# The relationship between preoperative blood pressure during anesthetic examinations and pre-intubation blood pressure

## TL;DR

This study found that blood pressure measured during preoperative anesthetic exams correlates well with blood pressure before intubation, possibly due to stress or white-coat hypertension.

## Contribution

The study identifies a strong correlation between intra-examination systolic BP and pre-intubation systolic BP, suggesting its predictive value.

## Key findings

- Intra-examination systolic BP showed the strongest correlation with pre-intubation systolic BP (r = 0.5230).
- Bland–Altman analysis showed better agreement for intra-examination BP with pre-intubation BP.
- Higher preoperative BP during exams may reflect anxiety or white-coat hypertension.

## Abstract

There have been few reports showing the relationship between blood pressure (BP) measured at clinics preoperatively and BP measured before anesthetic intubation/induction. The purpose of this study was to examine the relationship between BP measured at different times and settings preoperatively and BP measured before intubation/induction.

A total of 182 patients who underwent general anesthesia between March 2021 and April 2022 in a university hospital were examined. In addition to self-reported BP asked on an anesthetic examination sheet completed by each patient, BPs were measured three times, before, during, and after preoperative examination by the anesthesiologist. The derived parameter was compared with BP measured before intubation at the time of general anesthesia induction.

The systolic BP in the intra-examination period had the most significant correlation with pre-intubation systolic BP (r = 0.5230, p < 0.0001, 95% CI = 0.4050 to 0.6238). On Bland–Altman analysis, the intra-examination systolic BP seemed to be similar and showed better agreement with pre-intubation systolic BP than other measured BPs, with a mean bias of 2.2 mmHg and the narrowest 95% limits of agreement (-33.7 to + 38.1 mmHg).

The preoperative systolic BP value measured during the examination by the anesthesiologist was found to be closely related to pre-intubation systolic BP measured in the operating room. Higher BP during the preoperative examination may be a result of anxiety-induced stress or white-coat hypertension. Measuring BP during the anesthesiologist’s examination may be useful for predicting hypertension in the pre-intubation period.