Fig. 1.
The primary patient-specific visualization used in the multiparameter decision support system evaluated in this study, AlertWatch. The aortic arch is red (signifying the mean arterial pressure is below the hypotension threshold of 55 mmHg; there is a scrolling red text alert signifying current hypotension as well as the cumulative duration of hypotension thus far during the case). If the patient’s mean arterial pressure is greater than 60 mmHg, the aortic arch would be green, with no text alerts. If the mean arterial pressure is between 55 and 60 mmHg, the aortic arch would be colored yellow, with a text alert giving the current mean arterial pressure, indicating that the hypotension threshold of 55 mmHg is approaching. The decision support system display receives information from physiologic monitors, anesthesia information management system, and laboratory systems, and displays it in easily identifiable icons of human organs. It is color-coded to signify normal (green), slightly abnormal (yellow), and abnormal (red) ranges. Organs highlighted in orange have comorbidities. The left side of the display provides patient case data and the calculated input and output balance, as well as the presence of infectious disease, the preoperative pain score, and the presence of infusions. Text alerts are presented on the right side of the display in the following hierarchy: black text is informational, red text is for important alerts, and scrolling red alerts are those that need immediate attention. There are more than 47 alerts originating from the 250 pieces of information continuously being extracted from the medical records. The central portion of the display is composed of icons of organ systems: brain, lungs, heart, liver, and kidneys. The level within the heart signifies the fluid status with respect to input and output balance: green (±20% of the estimated blood volume), yellow (high or low, representing ±20 to 40% of the estimated blood volume), and red (very low or very high level, representing greater than 40% positive or negative fluid balance). If there is an invasive arterial catheter or central venous catheter, the level of fluid level and color within the heart is guided by the normal ranges of systolic pressure variation or central venous pressure. Note: in this patient, the fluid level in the heart is in the normal range with a systolic pressure variation of 6 mmHg.