Amith Zainudheen1, Ian A Scott1, Xenia Caney1. 1. Department of Internal Medicine and Clinical Epidemiology, Princess Alexandra Hospital, Brisbane, Queensland, Australia.
Abstract
BACKGROUND: Renin angiotensin antagonists (RAA) may block protective vasopressor responses during surgery. Evidence linking RAA with intraoperative hypotension and perioperative adverse events is conflicting. AIM: To compare the incidence of intraoperative hypotension and adverse events between patients receiving or not receiving RAA. METHODS: This is a retrospective case-control study of 258 consecutive patients who underwent elective total knee or hip replacement between 1 January 2013 and 31 August 2016 and who were chronically prescribed a single blood pressure-lowering agent up to the time of surgery. Primary outcome measures were differences between patients receiving RAA (cases; n = 129) and patients receiving non-RAA medications (controls; n = 129) in incidence of intraoperative hypotension (systolic blood pressure <90 mmHg), perioperative acute kidney injury (AKI, >30% increase in serum creatinine from baseline on Day 1 post-operatively) and new onset major adverse cardiac or cerebrovascular events (MACCE) or in-hospital death over 72 h post-operatively. RESULTS: Patients receiving RAA had significantly higher preoperative systolic blood pressure, greater prevalence of hypertension and chronic kidney disease, lower prevalence of ischaemic heart disease and lower cardiac risk compared to controls. Age, gender, type of operation, operative fitness, mode and duration of anaesthesia and prevalence of other types of cardiovascular disease, dyslipidaemia and diabetes were similar between groups. Compared to controls, patients receiving RAA had higher incidence of intraoperative hypotension (76.0 vs 45.9%, P < 0.001), AKI (11.6 vs 1.6%, P = 0.002) and MACCE (6.2 vs 0%, P = 0.007), with all adverse events associated with intraoperative hypotension. CONCLUSION: This study provides further observational evidence of RAA-induced harm in patients undergoing elective surgery, although determining benefits and harms of preoperative withdrawal of RRA requires prospective randomised trials.
BACKGROUND:Renin angiotensin antagonists (RAA) may block protective vasopressor responses during surgery. Evidence linking RAA with intraoperative hypotension and perioperative adverse events is conflicting. AIM: To compare the incidence of intraoperative hypotension and adverse events between patients receiving or not receiving RAA. METHODS: This is a retrospective case-control study of 258 consecutive patients who underwent elective total knee or hip replacement between 1 January 2013 and 31 August 2016 and who were chronically prescribed a single blood pressure-lowering agent up to the time of surgery. Primary outcome measures were differences between patients receiving RAA (cases; n = 129) and patients receiving non-RAA medications (controls; n = 129) in incidence of intraoperative hypotension (systolic blood pressure <90 mmHg), perioperative acute kidney injury (AKI, >30% increase in serum creatinine from baseline on Day 1 post-operatively) and new onset major adverse cardiac or cerebrovascular events (MACCE) or in-hospital death over 72 h post-operatively. RESULTS:Patients receiving RAA had significantly higher preoperative systolic blood pressure, greater prevalence of hypertension and chronic kidney disease, lower prevalence of ischaemic heart disease and lower cardiac risk compared to controls. Age, gender, type of operation, operative fitness, mode and duration of anaesthesia and prevalence of other types of cardiovascular disease, dyslipidaemia and diabetes were similar between groups. Compared to controls, patients receiving RAA had higher incidence of intraoperative hypotension (76.0 vs 45.9%, P < 0.001), AKI (11.6 vs 1.6%, P = 0.002) and MACCE (6.2 vs 0%, P = 0.007), with all adverse events associated with intraoperative hypotension. CONCLUSION: This study provides further observational evidence of RAA-induced harm in patients undergoing elective surgery, although determining benefits and harms of preoperative withdrawal of RRA requires prospective randomised trials.