Nose breathing

For Type F, there is rapid 100% absorption within 10 minutes of the material deposited in the BB, bb, and AI regions, and 50% of material deposited in ET2. Thus, for nose breathing, there is rapid absorption of approximately 25% of the deposit in ET for mouth breathing, the value is 50%. 

During normal nose breathing the majority of inhaled environmental particles are deposited in the nose and pharynx, as described in Chapter 9 (Section 9.2). Hence for pulmonary drug delivery, the aerosols are inhaled via the mouth. 

Figure 9.51 Regional deposition of inhaled particulate matter as a function of particle size nose breathing at 15 respirations per minute and 730 cm tidal volume (the pulmonary compartment refers to deposition beyond the terminal bronchiole).

Following exposure to 500 ppm ammonia for 10-27 minutes, healthy male subjects eliminated 70-80% of the inspired ammonia by this route (Silverman et al. 1949). Analysis of endogenous ammonia levels in the expired air of rats showed concentrations ranging from 10-353 ppb (mean=78 ppb) in nose-breathing animals (Barrow and Steinhagen 1980). 

Breathe through your nose. This takes a little practice (and you may not be able to do it if you re congested), but nose breathing is a terrific way to channel oxygen right into the brain, with marvelous effects on your brain chemistry. 

Theoretical results have been determined for total lung deposition in adults based on breathing pattern. Theoretical results for mouth breathers were not found in the literature therefore, this comparison is limited to nose breathing individuals. The estimates determined in this study have been compared to the results of the ICRP 66 (1994) and the results of Yu and Diu (1982). These theoretical estimates are shown in Table 27.5. 

B. Total and Regional Deposition After Nose Breathing... 

Experimental data on total and regional deposition during nose breathing were obtained by Heyder et al. (99) in healthy adult volunteers who inhaled monodis-perse particles with increasing particle diameter through the nose at a fixed flow... 

Heyder et al. found that particles <3 pm do penetrate beyond the nose and deposit primarily in the alveolar region. However, the number of particles that bypass the nose appears to be lower than what is predicted from the model (i.e., -20%). In addition, only about 3% of 1- to 5-pm particles deposit in the bronchial airways during nose breathing. Therefore, if one is interested in targeting those airways, it will be necessary to administer large amounts of aerosol to compensate for the losses in the nose. 

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