Volume ventilation

Alveolar ventilation Volume of air passing through the alveoli and alveolar... 

Minute ventilation Volume of air expired or inspired during one minute of... 

Dodd et al.48 tested 17 moderately trained males for V02 max and time to exhaustion on a bicycle ergometer. Experimental trials involved the administration of 3- or 5-mg/kg caffeine 1 h prior to testing. Caffeine had no effect on exercise performance. Since nearly half of the subjects were caffeine naive (<25 mg/d), while the other half were caffeine tolerant (>310 mg/d), the researchers were able to conclude that even though caffeine had no significant effects on performance, it did produce a variety of physiologically significant effects (heart rate and expired ventilation volume) in the caffeine naive group. 

N. J. Rummo, J. H. Knelson, S. Lassiter, and J. Cam (personal communication) exposed 22 male volunteers, aged 19-27, to ozone at 0.4 ppm for up to 4 h in relatively clean ambient air or to ambient air alone. Subjects were seated during exposure, except for two 15-min exercise periods on a bicycle ergometer at 700 kg-m-min exercise that about doubled the heart rate and quadrupled the ventilation volume. 

In addition, once a particular model has been chosen, input values must be assigned to parameters with appropriate certifications in the documentation, since there are infinite possibilities for quantifying parameters for the model. Documentation should not only contain the parameter values used in the assessment, but also their relevance with respect to the aim of the assessment ( worst-case versus actual) and country- or site-specific characteristics (e.g. mechanical versus natural ventilation traditions). For instance, a worst-case assessment of indoor use would employ small room sizes and ventilation volumes, while an assessment for an actual case would employ the values as valid for that particular case. To... 

In addition to these various characteristics, patient-specific factors can affect delivery of aerosolized antimicrobials to the lung. Patient breathing technique and several physiologic variables affect ultimate deposition, including age, breathing pattern, ventilation volumes, and the presence of disease [9]. 

In some studies, the relationship between uptake efficiency and the ventilation rate has been demonstrated [51]. Under hypoxic conditions, rainbow trout increased their ventilation volume which resulted in a higher uptake rate constant for a hydrophobic chemical, since the uptake efficiency remained constant. At very high ventilation rates, however, the uptake efficiency decreased with increasing ventilation flow, which resulted in a constant uptake rate constant at high ventilation rate [51]. It was shown later that ventilation rate related uptake rate constants were only found for relatively large fish of 5-10 g or more, while uptake rate constants were independent of flow rate for smaller fish [52-54]. 

Spirometry has its limitations, however. It can measure only ventilated volumes. It cannot measure lung capacities that contain the residual volume. Measurements of TLC, FRC, and RV have diagnostic value in defining lung overdistension or restrictive pulmonary disease the body plethysmograph can determine these absolute lung volumes. 

Other aspects such as hand position, use of a noncompressible underlying surface, opening the airway, and ventilation volumes have been discussed and adapted over time but have remained less central to the survival question. In Table 18.1 a summary is presented showing the consistency of the values over time. 

Fugitive emissions may be very important, but are hard to measure and quantify. Methods of estimating ventilation volumes or deposition rates can be used to estimate them. One reliable method, which has been applied to primary copper smelting, shows that the magnitude of fugitive emissions can be much more significant than collected and abated emissions. Fugitive emissions can be more than two to three times the quantity of controlled emissions. [155, European IPPC Bureau, 2001]... 

Levels of 0.15 mg Pb/m are typically specified for the working atmosphere. Achieving this level is difficult in some working areas and requires the use of effective hooding and large ventilation volumes. 

Minimum Clear Area = Minimum Required Ventilation Volume (m /s) /... 

Magnetic resonance imaging (MRl) with hyperpolarized (HP) gases can also be used to estimate ventilation volumes in small animals (8). The signal intensity generated by the HP gases in the peripheral airspaces should correlate to the ventilating volume in the ROl. This technique and its applications in ventilation assessments are discussed in more detail in Section II. D. 

Smith FM, Jones DR. The effect of changes in blood oxygen-carrying capacity on ventilation volume in the rainbow trout (Salmo gairdneri). J Exp Biol 1982 97 325-334. 

The ability to generate a PCF, whether unassisted or manually assisted, > 160 L/min is considered critical for successful extubation and adequacy of long-term NIV. The threshold criteria are higher for elective, noninvasive respiratory management, non-invasive ventilation, volume recruitment, and assisted coughing of neuromuscular ventilatory failure (49). Intubated patients with a PCF <60 L/min (measured through the ETT) have a fivefold reduction in successful extubation and are up to 19 times more likely to die in hospital (35). 

The rarefaction phase is a characteristic of slow combustion in unconfined and ventilated volumes. The rarefaction phase amplitude may be comparable with the compression phase amplitude. When the flame propagation velocity and the sound speed in the mixture are comparable, pressure waves are generated. The pressure wave amplitude depends on the mixture composition, initial conditions, the geometry and the combustion regime. Gas dynamics of the process must be taken into... 

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