Sepsis Flashcards
5 examples of relevance… GO
1- Estimated to affect more the 30 million people worldwide 🌎 each year.
2- Every 4 hours someone in the UK dies of sepsis
3- 1 in 10 deaths associated with pregnancy and childbirth is due to sepsis.
4- 11 million people a year will die from sepsis.
5- 1 in 4 NHS trusts is failing to give antibiotics to half of their patients with sepsis within the recommended time.
Who is at risk form developing sepsis?
Anyone affected by an infection can progress to sepsis conditions but some vulnerable groups are at a higher risk. These include:
- Elderly 🧓
- Pregnant women
- Neonates
- Hospitalised patients
- People with HIV/ aids, liver cirrhosis, cancer, kidney disease and autoimmune diseases
What are the 4 causes of sepsis. Identify the main cause.
- Bacteria 🦠- causes 60% of all cases
- Viruses
- Parasites
- Fungi
4 fats about bacteria….GO
1- Single called organisms
2- Can exist in environments with or without O2
3- Can absorb nutrients from the host
4- Can replicate themselves with binary fission- requiring protein synthesis
What is Binary Fission?
Division from a single entity into 2 or more
Explain the 4 step process of binary fission…. GO
1- DNA 🧬 replication
2- Cell wall and membrane will invaginate (fold in on itself)
3- Invagination complete
4- Cells separate
What is a gram positive bacteria?
- A gram positive bacteria has a thick cell wall
- During a gram stain test it will be stained purple by the dye.
What is gram negative bacteria?
- A gram negative bacteria has a thin cell wall.
- During the gram stain test it will not be stained by the dye.
What are endotoxins?
- These are structural components of the bacterial cell wall.
- They are freed from the outer membrane of the bacteria when they are destroyed by the immune system
Endotoxins stimulate the release if 10 things.
Can you name five of them….GO
1- Tumour necrosis factor 2- Activation of the coagulation system 3- Prostaglandin, thromboxane, leukotrienes and prostacyclin release 4- Beta- endorphins 5- Bradykinin 6- Oxygen- derived free radicals 7- Platelet activating factor 8- Anaphylatoxins (C5a and C3a) 9- Myocardial depressant factor 10- Interleukin 1 and 2
What is an Exotoxin?
- These are products of microorganisms that are harmful to the host.
- Some bacteria 1 specific toxin to cause disease
- for example Tetanus, Diphtheria and streptococcus
- Another group of bacteria harms the host through actions of both endo and exo toxins.
What is the difference between endotoxins and exotoxins?
Endotoxins..
Are the lipid portion if the lipopolysaccharides (LPSs) that are part of the outer membrane of the cell wall of gram negative bacteria.
The endotoxins are freed when the bacteria die and the cell wall breaks apart.
Exotoxins
Are proteins inside the pathogenic bacteria, most commonly found in gram positive bacteria.
They are secreted/ released into the the surrounding medium following lysis.
Both substances (endotoxin and exotoxin) stimulate the inflammatory cascade
The endotoxins and exotoxins cause human mediators to be released, what does this cause in the case of sepsis?
- The human mediators released cause widespread vasodilation and increase the permeability of tissues.
- These physical changes are caused by endo and exotoxins
- Inflammation is a normal response but in sepsis and exaggerated, excessive inflammatory response is produced throughout the body.
What is a histamine?
- These are found in mast and basophils cells.
- Histamines are a profound vasodilator and they increase cellular permeability.
What are kinins ?
- These are rapidly generated in blood 🩸 plasma after a tissue injury, leading to vasodilation, increased vascular permeability and cell migration.
What are prostaglandins?
- A potent hormone like substance found in most tissues- influences vascular tone, platelet aggregation and inflammatory response
How does sepsis develop?
- Bacteria can gain entry to the host ie via an open wound.
- Bacterial endotoxin binds to the CD14 macrophage receptor.
- This stimulates white blood cells to release tumour necrosis factor
- This stimulates other white blood cells to release other cytokines
- Stimulates a massive inflammatory response
What is the clinical effect of Tumour necrosis factor (TNF)
- Activates the inflammatory cascade Causes - Fever 🥵 - Hypotension (low BP) - Tachycardia (fast heart rate) - tachypnoea (fast resp rate) - Hyperglycaemia (Hugh glucose) - Metabolic acidosis
What is the clinical effect of interleukin 1?
- Fever
- Increased white blood cell count
- Increase in amino acids produced by muscles
- Decreased systematic vascular resistance
What is the clinical effect of interleukin 6?
- Fever
- Antibody secretion
- Neutrophil production
What is the clinical effect of interleukin 8?
- Stimulates neutrophil functions
- Attracts inflammatory cells to the site of infection/ injury
What are the classic symptoms of Sepsis?
- Temp higher the 38 or lower then 36
- White blood cell count higher the 12000 mml or lower then 4000mml
- Hypoxaemia - ( low O2)
- Lactate higher then 4
- Decreased urine operation
- Hyperglycaemia(high blood sugar)
The SEPSIS acronym helps diagnose sepsis.
Explain the acronym.
S= Slurred speech 🎤 E= Extreme muscle pain P= Passing no urine S= Severe breathlessness I= I feel I might die S= Skin mottled or discoloured
Please explain the physiology of Pyrexia (high temp)
- Infection causes damaged cells
- Damaged cells release pyrogens
- Example of these pyrogens are Interleukin 1 and tumour necrosis factor (TNF)
- Interleukin 1 and TNF act directly on the hypothalamus
- They change the set point of the hypothalamus
- The nervous system perceives the the person top be colder then normal.
- Causing shivering
- Temperature 🤒 increases
- High temperature 🤒 is a classic symptom of Sepsis
