Comparing 6-Minute Walk Tests for Ambulatory Oxygen Assessment

Study Overview
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Brief Summary
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Patients with lung disease who report breathlessness on exertion are often referred for a 6MWT. Due to the nature of the 6MWT (hereon referred to as a Max-6MWT), patients are required to walk as far as they can in 6 minutes. This may lead to an inaccurate assessment of their requirement for ambulatory oxygen as this form of exercise may not correspond to their normal daily activities. In this study, patients who are routinely referred for a Max-6MWT to investigate possible exercise-induced hypoxaemia will be invited to perform an additional walking test which is performed at their normal walking speed, referred here on in as a Nor_6MWT. We hypothesise that performing a Nor_6MWT will provide a more accurate assessment of a patients' oxygen requirement, primarily from their oxygen desaturation during the test.

Detailed Description
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Patients with lung disease who report breathlessness on exertion are often referred for a 6MWT. During this test patients are asked to walk up and down a corridor (or other flat area) for six minutes whilst their blood oxygen levels and heart rate are non-invasively measured using a pulse oximeter (finger probe) and the distance walked is measured. In addition, a questionnaire that obtains a Borg Score measures the patients perceived breathlessness and leg muscle fatigue both before and immediately following the test. Due to the nature of the 6MWT (hereon referred to as a Max-6MWT), patients are required to walk as far as they can in 6 minutes. This may lead to an inaccurate assessment of their requirement for ambulatory oxygen as this form of exercise may not correspond to their normal daily activities. It may also not accurately measure the normal changes in oxygen saturation (or desaturation) that occurs in these patients during their normal daily activities (such as walking to the shops, walking up the stairs, gardening). In this study, patients who are routinely referred for a Max-6MWT to investigate possible exercise-induced hypoxaemia will be invited to perform an additional walking test which is performed at their normal walking speed, referred here on in as a Nor_6MWT. We hypothesise that performing a Nor_6MWT will provide a more accurate assessment of a patients' oxygen requirement, primarily from their oxygen desaturation during the test.

Official Title
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Comparison of the Standard 6-Minute Maximal Speed Walk Test Against a 6-Minute Normal Speed Walk Test as an Alternative and More Accurate Assessment for Ambulatory Oxygen Requirement.

Conditions
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Respiratory Disease

Intervention / Treatment
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* Diagnostic Test: Maximal 6-minute Walk Test (Max_6MWT)
* Diagnostic Test: Normal speed 6-minute Walk Test (Nor_6MWT)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Referred for a standard 6-minute walk test Has the capacity to give informed consent Is aged between 18 and 90 Exclusion Criteria: Lack of capacity to provide informed consent Poor peripheral perfusion that prevents an accurate measurement of SpO2 Contraindicated to perform a Max_6MWT as indicated in the standard HHFT 6MWT SO

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 90 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Health Services Research
Allocation: Randomized
Intervention Model: Sequential Assignment
Interventional Model Description: Perform test A followed by test B (randomised order)
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Maximal then Normal Speed Walk Test<br>Maximal speed walking test (Max_6MWT) followed by normal speed walking test (Nor_6MWT). | Diagnostic Test: Maximal 6-minute Walk Test (Max_6MWT)<br>* Instructions given to perform the walk test following the international guidelines using the phrase 'as far as you can'.<br>Diagnostic Test: Normal speed 6-minute Walk Test (Nor_6MWT)<br>* Instructions given to perform the walk test following the international guidelines except using the phrase 'at a speed you would normally walk'.<br>|
| Active Comparator: Normal then Maximal Speed Walk Test<br>Normal speed walking test (Nor_6MWT) followed by Maximal speed walking test (Max_6MWT) | Diagnostic Test: Maximal 6-minute Walk Test (Max_6MWT)<br>* Instructions given to perform the walk test following the international guidelines using the phrase 'as far as you can'.<br>Diagnostic Test: Normal speed 6-minute Walk Test (Nor_6MWT)<br>* Instructions given to perform the walk test following the international guidelines except using the phrase 'at a speed you would normally walk'.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Average drop in SpO2 from baseline to nadir | Continuous monitoring of SpO2 will allow for the measurement in the drop from baseline to the lowest point (nadir) during the test. Between the walk tests, the average drop will be calculated and compared. | During the walk test | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Is there a difference in the time taken to reach nadir in SpO2? | The time from the start of the test and the lowest (nadir) SpO2 will be recorded and compared between the walk tests. | During the walk test | 
| Is there a difference in the absolute nadir SpO2 between maximal and normal walking.speed? | The absolute lowest (nadir) SpO2 value will be recorded during each test and compared. | During the walk test |