Oxygen in arterial blood

Figure 9.15. In vivo partial pressure of oxygen in arterial blood of dogs over the period of 10 h. The solid lines represent the analyses monitor by the instrument. Two different polymer solutions are shown. The dots represent the batch gas analysis measured with a Nova Biomedical blood gas analyzer. (From Ref. 21 with permission.)...

Q6 A thrombus is a blood clot which is fixed to the blood vessel wall. When it detaches and is carried in the blood, it is known as an embolus. Both thrombi and emboli can block blood vessels and deprive tissues of oxygen. In arteries blood clots usually form because the inner surface has been altered by deposition of atheroma. In contrast venous thrombosis results from slow or stagnant blood flow in veins, or defects in mechanisms which normally oppose inappropriate coagulation. Three major risk factors for pulmonary embolism are (i) venous stasis, (ii) hypercoagulability ofblood and (iii) injury to vascular endothelium following trauma or plaque rupture. 

The symbols used throughout the text are consistent with the recommendations of the Pappenheimer Committee [Federation Proc. 0, 602-605 (1950)]. Pio, should be read as the inspired partial pressure of oxygen. Pb should be read as the barometric pressure. P should be read as the partial pressure of oxygen in arterial blood. Paoj should be read as the partial pressure of oxygen in the alveoli. 

Clinical assessment of abnormalities in the regulation of respiration is usually limited to measurements of the concentration of carbon dioxide and oxygen in arterial blood (P COg and These measurements are made... 

It is convenient to use the prefixes in Table 1-3 to express quantities that vary over many orders of magnitude (powers of ten). For example, the pressure of dissolved oxygen in arterial blood is approximately 1.3 X 10 Pa. Table 1-3 tells us that 10 is assigned the prefix k for kilo. We can express the pressure in multiples of 10 as follows ... 

Abbreviations-. FEVl, forced expiratory volume in 1 second Pa02, partial pressure of oxygen in arterial blood Sa02, saturation of oxygen in arterial blood. 

Abbreviations-. Sp02, saturation of oxygen in arterial blood NIPPV, noninvasive intermittent positive pressure ventilation MAC, mechanically assisted cough CO2, carbon dioxide IPAP, inspiratory positive airway pressure BiPAP, bi-level positive airway pressure. 

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