The pressure is computed assuming an International standard sea-level pressure datum of 1013.25 hPa, and therefore is not necessarily the same as the aircraft's true altitude either above mean sea level or above ground level.he pressure is computed assuming an International standard sea-level pressure datum of 1013.25 hPa, and therefore is not necessarily the same as the aircraft's true altitude either above mean sea level or above ground level.
The term pleurisy (pleuritis) is inflammation or infection in the pleural space around the lungs. Pyothorax also known as empyema of the pleural cavity is the presence of pus in the pleural cavity between the layers of the pleural membrane Py/o-Pus.
The lungs are contained within a space called the pleural cavity, and when an excess of fluid is in the pleural cavity, it is called a pleural effusion. Pleural effusion can make breathing difficult and uncomfortable, and when cancer cells are in the fluid, it is called malignant pleural effusion.