Assessment of preload and afterload of patients having undergone cardiac surgery is commonly done by the monitoring of mean arterial and left atrial pressures (MAP, LAP). In this ICU, a central computer has been in use to sample routinely the MAP and LAP every 10 min. This computer has been programmed to activate an alarm sequence if a routinely acquired value of MAP or LAP is found to be outside of preset (“trend”) limits. The computer then initiates a repeat mode of sampling of MAP and LAP at 1 min intervals. If three consecutive repeated values of either variable remain outside of the preset limits, then the following occurs: 1) a plot of the trend of MAP and LAP over the preceding 3 h appears on the bedside video monitor, 2) a bedside light and audible chime are activated, and 3) the bedside keyboard is locked out to other functions until the alarm is reset. A study showed that this system can detect adverse trends appropriately, averaging only 1–2 false alarms/patient per 8-h shift.