38 (7.5%) patients. AH was a significant predictor of hypoperfusion-related events, regardless of the intraoperative hypotension definition applied (logOR 2.80 divided by 3.22; p < 0.05 for all). Only intraoperative hypotension defined as 'MAP < 65mmHg' was found to be a determinant of negative outcome (logOR = 2.85; 95%CI 1.35-5.98; p < 0.01), with AUROC = 0.83 (95%CI 0.0-0.86); p < 0.01. Conclusion. AH is a significant predictor of hypoperfusion-related events, regardless of the intraoperative hypotension definition applied. In hypertensive patients, hypoperfusion-related clinical consequences are more frequent in high-risk and long-lasting procedures. MAP < 65 mmHg lasting for >10 min during surgery was identified as most associated with the negative outcome.