What should be the optimal pressures during long-term noninvasive ventilation (NIV) in patients with chronic obstructive pulmonary disease (COPD)?
Andreas Freitag: I think that is probably one of the reasons why the current line paper that I talked about (see Noninvasive ventilation in long-term treatment of COPD), the positive paper on an outpatient basis, was successful. When they looked at the inspiratory pressures, they were on the order of around between 16 and 20 cm H2O. So your inspiratory positive airway pressure (IPAP) or pressure support was 16 to 20 cm H2O, and their positive end-expiratory pressure (PEEP) was around 6 to 8 cm H2O for the most part. They were able to aggressively scrub down their CO2, almost normalize their CO2, under those circumstances and that seemed to make a difference. So I think it is the titration, the actual prescription, the ventilation dosage to the patient, if you will, that may make a difference.