Photoplethysmographic Scaling of Dyspnoea

Study Overview
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Brief Summary
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Timely prediction of impending respiratory failure is vital, yet relies on subjective clinical assessment of the patient's respiratory status. Pulse oximetry plethysmographic signal analysis is indicative of the effort to breathe and may provide an objective measurement of respiratory loading.

Detailed Description
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Initiating invasive mechanical ventilation is a vital and delay-critical decision. Precise and timely prediction of impending respiratory failure would be highly consequential. Subjective evaluation of respiratory loading conditions is inconsistent, imprecise and may result in erroneous management. Photoplethysmographic (POP) waveform analysis provides a non-invasive, readily available tool to estimate breathing effort in a semiquantitative fashion. It is the aim of this study to examine: if the degree of dyspnoea, when clinically assessed by means of the respiratory rate and SpO2 values, correlates with the SpO2 wave variations (ΔPOP) in ICU spontaneously breathing COVID-19 and non-COVID-19 patients. if a ΔPOP threshold could be identified to adequately predict further need of orotracheal intubation and invasive mechanical ventilation. This study consists of three main steps: Clinical evaluation of dyspnoea based on: 1.1. Respiratory rate 1.2. Oxygen saturation (SpO2) Storage of SpO2 curve for ΔPOP computation according to a proprietary algorithm after offline POP analysis . Within a time frame of 10 days from when the first two steps are met, monitor for need of invasive ventilatory support.

Official Title
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Photoplethysmographic Signal Analysis as a Proxy for Excessive Effort and Impending Respiratory Failure

Conditions
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Respiratory Failure

Intervention / Treatment
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* Diagnostic Test: Pulse oximeter
* Diagnostic Test: ECG


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Informed consent from patient or next-of-kin according to local administrative decision Spontaneous breathing, including during prone position Sinus rhythm Minimum standards for ICU monitoring: ECG, blood pressure (invasive or non-invasive), respiratory rate (by ECG signal), SpO2 and temperature Exclusion Criteria: Suspected pregnancy Weight > 120 Kg or < 60 kg Emergency or urgency Intubated ( and mechanically ventilated) patient Non- sinus rhythm Left ventricular ejection fraction (LVEF) ≤ 30% Right ventricular (RV) dysfunction ( RVEF ≤ 30% at transthoracic echocardiography (TTE)) Significant pulmonary hypertension (PHT) (TTE: mean pulmonary arterial pressure (mPAP) ≥ 35 mm.Hg)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Spontaneous breathing ICU non-COVID<br>Spontaneously breathing non-COVID-19 critically ill patients with sinus rhythm. Inclusion and exclusion criterion are listed elsewhere. | Diagnostic Test: Pulse oximeter<br>* In both groups, pulse oximeters provide continuous monitoring of oxygen saturation (SpO2). Also, SpO2 curve can be recorded for off-line analysis.<br>Diagnostic Test: ECG<br>* ECG signal is used to monitor respiratory rate (RR).<br>|
| Spontaneous breathing ICU COVID<br>Spontaneously breathing COVID-19 critically ill patients with sinus rhythm. Inclusion and exclusion criterion are listed elsewhere. | Diagnostic Test: Pulse oximeter<br>* In both groups, pulse oximeters provide continuous monitoring of oxygen saturation (SpO2). Also, SpO2 curve can be recorded for off-line analysis.<br>Diagnostic Test: ECG<br>* ECG signal is used to monitor respiratory rate (RR).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rate of failure of spontaneous breathing | Number of patients who fail spontaneous breathing (SB). Failure of SB is defined as death or need of invasive mechanical ventilation whereas SB includes any form of non-invasive ventilatory support | Day 10 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Respiratory rate | Patient's respiratory rate during non-invasive respiratory support as derived from an ECG signal | Day 0 | 
| SpO2 under non-invasive respiratory support | Peripheral oxygen saturation (SpO2) as measured with a pulse oximeter during any form of non-invasive ventilatory support | Day 0 | 
| ΔPOP | Photoplethysmographic variation index following offline computation of the SpO2 curve stored at day 0 according to a proprietary algorithm | day 0 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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breathing, effort, plethysmography, pulse oximetry, dyspnoea, mechanical ventilation