iVAPS vs. S/T Modes as Non-invasive Weaning Strategy in COPD Patients
Condition: COPD Exacerbation
Study type: Interventional

Summary: 
      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: 
      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.
    

Intervention name(s): Extubation to NIV
Intervention type(s): Device
Intervention description(s): Weaning using NIV immediately after extubation with the mentioned parameters
Other intervention name(s): NIV portable device: Res MED(S9 VPAPTM ST)
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention 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 (Participant)
Primary purpose: Treatment
Keywords: NIV weaning strategy