Association Between Intraoperative Hypotension and Postoperative Adverse Outcomes in Patients Undergoing Vascular Surgery – A Retrospective Observational Study

Objective Intraoperative hypotension (IOH) is associated with adverse outcomes. It could be challenging to define IOH in vascular surgical patients with increased baseline blood pressure (BP). The authors studied the relationship between (1) absolute and relative BP thresholds of IOH, (2) preoperative pulse pressure (PP) and isolated systolic hypertension, and (3) endovascular versus open surgical approach with adverse outcomes in vascular surgical patients. Design Retrospective observational study. Setting Teaching hospital. Patients A total of 566 vascular surgical patients from 2011 to 2018. Intervention None. Measurements and Main Results BP thresholds were as follows: IOH - absolute mean arterial pressure (MAP) 20% decrease from baseline, preoperative PP hypertension - PP >40 mmHg, isolated systolic hypertension - baseline systolic BP ≥140 mmHg with diastolic BP 20% decrease from baseline and preoperative BP. Significant interaction was observed with the surgical approach and outcome (p = 0.031), which was stronger after 60 minutes of IOH in endovascular approach. Conclusion Longer periods of IOH (MAP 60 minutes) during endovascular surgery were associated with adverse outcomes. Relative fall in BP from baseline, preoperative isolated systolic, and PP hypertension were not associated with postoperative complications.