Sepsis Flashcards
What is SIRS?
Systemic inflammatory response syndrome = a clinical response arising from a non-specific insult
What can sepsis lead to?
Tissue damage, organ failure, death
What are the stages of sepsis?
1) Infection/trauma
2) SIRS
3) Sepsis syndrome
4) Severe sepsis
How do you diagnose SIRS?
1) Temp ≥ 38 or ≤ 36 (some elderly people decrease temp) 2) HR ≥ 90 3) RR ≥ 20 (or PaCO2 < 32 mmHg) 4) WCC ≥ 12,000/mm3 or ≤4,000/mm3 (some elderly people can lose white cells) or >10% immature forms
What is sepsis syndrome?
SIRS with a presumed or confirmed infectious process
What is severe sepsis?
Sepsis with > 1 sign of organ failure/acute organ dysfunction (incl. hypoperfusion and hypotension) caused by sepsis:
1) Cardiovascular (refractory hypotension) - shock
2) Renal
3) Respiratory
4) Hepatic
5) Haematologic
6) CNS
7) Unexplained metabolic acidosis
What is sepsis?
- At least two SIRS criteria cause by known or suspected infection
- Life threatening organ dysfunction caused by abnormal response to infection
What is septic shock?
- Sepsis with persistent or refractory hypotension or tissue hypoperfusion despite adequate fluid resuscitation
- Sepsis where medication is required (vasopressors) to maintain BP
What is the main fungus that causes sepsis (fungaemia)?
Candida
What is the main parasite that causes sepsis (parasitaemia)?
Malaria
What microbial components trigger shock?
1) Endotoxin (LPS) - gram negative
2) Lipoteichoic acid - gram positive
3) Direct - vascular endothelium injury
What are the immune mediators of the shock response?
1) Toll like receptors
2) Complement cascade
3) Coagulation cascade via cytokines IL-1, IL-6, TNF
4) Depletion of protein C
What are superantigens?
Antigens produced by certain Group A strep and staph aureus TSST-1 which bypass the normal antigen response
How does organ failure occur in sepsis?
1) Vasodilation, decreased blood pressure and red cell deformability and thrombosis leads to tissue hypoperfusion
2) This, loss of barrier function due to cell shrinkage and death and mitochondrial dysfunction leads to decreased tissue oxygenation and organ failure
Why do you need to interfere within the 1st hour of presentation of sepsis?
Bc of the vicious cycle of inflammation and coagulation which can quickly lead to death
What are the main gram negative causes of infection-related shock mortality?
1) E.coli (and other coliforms)
2) Meningococci
3) Pseudomonas (device/CF associated chest infection)
4) Haemophilus (flu and pneumonia)
5) Klebsiella
What are the main gram positive causes of infection-related shock mortality?
1) Staph aureus
2) Group A streptococci (S.pyogenes)
3) S. pneumoniae
4) Clostridium
5) Enterococcus
What is the main viral cause of infection-related shock mortality?
Viral haemorrhagic fevers
What are 3 causes of neonatal sepsis?
1) Group B strep
2) Listeria
3) E.coli
What are the most common infections associated with septicaemia and shock (that get into bloodstream)?
1) Severe UTI with pyelonephritis (kidneys to blood)
2) Meningococcal disease
3) Gut perforation
4) Infection of IV lines, catheters and devices
5) Skin and soft tissue infection (SSTIs)
6) Endocarditis (heart valves, direct access to blood)
7) Pneumonia
8) Cholecystitis, cholangitis, pancreatitis e.g. fatal peritonitis from ruptured appendix with purulent exudate in right colic gutter
How would you diagnose sepsis using investigations?
1) Clinical according to sepsis criteria
2) Determine the site of origin/specific cause
3) Blood cultures (incl. through catheters) - collect before abx which need to be given in first hour
4) Cultures of urine, IV lines, pus etc
5) Blood tests incl. WCC, CRP, LFTs etc
What are the differential diagnoses in septic shock?
1) Burns, trauma, pancreatitis
2) PE, ruptured AAA, haemorrhage
3) MI, cardiac tamponade, drug overdose
4) Adrenal insufficiency
5) Anaphylaxis
How would you manage sepsis?
1) Fluids, dopamine, transfusion (ICU)
2) Resolution of precipitating problems
3) Monitor blood gases, renal function, CNS, GCS< LFTs, myocardial function
4) Antimicrobials
What are negative outcomes of sepsis?
1) Mortality 30-60%
2) Multi-organ failure
3) Loss of extremities
4) Prolonged hospital stay and costs