Airways visualizing

A fiberoptic camera is inserted through the airways to examine the site of the suspected lesion. Once the lesion. Once the lesion is visualized, a tool attached to the camera allows for a tissue biospy. 

The answer is c. (Hardman, pp 156-158.) A wide variety of clinical conditions are treated with antimuscarinic drugs. Dicyclomine hydrochloride and methscopolamine bromide are used to reduce Gl motility, although side effects—dryness of the mouth, loss of visual accommodation, and difficulty in urination—may limit their acceptance by patients. Cyclopentolate hydrochloride is used in ophthalmology for its mydriatic and cycloplegic properties during refraction of the eye. Trihexyphenidyl hydrochloride is one of the important antimuscarinic compounds used in the treatment of parkinsonism. For bronchodilation in patients with bronchial asthma and other bronchospastic diseases, ipratropium bromide is used by inhalation. Systemic adverse reactions are low because the actions are largely confined to the mouth and airways. 

Exposure around 0.1 ppm 03 for 10-30 minutes causes irritation and dryness of the throat above 0.1 ppm, one finds changes in visual acuity, substernal pain, and dyspnea. Pulmonary function is impaired at concentrations exceeding 0.8 ppm. Airway hyperresponsiveness and airway inflammation have been observed in humans. 

The angles of branching, the diameter and lengths of different elements of the airways, and the pulmonary air spaces must be visualized in an arbitrary and oversimplified form to make practical use of anatomic data. Some of the details ofthe divisions of the respiratory system that have been assumed by Landahl [53] and the anatomic flow rate and transitional features in these areas are shown in Table 5. 

Spirometry is the most widely available and useful PFT. It takes only 15 to 20 minutes, carries no risks, and provides information about obstructive and restrictive disease. Spirometry allows for the measurement of aU lung volumes and capacities except RV, FRC, and TLC and allows assessment of FEVi and FEF25%-7s%. Spirometry measurements can be reported in two different formats—standard spirometry (Eig. 25-2) and the flow-volume loop (Fig. 25-3). In standard spirometry, the volumes are recorded on the vertical (y) axis and the time on the horizontal (x) axis. In flow-volume loops, volume is plotted on the horizontal (x) axis, and flow (derived from volume/time) is plotted on the vertical (y) axis. The shape of the flow-volume loop can be helpful in differentiating obstructive and restrictive defects and in the diagnosis of upper airway obstruction (Fig. 25 ). This curve gives a visual representation of obstruction because the expiratory descent becomes more concave with worsening obstruction. 

CT offers the possibility to demonstrate both airway and vascular pathology (e.g. bronchiectasis, bronchogenic carcinoma, aneurysmal disease of the thoracic aorta), and has been reported to be the modality of first choice in patients with hemoptysis [18]. In patients who have a non-diagnostic fiberoptic bronchoscopy, CT can provide a diagnosis in half of the cases, while in patients with non-conclusive chest radiography this rate varies from 39% to 88% [16, 17]. Localization of the bleeding site can be achieved in 63%-100% of all cases [7, 15]. Current multidetector CT scanners also allow visualization of bronchial and non-bronchial systemic artery anatomy, and may thus be of help for the interventionalist to plan the procedure [8,13,19, 20]. 

Fig. 14.10. While airways are nicely visualized in minMip, the obstruction of the left main bronchus is only visible partly...

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