Comparative analysis of comfort of Non-invasive ventilation (NIV) with conventional oronasal mask and bridge free oronasal mask A Randomised controlled trial

The enrolled patients will be randomized in AB or BA sequence. In the AB sequence, 2 hours NIV trial with Bridge free oronasal mask, followed by 2 hour NIV trial with a conventional oronasal mask, while in the BA sequence, 2 hour NIV trial with a conventional oronasal mask, followed by NIV with Bridge free oronasal mask. The sequence allocated will be concealed in sealed opaque envelopes. The NIV will be applied with an appropriate size conventional or bridge-free oronasal mask.

The comfort of the NIV mask will be assessed by LIKERTS SCALE using S3NIV [11] standardized questionnaire and each question has a score of a minimum of 0 to a maximum of 4 And questionnaire includes 5 questions 1. My mask is comfortable 2. I don’t have any difficulty speaking 3. My mask is lightweight 4. I am not having claustrophobia 5. I am not suffering from nasal or oral dryness  And scoring will be assessed for each question based on the response of the patient as follow 0- Completely untrue 1- Mostly untrue 2- Sometimes true 3- Mostly true 4- Always true With 0 as minimum satisfaction and 4 as maximum satisfaction And for total maximum allowable score is 20 and the minimum is 0. The questionnaire will be asked at the end after the trial with both the brige free and conventional niv mask.

The hemodynamic parameters such as RR, HR, NIBP/ABP, and SpO2 will be recorded every 30 minutes. Ventilatory parameters like fio2 and leakage The ABG sample will be taken at baseline and every 2 hours during the intervention. Complications of NIV mask-like facial skin erythema, nasal congestion, nasal or oral dryness, nose/sinus/ear pain, and airway dryness will be assessed after the intervention.

NIV failure: If patients will not improve with the first treatment of both arms (RR >35 bpm or spo2 <92% or increased work of breathing) then patients will not be exposed to the second treatment and labeled as NIV failure. These patients will be not included in the analysis.

Device or mask failure: If patients respond to the first treatment but do not respond to the second treatment then further treatment will be based on the decision of the treating consultant, whether go for the first treatment or take the decision of invasive ventilation.