RESUMO
Fractional exhaled nitric oxide (FENO) is used to assess eosinophilic inflammation of the airways. FENO values are influenced by the expiratory flow rate and orally produced NO. We measured FENO at four different expiratory flow levels after two different mouthwashes: tap water and carbonated water. Further, we compared the alveolar NO concentration (CANO), maximum airway NO flux (J'awNO) and airway NO diffusion (DawNO) after these two mouthwashes. FENO was measured in 30 volunteers (healthy or asthmatic) with a chemiluminescence NO-analyser at flow rates of 30, 50, 100 and 300 mL/s. A mouthwash was performed before the measurement at every flow rate. The carbonated water mouthwash significantly reduced FENO compared to the tap water mouthwash at all expiratory flows: 50 mL/s (p < .001), 30 mL/s (p = .001), 100 mL/s (p < .001) and 300 mL/s (p = .004). J'awNO was also significantly reduced (p = .017), however, there were no significant differences in CANO and DawNO. In conclusion, a carbonated water mouthwash can significantly reduce oropharyngeal NO compared to a tap water mouthwash at expiratory flows of 30-300 mL/s without affecting the CANO and DawNO. Therefore, mouthwashes need to be taken into account when comparing FENO results.
Assuntos
Asma/metabolismo , Expiração/efeitos dos fármacos , Antissépticos Bucais/farmacologia , Óxido Nítrico/análise , Espirometria/normas , Adolescente , Adulto , Idoso , Asma/imunologia , Asma/patologia , Testes Respiratórios/métodos , Água Carbonatada/análise , Estudos de Casos e Controles , Água Potável/análise , Eosinófilos/efeitos dos fármacos , Eosinófilos/imunologia , Eosinófilos/metabolismo , Eosinófilos/patologia , Feminino , Fluxo Expiratório Forçado/efeitos dos fármacos , Fluxo Expiratório Forçado/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Óxido Nítrico/biossíntese , Alvéolos Pulmonares/efeitos dos fármacos , Alvéolos Pulmonares/imunologia , Alvéolos Pulmonares/metabolismo , Alvéolos Pulmonares/patologiaRESUMO
Fractional exhaled nitric oxide (FENO) assesses eosinophilic inflammation of the airways, but FENO values are also influenced by oral nitric oxide (NO). The aim of this pilot study was to measure FENO and compare the effect of two different mouthwashes on FENO and analyse the duration of the effect. FENO was measured in 12 randomized volunteers (healthy or asthmatic subjects) with a NIOX VERO® analyser at an expiratory flow rate of 50 mL/s. After a baseline measurement, a mouthwash was performed either with tap water or carbonated water and was measured during 20 min in 2 min intervals. The procedure was repeated with the other mouthwash. We found that both mouthwashes reduced FENO immediately at the beginning compared to the baseline (p < .001). The carbonated water mouthwash effect lasted 12 min (p ranging from <0.001 to <0.05). The tap water mouthwash reduced FENO statistically significantly only for 2 min compared with the baseline. We conclude that a single carbonated water mouthwash can significantly reduce the oropharyngeal NO contribution during a 12 min time interval.