Assessment of Dyspnea in Critically Ill Patients: A Comparative Analysis of Evaluation Scales

Purpose This study aimed to evaluate the Respiratory Distress Observation Scale (RDOS), Intensive Care RDOS (IC-RDOS), and Mechanical Ventilation RDOS (MV-RDOS) as potential markers of dyspnea in ICU patients by describing their relationship with the Dyspnea Visual Analog Scale (D-VAS). Materials and methods A researcher and a trained nurse independently assessed ICU patients simultaneously. One researcher assessed the RDOS (IC/MV-RDOS) and the depth of sedation. An objective evaluation using the observational D-VAS was simultaneously performed by a trained nurse. Results The correlation coefficients for each scale were 0.338 for the D-VAS and RDOS, 0.239 for the IC-RDOS, and 0.237 for the MV-RDOS, indicating a low correlation. The prediction of self-reported dyspnea showed that each scale's area under the curve (AUC) as a predictor of D-VAS ≥4 was 0.79 (95% Confidence Interval [CI] 0.71-0.87) for RDOS, 0.77 (95% CI 0.68-0.84) for IC-RDOS, and 0.73 (95% CI 0.64-0.81) for MV-RDOS. Conclusions The objective rating scales RDOS, IC-RDOS, and MV-RDOS can predict subjective dyspnea to a certain extent; however, they have limitations in accurately discriminating dyspnea intensity.