Validity and Reliability of the Richmond Agitation-Sedation Scale in Pediatric Intensive Care Patients: A Multicenter Study

Abstract

Background: There is limited data about the psychometric properties of the Richmond Agitation-Sedation Scale (RASS) in children. This study aims to analyze the validity and reliability of the RASS in assessing sedation and agitation in critically ill children. Methods: A multicenter prospective study in children admitted to pediatric intensive care, aged between 1 month and 18 years. Twenty-eight observers from 14 PICUs (pediatric intensive care units) participated. Every observation was assessed by 4 observers: 2 nurses and 2 pediatric intensivists. We analyzed RASS inter-rater reliability, construct validity by comparing RASS to the COMFORT behavior (COMFORT-B) scale and the numeric rating scale (NRS), and by its ability to distinguish between levels of sedation, and responsiveness to changes in sedative dose levels. Results: 139 episodes in 55 patients were analyzed, with a median age 3.6 years (interquartile range 0.7-7.8). Inter-rater reliability was excellent, weighted kappa (κ_w) 0.946 (95% CI, 0.93-0.96; p < 0.001). RASS correlation with COMFORT-B scale, rho = 0.935 (p < 0.001) and NRS, rho = 0.958 (p < 0.001) was excellent. The RASS scores were significantly different (p < 0.001) for the 3 sedation categories (over-sedation, optimum and under-sedation) of the COMFORT-B scale, with a good agreement between both scales, κ_w 0.827 (95% CI, 0.789-0.865; p < 0.001), κ 0.762 (95% CI, 0.713-0.811, p < 0.001). A significant change in RASS scores (p < 0.001) was recorded with the variance of sedative doses. Conclusions: The RASS showed good measurement properties in PICU, in terms of inter-rater reliability, construct validity, and responsiveness. These properties, including its ability to categorize the patients into deep sedation, moderate-light sedation, and agitation, makes the RASS a useful instrument for monitoring sedation in PICU.

Keywords: anesthesia and analgesia; intensive care unit; monitoring; nursing assessment; pediatric; physiologic; reproducibility of results; validation studies as topic.

Figure 1

Scores of the 546 observations in 139 patient episodes according to the scale used: (A) Richmond Agitation-Sedation Scale based on the epigraph (RASSe). (B) Richmond Agitation-Sedation Scale based on the description of the conduct (RASSc). (C) COMFORT Behavior Scale (COMFORT-B). (D) Numeric Rating Scale (NRS).

Figure 2

Responsiveness of the RASS: Modification in sedation-agitation scores of the different scales used, before and after a sedative intervention. Increasing/initiation of sedatives (A) RASSe; (B) RASSc; (C) COMFORT-B; (D) NRS. Diminishing/stopping of sedatives (E) RASSe; (F) RASSc; (G) COMFORT-B; (H) NRS. RASSe, Richmond Agitation-Sedation Scale based on the epigraph; RASSc, Richmond Agitation-Sedation Scale based on the description of the conduct; COMFORT-B, COMFORT Behavior Scale; NRS, Numeric Rating Scale.