Measuring Heart and Lung Function in Critical Care

• Conditions: Gas Exchange Impairment; Respiratory Distress Syndrome, Adult; Mechanical Ventilation Complication; Critical Illness; Haemodynamic Instability

• Registration Number: NCT03424798
• Lead Sponsor: University of Oxford

Brief Summary

This is a feasibility study of the use of a novel technique called 'Inspiwave' to measure heart and lung function in adult patients in critical care.

The preliminary work has already been undertaken in animal models and in healthy volunteers. The ultimate aim of this study is to develop a clinical tool for measuring (and therefore being able to make treatment changes based on) indices of heart and lung function in critical care patients. This study is the first assessment of the technique in this population, and whilst we know it works in patients undergoing general anaesthesia, we now need to assess whether Inspiwave can be used at all in critical care patients who may have much more physiological derangement. The purpose of this phase of the research is to determine whether it is feasible to use Inspiwave in critical care.

Inspiwave generates a sinusoidally modulated tracer gas signal in the inspired air. It also measures the resulting signal in the expired air. The unique handling of this signal by the patient can used be to derive key variables related to cardiopulmonary function such as lung volume, pulmonary blood flow, the deadspace (wasted ventilation) and the degree to which ventilation and blood flow are non-uniform. These are 'vital signs' in sick patients, yet are currently technically difficult to measure, particularly non-invasively.

Detailed Description

Not available

Basic Information
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Recruitment & Eligibility
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Study & Design
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Trial Locations

Study Timeline

• Study First Submitted: 2017-08-09
• Study Start: 2017-10-21
• Status Verified: 2018-01
• Study First Submitted QC: 2018-01-31
• Last Update Submitted: 2018-01-31
• Study First Posted: 2018-02-07
• Last Update Posted: 2018-02-07
• Primary Completion: 2019-09
• Study Completion: 2020-09

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 80

Inclusion Criteria

• patients requiring mechanical ventilation in a critical care area

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Exclusion Criteria

• decision of participant not to be included
• consultee declaration not to be included
• Severely impaired gas exchange as declared by the managing clinician
• oxygen requirement exceeding 90% FIO2

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Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Production of any numerical values of effective lung volume and pulmonary blood flow	Sept 2020	We wish to know whether the technique can be applied, and whether the signal to noise ratio allows computation of the variables of interest. It is yet unclear whether or not the device can operate in a critical care environment.

Secondary Outcome Measures

Name	Time	Method
Comparison of measurements of effective lung volume and pulmonary blood flow under changes in observed clinical condition.	Sept 2020	To observe if changes in clinical condition can be detected by the device.
Signal:noise ratio of measured data.	Sept 2020	If values for effective lung volume and pulmonary blood flow can be produced, are these with adequate signal:noise ratio to allow inverse modelling.

Trial Locations

Locations (1)

Oxford University Hospitals NHS Foundation Trust; 🇬🇧 Oxford, United Kingdom