Sepsis Flashcards
What factors should be considered when making a diagnosis of sepsis?
Age Physiological state Pathological state Social factors Relative time
What needs to be established regarding pathological state in sepsis?
Any ongoing past medical history that could impact the diagnosis
Give two examples of ongoing medical history that could impact a diagnosis of sepsis
Diabetes
Cancer
What is the importance of social factors in a diagnosis of sepsis?
If they are in close contact with other people, could impact on potential source and potential for spread
What contributes to a diagnosis of sepsis?
History
Examination
Investigations
What is important when making a diagnosis of sepsis?
The process of diagnosis needs to be condensed into essential information, as a very rapid assessment needs to be made
What features will be seen on examination of a patient with sepsis?
Pale Clammy Very high temperature Increased pulse BP may be normal, or may be raised Raised respiratory rate
How is a clinical assessment made of a patient who looks like they may have sepsis?
Using an early warning score (EWS)
What is a healthy EWS score?
0
What is considered to be a high EWS score?
3+
What is the EWS based on?
Basic observations; RR HR Temp BP Conscious and alert?
Give three examples of clinical features suggesting a source that could be considered when making a diagnosis of sepsis
Pneumonia
UTI
Meningitis
What are the clinical features of sepsis?
Neck stiffness
Non-blanching rash
What are the red flags in sepsis?
High RR
Low BP
Unresponsive
What does a low BP indicate in sepsis?
Heading towards septic shock
What is required if a patient has red flag sepsis?
Urgent action is required; inform senior doctor for review, and send for urgent investigations
What is the sepsis 6 bundle?
Oxygen Blood cultures IV antibiotics Fluid challenge Lactate Measure urine output
What timeline should the sepsis 6 bundle be performed on?
All needs to occur within a one hour timeline
What urgent investigations should be made with sepsis?
Full blood count EDTA bottle for PCR Blood sugar Liver function tests C-reactive protein Coagulation studies Blood gases Other microbiology samples
What should be looked for in the full blood count of a sepsis patient?
Urea and electrolytes
What does the measurement of urea and electrolytes in a sepsis patient determine?
Renal function
What is C-reactive protein?
An acute phase reactant
What other microbiological samples should be taken in sepsis?
CSF
Urine
How can a diagnosis of sepsis be confirmed?
Blood culture
PCR of blood
Lumbar puncture
What must a blood culture investigating sepsis determine?
Antibiotic susceptibility
Why must a blood culture in sepsis determine susceptibility?
Because of antibiotic resistance
When should a lumbar puncture be done?
Only after checking contraindiciations
What investigations can be done subsequent to a lumbar puncture?
Microscopy and culture of cerebrospinal fluid
PCR of CSF
Glucose and protein estimation in biochemistry
Appearance
Gram stain
What should be assessed when looking at the appearance of a lumbar puncture sample?
Turbidity
Colour
How many cells should the CSF normally contain?
Virtually none
What colour should the CSF normally be?
Clear
Why is a gram stain performed following a lumbar puncture?
Most rapid way of determining likely diagnosis
How has the definition of sepsis changed?
Terms SIRs and severe sepsis are no longer used
How has the definition of sepsis not changed?
Process of recognition, and specifics of management not changed
What is sepsis?
Life threatening organ dysfunction due to a dysregulated host response to infection
What organs may be dysfunctioning in sepsis?
Kidney
Heart
Brain
Haemopoetic
What is meant by dysregulation of host response?
Overreaction of host to the insult of infection
What is septic shock?
Persisting hypotension requiring treatment to maintain blood pressure despite fluid resuscitation
What is the prognosis of septic shock?
Imminently fatal unless treated very quickly
What is required in the case of septic shock?
Transfer to ICU
What is bacteraemia?
Presence of bacteria in the blood, with or without clinical features
How severe is bacteraemia?
Can be asymptomatic, or may be very unwell
What does bacteraemia specifically require?
Demonstration
How is bacteraemia demonstrated?
Blood cultures
What is septicaemia?
An outdated clinical term meaning generalised sepsis
What is the pathogen in meningococcal meningitis sepsis?
Bacteria Neisseria meningitidies
What kind of bacteria is meningococcal meningitis?
Gram -ve dipolococcus
What are the main serogroups of Neisseria meningitis?
A
B
C
W-135
What does the serogroup of Neisseria meningitides depend on?
The polysaccharide capsular antigen
What is the purpose of Neisseria meningitides polysaccharide capsular antigen?
Evades immune response by preventing phagocytosis
What does the outer membrane of Neisseria meningitides act as?
An endotoxin
How is meningococcal meningitis spread?
Direct contact with respiratory secretions
What % of young adults may be carriers of meningococcal meningitis?
Up to 25%
What is meant by being a carrier of meningococcal meningitis?
Colonised with no signs or symptoms of infections
What does acquisition of meningococcal meningitis lead to?
Either clearance, carriage, or invasion
What is the problem with young adults being carriers of meningococcal meningitis?
May spread to other people
How can carriers of meningococcal meningitis spread the pathogen to other people?
By aerosols and nasopharyngeal secretions
What can happen in a few people who are infected with meningococcal meningitis?
The infection can be rapidly progressive, invasive, and potentially fatal if not recognised and treated promptly
How many cases of meningococcal meningitis are there per year in England?
~1000
What serogroup are the cases of meningococcal meningitis in England?
Group B
Give an example of where other serogroups of meningococcal meningitis predominate?
Meningitis belt across Africa is the group A strain
What is the fatality rate of meningococcal meningitis?
~10%
What is happening to the fatality rate of meningococcal meningitis?
It is improving over the years
Why is the fatality rate of meningococcal meningitis improving over the years?
Getting better at recognising and managing
How can meningococcal meningitis be prevented?
Vaccination
Antibiotic prophylaxis
What are the vaccines available for meningococcal meningitis?
Meningococcal C conjugate vaccine
ACWY vaccine
Serogroup B vaccine
How effective is the meningococcal C conjugate vaccine?
Very
When was the meningococcal C conjugate vaccine introduced in the UK?
1999
What did the introduction of the meningococcal C conjugate vaccine lead to?
A dramatic drop in cases
Who is the ACWY vaccine for?
Originally for immunocompromised patients and travel protection, especially for middle east, but is now replacing the MenC vaccine
Why is the ACWY vaccine replacing the MenC vaccine?
Due to the increase in W cases in the UK
When was the serogroup B vaccine introduced in the UK?
Sep 2015
Why was a meningitis serogroup B vaccine hard to develop?
It is a very different strain in terms of vaccination, and the B capsule is poorly immunogenic and similar to neural tissue
What is the result of the meningitis serogroup B capsule being similar to neural tissue?
Potential side effects
Why are potential side effects not acceptable in a meningitis vaccine?
As you are giving it to 10,000s of people against a rare disease
How was the serogroup B vaccine developed?
After screening candidate subcapsular antigens from genome studies
How many antigens does the current serogroup B vaccine have?
4
When is the serogroup B vaccines given?
At 2, 4, and 12 months, and adults at increased risk
What has there been massive debate over regarding the serogroup B vaccine?
Millions of pounds versus a small number of cases
What is the result of the serogroup B vaccine introduction?
Beginning to see drop in number of cases
What is meant by meningitis being a notifiable disease?
Person diagnosing, e.g. GP, has to inform local Health Protection Unit of PHE of any cases
What happens once PHE has received notification of a meningitis case?
They decide what, if any, action to take
What action may PHE take on receiving notification of a case of meningitis?
Close contacts are determined, and can be given antibiotic prophylaxis and considered for vaccination
Why would close contacts of someone with meningitis be considered for antibiotic prophylaxis?
Break chain of transmission
How does giving antibiotic prophylaxis to the close contacts of a person with meningitis break the chain of transmission?
Removes strain from carriers
Short term protection for those in close contact
What is the inflammatory cascade intended to do?
Combat infectious stimulus
How does the inflammatory cascade combat an infectious stimulus?
Confine infection to produce a local abscess
What happens when endotoxins bind to macrophages?
They cause local and systemic effects
What are the local effects of endotoxins binding to macrophages?
Cytokines are released
What cytokines are released locally when endotoxins bind to macrophages?
Tissue necrosis factors and interleukins
Give an example of a tissue necrosis factor
TNF-alpha
Give an example of an interleukin
IL-1
What do tissue necrosis factors and interleukins do when released locally?
Stimulates inflammatory response, promoting wound repair and recruits RE system
What are the systemic effects of endotoxins binding to macrophages?
Cytokines are released into the circulation
What is the result of cytokines being released into the circulation?
Stimulates growth factor, macrophages, and platelets
What is the goal of releasing cytokines systemically?
Control of infection
What is the result of the infection not being controlled in sepsis?
Cascades are activated to a degree that there is insult to host
What do cytokines lead to in sepsis?
Activation of humoral cascades and the RE system, leading to circulatory insult
What does circulatory insult include in sepsis?
Disseminated intravascular coagulation and organ injury
What is the problem with disseminated intravascular coagulation in sepsis?
Because clotting is dysregulated, organs can loose their effective blood supply, and start to fail
Why do cytokines cause problems with clotting?
They initiate the production of thrombin and thus promote coagulation
Inhibit fibrinolysis
What happens if cytokines promote coagulation in small vessels?
It impairs circulation
What does the coagulation cascade lead to in sepsis?
Microvascular thrombosis
What does microvascular thrombosis lead to?
Organ ischaemia
Dysfunction
Failure
What is microvascular injury a major cause of?
Shock and multiorgan failure
Progressive necrosis
Why does microvascular injury lead to progressive necrosis?
Circulatory collapse means the supply to non-essential organs, such as hands and feet, is lost
What is sometimes required to preserve life as a result of microvascular injury in sepsis?
All four limbs need to be amputated
What are the specific treatments for sepsis?
Antimicrobials
Surgery
What antimicrobial agent should be used in sepsis?
One likely to be active against the pathogens that cause meningitis in the age group
Must be agent that penetrates into the CSF
Why is it important to consider the age group when looking to treat sepsis?
The causative organism is going to be different in neonates and the elderly
What is the emperic antimicrobial choice in sepsis?
Ceftriaxone
Why may surgery be required for sepsis?
Drainage
Debridement
Why might surgical drainage be required in sepsis?
If large collection of pus
Why might debridement be required in sepsis?
If lots of dead tissue, or if infected limb needs to be amputated
What are the supportive treatments for sepsis?
Symptom relief Physiological restoration Consider early referral to ITU Sepsis six Regular monitoring and reassessment
How can the symptoms of sepsis be relieved?
Pain relief
Blood if anaemia
Prevent clotting
When can life threatening complications of sepsis occur?
Immediately, or over next few hours/days
What are the life threatening complications of sepsis?
Respiratory failure
Acute kidney injury
Raised intracranial pressure
Ischaemic necrosis of digits/hands/feet
Can respiratory failure occur if a sepsis patient is ventilated?
Yes
Why may sepsis lead to acute kidney injury?
Kidney is unable to excrete urea and creatinine
What is the result of AKI in sepsis?
The patient is poisoned
