(1) Objectives: Investigation of efficiency of noninvasive positive pressure ventilation in patients with moderate and severe asthma attacks referring to the emergency room of Masih Daneshvari Hospital
(2) Design: Study population: all patients with moderate and severe asthma attacks referring to the emergency room of Masih Daneshvari Hospital, Sample Size: 34, blinding: double-blind, groups and randomization: random dividing of patients into intervention and control groups, study phase: clinical trial phase 2.
(3) Setting and conduct: a) base line assessments in 34 patients, b) performing non-invasive ventilation in the intervention group with the inspiratory pressure equal to 12 cm H2O and expiratory pressure equal to 4 cm H2O via a face mask, c) using a same mask in the control group, d) comparing the results of two groups.
(4) Participants including major eligibility criteria: Inclusion criteria: (1) Age between 18-75 years, (2) confirmed diagnosis of asthma. Exclusion criteria: (1) Chronic obstructive pulmonary disease, (2) patients inability to use mask
(5) Intervention: in the intervention group: non-invasive ventilation using a face mask with an inspiratory pressure equal to 12 cm H2O and an expiratory pressure equal to 4 cm H2O for 120 minutes. In the control group: using a same mask without any pressure for 120 minutes.
(6) Main outcome measures (primary and secondary outcome variables): primary outcome variable: forced expiatory volume in 1st second, secondary outcome variables: arterial PO2, arterial PCO2, blood pressure, heart rate, Dyspnea.