Septic shock causes approximately 215,000 deaths every year in America, according to Joseph Parrillo, M.D., writing in the New England Journal of Medicine. This is approximately the same number of people who die every year from an acute myocardial infarction, or heart attack. People in septic shock have low blood pressure, so their organs are not receiving enough blood. This can cause several organs to fail, especially the kidneys, lungs and liver.
Systemwide Clinical Characteristics
The most common cause of septic shock is bacteria. However, viruses, fungi and protozoans can also cause this disorder, according to Jonathan Jui, M.D., in "Tintinalli's Emergency Medicine." Septic shock starts as an infection. The organisms will either multiply at the infected site or go into the bloodstream. In either case, they will release toxins, or poisons. The immune system will respond. But all this leads to tachycardia, or fast heartbeat, tachypnea, or fast breathing, an increase or decrease in body temperature, mental confusion, agitation and even coma.
Acute Renal Failure
Acute renal failure means the kidneys are rapidly losing their ability to function. This can take weeks or happen in just a few days. The heart normally pumps five liters of blood every minute. And every minute, one liter of that blood goes to the kidneys. This is the amount of blood they need to properly function. As septic shock develops, people will develop hypotension, or low blood pressure. The kidneys will not get the normal amount of blood. They are harmed and develop what is called ischemic injury. This is an injury due to ischemia, or from not getting the amount of blood that they need. As the kidneys fail, people develop oliguria, or decreased urine production and excretion.
Adult Respiratory Distress Syndrome
The toxins released by bacteria can damage the capillaries throughout the body, especially those in the lungs. The alveoli can also be damaged; this is the part of the lungs where oxygen crosses to enter the capillaries. As explained by Brian Gehlbach, M.D., in "The Merck Manual for Healthcare Professionals," parts of cells, protein and fluid are now able to cross into the alveoli. People in septic shock who have fluid in the alveoli of their lungs will have difficulty breathing. Because some of the alveoli now have fluid instead of air, they will also have hypoxemia, or low levels of oxygen in their bloodstream. Their lungs will feel heavy.
Liver Abnormalities
Dr. Jui explains in "Tintinalli's Emergency Medicine" that toxins released by bacteria, along with the immune response of the body, can cause the red blood cells to break. But parts of the red blood cells are always recycled. One part is changed to a substance called bilirubin. Bilirubin is changed again in the liver so it can be excreted. However, the low blood pressure that people have in septic shock can also harm the liver. The liver will not get the amount of blood that it needs to be able to function as it should. The bilirubin will not be changed in the liver but will accumulate and lead to jaundice, which gives a yellow color to the skin.
References
- The Merck Manual for Healthcare Professionals: Acute Hypoxemic Respiratory Failure (AHRF, ARDS)
- "The New England Journal of Medicine"; Septic Shock --- Vasopressin, Norepinephrine, and Urgency; February 2008
- "Tintinalli's Emergency Medicine: A Comprehensive Study Guide"; Judith Tintinalli, M.D., Gabor Kelen, M.D. et al.; 2004
