Current monitoring systems for patients receiving vasopressor support generally rely on bedside monitors with audible alarms that are activated when blood pressure declines below pre-established thresholds, which can result in fluctuations that may increase risk of myocardial ischemia. This pilot study evaluated the effects of three bedside monitors on mean arterial blood pressure and percentage of time at mean arterial pressure among critically ill patients. The monitors were the standard display with audible alarm or one of two types of clinical decision support systems including Intellivue Horizon Trends (Philips Healthcare, Andover, MA) and Horizon Trends and ST Map (Philips Healthcare). Patients in the two groups monitored with Horizon Trends had significantly higher mean arterial pressure (72.8 ± 7.0 mm Hg) compared with those monitored with the standard monitor (68.1 ± 6.8 mm Hg; P= .004). Patients monitored with Horizon Trends also spent a significantly higher percentage of time within their target mean arterial pressure range compared with those in the standard monitor group (P = .031). These findings suggest that further study is needed to assess the impact of clinical decision support tools on management of blood pressure variability in critically ill patients receiving vasopressor therapy.