Sepsis. It’s a dirty sounding word, isn’t it? Like a septic tank. Or a sewer. A stew of germs in an old pot. Well, the word sepsis is a common one in hospitals, and it is among the most common reasons an Infectious Diseases specialist is consulted to see a patient. In this post, through the demonstration of a case, you will find out what exactly sepsis is, the specific reasons why the body goes haywire during sepsis, and the reason someone with sepsis can continue to be very ill and sometimes die, even when we are appropriately treating the culprit germ.
Imagine this…one day, you are preparing your children for school, 2 days later you are in the intensive care unit (ICU) fighting for your life. It turns out you had a kidney stone. The stone started to move down from the kidney. However, on it’s way through the ureter (the tube connecting the kidney to the urinary bladder), it got stuck. The kidney was still working and continued to produce urine. However the urine could not pass through to the bladder, therefore it started backing up into the kidney. The stagnant urine, full of waste products to be eliminated from the body via the urinary bladder, now becomes a breading ground for bacteria. As the amount of stagnant urine increases, it starts to stretch the ureter and kidney, causing them to become distended and inflamed. The inflamed tissues become porous (or leaky) and the brewing bacteria in the stagnant urine invades these tissues and escapes through the blood vessel walls and into the blood stream.
This is when things start to turn ugly. The blood, which is normally sterile, is now infected with bacteria. The immune system is activated to immediately deal with this threat. The heart rate goes up to increase blood flow to the source of the infection in order to try to flush away the bacteria. The body temperature rises (fever) in an attempt to inhibit growth of the bacteria. Additionally, high body temperature also results in increased blood flow to inflamed areas. The activated immune system causes a rapid increase in the number of cells responsible for fighting infection. These cells attempt to literally eat up the bacteria. In the process of destroying the bacteria, waste products are produced along with chemicals such as cytokines. The entire response just described is called sepsis.
The cytokines and other chemicals produced during sepsis cause significant inflammation in the body. This inflammation, when severe, results in leakiness of the blood vessels throughout the body. Therefore fluid leaks into the surrounding tissues causing swelling. Swelling is often noticed of the entire body from face to feet. Fluid can also leak into the lungs, causing difficulty breathing. It can leak into the abdominal cavity, causing pressure on the bowels, and difficulty with digestion. If fluid leaks out of the blood vessels faster than it is replaced, the blood pressure drops, causing decreased circulation to vital organs including the brain (resulting in confusion), the heart (giving rise to abnormal function and sometimes even a heart attack), and the kidneys (causing kidney failure, sometimes resulting in the need for dialysis). Septic shock may result. In layman terms, the body shuts down and the patient is in ICU holding onto dear life.
Ultimately, the most important thing to do in a patient with suspected sepsis, is to urgently start a combination of antibiotics to cover the most likely germs causing the infection. Intravenous fluids and medications are needed to maintain a blood pressure level high enough to pump blood through the vital organs. Sometimes patients with severe sepsis need to be put on the ventilator to ensure that adequate levels of oxygen are going through their lungs, reaching the tissues of the body, especially those where the infection is present.
Up to 50% of patients who have severe sepsis with shock (low blood pressure with organs shutting down) end up succumbing to their illness. When death occurs, it is often not from ongoing infection, but from the effects of severe inflammation on the body. For those who survive, recovery does not happen overnight, but rather over a period of weeks to months. This is one of the issues family members of patients with sepsis sometimes have a hard time understanding. They feel, well, if we are definitely treating the bacteria causing the sepsis, why isn’t the patient getting better already?
One day I was trying to explain the reason to a patient’s family, and the ICU nurse with me did it beautifully. She said, “when a person is septic, it’s like their entire body is one big bruise!” Everyone knows what a bruise looks like – an inflamed, swollen, red, tender area on the skin. It usually takes at least a few days to get better. In sepsis, the inflammation is systemic, that is, throughout the entire body. So, as the nurse put it, the entire body is bruised! Whereas on the skin’s surface the swelling can expand outward, within the body, there is not much space for the inflamed tissues to expand so everything gets squeezed. No wonder there is so much soreness and profound weakness with sepsis. If a bruise on the skin takes days or longer to heal, then you can understand why the entire body will take weeks to heal after an episode of severe sepsis.
The patients who do better with sepsis tend to be younger, closer to normal body weight, and have less chronic medical problems. Usually multiple medical disciplines come together to cure a patient from sepsis. After the infection is treated, rehabilitation is often needed for return of coordination and strength. Excellent family support is vital in the recovery process as well, which can be extremely emotional. Some patients with a lot medical problems never get back to their normal self after an episode of severe sepsis. For those who were in relatively good health, I usually tell them that within 3 to 6 months after sepsis resolves, they should expect to be back to their normal, healthy self.