Sniff nasal inspiratory pressure in children with muscular, chest wall or lung disease

¹ AP-HP, Hôpital Armand Trousseau, paediatric Pulmonary Dept, Paris, France; and Université Pierre et Marie Curie-Paris6, INSERM UMR S-893 Equipe 12, Paris, France
² AP-HP, Hôpital Armand Trousseau, paediatric Pulmonary Dept, Paris, France
³ AP-HP, Hôpital Raymond Poincaré, Université de Versailles Saint Quentin en Yvelines, Dept of Clinical Physiology, Garches, France and INSERM U 851, Créteil, France

^* To whom correspondence should be addressed. E-mail: brigitte.fauroux{at}trs.aphp.fr.

	Abstract

Sniff nasal inspiratory pressure is proposed as a noninvasive test of inspiratory muscle strength. During this manoeuvre, the nasal pressure is supposed to reflect oesophageal pressure. The aim of the study was to compare the nasal pressure with the oesophageal pressure during a maximal sniff in children with neuromuscular disease (NM, n=78), thoracic scoliosis (n=12), and cystic fibrosis (CF, n=23).

A significant correlation was observed between the sniff nasal and oesophageal pressure. The ratio of the sniff nasal/oesophageal pressure was lower in patients with CF (0.72±0.13) than in NM patients (0.83±0.17), or patients with thoracic scoliosis (0.86±0.10). In patients with CF and NM disease, this ratio was not correlated to age or spirometric data. The difference between the sniff oesophageal and nasal pressure exceeded 15 cm H₂O in 17% of the NM patients, 33% of the patients with thoracic scoliosis, and 87% of the CF patients.

Sniff nasal pressure often underestimates the strength of inspiratory muscles in CF. Such an underestimation occurs more rarely in NM disorders and in thoracic scoliosis. A normal value excludes inspiratory muscle weakness but a low value requires the measurement of the oesophageal pressure.