Optimization of Ventilator Setting for Acute Exacerbations of Chronic Obstructive Pulmonary Disease

Study Overview
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Brief Summary
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The analysis of flow and pressure curves generated by ventilators can be useful in the individuation of patient-ventilator asynchrony, notably in COPD patients. To date, however, a real clinical benefit of this approach to optimize ventilator setting has not been proven. The aim of the present study was to compare: optimized ventilation, driven by the analysis of flow and pressure curves, and standard setting (same initial setting, same time at the bedside, same physician, while the ventilator screen was obscured with numerical data always available). The primary aim was the normalization of pH at two hours, whilst secondary aims were change in PaCO2, respiratory rate, patient's tolerance to ventilation (all parameter evaluated at baseline, 30, 120, 360 minutes and 24 hours after the beginning of ventilation). 70 patients (26 females, aged 78±9 years, PaCO2 74±15 mmHg, pH 7.28±0.05, mean±SD) have been enrolled, with no basal difference between the two groups.

Official Title
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Optimization of Ventilator Setting by Flow and Pressure Curves Analysis During Noninvasive Ventilation for Acute Exacerbations of Chronic Obstructive Pulmonary Disease

Conditions
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Acute Exacerbation of Chronic Obstructive Airways Disease

Intervention / Treatment
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* Procedure: Optimized ventilation
* Procedure: Standard ventilation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Consecutive patients aged > 40 years affected by COPD exacerbation (defined as an acute change in a patient's baseline dyspnoea, cough and/or sputum beyond day-to-day variability sufficient to warrant a change in therapy), and respiratory acidosis (pH < 7.35) that were treated by NIV in addition to standard medical therapy Exclusion Criteria: The needing of intubation The lack of informed consent

Ages Eligible for Study
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Minimum Age: 40 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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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 1- optimized ventilation<br>35 COPD patients ventilated for acute exacerbations in NIV with pressure support mode. | Procedure: Optimized ventilation<br>* Patients, ventilated in pressure support mode, were ventilated with initial setting PEEP and pressure support of 4 and as maximum tolerated cmH2O, inspiratory and expiratory trigger of 5 L/min and 50% of peak inspiratory flow, with changes driven by the analysis of flow and pressure curves; with a FiO2 to reach a SpO2 level between 88 and 92%.<br>|
| Experimental: 2-standard setting of ventilation<br>35 COPD patients ventilated for acute exacerbations in NIV with pressure support mode. | Procedure: Standard ventilation<br>* Patients, ventilated in pressure support mode, were ventilated with standard setting of ventilation: -same initial setting, same time at the bedside (15 minutes at the beginning of NIV, and 5 minutes at each patients' new evaluation) same physician that optimized ventilation mode, while the ventilator screen was obscured (numerical data were, however, always available).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| arterial pH | The primary outcome was the normalization of arterial pH (=pH≥7.35) at 2 hours from the beginning of non invasive ventilation | 2 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| carbon dioxide tension in arterial blood (PaCO2) | carbon dioxide tension (mmHg) in arterial blood measured 12O, 360 minutes and 24 hours after beginning of non invasive ventilation | 120, 360 minutes and 24 hours | 
| respiratory rate (RR) | respiratory rate (RR) measured 120, 360 minutes and 24 hours after the beginning of non invasive ventilation | 120, 360 minutes and 24 hours after the beginning of ventilation | 
| patient's tolerance to ventilation | The patients tolerance to ventilation was evaluated on a visual analogue scale. This scale has been used and validated in previous studies and has five scores: 1) bad; 2) poor; 3) sufficient; 4) good; and 5) very good. | 30, 120, 360 minutes and 24 hours after the beginning of ventilation | 
| mortality | 30-day mortality after beginning of non invasive ventilation | 30 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Non invasive ventilation, acute exacerbation of COPD, optimized ventilation