What is SIRS
Systemic Inflammatory Response Syndrome
What is a shock
It is a state in which there is diminished cardiac output or reduced circulating blood volume impairs tissue perfusion, leading to cellular hypoxia
What is septic shock
It is a sub category of shock, it is caused by infectious organism, by their by products, by the inflammatory cytokines that are released in response to the presence of microbes. This induces SIRS in the body, which if not inhibited can lead to death of the patient. Important note: The organism doesnt have to be in the blood stream
What is the golden hour
Time by which hypoxia has to be reversed to avoid irreversible injury. For brain, it is about 4 minutes
Describe the different kinds of shock
1. Cardiogenic shock: failure of the left ventricle of the heart 2. Hypovolemic shock: there is not enough blood volume 3. Septic shock: caused by microbe or its by product
What are the clinical staging of a shock
1. Non-progressive phase: Hypoxia is induced and there are compensatory mechanisms to temporarily deal with hypoxia such as anaerobic metabolism pathways. 2. Progressive phase: There is accumulation of lactic acid due to persistent hypoxia 3. Irreversible phase or stagnant phase
Explain the clinical staging of shock in detail
Normal circulation 1. AV shunts are controlled 2. Good tissue perfusion 3. Sphincters are controlled 4. Minimal hypoxia and drop of pH across capillary beds
What happens next?
Reversible or non progressive phase: 1. Peripheral vasoconstriction due to epinephrine and increase in activity of PS in ANS 2. Hemodilution: interstitial fluid in vascular spaces 3. Drop in pH across capillary bed 4. AV shunts open to redirect more blood to the heart and brain, renal output declines
What happens in the next phase
1. The decrease in blood pressure and cardiac output continues
2. Lactic acidosis results
3. Decreased capillary bed perfusion causes the endothelial cells to die
4. Once the endothelial cells die, sludging and clothing begins.
The patient can still be saved but we are towards the end of the golden hour
What is one way to diagnose whether the patient died in shock
In the autopsy we can see corticomedullary shunting in the kidneys
What happens in the next phase
1. Arterioles give up - there is vasodilation
2. This causes a dramatic increase in hydrostatic pressure in the capillary bed, causing edema
3. Severe lactic acidosis that is not reversible
4. Decreased function of vital organs and death
What is DIC
Diseminated Intravascular Coagulation, cloths forms in the vessels, may block blood flow into the organs
What bacterium most commonly release LPS which is detected by the body as a biomarker for bacterial infection
Gram negative bacterium
Some facts about septic shock
Most common cause of deaths in tertiary hospitals, mortality is about 20%, can be caused by bacteria, fungi or viruses such as Ebola virus
How do endothelial cells repsond when the body is in a state of shock
They are induced such that they increase the tendency of the blood to cloth which results in DIC
SIRS is caused by massive release of cytokines in the blood, what Fishback calls a cytokine storm. Mortality is high and its treatment with monoclonal antibodies has been ineffective.
Important to note that infectious organisms from the blood are isolated only 20% of the time, which implies that the microbes are not present in the blood but they have resided at some other place in the body
It is a condition where platelets and clothing factors are consumed extensively in massive intravascular coagulation events that happen intravascularly. This leads to uncontrolled hemorrhage in other areas of the body. This causes uncontrolled bleeding in other parts of the body.
What are some of the other names of DIC
Consumption coagulopathy and microangiopathic hemolytic anemia
How do you fix DIC
Once temperory way to treat DIC is to give platelets and clothing factors to the patient to stop the bleeding. However clothing factors and platelets will be consumed quickly and so this is not the permanent solution. DIC can only be solved by solving the underlying problem, if it is an infection then the patient has to be administered antibodies to kill the microbe, if it is due to a pregnency complication then a C section would have to be done
Why does amniotic fluid causes clothing
Amniotic fluid has thromboplastin in it which causes widespread clothing
What is the pathophysiology of DIC
It is marked by intrinsic or extrinsic activation of cascade of events that causes massice intravascular clothing. It can also be caused by different factors that cause damage to the epithelium or both of these events can happen at the same time
Arrows point to the fibrin meshwork that has formed due to DIC, which can be seen as consistent pink patches
PTH stains fibrin black
Schistocytes or helmet cells which are fragmented RBCs, diagnostic of DIC
What is Waterhouse Friderichson Syndrome
When a patient goes into a shock, the adrenal glands infarct. The adrenal glands die as a result so there is nothing in the body producing cortisol and epinephrine. Patients experiencing this condition develops low blood pressure and do not respond when IV fluids are administered so they also have to be given drugs that would performs the function of cortisol and epinephrine so they respond to IV fluids.
Waterhouse Frederichson Syndrome
Alveolar cells starts to die due to hypoxia, which are replaced by hyaline layer, air cannot pass through hyaline which leads to further complications.
Arrows point to dark pink spots which are hyaline deposits.
Nutmeg liver or shock liver.
Congestion of rbcs around the central veins.
Steps to treat DIC
1. IV fluids, saline solution or anything will work
2. Pressors such as dopamine to increase blood pressure
3. Antibiotics if bacterial sepsis is suspected
4. Corticosteroids if Waterhouse Frederichson Syndrome is suspected
5. Ventillary support to provide oxygen and prevent hypoxia
6. Other therapy such as providing them with platelet factors
There is only 1 way to treat shock or DIC which is to fix the underlying cause