Intraoperative hypotension and postoperative complications in noncardiac surgery: a narrative review

Background: The incidence of IOH varies between 5% and 99%, depending on w hich definition is used. There have been numerous reports on the association between IOH and different postoperative outcomes. Objective: The goal of this study was to evaluate the association between intraoperative hypotension (IOH) and common postoperative outcomes, namely acute kidney injury, myocardial injury, cerebral ischemia, and postoperative delirium. Methods: For this review, we developed a search strategy and searched all relevant medical databases. We searched for cohorts focusing on IOH and the different postoperative outcomes conducted in the past ten years. Eventually we were able to include 16 articles. Results: Regarding acute kidney injury ( AKI), there is sufficient high-quality evident that IOH is an independent risk factor for developing AKI. We identified three studies evaluating the association between IOH and myocardial injury. They found a high incidence of myocardial injury, up to 30%. Furthermore, we found an independent association between IOH and myocardial injury. Regarding cerebral ischemia, we identified four cohorts. For now, there has not been a consensus regarding the association between IOH and cerebral ischemia. A few, but not all,studies find an association between IOH and cerebral ischemia. Conflicting evidence regarding a possible association between IOH and postoperative delirium was found. Discussion and conclusion: There seems to be enough evidence that episodes of IOH might be associated with both AKI and myocardial ischemia. The data regarding IOH and cerebral ischemia and POD however are inconsistent. There is a lot of variety between studies regarding the definition of IOH as the study population, so no hard conclusion can be drawn from t his review.