Normal sniff nasal inspiratory pressure (SNIP) and maximal inspiratory pressure (PI max)

Age groups (years)	N (number of subjects)	SNIP cm H₂O (standard deviation)	PI max (FRC) cm H₂O (standard deviation)
Males
20 to 35	20	117 (29.5)	109.5 (27)
36 to 50	20	105 (24.5)	105 (20.5)
51 to 65	20	111.5 (15.5)	103.5 (21.5)
66 to 80	20	91 (21.5)	82.5 (22.5)
Females
20 to 35	20	84 (14.5)	77.5 (18)
36 to 50	20	94 (21)	86.5 (21)
51 to 65	20	83.5 (18)	79.5 (17)
66 to 80	20	75.5 (11)	58 (16)

Table representing maximum values of SNIP and PI max at functional residual capacity (FRC) in healthy adults.

Data from: Uldry C, Fitting JW. Maximal values of sniff nasal inspiratory pressure in healthy subjects. Thorax 1995; 50:371.

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