<prompt> Which of the following circumstances trigger non invasive to invasive ventilationRespiratory arrestRR 35 minSev acidosis 7.25All of the above  <response>: Circumstances in which non invasive positive pressure ventilation should be changed to invasive ventilation Resp arrest Rr 35min Sev dyspnea with use of accessory muscles and possibly paradoxical breathing Life threatening hypoxemia PaO2 40 mm hg Or PaO2FiO2 200 Sev acidosis pH 7.25 and hyperapnia PaCO2 60 mm hg Hypersomnolence , impaired mental status Cardiovascular complication Failure of non invasive positive pressure ventilation Other circumstances e.g metabolic abnormalities ,sepsis , pneumonia , pulmonary embolism , barotrauma, massive pleural effusion 