One of the patents for ddI expired in the United States on August 29, 2006, but other patents extend beyond that time. Sources
Further reading
External links
"Didanosine". Drug Information Portal. U.S. National Library of Medicine.
Due to this, even commercial flying may produce severe cases of barotraumas, although most of the cases are observed in high performance aircraft with lower pressurized cabins. Diagnosis
Most cases occur in scuba divers and fliers, and is easily diagnosed when presented to physicians immediately after exposure. On the other hand, the problem may remain undiagnosed when the history fails to relate the symptoms to exposure to environmental pressure changes or if the focus is on other etiologies. Grades
Weissman defined three grades of sinus barotraumas according to symptomatology. Grade I includes cases with mild transient sinus discomfort without changes visible on X-ray. Grade II is characterized by severe pain for up to 24 h, with some mucosal thickening on X-ray. Patients with grade III have severe pain lasting for more than 24 h and X-ray shows severe mucosal thickening or opacification of the affected sinus; epistaxis or subsequent sinusitis may be observed. Treatment
Mild cases of barotrauma are readily treated by topical decongestants and painkillers. In severe cases or cases resistant to local treatment, functional endoscopic sinus surgery is indicated in order to re-establish drainage and ventilation of the sinuses. This treatment has shown good results in aviators who have recurrent sinus barotrauma. Computer-aided surgery has re-established the drainage of affected sinuses, especially with regard to the sphenoid sinuses. When the sphenoids were entered endoscopically, mucosal petechia and hematoma were clearly seen. History
Sinus barotrauma or aerosinusitis has been known since the early development of aviation medicine.