Pneumomediastinum
Also known as mediastinal emphysema to divers, pneumomediastinum is a volume of gas inside the mediastinum, the central cavity in the chest between the lungs and surrounding the heart and central blood vessels, usually formed by gas escaping from the lungs as a result of lung rupture.Gas bubbles escaping from a ruptured lung can travel along the outside of bronchioles and blood vessels until they reach the mediastinal cavity round the heart, major blood vessels, oesophagus and trachea. Gas trapped in the mediastinum expands as the diver continues to rise. The pressure of the trapped gas may cause intense pain inside the rib cage and in the shoulders, and the gas may compress the respiratory passageways, making breathing difficult, and collapse blood vessels. Symptoms range from pain under the sternum, shock, shallow breathing, unconsciousness, respiratory failure, and associated cyanosis. The gas will usually be absorbed by the body over time, and when the symptoms are mild, no treatment may be necessary. Otherwise it may be vented through a hypodermic needle inserted into the mediastinum. Recompression is not usually indicated. Diagnosis
Diagnosis of barotrauma generally involves a history of exposure to a source of pressure which could cause the injury suggested by the symptoms. This can vary from the immediately obvious if exposed to explosive blast, or mask squeeze, to rather complex discrimination between possibilities of inner ear decompression sickness and inner ear barotrauma, which may have nearly identical symptoms but different causative mechanism and mutually incompatible treatments.
Mitotane, sold under the brand name Lysodren, is a steroidogenesis inhibitor and cytostatic antineoplastic medication which is used in the treatment of adrenocortical carcinoma and Cushings syndrome. It is a derivative of the early insecticide DDT and an isomer of p,p-DDD (4,4-dichlorodiphenyldichloroethane) and is also known as 2,4-(dichlorodiphenyl)-2,2-dichloroethane (o,p-DDD). Medical uses
Mitotane has been produced by Bristol Myers Squibb but it is marketed as an orphan drug for adrenocortical carcinoma due to the small number of patients in need of it. Its main use is in those patients who have persistent disease despite surgical resection, those who are not surgical candidates, or those who have metastatic disease. In a 2007 retrospective study of 177 patients from 1985 to 2005 showed a significant increase in the recurrence-free interval after radical surgery followed by mitotane when compared to surgery alone. The drug is also sometimes used in the treatment of Cushings syndrome. Side effects
The use of mitotane is unfortunately limited by side effects, which, as reported by Schteinberg et al., include anorexia and nausea (88%), diarrhea (38%), vomiting  (23%), decreased memory and ability to concentrate (50%), rash (23%), gynecomastia (50%), arthralgia (19%), and leukopenia (7%). Pharmacology
Pharmacodynamics
Mitotane is an inhibitor of the adrenal cortex. It acts as an inhibitor of cholesterol side-chain cleavage enzyme (P450scc, CYP11A1), and also of 11β-hydroxylase (CYP11B1), 18-hydroxylase (aldosterone synthase, CYP11B2), and 3β-hydroxysteroid dehydrogenase (3β-HSD) to a lesser extent.