Exploring Pulse OXimeter Accuracy Across SKin Tones

NCT05481515 | Completed DMC

• 1 other identifier: EXAKT Sub-Study
• Study Type: observational
• Target: 903
• Locations: 1 country
• Sites: 1

Brief Summary

This study within a trial (SWAT) will be a sub-study of the UK-ROX trial (ISRCTN13384956), which is currently running in intensive care units across the UK. UK-ROX is large-scale randomised controlled trial evaluating conservative oxygen therapy (a target SpO2 of 88-92%) versus usual oxygen therapy in mechanically ventilated adult patients admitted to ICUs in the UK. The purpose of this observational sub-study is to compare pulse oximeter-derived peripheral oxygen saturation (SpO2) values to co-oximeter-derived arterial oxygen saturation (SaO2) measurements from arterial blood gas (ABG) samples, for a range of fingertip pulse oximeters in an ethnically diverse group of adult patients admitted to UK intensive care units (ICUs). Approximately 900 patients will be recruited over 12 month period from 24 sites to provide an anticipated 10,800 paired SpO2 and SaO2 measurements. Patient skin tone will be objectively measured using a handheld spectrophotometer. Data from the sub-study will be used to determine the accuracy of the tested pulse oximeters across a range of skin tones and arterial oxygenation levels.

Conditions

Critical Illness; Hypoxemia

Outcome Measures

Primary Outcomes (1)

• Accuracy of SpO2 measurements

  Accuracy of SpO2 measurement, validated against co-oximeter derived SaO2 arterial blood gas analysis (calculated as SpO2 minus paired SaO2)

  Over 24 hour observation window

Secondary Outcomes (2)

• Detection of hypoxaemia

  Over 24 hour observation window

• Detection of occult hypoxaemia

  Over 24 hour observation window

Study Arms (1)

Critically ill adults

Adult patients admitted to an intensive care unit who require mechanical ventilation and supplemental oxygen

Device: Pulse oximetry; Device: Spectrophotometry

Interventions

Pulse oximetry DEVICE

Pulse oximeters will be evaluated against routine arterial blood gas measurements

Critically ill adults

Spectrophotometry DEVICE

Spectrophotometry will be used to measure skin tone

Critically ill adults

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Adult patients admitted to an ICU who require mechanical ventilation and supplemental oxygen.

You may qualify if:

• Adult (aged ≥18 years)
• Receiving invasive mechanical ventilation in the ICU following an unplanned ICU admission OR invasive mechanical ventilation started in the ICU (i.e. the patient was intubated in the ICU).
• Receiving supplemental oxygen (\> 21% oxygen) at the time of enrolment

You may not qualify if:

• The clinician considers that one study treatment arm is either indicated or contraindicated.
• In order in increase the number of patients eligible for this observational diagnostic accuracy study, we will have also received ethical approval to enrol mechanically ventilated adult patients who have been screened for, but not enrolled into, the UK-ROX trial. These may include patients who missed the 12 hour recruitment window for the main trial and patients in whom the clinical team decided that one study treatment arm is either indicated or contraindicated.

Sponsors & Collaborators

• Intensive Care National Audit & Research Centre: lead
• Lewisham Council: collaborator
• Centre Ethnic Health Research: collaborator

Study Sites (1)

Intensive Care National Audit and Research Centre

London, London, WC1V 6AZ, United Kingdom

Location

Related Publications (1)

• Martin DS, Doidge JC, Gould D, Shahid T, Cowden A, Charles WN, Francis Johnson A, Garrett R, Mbema C, Olusanya O, Healy E, Rowan K, Mouncey P, Harrison DA; EXAKT Study Investigators. The impact of skin tone on performance of pulse oximeters used by NHS England COVID Oximetry @home scheme: measurement and diagnostic accuracy study. BMJ. 2026 Jan 14;392:e085535. doi: 10.1136/bmj-2025-085535.

  PMID: 41534914 DERIVED

MeSH Terms

Conditions

Critical Illness; Hypoxia

Interventions

Oximetry; Spectrophotometry

Condition Hierarchy (Ancestors)

Disease Attributes; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Signs and Symptoms, Respiratory; Signs and Symptoms

Intervention Hierarchy (Ancestors)

Blood Gas Analysis; Blood Chemical Analysis; Clinical Chemistry Tests; Clinical Laboratory Techniques; Diagnostic Techniques and Procedures; Diagnosis; Heart Function Tests; Diagnostic Techniques, Cardiovascular; Respiratory Function Tests; Diagnostic Techniques, Respiratory System; Investigative Techniques; Photometry; Chemistry Techniques, Analytical; Spectrum Analysis

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: July 22, 2022
• First Posted: August 1, 2022
• Study Start: June 24, 2022
• Primary Completion: August 15, 2024
• Study Completion: October 31, 2024
• Last Updated: March 12, 2025

Record last verified: 2025-03

Locations

GB (1)