Prognosis
Death could occur from untreated OSA due to lack of oxygen to the body.There is increasing evidence that sleep apnea may lead to liver function impairment, particularly fatty liver diseases (see steatosis).It has been revealed that people with OSA show tissue loss in brain regions that help store memory, thus linking OSA with memory loss. Using magnetic resonance imaging (MRI), the scientists discovered that people with sleep apnea have mammillary bodies that are about 20% smaller, particularly on the left side. One of the key investigators hypothesized that repeated drops in oxygen lead to the brain injury.The immediate effects of central sleep apnea on the body depend on how long the failure to breathe endures. At worst, central sleep apnea may cause sudden death. Short of death, drops in blood oxygen may trigger seizures, even in the absence of epilepsy. In people with epilepsy, the hypoxia caused by apnea may trigger seizures that had previously been well controlled by medications. In other words, a seizure disorder may become unstable in the presence of sleep apnea. In adults with coronary artery disease, a severe drop in blood oxygen level can cause angina, arrhythmias, or heart attacks (myocardial infarction). Longstanding recurrent episodes of apnea, over months and years, may cause an increase in carbon dioxide levels that can change the pH of the blood enough to cause a respiratory acidosis. Epidemiology
The Wisconsin Sleep Cohort Study estimated in 1993 that roughly one in every 15 Americans was affected by at least moderate sleep apnea.
Pneumonic plague is a severe lung infection caused by the bacterium Yersinia pestis. Symptoms include fever, headache, shortness of breath, chest pain, and coughing. They typically start about three to seven days after exposure. It is one of three forms of plague, the other two being septicemic plague and bubonic plague.The pneumonic form may occur following an initial bubonic or septicemic plague infection. It may also result from breathing in airborne droplets from another person or animal infected with pneumonic plague. The difference between the forms of plague is the location of infection; in pneumonic plague the infection is in the lungs, in bubonic plague the lymph nodes, and in septicemic plague within the blood. Diagnosis is by testing the blood, sputum, or fluid from a lymph node.While vaccines are being developed, in most countries they are not yet commercially available. Prevention is by avoiding contact with infected rodents, people, or cats. It is recommended that those infected be isolated from others. Treatment of pneumonic plague is with antibiotics.Plague is present among rodents in Africa, the Americas, and Asia. Pneumonic plague is more serious and less common than bubonic plague. The total reported number of cases of all types of plague in 2013 was 783. Left untreated, pneumonic plague is nearly always fatal. Some hypothesize that the pneumonic version of the plague was mainly responsible for the Black Death that resulted in approximately 75 - 200 million deaths in the 1300s.