Sniff nasal inspiratory pressure in children

Maximal static inspiratory pressure (P-IMAX) generated at the mouth is one of the tests of inspiratory muscle strength in children. In adults, inspira tory muscle strength has also been assessed using sniff nasal inspiratory p ressure (SNIP). this test is easier to perform than P-IMAX and might theref ore be applicable to children. To test this hypothesis, we measured P-IMAX and SNIP in 116 children aged 4 to 11 years (54 girls, 62 boys). P-IMAX was measured using a tube mouthpiece and SNIP using a tightly fitting plug in one nostril, while a sniff was performed through the other nostril. Both te sts were performed from functional residual capacity (FRC). Pressure was me asured with a differential pressure transducer and displayed in real time o n a computer screen. Weight, standing height, sitting height, gender, and a ge were recorded. There was a significant difference (P < 0.01) in group mean (SD) data betwe en SNIP (81.3 (27.4) cmH(2)O) and P-IMAX (67.9 (28.1) cmH(2)O). Bland/Altma n analysis demonstrated a mean difference of -13.5 cmH(2)O (SD 21.4) betwee n the techniques. Regression analysis indicated highly significant relation s (P < 0.01) between SNIP and P-IMAX, and between weight, standing and sitt ing height, and age for SNIP, and between weight, standing height, and age for P-IMAX. SNIP and P-IMAX were greater in boys than girls (83.2 vs. 79.2 cmH(2)O SNIP; 72.9 vs. 62.0 cmH(2)O P-IMAX), but this difference was only s ignificant for P-IMAX (P < 0.05). SNIP was significantly greater than P-IMA X (P < 0.01) in both boys and girls. These data suggest that SN14 provides a simple, noninvasive additional test to P-IMAX for assessing inspiratory muscle strength in children. (C) 2000 Wiley-Liss, Inc.