The Association between Preoperative Blood Pressure Elevations and Postoperative Adverse Outcomes after Non-cardiac Surgery: A Single-center Retrospective Observational Study

Blood pressure (BP) often rises before surgery. This study investigated whether BP elevation immediately before surgery was associated with adverse outcomes. Medical records of 11,732 patients (average age: 61 years; male: 47.4%) who underwent non-cardiac elective inpatient surgery under general anesthesia at Kagawa University Hospital between January 2011 and June 2019 were reviewed. Differences between the first BP values measured on the day before surgery and the first BP values in the operating room were defined as Δ systolic BP (ΔSBP) and Δ diastolic BP (ΔDBP). The relationships between ΔSBP/ΔDBP and 30-day mortality, 30-day readmission, and over-the-standard length of hospital stay (OSLOS) were assessed. OSLOS was defined as a hospital stay longer than mean+2 standard deviations and was calculated using the Japanese Diagnosis Procedure Combination data. In univariate analysis, the differences in ΔSBP and ΔDBP between the OSLOS and standard LOS groups were both 2 mmHg. In multivariate logistic regression analysis, only ΔDBP was associated with OSLOS. The adjusted odds ratio (95% confidence interval) for the largest quartile was 1.31 (1.02-1.69) (p<0.05). ΔDBP was associated with OSLOS; however, there may be little need to worry about large ΔSBPs and ΔDBPs in clinical practice.