Nasal pressure support ventilation

Nava S, Ambrosino N, Rubini F, et al. Effects of nasal pressure support ventilation and external PEEP on diaphragmatic activity in patients with severe stable COPD. Chest 1993 103 143—150. Vitacca M, Naza S, Confalonieri M, et al. The appropriate setting of noninvasive pressure support ventilation in stable COPD patients. Chest 2000 118 1286-1293. 

Meecham Jones DJ, Paul EA, Jones PW, et al. Nasal pressure support ventilation plus oxygen compared with oxygen therapy alone in hypercapnic COPD. Am J Respir Crit Care Med 1995 152(2) 538-544. 

Restrick LJ, Fox NC, Braid G, et al. Comparison of nasal pressure support ventilation with nasal intermittent positive pressure ventilation in patients with nocturnal hypoventilation. Eur... 

Questionnaire NPSV, nasal pressure support ventilation. Source Modified from Ref. 18. 

Fauroux B, Boule M, Lofaso F, et al. Chest physiotherapy in cystic fibrosis improved tolerance with nasal pressure support ventilation. Pediatrics 1999 103(3) E32. 

Improved alveolar ventilation may be partly compromised by an increase in the dynamic dead space (VDdyn), derived from the physiologic dead space (VDphys) plus the dead space of the apparatus (VDap). Whereas the physiologic dead space is influenced by the tidal volume, the dead space of the apparatus is a fixed consequence of the internal volume of the interface. Differences in flow pattern and pressure waveform associated with the machine and mode of ventilation, also affect the dead space of the apparatus. Saatci et al. (36) noted that during spontaneous breathing, a face mask increased VDdyn from 32% to 42% of tidal volume (VT) above VDp ys. Positive pressure during the expiratory phase reduced VDdyn close to VDphys, while inspiratory pressure support without positive end-expiratory pressure decreased VDdyn from 42% to 39% of VT, i.e., VDdyn remained higher than VDphys. When the exhalation port was placed close to the nasal bridge, VDdyn was lower than VDp ys as a consequence of a beneficial flow path that decreased VDdyn (from 42% to 28% of VT), in the presence of an expiratory positive pressure. 

Noninvasive positive-pressure ventilation (NPPV) provides ventilatory support with oxygen and pressurized airflow using a face or nasal mask with a tight seal but without endotracheal intubation. In patients with acute respiratory failure due to COPD exacerbations, NPPV was associated with lower mortality, lower intubation rates, shorter hospital stays, and greater improvements in serum pH in 1 hour compared with usual care. Use of NPPV reduces the complications that often arise with invasive mechanical ventilation. NPPV is not appropriate for patients with altered mental status, severe acidosis, respiratory arrest, or cardiovascular instability. 

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