Oxygen With Cold Bubble Humidification Is No Better Than Dry Oxygen in Preventing Mucus Dehydration, Decreased Mucociliary Clearance, and Decline in Pulmonary Function.

BACKGROUND: Little is known about the effects of long-term nasal low-flow oxygen (NLFO) on mucus and symptoms and how this variable is affected by dry or cold humidified gas. The aim of this study was to investigate the effects of dry-NLFO and cold bubble humidified-NLFO on nasal mucociliary clearance (MCC), mucus properties, inflammation, and symptoms in subjects with chronic hypoxemia requiring long-term domiciliary oxygen therapy. METHODS: Eighteen subjects (mean age, 68 years; 7 male; 66% with COPD) initiating NLFO were randomized to receive dry-NLFO (n = 10) or humidified-NLFO (n = 8). Subjects were assessed at baseline, 12 h, 7 days, 30 days, 12 months, and 24 months by measuring nasal MCC using the saccharin transit test, mucus contact angle (surface tension), inflammation (cells and cytokine concentration in nasal lavage), and symptoms according to the Sino-Nasal Outcome Test-20. RESULTS: Nasal MCC decreased significantly (40% longer saccharin transit times) and similarly in both groups over the study period. There was a significant association between impaired nasal MCC and decline in lung function. Nasal lavage revealed an increased proportion of macrophages, interleukin-8, and epidermal growth factor concentrations with decreased interleukin-10 during the study. No changes in the proportion of ciliated cells or contact angle were observed. Coughing and sleep symptoms decreased similarly in both groups. There were no outcome differences comparing dry vs cold bubble humidified NLFO. CONCLUSIONS: In subjects receiving chronic NLFO, cold bubble humidification does not adequately humidify inspired oxygen to prevent deterioration of MCC, mucus hydration, and pulmonary function. The unheated bubble humidification performed no better than no humidification. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT02515786; URL: www.clinicaltrials.gov.

Mucociliary clearance, airway inflammation and nasal symptoms in urban motorcyclists.

OBJECTIVES: There is evidence that outdoor workers exposed to high levels of air pollution exhibit airway inflammation and increased airway symptoms. We hypothesized that these workers would experience increased airway symptoms and decreased nasal mucociliary clearance associated with their exposure to air pollution. METHODS: In total, 25 non-smoking commercial motorcyclists, aged 18-44 years, were included in this study. These drivers work 8-12 hours per day, 5 days per week, driving on urban streets. Nasal mucociliary clearance was measured by the saccharine transit test; airway acidification was measured by assessing the pH of exhaled breath condensate; and airway symptoms were measured by the Sino-nasal Outcome Test-20 questionnaire. To assess personal air pollution exposure, the subjects used a passive-diffusion nitrogen dioxide (NO2) concentration-monitoring system during the 14 days before each assessment. The associations between NO2 and the airway outcomes were analyzed using the Mann-Whitney test and the Chi-Square test. Clinicaltrials.gov: NCT01976039. RESULTS: Compared with clearance in healthy adult males, mucociliary clearance was decreased in 32% of the motorcyclists. Additionally, 64% of the motorcyclists had airway acidification and 92% experienced airway symptoms. The median personal NO2 exposure level was 75 mg/m3 for these subjects and a significant association was observed between NO2 and impaired mucociliary clearance (p=0.036). CONCLUSION: Non-smoking commercial motorcyclists exhibit increased airway symptoms and airway acidification as well as decreased nasal mucociliary clearance, all of which are significantly associated with the amount of exposure to air pollution.

Aging, diabetes, and hypertension are associated with decreased nasal mucociliary clearance.

BACKGROUND: We showed previously that nasal mucociliary clearance was decreased in critically ill elderly subjects, most of whom had diabetes mellitus (DM) and/or hypertension (HTN). To determine if these changes were due to the effects of aging, disease, or critical illness, we studied nasal mucociliary clearance and mucus properties in an ambulatory population consisting of young, elderly, and healthy subjects and those with DM, HTN, or both. METHODS: Of 440 subjects contacted, 252 entered the study. The subjects were divided into the following groups: (1) healthy (n 5 79, 18-94 years, 50 men) and (2) DM and/or HTN, of which 37 had DM (14-90 years, 12 men), 52 had HTN (23-90 years, 12 men), and 84 had both DM and HTN (25-82 years, 33 men). Subjects were also grouped by age: , 40 years, 40 to 59 years, and 60 years. We assessed demographic and clinical data, quality of life using the 36-Item Short Form Health Survey (SF-36) questionnaire, nasal mucociliary clearance using the saccharine transit test (STT), and in vitro mucus properties by examining the sneeze (high airflow) clearability and contact angle. A logistic regression analysis for prolonged STT . 12 min was used, and we controlled for age, sex, and diseases. RESULTS: Subjects aged . 60 years reported a decreased SF-36 physical component relative to other age groups. Sex, BMI, BP, heart rate, pulse oximetry, blood glucose level, and mucus properties were not associated with prolonged STT. Aging and DM and/or HTN independently increased the risk of prolonged STT. CONCLUSIONS: Aging and DM, HTN, or both diseases are independently associated with decreased nasal mucociliary clearance. This may predispose toward respiratory infections.

CPAP has no effect on clearance, sputum properties, or expectorated volume in cystic fibrosis.

BACKGROUND: Positive expiratory pressure (PEP) is used for airway clearance in cystic fibrosis (CF) patients. Hypertonic saline (HTS) aerosol increases sputum expectoration volume and may improve respiratory secretion properties. CPAP may also be used to maintain airway patency and mobilize secretions. To evaluate if CPAP would increase the beneficial clearance effect of HTS in subjects with CF, we investigated the effects of CPAP alone and CPAP followed by HTS on sputum physical properties and expectoration volume in CF subjects. METHODS: In this crossover study, 15 CF subjects (mean age 19 y old) were randomized to interventions, 48 hours apart: directed coughs (control), CPAP at 10 cm H(2)O, HTS 7%, and both CPAP and HTS (CPAP+HTS). Sputum collection was performed at baseline and after interventions. Expectorated volume was determined and in vitro sputum properties were analyzed for contact angle and cough clearability. RESULTS: There were no significant differences between any treatment in arterial blood pressure, heart rate, or pulse oximetry, between the 2 time points. HTS and CPAP+HTS improved cough clearability by 50% (P = .001) and expectorated volume secretion by 530% (P = .001). However, there were no differences between control and CPAP on sputum contact angle, cough clearability, or volume of expectorated secretion. CONCLUSIONS: CPAP alone had no effect on mucus clearance, sputum properties, or expectorated volume, and did not potentiate the effect of HTS alone in CF subjects.