REN and acute kidney injury: Several observational studies and meta-analyses, have suggested that continuation of renin–angiotensin system inhibitors (RASi) might be associated with an increased risk of intraoperative hypotension and potentially postoperative complications (e.g. acute kidney injury [AKI]).6, 7, 8 However, those studies are prone to residual confounders, which can introduce bias and compromise the reliability of the findings.9