Septic shock - pathophysiology and symptoms | NCLEX-RN | Khan Academy

Summary

Septic shock is a severe medical condition caused by widespread infection and inflammation in the body, leading to low blood pressure and impaired oxygen delivery to tissues. It results from blood vessels dilating and becoming leaky, reducing vascular resistance and causing fluid buildup in tissues, making oxygen hard to deliver. White blood cells fighting the infection cause further damage to blood vessels and can lead to complications like disseminated intravascular coagulation (DIC) and acute respiratory distress syndrome (ARDS). Without treatment, septic shock can damage organs and cause death. Immediate intervention is critical for survival.

Takeaways

• 😀 Septic shock is a severe condition where infection causes widespread inflammation, leading to low blood pressure and decreased oxygen supply to tissues.
• 😀 The word 'septic' comes from the Latin term for 'rotten', referring to the infection causing tissue damage.
• 😀 Shock is characterized by decreased oxygenation of tissues due to infections affecting blood vessels and circulation.
• 😀 White blood cells react to infective material by releasing molecules like nitric oxide, which dilate blood vessels and increase their permeability.
• 😀 Blood vessels dilate and become leaky to allow white blood cells to reach infection sites, but this also causes a drop in blood pressure and reduced tissue perfusion.
• 😀 Low oxygenation of tissues occurs because of fluid buildup in tissues, which impairs oxygen diffusion from red blood cells to cells.
• 😀 Lytic enzymes and reactive oxygen species released by white blood cells not only damage pathogens but also harm blood vessels, leading to widespread damage.
• 😀 Disseminated intravascular coagulation (DIC) occurs when coagulation factors are used up to form clots, leading to both clotting and bleeding in the blood vessels.
• 😀 Acute Respiratory Distress Syndrome (ARDS) can occur due to damage to blood vessels in the lungs, impairing oxygen absorption and leading to respiratory failure.
• 😀 Cardiac output initially increases to compensate for low vascular resistance, but over time, it decreases as the heart becomes damaged by immune molecules.
• 😀 Symptoms of septic shock include fever, chills, sweating, and warm skin initially, but as the condition progresses, the skin becomes cooler, indicating severe shock.

Q & A

What is septic shock?

Septic shock is a serious condition where the body's response to an infection leads to dangerously low blood pressure and inadequate oxygen supply to tissues, potentially causing organ failure.

What does the term 'septic' refer to in septic shock?

The term 'septic' comes from the Latin word meaning 'rotten' and refers to the infection or infective material causing the condition.

What happens to the blood vessels during septic shock?

During septic shock, blood vessels dilate and become leaky due to immune responses, which lowers vascular resistance and leads to decreased blood pressure and reduced oxygen delivery to tissues.

How does an infection lead to septic shock?

Infections introduce pathogens into the bloodstream, where white blood cells release molecules that dilate blood vessels, decrease vascular resistance, and increase blood vessel permeability, all of which contribute to septic shock.

What is disseminated intravascular coagulation (DIC)?

DIC is a condition that occurs in septic shock where blood vessels are damaged and clotting factors are consumed in an attempt to repair the vessels, leading to widespread clotting inside blood vessels while also causing bleeding outside them.

Why does oxygen delivery to tissues become impaired in septic shock?

Oxygen delivery is impaired because fluid leaks into the tissues due to the increased permeability of blood vessels, making it difficult for oxygen to diffuse from the blood to the cells.

What is Acute Respiratory Distress Syndrome (ARDS), and how is it related to septic shock?

ARDS is a condition where damage to blood vessels in the lungs impairs oxygen absorption, making it difficult for the body to take in enough oxygen from the environment, which is common in severe septic shock cases.

How does cardiac output change in septic shock?

Initially, cardiac output increases to compensate for low vascular resistance and help maintain blood pressure. However, over time, immune molecules can damage the heart, reducing cardiac output and further lowering blood pressure.

What are the early symptoms of septic shock?

Early symptoms of septic shock include fever, chills, sweating, and warm skin due to blood vessel dilation in response to infection.

What does cool skin indicate in septic shock patients?

Cool skin in septic shock patients is a sign of progressing shock, where the body's sympathetic nervous system attempts to constrict blood vessels to maintain blood pressure, reducing blood flow to the skin.