"Turkish Validation of the Respiratory Distress Observation Scale in Palliative Care"

Adaptation, Validity, and Reliability of the Respiratory Distress Observation Scale in Adult Palliative Care Patients: A Turkish Version

Dyspnea is a subjective experience influenced by physiological, cognitive, behavioral, and sociocultural factors. While self-reported scales are commonly used to assess dyspnea severity, they are unsuitable for patients unable to communicate, such as those with cognitive impairment or sedation. The Respiratory Distress Observation Scale (RDOS), developed by Campbell in 2008, is a reliable and valid tool for evaluating dyspnea in non-communicative palliative care patients. The RDOS has been adapted into Chinese and Italian, but a Turkish version is lacking. This study aims to assess the reliability and validity of the Turkish version of the RDOS.

Study Overview

• Status: Completed
• Conditions: Palliative Care; Dyspnea; Reliability and Validity

Detailed Description

Any disorder affecting the components of the respiratory system directly impacts respiratory function, while impairments in other systems related to this system indirectly hinder respiratory function. This condition manifests in patients in various ways, including shortness of breath, air hunger, difficulty breathing, a sensation of suffocation, and chest tightness, influenced by physiological, cognitive, behavioral, and sociocultural factors. Under normal conditions, breathing is an unconscious physiological act that goes unnoticed. However, in the presence of the aforementioned disturbances, conscious awareness of the act of breathing emerges. According to the American Thoracic Society (ATS) report, dyspnea is defined as "a subjective experience of breathing discomfort that consists of qualitatively distinct sensations of varying intensity" and is acknowledged as a subjective sensation.

Dyspnea does not result from a single pathophysiological mechanism but may develop due to dysfunctions in multiple systems. Therefore, both identifying the underlying pathophysiology of dyspnea and measuring its presence and severity, given its subjective nature, are of great importance. Dyspnea assessment has been conducted using psychophysical methods and clinical scales. Psychophysical tests measure the perception of respiratory changes in response to externally applied loads, whereas clinical scales aim to determine the magnitude of the work contributing to breathlessness in patients. In addition to identifying the cause of dyspnea and initiating appropriate treatment, accurately measuring dyspnea severity plays a crucial role in planning both medical treatment and pulmonary rehabilitation interventions.

The assessment of dyspnea presence and severity is based on self-reported scales, which are considered partially objective. However, some patients-such as those with cognitive impairment, loss of consciousness, intubation, sedative medication use, or brain injury-are unable to provide self-reports. Monitoring dyspnea in patients unable to self-report has been reported as challenging. In clinical settings, healthcare professionals rely on respiratory rate and oxygen saturation levels to assess dyspnea severity and determine appropriate treatment strategies for such patients.

In Turkey, scales used to assess the presence and severity of dyspnea are based on self-reporting and are therefore not suitable for patients unable to communicate their symptoms. In 2008, Dr. Campbell developed the Respiratory Distress Observation Scale (RDOS) and demonstrated its reliability and validity in patients receiving palliative care-such as those with cancer, chronic obstructive pulmonary disease (COPD), heart failure, and pneumonia-who are unable to self-report their dyspnea. The RDOS consists of eight indicators related to dyspnea and takes less than five minutes to administer. Originally developed in English, the RDOS has been translated into Chinese and Italian. However, a Turkish version of the scale is needed. This study aims to examine the reliability and validity of the Turkish version of the RDOS.

• Study Type: Observational
• Enrollment (Actual): 100

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Istanbul, Turkey (Türkiye)
    • Istınye University, Istanbul,

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Probability Sample

Study Population

Patients receiving inpatient treatment in the Intensive Care Unit who meet the inclusion criteria will be included in the study. The relatives of eligible patients will be informed about the study, and informed consent will be obtained. The study will be conducted in accordance with the principles of the Helsinki Declaration and Good Clinical Practice guidelines. Participants included in the study will be assigned a unique code (based on date of birth and order of participation).

Description

Inclusion Criteria:

• Aged 18 years or older,
• Diagnosed with lung or pleural cancer, chronic kidney failure, congestive heart failure, COPD, asthma, or pneumonia, and experiencing dyspnea,
• Specifically referred for treatment of dyspnea,
• Residing in a palliative care unit for at least 1 day,
• Willing to participate in the study, either personally or through consent from a family member.

Exclusion Criteria:

• Completely dependent on a ventilator,
• Diagnosed with a central nervous system disorder (Quadriplegia, Bulbar ALS).

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Adult Palliative Care Patients With Respiratory Distress; Adult inpatients (≥18 years) receiving palliative care in hospital units, diagnosed with conditions such as lung or pleural cancer, chronic kidney disease, congestive heart failure, COPD, asthma, or pneumonia, and experiencing respiratory distress. Patients must have been staying in the palliative care unit for at least one day and either personally or via a family member provided informed consent to participate in the study.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Respiratory Distress Observation Scale (RDOS)	The RDOS was developed by Campbell to measure the presence and intensity of respiratory distress for patients who are unable to self-report dyspnea. The eight parameters assessed by the observer are assess heart rate, respiratory, restlessness, paradoxical breathing pattern, accessory muscle use, grunting at end-expiration, nasal flaring, and look of fear. Four parameters scored between 0 and 2 points; the other four parameters scored 0, or 2 points and progressed from most to least severity of distress. The intensity of respiratory distress is reflected by a total score ranging from 0 to 18. A high total score increases the risk of developing respiratory distress. RDOS score of 0 to 2 suggests no respiratory distress; a score of 3, mild distress; scores of 4 to 6, moderate distress; and 7 or greater, severe distress, with an adequate cutoff point for assigning clinical significance at a score of 3.	Within the first assessment (Day 1) and repeated measures within 2 hours after baseline assessment

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Heart Rate Assessment	Heart rate (beats per minute) will be extracted from patient records within 30 minutes before the RDOS (Respiratory Distress Observation Scale) assessment.	Within 30 minutes prior to RDOS administration
Systolic Blood Pressure Assessment	Systolic blood pressure (mmHg) will be recorded from clinical documentation within 30 minutes before RDOS administration.	Within 30 minutes prior to RDOS administration
Diastolic Blood Pressure Assessment	Diastolic blood pressure (mmHg) will be obtained from the patient's chart and used as a physiological indicator at the time of RDOS evaluatio	Within 30 minutes prior to RDOS administration
Respiratory Rate Assessment	Respiratory rate (breaths per minute) will be noted from medical records as a clinical vital sign prior to RDOS assessment.	Within 30 minutes prior to RDOS administration
Oxygen Saturation Assessment	Peripheral oxygen saturation (SpO₂, %) will be documented from the monitoring system or medical record shortly before RDOS scoring.	Within 30 minutes prior to RDOS administration
Body Temperature Assessment	Body temperature (°C) will be recorded from the most recent measurement available before the RDOS is administered.	Within 30 minutes prior to RDOS administration
Partial Pressure of Oxygen (PaO₂) Assessment	The most recent arterial partial pressure of oxygen (PaO₂, mmHg) will be obtained from medical records. The sample must be collected within 30 minutes prior to RDOS assessment.	Within 30 minutes prior to RDOS administration
Partial Pressure of Carbon Dioxide (PaCO₂) Assessment	Arterial partial pressure of carbon dioxide (PaCO₂, mmHg) will be recorded from laboratory results. The value must be based on a sample taken no more than 30 minutes before RDOS administration.	Within 30 minutes prior to RDOS administration
Arterial Oxygen Saturation (SaO₂) Assessment	SaO₂ (%) will be documented from arterial blood gas analysis and used as an objective indicator of blood oxygenation status.	Within 30 minutes prior to RDOS administration
Blood pH Assessment	Arterial blood pH values will be extracted from the most recent arterial blood gas test, conducted within 30 minutes prior to RDOS application.	Within 30 minutes prior to RDOS administration
Bicarbonate (HCO₃-) Assessment	The bicarbonate (HCO₃-, mmol/L) level will be obtained from arterial blood gas test results and analyzed as part of metabolic status assessment.	Within 30 minutes prior to RDOS administration
Dyspnea Assessment	Verbal Dyspnea Scale (VDS):Conscious patients will self-rate their level of breathlessness on a 0-10 numeric rating scale, where 0 indicates no dyspnea and 10 indicates the most severe dyspnea.	At baseline
ICU Stay Duration	Duration of stay in the intensive care unit (ICU) will be recorded in days from hospital records.	At enrollment
Clock Drawing Test Assessment	Cognitive function will be assessed using the Clock Drawing Test, scored based on spatial and time-setting accuracy.	At enrollment
Type of Respiratory Support Assessment	The type of respiratory support (e.g., High-Flow Oxygen [HFO], Non-Invasive Mechanical Ventilation [NIMV], Invasive Mechanical Ventilation [IMV]) used at the time of RDOS assessment will be documented.	At enrollment
Fraction of Inspired Oxygen (FiO₂) Assessment	FiO₂ (%) values will be documented from respiratory support devices to assess oxygen delivery.	At baseline
PaO₂/FiO₂ Ratio Assessment	The ratio of arterial oxygen pressure (PaO₂) to inspired oxygen fraction (FiO₂) will be calculated to assess oxygenation efficiency.	At baseline
Glasgow Coma Scale (GCS) Assessment	The Glasgow Coma Scale score will be recorded to assess the participant's level of consciousness. The Glasgow Coma Scale (GCS) will be used to determine the patient's level of consciousness. The Glasgow Coma Scale (GCS) assesses consciousness by evaluating three components: eye opening (4-1), verbal response (5-1), and motor response (6-1). Scores range from 3 (deep coma) to 15 (fully alert), with lower scores indicating more severe impairment. A score of 8 or below typically suggests the need for immediate intervention.	At enrollment
Palliative Performance Scale (PPS) Score Assessment	The Palliative Performance Scale (PPS) is a validated clinical tool used to assess the functional status of patients receiving palliative care. It ranges from 0% (death) to 100% (fully active) in 10% increments, based on five parameters: ambulation, activity level and extent of disease, self-care ability, oral intake, and level of consciousness. A high PPS score (e.g., 80-100%) indicates that the patient is active, independent, and has minimal care needs, while a low PPS score (e.g., 10-30%) reflects a patient who is bedbound, has limited intake and consciousness, and requires full care. PPS is widely used to estimate survival time, guide care planning, and classify patients in clinical research. Lower scores are associated with reduced life expectancy and higher dependency.	At enrollment

Collaborators and Investigators

• Sponsor: Istinye University

Publications and helpful links

General Publications

• Parshall MB, Schwartzstein RM, Adams L, Banzett RB, Manning HL, Bourbeau J, Calverley PM, Gift AG, Harver A, Lareau SC, Mahler DA, Meek PM, O'Donnell DE; American Thoracic Society Committee on Dyspnea. An official American Thoracic Society statement: update on the mechanisms, assessment, and management of dyspnea. Am J Respir Crit Care Med. 2012 Feb 15;185(4):435-52. doi: 10.1164/rccm.201111-2042ST.
• Eakin EG, Resnikoff PM, Prewitt LM, Ries AL, Kaplan RM. Validation of a new dyspnea measure: the UCSD Shortness of Breath Questionnaire. University of California, San Diego. Chest. 1998 Mar;113(3):619-24. doi: 10.1378/chest.113.3.619.
• Tinti S, Destrebecq A, Terzoni S, De Maria B, Falcone G, Da Col D, Pairona G, Longhi C, Giudici E, Pidone IM, Alberti A, Sofia M, Ramponi I, Campbell ML. Respiratory Distress Observation Scale Italian Version: Cultural-Linguistic Validation and Psychometric Properties. J Hosp Palliat Nurs. 2021 Apr 1;23(2):187-194. doi: 10.1097/NJH.0000000000000736.
• Pianosi PT, Zhang Z, Hernandez P, Huebner M. Measuring Dyspnea and Perceived Exertion in Healthy Adults and with Respiratory Disease: New Pictorial Scales. Sports Med Open. 2016;2:17. doi: 10.1186/s40798-015-0038-4. Epub 2016 Jan 7.
• Ambrosino N, Porta R. Measurement of dyspnoea. Monaldi Arch Chest Dis. 2001 Feb;56(1):39-42.
• Dyspnea. Mechanisms, assessment, and management: a consensus statement. American Thoracic Society. Am J Respir Crit Care Med. 1999 Jan;159(1):321-40. doi: 10.1164/ajrccm.159.1.ats898. No abstract available.
• Coccia CB, Palkowski GH, Schweitzer B, Motsohi T, Ntusi NA. Dyspnoea: Pathophysiology and a clinical approach. S Afr Med J. 2016 Jan;106(1):32-6. doi: 10.7196/samj.2016.v106i1.10324.

Study record dates

Study Major Dates

• Study Start (Actual): February 1, 2025
• Primary Completion (Actual): May 20, 2025
• Study Completion (Actual): May 30, 2025

Study Registration Dates

• First Submitted: April 3, 2025
• First Submitted That Met QC Criteria: April 3, 2025
• First Posted (Actual): April 10, 2025

Study Record Updates

• Last Update Posted (Actual): February 10, 2026
• Last Update Submitted That Met QC Criteria: February 6, 2026
• Last Verified: March 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Respiratory Tract Diseases; Respiration Disorders; Signs and Symptoms, Respiratory; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Dyspnea
• Other Study ID Numbers: ISU-2025-001

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No