Assessment of Respiratory Distress Using the Respiratory Distress Observation Scale: Exploratory Analysis of Its Relationship with Functional Status and Symptoms in Patients with Cancer Receiving Palliative Care.

INTRODUCTION

Dyspnea is a common and distressing symptom in patients with cancer, particularly in advanced stages and lung cancer. It is associated with poor quality of life and is often challenging to manage. The Respiratory Distress Observation Scale (RDOS) is a validated tool for assessing dyspnea in noncommunicative patients.

OBJECTIVES

To assess the validity of the RDOS by comparing it with patient-reported dyspnea using the revised Edmonton Symptom Assessment System (ESAS-r) in patients with cancer receiving palliative care (PC), and to explore associations with functional status.

DESIGN

Observational, cross-sectional study.

SETTING/SUBJECTS: The study was conducted at the National Cancer Institute (INCan) in Mexico City from October 2022 to February 2023. A total of 194 adult cancer patients with dyspnea receiving PC were included.

MEASUREMENTS: RDOS, ESAS-r, and Karnofsky Performance Status (KPS) scores were assessed. Analyses included Spearman's correlation and comparisons across KPS groups.

RESULTS

Median RDOS score was 5 (interquartile range 3-9), with 36.1% experiencing severe dyspnea. Higher RDOS scores were observed in patients with KPS ≤40. RDOS scores correlated significantly with ESAS-r dyspnea, insomnia, and drowsiness. Agreement between RDOS and ESAS-r was higher in moderate/severe cases (79.08%) than in none/mild (63.41%). Notably, 36.59% of patients rated as mild by ESAS-r were classified as moderate/severe by RDOS.

CONCLUSION

RDOS is a valuable tool for detecting respiratory distress in cancer patients unable to self-report. Early identification and comprehensive management of dyspnea are crucial, particularly in patients with compromised functional status, or advanced disease, and those vulnerable to undetection because of inability to self-report distress.