Pulmonary circulation and

Fig. 3. Schematic representation showing the anatomical basis for differences in the quantitative supply of absorbed material to the Hver. By swallowing (oral route), the main fraction of the absorbed dose is transported direcdy to the Hver. FoUowing inhalation or dermal exposure, the material passes to the pulmonary circulation and thence to the systemic circulation, from which only a portion passes to the Hver. This discrepancy in the amount of absorbed material passing to the Hver may account for differences in toxicity of a material by inhalation and skin contact, compared with its toxicity by swallowing, if metaboHsm of the material in the Hver is significant in its detoxification or metaboHc activation.

Q9 Fibrinolytic drugs, such as streptokinase, are given intravenously to lyse clots in the pulmonary circulation and coronary circulation. Occasionally, the thrombotic mass must be removed surgically. Streptokinase activates plasminogen to form plasmin, which degrades the fibrin in the thrombus. Heparin may be given intravenously to prevent further coagulation. 

Doses from/with smoking. Nicotine causes release of catecholamines in the CNS, also serotonin, and antidiuretic hormone, corticotrophin and growth hormone. The effects of nicotine on viscera are probably largely reflex, from stimulation of sensory receptors (chemoreceptors) in the carotid and aortic bodies, pulmonary circulation and left ventricle. Some of the results are mutually antagonistic. 

In patients with impaired function of the left ventricle, NO has a potential to further impair left ventricular performance by dilating the pulmonary circulation and increasing the blood flow to the left ventricle, thereby increasing left atrial pressure and promoting pulmonary edema formation. Careful monitoring of cardiac output, left atrial pressure, or pulmonary capillary wedge pressure is important in this situation. 

The geometrical parameters of the canine systemic and pulmonary circulations are summarized in Table 56.1. Vessel diameters vary from a maximum of 19 mm in the proximal aorta to 0.008 mm (8 m) in the capillaries. Because of the multiple branching, the total cross-sectional area increases from 2.8 cm in the proximal aorta to 1357 cm in the capillaries. Of the total blood volume, approximately 83% is in the systemic circulation, 12% is in the pulmonary circulation, and the remaining 5% is in the heart. Most of the systemic blood is in the venous circulation, where changes in compliance are used to control mean circulatory blood pressure. This chapter will be concerned with flow in the larger arteries, classes 1 to 5 in the systemic circulation and 1 to 3 in the pulmonary circulation in Table 56.1. Flow in the microcirculation is discussed in Chapter 59, and venous hemodynamics is covered in Chapter 60. 

Rare complications as have been reported in literature are aortic and bronchial necrosis [58], bronchial stenosis [59], unilateral diaphragmatic paralysis [60], pulmonary infarction (especially in patients who have suffered pulmonary artery embolism), left main bronchial-esophageal fistula [61], and non-target embolization (colon, coronary and cerebral circulation) [62]. Especially the newer spherical embolic materials (tris-acryl gelatin) can traverse from the bronchial into the pulmonary circulation, and then through unoccluded pulmonary arteriovenous malformations into the systemic circulation [41]. 

Generally speaking, a moderate to high iodine delivery rate (IDR) is needed for CTA of the chest. Therefore, 1.5-2.0 g iodine/s should be administered intravenously. The contrast medium delivery has to be maintained for a longer time, as an opacification of the pulmonary circulation and the systemic circulation is needed at the same time. Dual-head power injectors, individual adaptation of the contrast delivery... 

The lung has two separate blood supplies one for the pulmonary circulation and the other for bronchial... 

Sometimes extracorporeal membrane oxygenation (ECMO) or cardiopulmonary bypass is required, especially in patients with pulmonary hypertension, to protect the pulmonary circulation and the left ventricle from volume overload. After single-lung TX double-lumen tracheal tubes are sometimes used to ventilate both lungs separately for some hours to avoid hyperinflation of the native emphysematous lung. 

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