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.
A pleural effusion is an abnormal amount of fluid around the lung. Pleural effusions can result from many medical conditions. Most pleural effusions are not serious by themselves, but some require treatment to avoid problems.ymptoms are more likely when a pleural effusion is moderate or large-sized, or if inflammation is present. Symptoms of pleural effusions may include: 1  Shortness of breath. 2  Chest pain, especially on breathing in deeply (pleurisy, or pleuritic pain). 3  Fever. 4  Cough.