Lung volumes closing volume

Phase 4 Draw a final upstroke. This occurs at the closing volume. Note that the volume on the x axis at this point is not the value for the closing volume itself but rather the volume exhaled so far in the test. The closing volume represents the volume remaining within the lung at this point. 

Closing Volume (cv) - Buist and Ross S measured the lung volume at... 

Recent work with insulin provides evidence that the total lung volume at the end of the delivery impacts the kinetics of absorption of this peptide delivery of fine particle insulin aerosol resulted in faster absorption with a higher plasma peak level in humans when the inhalation was done with a deep breath (close to vital capacity), as compared with a more shallow breath (about 50% of the vital capacity).The kinetics following the latter was similar to subcutaneous absorption of insulin. The exact reasons for this observation are unknown. However, the lung does have the above-described water channels that could expand during breathing. If the size of the peptide or protein molecule approaches the diameter of these channels, it would be expected that the channel expansion would lead to faster absorption. For molecules whose size exceeds the channel diameter, the lung volume does not play a role in their pulmonary absorption rate. ... 

Increased static lung volumes (FRC and TLC), as assessed by whole-body plethysmography, are also a diagnostic feature of asthma (Fig. 9). This is presumably due to premature closing of the airways during expiration be-... 

Several animal inhalation toxicity studies have been conducted on various jet fuels (summarized in Table 4-2). In one study, male F344 rats were exposed to shale-oil-derived JP-4 continuously for 90 days by inhalation at 1,000 mg/m3. The exposure resulted in no effects on lung volumes, dynamic resistance and compliance, quasistatic compliance, partial and full forced vital capacities, carbon monoxide diffusion capacity, and closing volume. There... 

Lung volume increases approximately 10-fold between 1 month and 7 years (Table 1), but it then slows down until the age of 18 years (Fig. 9). The associated increase in elastic recoil pressure combined with a progressive decrease in closing volume will affect patterns of aerosol distribution and may... 

A third method for measuring lung volumes uses a device known as a body plethysmograph, also referred to as a body box. The body box is a large rigid-walled structure in which the patient is seated, after which the door is closed and sealed completely. In one variety, a small hole in the wall of the cabinet leads to a spirometer or flow sensor. Respiratory efforts within the box cause changes in volume to be recorded on this spirometer as chest wall movement displaces air within the box. In a second variety of body box, there is no hole in the wall of the box and respiratory efforts instead... 

By the measurement of lung and forced expiratory volumes, nasal, lower and total airway resistances, closing volume data, the phase III slope of the alveolar plateau, and the maximum expiratory ow volume, peripheral airway dysfunction was con rmed in 24 adults with common colds. In a randomized, controlled trial, an aromatic mixture of menthol, eucalyptus oil, and camphor (56%, 9%, and 35% w/w, respectively) were vaporized in a room where the subjects were seated. Respiratory function measurements were made at baseline, 20 and 60 min after exposure. After the last measurement, phenylephrine was sprayed into the nostrils and the measurements taken again 5-10 min later to determine potential airway responsiveness. The control consisted of tap water. The results showed sign cant changes in forced vital capacity, forced expiratory volume, closing capacity, and the phase III slope after aromatic therapy as compared to the control. It was con eluded that the aromatic inhalation favorably modi ed the peripheral airway dysfunction (Cohen and Dressier, 1982). 

In resume, inspiratory breathing exercises coupled with mobilization and body positioning are used to increase lung volumes and improve ventilation. They can promote relaxation and reduce anxiety. Expiratory breathing techniques with an open glottis (a huff) or with a closed glottis (a cough) are used to increase expiratory flow rates and, thus, enhance airway clearance. Forced expiratory maneuvers should be used with caution in patients with bronchospasm to avoid exacerbation of spasm, or cardiac dysfunction. 

A manometer is inserted into the system between the valve and the resistance to monitor the pressure. This pressure should be 10 20 cmH20 at mid-expiration. Tidal breathing, with a slightly active expiration, is used and lung volume is retained at a raised level by avoiding complete expiration. The forced expiration technique is used to clear the secretions that are mobilized. The duration and frequency of treatment are adapted for each individual. PEP increases the pressure gradient between the open and closed alveoli, thus tending to maintain alveoli patency. It increases the functional residual capacity (FRC). This reduces the resistance in collateral and small airways. 

Gas dilution lung volumes are usually measured with helium. The subject is connected to a closed... 

The volume of gas remaining in the lung when the small airways start to close (ml). 

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