About Sepsis

Sepsis is a serious medical condition caused by a systemic immune response to an infection in the bloodstream, which can be caused by a bacterium, virus, or fungi. If not rapidly treated, the infection can lead to septic shock. Septic shock falls under the category of ‘distributive shock’ as the systemic inflammatory reaction causes widespread vasodilation, eventually leading to a severe drop in blood pressure. This drop prevents proper perfusion and oxygenation of tissues. Intervention must happen quickly and aggressively, as poor or absent perfusion to organ tissues means a lack of oxygenation, nutrient delivery, and removal of waste. Over time, cell damage, organ failure, and ultimately death will follow. 

Sepsis incidences have increased as a result of antibiotic resistance, making it one of the leading causes of death in ICUs across the US. Every year more than a million Americans get sepsis, with 30%-50% of those cases ending in death. People with compromised immune systems or blood disorders are at particular risk of sepsis and have a higher death rate of up to 60%.

How it Affects the Body

A source infection of sepsis may begin anywhere in the body, including the lungs, abdomen (appendicitis), urinary tract, or skin. Bacteria can also enter the bloodstream during invasive medical procedures such as dental work or surgeries. When an infection is discovered in the bloodstream, white blood cells activate and acquire more white blood cells to help fight the infection. As white blood cells accumulate and activate, they release nitrous oxide, which causes vasodilation. Vasodilation decreases vascular resistance, which in turn decreases blood pressure as we know from the equation: 

                                                           Cardiac Output (CO) x Systemic Vascular Resistance (SVR) = Blood pressure (BP)

White blood cells also release enzymes that damage the infectious pathogens. However, in the process, the enzymes damage the blood vessels as well causing them to leak fluid into the tissues, further dropping blood pressure. As this is a systemic infection, blood vessels all over the body dilate, which means almost all tissues in the body are at risk of poor perfusion. As the damage occurs to vessels in the lungs, oxygen is unable to make its way into the bloodstream causing acute respiratory distress syndrome (ARDS). If left untreated long enough, cardiac output decreases as damage to the heart itself occurs. Poor perfusion will inititally present as tachycardia. As the patient decompensated, you will note changes in blood pressure and mental status. Also be on the lookout for skin that is flushed and hot to the touch. Sepsis is a serious condition, and early recognition is key to patient survival.