CO2 Clearance During Noninvasive Ventilation (NIV)

Study Overview
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Brief Summary
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In this randomized cross over study the investigators will evaluate the effects on gas exchange and patients' tolerance of a new CO2 non rebreathing devices incorporated in the mask vs the traditional mask COPD patients undergoing NIV for an episode of Acute Hypercapnia Respiratory Failure, will be randomized after at least 12 hour of ventilation to 1 h.trial with the usual full face mask or the same mask with the addition of a new CO2 clearance device

Detailed Description
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In this randomized cross over study the investigators will evaluate the effects on gas exchange and patients' tolerance of a new CO2 non rebreathing devices incorporated in the mask vs the traditional mask COPD patients undergoing NIV for an episode of Acute Hypercapnia Respiratory Failure, will be randomized after at least 12 hour of ventilation to 1 h.trial with the usual full face mask (FM) or the same mask with the addition of a new CO2 clearance device (FM+d) In the interval between NIV sessions, arterial blood gases will be monitored and if PaCO2 will return to a baseline value with a tolerance of 10%, the patients will undergo another 1 h trial using the other mask. The subjects will be studied in the sitting position and asked to relax throughout the period of the study. The patients will be ventilated using pressure support ventilation (PSV) The order of use of the two interfaces will be determined for each patient by a previously generated randomized sequence. FIO2 will be adjusted to obtain oxygen saturation around 92% at baseline and never modified throughout the study. End-expiratory pressure will always fixed at 2 cm H2O, and trigger sensitivity will set at -0.5 cm H2O. Inspiratory assistance during either PSV will be titrated to achieve a tidal volume between 6-8 mL/kg while avoiding occurrence of discomfort or visually assessed wasted efforts. The ventilatory settings will determined at the beginning of the first trial, and maintained unmodified throughout all the 3 runs. Patient tolerance to NIMV, defined as the level of comfort using the different mask, will be assessed by means of a scale used and validated in previous studies that is defined as follows: 1, bad; 2, poor; 3, sufficient; 4, good; 5, very good. The patients were asked by the respiratory therapist to answer the following question: How do the patient feel your breathing is using this mask? The patient will give the score to the therapist at the end of each run, just before ABG measurements.

Official Title
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Evaluation of a New System to Clear CO2 During Noninvasive Ventilation (NIV)

Conditions
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Acute Hypercapnic Respiratory Failure

Intervention / Treatment
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* Device: DiMax Zero Total face mask R,
* Device: traditional face mask


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: COPD diagnosis sign inform consent able to tolerate the application of NIV Exclusion Criteria: inability to tolerate the mask contraindication to NIV cancer, neurological diseases, and need of another life support besides the ventilator

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 85 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: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: mask plus CO2 removal device<br>a traditional mask with inserted a new CO2 removal device that is called DiMax Zero Total face mask R, | Device: DiMax Zero Total face mask R,<br>* a non-CO2 rebreathing device included directly in the full face mask<br>|
| Active Comparator: traditional face mask<br>Traditional mask without a CO2 clearance device inserted | Device: traditional face mask<br>* a traditional mask without a non-CO2 rebreathing device included directly in the full face mask<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| changes in arterial blood gases (ABGs) | Recording of carbon dioxide arterial tensione and oxygen arterial tension using an arterial puncture performed in the radial artery | immediate | 
| patient's tolerance to the mask | the tolerance will be recorded using an ad hoc scale | immediate |