**7. Application, setting and adjustments of NPPV**

The first hours of NPPV are associated with an increased workload for health care personnel that requires a specific management protocol, including monitoring mask ventilation and monitoring the patient (Nava and Hill 2009). Recommended application, setting and adjustments of NPPV in the ICU, HDU, respiratory wards and emergency departments (EDs) are summarised as in the following:


are 4 cm H20 and 20 cm H20, respectively. PS should be increased in order to optimize CO2 removal and control of auto-positive end expiratory pressure (PEEP), according to the patient's tolerance. A backup rate (ST mode) should be used in all patients with low respiratory rate, in patients who unreliably trigger IPAP/EPAP cycle due to muscle weakness and in patients who do not achieve adequate ventilation or respiratory muscle rest with the maximum tolerated PS in the spontaneous mode. The inspiratory duration should be as short as possible.


Predictors of NPPV failure are no improvement or a fall in pH and PC02, no change or a rise in breathing frequency after 1-2 hours and lack of cooperation. Delays in intubation of these patients run the risk of unanticipated respiratory or cardiac arrest with attended morbidity and mortality. NPPV failure occurs more frequently in the first hours of ventilation, and was reported to be predicted by the following clinical factors: severe acidosis, high severity score, severe impairment of consciousness, presence of co-morbidities and lack of improvement of arterial blood gases after 1-2 hours of initial ventilation (Ambrosino et al. 1995; Elliott 2002; Nava & Ceriana 2004)
