INTRODUCTION Nasal cannulas are commonly used to deliver oxygen in acute and chronic care settings; however, there are few data available on delivered fraction of inspired oxygen (F(IO(2))). The purposes of this study were to determine the delivered F(IO(2)) on human subjects using low-flow and high-flow nasal cannulas, and to determine the effects of mouth-closed and mouth-open breathing on F(...

There are a number of evidences suggesting that lung perfusion distribution is under active regulation and determined by several factors in addition to gravity. In this work, we hypothesised that autoinhalation of nitric oxide (NO), produced in the human nasal airways, may be one important factor regulating human lung perfusion distribution in the upright position. In 15 healthy volunteers, we ...

OBJECTIVE To investigate abnormal breathing patterns during sleep in prepubertal children using nonstandard polysomnographic patterns in association with an apnea-hypopnea scoring technique. PATIENTS AND METHODS Study participants included 400 children with suspected sleep-related breathing disorders and 60 control children. We analyzed clinical signs and symptoms at entry into the study and ...

We assessed the effect of dry air (DA) nasal breathing on nasal clearance rate in healthy nonsmoking subjects. We measured saccharin nasal transit time (SNTT), an index of mucociliary clearance rate, in eleven normal subjects (six males, five females) breathing either room air (RA) or DA through the nose in random order on six different study days. On each study day, the trial was conducted at ...

I t has been suggested that conditions associated with nasal obstruction predispose to the development of snoring and OSA (1,2). Some authors indicated that the nose accounts for approximately half of the total airway resistance to airflow (3). Nasal obstruction may contribute to an increase in snoring and sleep apnea frequency and severity (4). For this reason, nasal dilators have been propose...

Defective nasal respiration is not synonymous with nasal stenosis, and many mouth-breathers have no obstruction in the nasal passages sufficient to prevent them breathing through the nose. Why and how imperfect nasal respiration becomes a 3 Vol. XXIV. No. 91.

Timed vital capacity of one second, peakflow, maximum breathing capacity (maximum voluntary ventilation), maximum middle half flow rate, total vital forced expiratory and inspiratory capacities, tidal and minute volume tested via the mouth and each "nose" separately for the diagnosis of nasal airway disturbance have proved to be valuable parameters of pulmonary function for the evaluation of th...

INTRODUCTION Nasal obstruction is a common symptom in childhood, related to rhinitis and pharyngeal tonsil hypertrophy. In the presence of nasal obstruction, nasal patency may be reduced, and nasal breathing is replaced by mouth breathing. Orofacial and otorhinolaryngologic changes are related to this breathing mode. Objective evaluation of upper airways may be obtained through nasal patency me...

Increased resistance in the upper airway is known to be a contributing factor to deviant facial growth patterns. These patterns are the result of a prolonged presence of unbalanced oropharyngeal muscle activity. We hypothesized that mechanically increasing airway resistance would enhance the activity of the muscles facilitating respiration, and we attempted to demonstrate that the increased mus...