septic shock
septic shock, severe and potentially life-threatening condition characterized particularly by dangerously low blood pressure, confusion and disorientation, and organ dysfunction. Septic shock is the third and final stage of sepsis—a systemic inflammatory condition that occurs as a complication of infection.
Septic shock occurs most often in newborns, the elderly, and persons who are immunocompromised. Infections that culminate in septic shock can begin anywhere in the body but most often originate in the lungs, the skin, or the urinary, gastrointestinal, or biliary tracts, and they can be caused by various species of microorganisms. Examples include bacteria, such as Escherichia coli, Staphylococcus aureus, and Streptococcus pneumoniae; fungi—including species of Candida, a type of yeast; and viruses. Toxins released by microorganisms induce a strong inflammatory response, which ultimately damages the inner lining of blood vessels (the endothelium), causing the vessels to leak. Blood pressure drops, and heart function declines, resulting in a lack of blood flow that harms vital organs.
Symptoms of septic shock include light-headedness, an altered mental state, heart palpitations, a skin rash, little or no urine output, diarrhea, nausea, vomiting, and cold, clammy, and pale skin. Organ failure may ensue, and gangrene may develop in tissues deprived of oxygen from reduced blood flow. The condition must be treated promptly; once severe lactic acidosis (the buildup of lactic acid in the blood, due to a lack of oxygen) and metabolic acidosis (the buildup of acids in the blood) develop, death is likely. Treatment typically consists of intravenous fluids and the administration of medications that increase blood pressure and blood flow. Inotropic drugs may be used to increase the strength of heart contractions. Other treatments include antibiotics to fight the initial infection, oxygen therapy to increase the amount of oxygen in the bloodstream, the administration of insulin to stabilize blood glucose levels, and surgery to remove tissues that have died from being starved of nutrients and oxygen.
Complete recovery from septic shock may take months or years. Long-term complications, known as post-sepsis syndrome, may include fatigue, insomnia, poor appetite, weakened immune function, anxiety, depression, and nightmares or flashbacks. Older adults and those who had an especially serious case of sepsis may suffer long-term lung injury, neuronal injury, or cognitive impairment.