iVAPS vs. S/T Modes as Non-invasive Weaning Strategy in COPD Patients

Study Overview
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Brief Summary
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Invasive mechanical ventilation (IMV) is associated with numerous complications. Hence, patients should be weaned from the ventilator as early as possible. A number of randomized controlled trials have addressed whether noninvasive ventilation (NIV) can facilitate weaning in patients failing spontaneous breathing trials (SBT)s. Compared to invasive weaning, NIV weaning strategy showed reduced mortality, greater weaning success, less ventilator-associated pneumonia, shorter length of ICU and hospital stay and less re-intubation rate. Most of the previous studies used pressure support ventilation with fixed pressure support, but no studies published on hybrid NIV modes. Intelligent Volume Assured Pressure Support (iVAPS) is a recent NIV mode, which achieves a target alveolar ventilation by adjusting pressure support and respiratory rate automatically. In iVAPS, the target is alveolar ventilation not the tidal volume, taking into account a predicted dead space . This new mode has been investigated in stable chronic obstructive pulmonary disease (COPD) patients with domiciliary NIV and it was comparable to pressure support ventilation (PSV) regarding improvement in oxygenation, carbon dioxide (CO2) wash and therapy compliance. Yet, less numerous studies have been performed on this mode when used for acute respiratory failure. These studies found that i-VAPS was comparable to PSV as regards PaCO2 and pH improvements, minute volume, pressure support and respiratory rate. No published data so far about the role of i-VAPS as a weaning mode in mechanically ventilated patients. So, this study aims to investigate this new mode in comparison to the standard S/T mode in weaning COPD patients using NIV.

Detailed Description
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Invasive mechanical ventilation (IMV) is associated with numerous complications. Hence, patients should be weaned from the ventilator as early as possible . Approximately 25% and (14-22) % of mechanically ventilated patients experience difficult and prolonged weaning respectively. A number of randomized controlled trials have addressed whether NIV can facilitate weaning in patients failing SBTs. The most recent systemic review included 16 trials -mainly COPD patients- found that patients weaned with NIV had reduced mortality, greater weaning success, less ventilator-associated pneumonia, shorter length of ICU and hospital stay and less reintubation rate. Most of the previous studies used pressure support ventilation with fixed pressure support, but no studies published on hybrid NIV modes. Intelligent Volume Assured Pressure Support (iVAPS) is a recent NIV mode, which achieves a target alveolar volume by adjusting pressure and respiratory rate automatically. In iVAPS, the target is alveolar ventilation not the tidal volume. taking into account a predicted dead space. This new mode has been investigated in stable COPD patients with domiciliary NIV and it was comparable to pressure support ventilation (PSV) regarding improvement in oxygenation, CO2 wash and therapy compliance. Other studies focused on sleep quality and found that iVAPS was comparable to PSV regarding sleep quality, arousal, O2 de-saturation index, increase in therapy adherence and decrease in median PS needed with iVAPS. Yet, less numerous studies have been performed on this mode when used for acute respiratory failure. These studies investigated the outcomes in acute hypercapnic respiratory failure and found that iVAPS was comparable to PSV as regards PaCO2 and logarithm of hydrogen ion concentration (pH) improvements, minute volume, pressure support and respiratory rate. No published data about the role of iVAPS as a weaning mode in mechanically ventilated patients.

Official Title
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Intelligent Volume Assured Pressure Support (iVAPS) vs. Spontaneous/Timed Mode as Noninvasive Modes for Weaning of COPD Patients

Conditions
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COPD Exacerbation

Intervention / Treatment
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* Device: Extubation to NIV


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: All patients in acute exacerbation of COPD who are mechanically ventilated will be included in this study. Exclusion Criteria: Age < 18 years or >75 years. Other chest diseases (pneumonia, bronchiectasis, pulmonary embolism, pulmonary fibrosis…). Tracheostomized patients.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 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
Interventional Model Description: All patients will be subjected to history and clinical examination,severity assessment(mMRC dyspnea scale,APACHE II Score and CAT score). A) Extubation to NIV: SBT will be attempted once the patients achieve stability regarding clinical, neurological and biochemical parameters.Failure of SBT is considered if:pH < 7.35,PaCO2 > 15-20% increase above baseline,PaO2 < 50 mmHg.Heart rate > 100 bpm or respiratory rate > 35 cycle/min. RSBI and P 0.1. will be recorded while on SBT B) The patients will be randomized to receive NIV using either ST or iVAPS mode. C) The patients will be categorized in analysis into 3 groups,Group I: Simple weaning ,Group II: Difficult weaning and Group III: Prolonged weaning. -The following parameters will be recorded for the patients at the beginning of the study and at 1, 2, 12, 24 and 48 hours after initiation of NIV therapy:GCS,Vital signs (HR, SBP& DBP,RR), ABG analysis and Patient's comfort.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: I) Extubation to NIV (S/T mode)<br>The patients will receive NIV using S/T mode after extubation with the following parameters: Expiratory Positive Airway Pressure (EPAP): 4-8 centimeter water (cmH2O). Inspiratory Positive Airway Pressure (IPAP): 12-20 cmH2O. Respiratory rate (RR): 10-12 breath/minute. | Device: Extubation to NIV<br>* Weaning using NIV immediately after extubation with the mentioned parameters<br>* Other names: NIV portable device: Res MED(S9 VPAPTM ST);|
| Experimental: II) Extubation to NIV (iVAPS) mode<br>The patients will receive NIV using iVAPS mode after extubation with the following parameters: Patient's height in cm.. Target alveolar ventilation (Va): adjusted provided that tidal volume is 8 ml/kg of ideal body weight (IBW). Expiratory Positive Airway Pressure (EPAP) :4-8 cmH2O Minimum and maximum Pressure Support (PS) :8-16 Respiratory rate :10-12 breath/min. | Device: Extubation to NIV<br>* Weaning using NIV immediately after extubation with the mentioned parameters<br>* Other names: NIV portable device: Res MED(S9 VPAPTM ST);|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Success rate of either modes. | -Success is considered when the patient is able to achieve the following: pH >7.35,decrease in partial pressure of carbon dioxide (PaCO2) of >15-20%, partial pressure of oxygen (PaO2)>60 mmHg, arterial oxygen saturation (SaO2)> 90% on fraction of inspired oxygen (FiO2) <40%, RR < 24 bpm and no signs of respiratory distress like agitation, diaphoresis or anxiety. Numbers of successful cases is recorded | 48 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Re-intubation rate in each group. | Measured by number of the patients re-intubated in each arm | 30 days | 
| Mortality rate in each group | Measured by number of the patients re-intubated in each arm | 30 days | 
| Duration spent on NIV | Measured in days | An average of 30 days | 
| Length of ICU stay | Measured in days | An average of 30 days | 
| Degree of patient's comfort | A specific questionnaire (pain in the forehead, nose, cheeks, and chin, air leak at eyes and mouth, dry nose and mouth, skin inflammation and claustrophobia. The patients answers to each question (sore0-3 in terms of intensity). The total score is calculated by adding the individual scores of each item mentioned above. | An average of 30 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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NIV weaning strategy