sepsis and multiorgan dysfunction syndrome Flashcards
definition of sepsis
life threatening organ dysfunction caused by dysregulated host response to an infection
definition of septic shock
subset of sepsis
co-existence of persistent hypotension requiring vasopressors to maintain MAP >65mmHg nad serum lactate >2mmol/L
indicates profound circulatory, cellular, and metabolic deterioration
associated with a greater risk of mortality than with sepsis alone
pathophysiology of sepsis
it is a hyperinflammatory systemic reaction
- local activation of inflammatory mediators (complement, mast cells, macrophages) = vasodilation and release of pro-inflammatory cytokines (TNF-a, IL1)
- generalised endoltelial disruption -> capillary leak -> generalised oedema (because shift of intravacular fluid and albumin into surrounding tissue)
- intravascular hypovolaemia -> excessive triggering of the extrinsic coagulation cascade -> DIC and microvascular thrombosis
- decreased oxygen utilisation adn tissue ischemia -> widespread cellular injury -> multiorgan dysfuntcion
RF for sepsis
- immunocompromise
- indwelling lines or catheters
- recent surgery or invasive procedures
- haemodialysis
- dm
- IV drug
- alcohol dependancy
- pregnancy
- breached skin integrity
causative organisms for sepsis
staph auyreus
pseudomonas species
e coli
fungal
epidemiology of sepsis
more in men
>65yrs
In 2017/18, 186,000 hospital admissions in the UK were for people with a primary diagnosis of sepsis
sx and signs of sepsis
- signs associated with specific infection eg cough
- high early warning score eg NEWS 5 or more
- tachypnoea
- high or low temp - sometimes with rigors
- tachycardia
- altered mental status
- low ox sats
- hypotension
- oliguria
- poor cap refill, mottling of the skin, ashen appearance, cyanosis
Ix for sepsis
- blood cultures
- serum lactate
- hourly UO - low - marker of AKI or intravascular volume depletion - therefore sepsis severity
- FBC - thrombocytopenia and lymphocytopenia
- UE - inc creatinine
- serum glucose
- CRP - elevated
- serum procalcitonin - elevated
- clotting screen
- LFT
- blood gas - PaCO₂ <4.3 kPa (32 mmHg) or can by hypoxaemia, hypercapnia
- ECG - ischemia, AF, or arrhythmia
LFTs in sepsis
high
- BR
- ALT
- AAT
- ALP
- and GGT
show organ dysfunction
clotting screen in sepsis
elevated PT; elevated PTT; elevated D-dimer; elevated fibrinogen
established coagulopathy with sepsis - associated with a worse prognosis
UE in sepsis
look for renal dysfunction
Patients with acute kidney injury due to sepsis have a worse prognosis than those with non-septic acute kidney injury
serum electrolytes frequently deranged;
blood urea - elevated;
creatinine - elevated
lactate in sepsis
high
marker of stress
marker of worse Px - as a reflection of the degree of stress
highlights possibility of tissue hypoperfusion
blood cultures in sepsis
take before AB - but dont delay AB for them
may be +ve for infection causing organism
definition of multiorgan dysfunction syndrome
a clinical syndrome of progressive failure of 2 or more organ systems in a critically ill patient
progressive and potentially reversible
aetiology of multiorgan system failure
inflammatory response in sepsis -> widespread tissue injury
there is apoptosis of immune, epithelial and endothelial cells and a shift to an anti-inflammatory phenotype
impaired organ perfusion because of hypotension, low CO, circulatory microthrombi, disordered microcirculation and tissue oedema
also from multiple trauma or burns
