To describe the day-to-day variation in nasal NO (nNO) and ambient NO (aNO) and examine the relationship between nNO and aNO in healthy non-smokers and tracheotomized patients.
Two groups were recruited: 1) ten healthy non-smokers (50% male), aged 33.9 ± 7.8 years with a body mass index < 30, no cold or flu-like symptoms in 30 days, known allergies, prescribed medications in 7 days, or diagnosis of acute or chronic illness, and 2) three tracheotomized patients (33% male), aged 77.0 ± 5.2 years, on mechanical ventilation (MV) for 43.67 ± 31.90 days and undergoing daily weaning trial. Tracheotomy placement was 8.33 ± 4.51 days after initiation of MV. nNO and aNO levels were measured using a chemiluminescence analyzer (Model LR2000; Logan Research, Rochester, UK) with a sampling flow rate of 250 ml/minute.
In normals (n=10), nNO was measured for 3 consecutive days (30 measures). There was no significant day-to-day difference in nNO (p=NS). In tracheotomized subjects (n=3), nNO was measured for two, 3 consecutive day periods with an intervening 10 days (18 measures). Twelve measures occurred while on MV and 6 measures occurred after weaning from MV (mean ± SD = 723.66 ± 391.75 ppb, and 1083.31 ± 302.90 ppb respectively). aNO levels varied each day in both normal and tracheotomized patients (range 0.65 –104.50 ppb, and 1.00 –112.20 ppb, respectively). In both groups, there were no significant correlations between nNO and aNO (p=NS).
nNO levels had little day-to-day variation in healthy non-smokers. Additionally, nNO levels were not different when tracheotomized patients were breathing either on or off MV. There was no significant relationship between nNO and aNO either in healthy non-smokers or tracheotomized patients, whether on or off MV.
Measurement of exhaled NO has been proposed as a non-invasive marker of airway inflammations. Further study is necessary to determine influence of an artificial airway and aNO levels on nNO.
nNO and ANO levels in Healthy Non-smokers and Tracheotomized PatientsHealthy non-smokersTracheostomyOn MVOff MVMeasures30126nNO1020.28 ±266.68723.66 ±391.751083.31 ±302.90ANO36.17±20.688.93±10.2550.4±46.23
JiYeon Choi, Product/procedure/technique that is considered research and is NOT yet approved for any purpose. The chemiluminescence analyzer (Model LR2000; Logan Research, Rochester, UK) is only available for research purposes at this time.