TABLE 4

Longitudinal tidal-breathing nasal nitric oxide (NO) measurements scheduled at <2 weeks and at 4, 8, 12, 18 and 24 months of age in 44 included healthy infants

CharacteristicsResults
Subjects n443931211216
Intended age at measurement<8 days4 months8 months12 months18 months24 months
Actual age at measurement1–14 days3.6–6.3 months7.6–9.8 months10.4–14.2 months15.2–21.0 months22.2–27.1 months
Tidal-breathing nasal NO# ppb46 (29–69)98 (56–130)129 (60–200)171 (110–228)178 (137–261)283 (203–389)
Tidal-breathing nasal NO# nL·min−115 (9.6–22.8)32 (18.5–42.9)42.6 (19.8–66)56.4 (36.3–75.2)58.7 (45.2–86.1)93.4 (67.0–128.4)
Adherence to scheduled measurements %10088.670.547.727.336.4

Data is presented as median (IQR) unless otherwise stated. #: sampling flow rate was 0.33 L·min−1 (conversion: nasal NO (ppb)×flowrate (L·min−1)=nasal NO (nL·min−1)).