Continuous Versus 1-min Oscillometric Arterial BP Monitoring

Overview

Hypotension is common during surgery and about one-third of hypotension occur during the period from anesthesia induction to skin incision. Therefore, monitoring blood pressure during this period is crucial. Two methods are used for measuring blood pressure during surgery: the intermittent measurement method (oscillometric method) and the continuous measurement method (arterial catheterization method). The latter is frequently used in surgical patients who require meticulous hemodynamic management, although there is no clearly defined indication for its use. Despite the benefits of arterial catheterization, it is often delayed after induction of general anesthesia, and blood pressure is monitored intermittently using the oscillometric method. A recent study showed that continuous arterial pressure monitoring using arterial catheterization method during the induction of general anesthesia reduced hypotension significantly compared to 2.5-min interval intermittent arterial pressure monitoring using oscillometric method. The study was conducted on patients scheduled for continuous arterial pressure monitoring during surgery and the group with continuous arterial pressure monitoring showed significantly lower incidence of hypotension during the first 15 minutes of anesthesia induction. However, measuring blood pressure using the oscillometric method at 1-min interval, rather than 2.5-min interval, may not be significantly inferior to continuous monitoring via arterial catheterization in terms of hypotension occurrence. This study aims to compare hypotension incidence between arterial catheterization method and oscillometric method with 1-min interval during induction of anesthesia in non-cardiac surgery patients.