Reducing Oxygen Consumption in Critical Care

Study Overview
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Brief Summary
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In normal practice oxygen supply can be easily met with existing hospital infrastructure. COVID - 19 however results in lung damage which greatly increases the amount of oxygen patients require - as a consequence some hospitals in the UK and other countries had situations where there was not enough oxygen for their inpatients. COVID - 19 has caused many more patients to requiring assistance with their breathing using a ventilator. Due to the limited supply of sophisticated ventilators that 're-use' oxygen patients breathe out, some hospitals have used ventilators normally used by patients at home (domiciliary ventilators). Whilst these are inexpensive and commonly available, any oxygen the patient breathes out is simply released into the atmosphere. The address this problem, and in turn reduce the oxygen demand on hospital infrastructure the biomedical engineering team (BME) at the Royal Brompton Hospital, London devised a simple 3-D printed modification which captures and reuses oxygen on commonly used domiciliary ventilators. Laboratory testing found this modification can increase the oxygen given by the ventilator without increasing the oxygen consumption of the ventilator - effectively reducing oxygen demand on hospital infrastructure. This study will evaluate this modification in patients admitted to intensive care requiring assistance with their breathing. This will involve measuring oxygen levels on domiciliary ventilators (Breas Nippy 4+, ResMed Lumis 150 or Vivo 1, 2 or 3) with and without the modification and with small increases in oxygen supplied to the patient for a total study period of 2 hours.

Official Title
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Reducing Oxygen Consumption in Critical Care (ROCC)

Conditions
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Mechanical Ventilation Complication

Intervention / Treatment
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* Device: Ventilator modification


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patient in critical care using a ResMed LumisTM 150, Breas® Nippy 4+ or Vivo 1, 2 or 3 ventilator or deemed safe by treating consultant safe to switch to one. 28% or more of entrained oxygen (FiO2) Judged to be safe to tolerate increased fraction of inspired oxygen for periods of 10 minutes Arterial line insitu for clinical reasons Exclusion Criteria: Thought to be clinically unstable during study protocol (2 hours)

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Device: Ventilator modification|The ventilator modification will be fitted to a ResMed Lumis 150, Breas® Nippy 4+ or Vivo 1, 2 or 3 ventilator. The participants oxygen level will be measured with and without the modification in place at their baseline ventilation, and with 1, 2 and 3 litres oxygen extra to their baseline. the researcher will then leave the modification on and slowly reduce the oxygen going into the ventilator, maintaining the participants SP02 at an acceptable level (>95%)|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Arterial blood gas analysis - baseline | PaO2 with and without modification fitted | After 10 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Arterial blood gas - modification and oxygen change | Oxygenation with and without modification in place with 1, 2 and 3 litres added to baseline FiO2 | After 10 minutes of each experimental condition | 
| Arterial blood gas - CO2 | Arterial CO2 levels at each experimental condition | After 10 minutes of each experimental condition |