Intraoperative Hypotension and Risk of Cuff Blood Pressure Inaccuracy.

Background: Intraoperative hypotension is associated with cardiovascular complications and mortality, making accurate blood pressure monitoring essential. However, the accuracy of noninvasive oscillometric cuff blood pressure (Cuff BP) during hypotension is uncertain. We examined the association between intraoperative hypotension and Cuff BP inaccuracy. Methods: A single-center retrospective cohort included 22,812 adults undergoing noncardiac surgery from April 2013 through November 2023, with 159,782 simultaneous Cuff BP and invasive arterial blood pressure (Arterial BP) pairs. Pairs with arterial systolic BP >120 mmHg or diastolic BP >80 mm Hg were excluded to focus on hypotensive range. Hypotension was defined as arterial mean arterial pressure (MAP) <65 mmHg and categorized as mild (55 to <65), moderate (45 to <55), or severe (35 to <45 mmHg). Cuff BP inaccuracy was defined as an absolute MAP difference >10 mmHg from Arterial BP. Multivariable logistic regression estimated adjusted odds ratios (ORs) and 95% CIs. Results: Compared with normal MAP (≥65 mmHg), hypotension was associated with greater odds of Cuff BP inaccuracy (adjusted OR, 1.45 [95% CI, 1.41-1.49]). Adjusted ORs increased with severity (P for trend <0.001): 1.23 (95% CI, 1.19-1.27) for mild, 2.36 (95% CI, 2.24-2.50) for moderate, and 7.39 (95% CI, 6.34-8.62) for severe hypotension. Sensitivity for correct MAP classification decreased from 87.1% for normal MAP to 32.0%, 19.6%, and 10.2% for mild, moderate, and severe hypotension. Conclusions: We found a significantly higher risk of Cuff BP inaccuracy in patients with intraoperative hypotension, supporting cautious interpretation of Cuff BP during intraoperative hypotension.