Despite the use of supportive care, an estimated 33–40% of patients will die or have end-stage renal disease (ESRD) with the first clinical manifestation of aHUS, and 65% of patients will die, require dialysis, or have permanent renal damage within the first year after diagnosis despite plasma exchange or plasma infusion (PE/PI) therapy. Patients who survive the presenting signs and symptoms of aHUS endure a chronic thrombotic and inflammatory state, which puts them at lifelong elevated risk of sudden blood clotting, kidney  failure, other severe complications and premature death.Historically, treatment options for aHUS were limited to plasma exchange or plasma infusion (PE/PI) therapy, which carries significant risks and has not been proven effective in any controlled trials. People with aHUS and ESRD have also had to undergo lifelong dialysis, which has a 5-year survival rate of 34–38%. Pathogenesis
HUS is one of the thrombotic microangiopathies, a category of disorders that includes STEC-HUS, aHUS, and thrombotic thrombocytopenic purpura (TTP). STEC-HUS occurs after ingestion of a strain of bacteria expressing Shiga toxin(s), usually types of E. coli, that expresses verotoxin (also called Shiga-like toxin). E. coli can produce stx1 and/or stx2 Shiga toxins, the latter being more dangerous. A combination of both toxins in certain ratios is usually associated with HUS. These Shiga toxins bind GB3 receptors, globotriaosylceramide, which are present in renal tissue more than any other tissue and are also found in central nervous system neurons and other tissue. Children have more GB3 receptors than adults which may be why children are more susceptible to HUS.
If it is severe enough, the hypoxemia resulting from fluid in the alveoli cannot be corrected just by giving supplemental oxygen; this problem is the cause of a large portion of the fatalities that result from trauma. Diagnosis
To diagnose pulmonary contusion, health professionals use clues from a physical examination, information about the event that caused the injury, and radiography. Laboratory findings may also be used; for example, arterial blood gasses may show insufficient oxygen and excessive carbon dioxide even in someone receiving supplemental oxygen. However, blood gas levels may show no abnormality early in the course of pulmonary contusion. X-ray
Chest X-ray is the most common method used for diagnosis, and may be used to confirm a diagnosis already made using clinical signs. Consolidated areas appear white on an X-ray film. Contusion is not typically restricted by the anatomical boundaries of the lobes or segments of the lung. The X-ray appearance of pulmonary contusion is similar to that of aspiration, and the presence of hemothorax or pneumothorax may obscure the contusion on a radiograph. Signs of contusion that progress after 48 hours post-injury are likely to be actually due to aspiration, pneumonia, or ARDS.Although chest radiography is an important part of the diagnosis, it is often not sensitive enough to detect the condition early after the injury. In a third of cases, pulmonary contusion is not visible on the first chest radiograph performed.