Exhaled nitric oxide in paediatric asthma and cystic fibrosis.

Cystic fibrosis (CF) patients characteristically have severe chronic airway inflammation associated with bacterial infection. A noninvasive marker of airway inflammation could be a useful guide to treatment of CF lung disease. The aim of this study was to assess whether measurement of hydrogen peroxide (H2O2) and nitric oxide (NO) in exhaled air can serve to monitor the effect of treatment with antibiotics in CF‐children with acute infective pulmonary exacerbations. Sixteen CF‐patients (mean age 12.3 yrs) with exacerbation of their lung infection were treated with intravenous antibiotics in an uncontrolled study. During treatment, H2O2 in exhaled air condensate was measured twice a week. In addition, serial NO measurements were performed in nine patients. During antibiotic treatment the median H2O2 concentration in exhaled air condensate decreased significantly from 0.28 µM (range 0.07–1.20 µM) to 0.16 µM (range 0.05–0.24 µM, p=0.002) and the mean forced expiratory volume in one second significantly increased from 55% predicted to 75% pred (p=0.001). In individual subjects, changes of H2O2 and FEV1 between pairs of serial measurements correlated weakly (p=0.08). Data on exhaled NO were inconclusive; exhaled NO did not change systematically during treatment. It is concluded that cystic fibrosis patients with an acute pulmonary exacerbation have abnormally high concentrations of hydrogen peroxide, but not of nitric oxide, in exhaled air, which decrease during intravenous antibiotic treatment. Further controlled studies should establish if exhaled hydrogen peroxide, may serve as a noninvasive parameter of airway inflammation to guide antibiotic treatment in cystic fibrosis lung disease.

Section: Discussioncontrasting

confidence: 54%

“…Exhaled nitric oxide (NO) has been put forward as another noninvasive marker of airway inflammation [16,17]. However, in stable CF-patients orally exhaled NO levels are not elevated [18,19]. Data in children on NO and H 2 O 2 during acute infectious respiratory tract exacerbation in CF are lacking.…”

mentioning

confidence: 99%

Hydrogen peroxide and nitric oxide in exhaled air of children with cystic fibrosis during antibiotic treatment

Jöbsis

Raatgeep²,

Schellekens³

et al. 2000

“…In allergic rhinitis the picture is less clear. Some groups have shown an increase in nasal NO in rhinitis [26][27][28], while others find normal values in these patients [24,29,30]. The reason for the discrepancies in studies on rhinitis is probably related to methodology.…”

Section: Discussionmentioning

confidence: 96%

“…For example, nasal NO is extremely low in primary ciliary dyskinesia (PCD) [4] and in cystic fibrosis [24]. In fact, a nasal NO test is currently part of the clinical routine at the national centre for PCD in the UK [25].…”

Section: Discussionmentioning

confidence: 99%

Assessment of nasal and sinus nitric oxide output using single-breath humming exhalations

Maniscalco¹,

Weitzberg²,

Sundberg³

et al. 2003

Nasal nitric oxide (NO) levels increase greatly during humming compared to silent exhalation. In this study, the physiological and anatomical factors that regulate NO release during humming have been characterised in 10 healthy subjects and in a model of the sinus and the nose.Single-breath humming caused a large initial peak in nasal NO output, followed by a progressive decline. The NO peak decreased in a step-wise manner during repeated consecutive humming manoeuvres but recovered completely after a silent period of 3 min. Topical nasal application of an NO synthase inhibitor reduced nasal NO by w50% but had no effect on the increase evoked by humming. Silently exhaled nasal NO measured immediately after repeated humming manoeuvres was between 5-50% lower than basal silent NO exhalation, suggesting variable continuous contribution from the sinuses to nasal NO. Among the factors known to influence normal sinus ventilation, ostium size was the most critical during humming, but humming frequency was also of importance.In conclusion, humming results in a large increase in nasal nitric oxide, which is caused by a rapid gas exchange in the paranasal sinuses. Combined nasal nitric oxide measurement with and without humming could be of use to estimate sinus ventilation and to better separate nasal mucosal nitric oxide output from sinus nitric oxide in health and disease. Eur Respir J 2003; 22: 323-329. This study was supported by a grant from the Swedish Heart-Lung Foundation, the Swedish Research Council and by a grant from University Federico II "Progetto scambi internazionali".Nitric oxide (NO) is released into the airway lumen [1], in particular in the upper airways [2][3][4]. The exact origin of NO found in nasal air and the relative contribution from different sources within the nasal airways are not known. The paranasal sinuses are major sources of NO in adult healthy subjects [5] and the concentrations in a healthy sinus may be very high, ranging 5-20 parts per million (ppm) [5]. The sinuses communicate with the nasal cavity through the ostia and the rate of gas exchange between these cavities is dependent on several factors, such as the size of the ostia, the volume of the sinus, the nasal airflow and intra-nasal pressure [6,7]. Proper ventilation is essential for maintenance of sinus integrity, and blockage of the ostium is a central event in the pathogenesis of sinusitis [8,9]. During normal ventilation, the time required to exchange all air in the sinuses is y30 min, with large inter-individual variation [7,10]. Sinus ventilation is much slower in patients with sinus disorders [10].Recently, the current authors have shown that nasal NO levels increase greatly during humming compared to normal silent nasal exhalation, probably by speeding up the sinus gas exchange, thereby increasing nasal NO output [11]. In a twocompartment model of the nose and sinus the authors demonstrated that pulsating airflow, created by humming, causes a dramatic increase in gas exchange between these cavities [11].In the ...

“…This may indicate that air speed will have to be taken into consideration in future nasal NO measurements and that different methods at different volume flow rates measure different aspects of nasal NO release. Interestingly, two studies on allergic rhinitis show an increase in nasal NO [6,27], while two show no difference in nasal NO [7,12].…”

Section: Discussionmentioning

confidence: 99%

Characterization of exhaled nitric oxide: introducing a new reproducible method for nasal nitric oxide measurements

Palm¹,

Gräf

Lundberg³

et al. 2000

Nitric oxide (NO) is present in the human nasal airways and has been suggested to originate primarily from the paranasal sinuses. The aim of this study was to establish a new and reproducible method for measurement of nasal NO.Through repeated single-breath measurements the intra-and inter-individual variations of NO levels in nasally (into a tightly fitting mask covering the nose) and orally exhaled air were determined in healthy humans. Variations due to the methods used were investigated. The contribution of oral NO to the nasal exhalations by introducing a mouthwash procedure was also studied.This study shows distinct individual values of NO in nasally and orally exhaled air of healthy humans. Some diurnal variability was also found with a rise in NO in nasally and orally exhaled air over the day, but no, or little, day-to-day variability when comparing the results from separate mornings. There was no correlation between NO levels in nasally and orally exhaled air, whereas there was a strong correlation between NO levels in air exhaled through the left and right nostril. The levels of NO in air exhaled at 0.17 L . s -1 through either nostril separately were higher than in air exhaled at the same flow rate through both nostrils simultaneously. After the introduction of a mouthwash procedure the level of NO in orally, but not nasally exhaled air was reduced.To conclude the method using nasal exhalation into a nose mask is highly reproducible. It is also suggested that subtracting the level of NO in orally exhaled air, after mouthwash, from that in nasally exhaled air, would adequately reflect nasal NO levels. Eur Respir J 2000; 16: 236±241.