Aerosolized epoprostenol may induce a selective pulmonary vasodilatation despite its half-life of 2 to 3 min ( Pappert..et a/ 1995). This selective vasodilatory effect is seen in patients with acute respiratory distress syndrome and after surgical repair of congenital heart defects, but not in patients with chronic pulmonary hypertension. Like inhaled NO, aerosolized epoprostenol may induce improvements in arterial oxygenation in both acute respiratory distress syndrome and postoperative pulmonary hypertension (T.§bJe.,..3). As with inhaled NO, a dose-dependent effect is seen with aerosolized epoprostenol. An increase in the dose of aerosolized epoprostenol may cause a 'spill-over' of the prostanoid into the systemic circulation, thereby reducing systemic vascular resistance. In contrast with NO inhalation, which allows exact measurement of the concentration administered by chemiluminescence or electrochemical fuel cells, it is not presently possible to define the dose of aerosolized epoprostenol acting upon the lung since there will be losses in the nebulizer chamber, ventilator tubing, the endotracheal tube, and the large airways. Moreover, the active aerosol fraction deposited in the alveolar spaces is dependent on physical and physiological factors which vary from patient to patient. It is estimated that the aerosol fraction deposited in the alveolar space during mechanical ventilation is below 10 per cent.
Table 3 Advantages and disadvantages of aerosolized epoprostenol
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Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...