Mathematically Arterialised Testing of Hypercapnic Subjects Study (MATHS)

A Prospective Observational Cohort Study to Investigate the Physiological Agreement Between Arterial Sampling (the Reference Method) and Mathematically Arterialised Venous Blood

Prospective observational cohort study of patients admitted to hospital with suspected hypercapnic respiratory failure and requiring treatment with non-invasive ventilation (NIV) as part of standard, routine management. Contemporaneous blood gas samples will be obtained via arterial, capillary, and venous methods. The venous samples will undergo mathematical arterialisation via the v-TAC system. In line with standard medical care, arterial samples will be obtained before starting NIV and at two set points afterwards (day 1 post-NIV, and pre-discharge). Pre-existing clinical thresholds will be used to assess the reliability of v-TAC against ABG, the existing gold standard and will conduct a retrospective model of decision-making once the blood sampling component of the study is concluded.

Study Overview

• Status: Completed
• Conditions: Hypercapnic Respiratory Failure

• Study Type: Observational
• Enrollment (Actual): 84

Contacts and Locations

Study Locations

• United Kingdom
  • Cambridgeshire
    • Cambridge, Cambridgeshire, United Kingdom, CB2 0AY
      • Royal Papworth Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: N/A
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Adult patients with suspected chronic hypercapnic respiratory failure admitted as part of routine clinical care for consideration of home NIV.

Description

Inclusion Criteria:

• Aged 18 years or above.
• Admitted for consideration of home Non Invasive Ventilation.
• Due to undergo arterial blood gas sampling as part of routine clinical care

Exclusion Criteria:

• Inability to provide informed consent.
• Clinical necessity to perform blood gas sampling prior to allowing sufficient time for informed consent.
• Inability to obtain reliable SpO2 readings

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in blood carbon dioxide level (PaCO2)	Change in PaCO2 between the pre-NIV (non-invasive ventilation) and day 1 NIV samples for ABG (arterial blood gas) versus v-TAC (arterialised venous blood gas)	Between day 0 and day 1

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in PaCO2 between ABG versus v-TAC versus Capillary Blood Gas (CBG) versus Venous Blood Gas (VBG)	Change in PaCO2 between ABG versus v-TAC versus Capillary Blood Gas (CBG) versus Venous Blood Gas (VBG) between the pre-NIV and day 1 samples	Between day 0 and day 1
Change in PaCO2 between ABG versus v-TAC versus Capillary Blood Gas (CBG) versus Venous Blood Gas (VBG)	Change in PaCO2 between ABG versus v-TAC versus Capillary Blood Gas (CBG) versus Venous Blood Gas (VBG) between the pre-NIV and pre-discharge samples	Between day 0 and through to study completion, up to 3 days
Relative difficult in sampling	Frequency of sampling error rate for ABG versus CBG versus VBG versus V-TAC	Between day 0 and through to study completion, up to 3 days
Patient experience	Using Numeric Pain Scale where 0 is no pain, 5 is moderate pain and 10 is worst pain possible	Between day 0 and through to study completion, up to 3 days
Patient preference	Patient preference for method of blood gas sampling will be recorded in medical records	Between day 0 and through to study completion, up to 3 days

Collaborators and Investigators

• Sponsor: Papworth Hospital NHS Foundation Trust
• Collaborators: Aalborg University
• Investigators: Principal Investigator: Michael Davies, Royal Papworth Hospital

Study record dates

Study Major Dates

• Study Start (Actual): October 15, 2018
• Primary Completion (Actual): October 8, 2020
• Study Completion (Actual): July 31, 2021

Study Registration Dates

• First Submitted: January 23, 2019
• First Submitted That Met QC Criteria: August 27, 2019
• First Posted (Actual): August 28, 2019

Study Record Updates

• Last Update Posted (Actual): September 28, 2022
• Last Update Submitted That Met QC Criteria: September 27, 2022
• Last Verified: May 1, 2022

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Respiratory Tract Diseases; Respiration Disorders; Signs and Symptoms, Respiratory; Respiratory Insufficiency; Hypercapnia
• Other Study ID Numbers: P02375

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No