Exhaled air volume

Exhaled air volume GC-MS Minute volume Mixed-exhaled air... 

Forced vital capacity (FVC) quantifies the maximum air volume expired following a maximal inspiration and is one of the basic measures of analyzing flow changes such as reduced airway patency observed in asthma. To measure FVC, an individual inhales maximally and then exhales as rapidly and completely as possible. FVC primarily reflects the elastic properties of the respiratory tract. The gas volume forcibly expired within a given time interval, FEV (where t is typically one second, FEVj q)... 

Spirometry A test method used to evaluate lung function that measures volume of exhaled air passing through a tube during a given time. 

A self-contained breathing apparatus contains 248 g of potassium superoxide. A firefighter exhales 116 L of air at 37°C and 748 mm 1%. The volume percent of water in exhaled air is 6.2. What mass of potassium superoxide is left after the water in the exhaled air reacts with it ... 

The absorption of inhaled -hexane has been investigated in six healthy male volunteers (Veulemans et al. 1982). Three different trials were performed on each volunteer 4-hour exposure at 102 ppm -hexane 4-hour exposure at 204 ppm, and exposure during exercise on a stationary bicycle ergometer at 102 ppm. Each trial was done at least two weeks apart. Lung clearance (from alveolar air to blood) and retention were calculated from -hexane concentrations in inhaled and expired air. After exposure, /7-hcxane in exhaled air was measured for up to 4 hours to determine respiratory elimination. Retention of -hexane (calculated from lung clearance and respiratory minute volume) was approximately 20-25%... 

The inhaled air volume (V in L) depends on the extent of chest enlargement. During normal breathing, the inhaled and exhaled volumes (tidal volume) are only part of the total lung volume [8,21]. The different parameters that describe pulmonary ventilation are shown in Figure 3.2. Table 3.1 presents a definition of the different parameters. Normal adults have a tidal... 

Concentration-time profile of the substance/metabolites in blood (plasma), tissues, and other biological fluids, such as urine, bUe, exhaled air, and the volume of the excreted fluids if appropriate... 

Carbon dioxide is found throughout nature. Its concentration in the air is 0.036% by volume. It is the primary component of exhaled air of all animals. It also is the product of oxidation of all carbonaceous matter and an end product of complete combustion. It also is found dissolved in natural waters. It occurs in the earth s crust and in volcanic eruptions. 

The half-life of radioactivity in blood after intravenous dosing of [ CJacetamide to rats averaged 20.6 0.3 h after a 10 mg/kg bw dose and 16.1 1.6 h after a 50 mg/kg bw dose. The volume of distribution was about 1 mL/g, total body clearance was 0.27 mL/min and renal clearance was 0.19 mL/min. Approximately 64-72% of [ CJacetamide was excreted in the urine, while only 0.5-0.8% appeared in exhaled air during the first 6 h after dosing. Thus, approximately 30% of the administered dose was not recovered and it was suggested that metabolized acetamide enters the acetate pool (Putcha et al., 1984). 

In a basal metabolism measurement timed at exactly 6 minutes, a patient exhaled 52.5 L of air, measured over water at 20°C. The vapor pressure of water at 20°C is 17.5 torn The barometric pressure was 750 torn The exhaled air analyzed at 16.75 volume % oxygen, and the inhaled air at 20.32 volume % oxygen (both on a dry basis). Neglecting any solubility of the gases in water and any difference in total volumes of inhaled and exhaled air, calculate the rate of oxygen consumption by the patient in cm3 (S.T.P.) per minute. 

Many different instruments have been used for the measurement of hydrocarbons in exhaled air. They include the Varian Model 6000 (Varian Instrument, Sunnyvale, CA, U.S.A.) (Zarling and Clapper, 1987), Shimadzu 6-AM (Shimadzu, Seiggkuska Ltd., Kyoto, Japan) (Lemoyne et al., 1987) and Hewlett-Packard Model 5750 (Lawrence and Cohen, 1984). Gas samples are injected either directly into a sampling loop (10 ml volume) (Zarling and Clapper, 1987) or via stainless steel loops (0.2 cm i.d. x 23.4 cm) packed with adsorbents such as activated alumina (80-100 mesh) (Lemoyne et al., 1987) in order to concentrate the alkanes in the sample. 

At a depth of 20 m, a 0.5-mL bubble of exhaled air is released from a scuba diver s mouthpiece. If the volume of the bubble just as it reaches the surface of the water is 1.5 mL, what was the pressure on the diver ... 

A resting adult requires about 240 mL of pure oxy-gen/min and breathes about 12 times every minute. If inhaled air contains 20 percent oxygen by volume and exhaled air 16 percent, what is the volume of air per breath (Assume that the volume of inhaled air is equal to that of exhaled air.)... 

Problem 5.11. The partial pressure of carbon dioxide in exhaled air is 28 torr. If the total pressure is 760 torr, the temperature 37 °C, and the volume of a lung is 3.0 L, what is the mass of COj exhaled by both lungs ... 

Volume of air exhaled over a specified volume range of the FVC divided by the time to exhale this volume, expressed as liter/min or liter/s. Examples ... 

Mixed-exhaled air. This technique involves the collection of the entire volume of exhaled air. It corresponds to a mixture of the alveolar air with air from the dead space. The collection apparatus may also contribute to the dead space. Total dead space should be considered and the concentration adjusted, either by subtraction, or by regression against some other technique unaffected by the dead space. Timing of the brea collection is important here since the concentration of the air in the dead space may equal that of the air in the workroom if the sample is taken during exposure, or it may equal zero if taken after the end of exposure. 

Six healthy males were exposed to 72 and 144 ppm, as well as 142 ppm with 2 half hours of 100 W of exercise. Uptake of PERC was calculated from the minute volume and the concentration of PERC in breath. PERC was measured in breath and blood and TCA was measured in blood and urine. During the first hour of exposure the uptake was higher by 25% than during the last hour and retention decreased with time and with exercise. The mean ratio of the concentration of PERC in venous blood and the concentration of PERC in mixed exhaled air was 23. Assuming a mix-exhaled air to end-exhaled air ratio of 0.71, they estimated a blood/ air partition coefficient of 16. After 20 hours fi om the end of exposure the half-life was estimated to be 12-16 hours, after 50 hours the half-life was estimated to be 30-40 hours and after 100 hours it was estimated at approximately 55 hours. The authors estimated that 80-100% of PERC was excreted unchanged through the lung, and about 2% was excreted as TCA in the urine. 

Entire volume of exhaled air collected from alveolar space and anatomically... 

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