A novel objective measure for terminal delirium: Activity scores measured by a sheet-type sensor

Abstract

Context: Delirium is a significant concern in end-of-life care. Continuous monitoring of agitation levels using objective methods may have advantages over existing measurement scales. Objectives: To examine whether an objective measure of activity scores measured using a sheet-type non-wearable sensor (Nemuri SCAN [NSCAN]) was correlated with agitation levels measured using the modified Richmond Agitation-Sedation Scale (RASS) in terminally ill patients with cancer. Methods: We conducted a single-center, prospective, observational study in a palliative care unit using the NSCAN to measure activity scores and the RASS to assess agitation levels. RASS scores were prospectively measured by ward nurses blinded to the NSCAN variables. A database was created to pair the RASS scores and activity scores at night on the same day. Results: During the observation period, 1209 patients were hospitalized, and 3028 pairs of assessments of 971 patients were analyzed. The NSCAN activity scores significantly increased with increasing RASS scores (Jonckheere–Terpstra test, p < 0.001). The mean values of the activity scores for each RASS score were RASS −5, 28.9; RASS −4, 36.4; RASS −3, 41.7; RASS −2, 57.4; RASS −1, 58.8; RASS 0, 62.6; RASS 1, 79.6; RASS 2, 106.5; and RASS 3, 118.7. Conclusion: The NSCAN activity significantly correlated with modified RASS agitation scores. Real-time NSCAN data on agitation may aid timely interventions for optimal symptom control. To improve outcomes for patients suffering from terminal delirium, more research on monitoring tools is warranted.