Time and number of displays impact critical signal detection in fetal heart rate tracings.

Interest in centralized monitoring in labor and delivery units is growing because it affords the opportunity to monitor multiple patients simultaneously. However, a long history of research on sustained attention reveals these types of monitoring tasks can be problematic. The goal of the present experiment was to examine the ability of individuals to detect critical signals in fetal heart rate (FHR) tracings in one or more displays over an extended period of time. Seventy-two participants monitored one, two, or four computer-simulated FHR tracings on a computer display for the appearance of late decelerations over a 48-minute vigil. Measures of subjective stress and workload were also obtained before and after the vigil. The results showed that detection accuracy decreased over time and also declined as the number of displays increased. The subjective reports indicated that participants found the task to be stressful and mentally demanding, effortful, and frustrating. The results suggest that centralized monitoring that allows many patients to be monitored simultaneously may impose a detrimental attentional burden on the observer. Furthermore, this seemingly benign task may impose an additional source of stress and mental workload above what is commonly found in labor and delivery units.

Monitoring simulated maternal-fetal heart rate signals.

The present study represents the first in a series aimed at examining how individuals monitor maternal-fetal heart rate signals over an extended period of time. Seventy-two undergraduate students monitored simulated maternal-fetal heart rate signals for late decelerations of either high or low amplitude for 48 minutes. The results showed that the ability to detect late decelerations was quite good and did not decline over time. Although the findings regarding detections are encouraging, the participants also made a lot of false alarms. Collectively, these results suggest that the observers still struggled to distinguish critical patterns from the background fetal heart activity.