Sepsis and Septic Shock Flashcards
Definition of sepsis
Body’s response to infection in presence of SIRS
Definition of severe sepsis
Sepsis plus evidence of organ dysfunction or hypoperfusion
Definition of septic shock
Severe sepsis and intractable hypotension - <90mmHg - causing tissue hypoperfusion
Definition of septicaemia
Signs and symptoms associated with multiplying bacteria in the blood
Definition of bacteraemia
Bacteria in bloodstream - may not be symptomatic or need treatment
Definition of endotoxins and exotoxins
Endotoxins - toxin that remains in the cell wall of bacteria. Heat stable
Exotoxins - toxins actively secreted by bacterium
Definition of colonisation
Presence of micro-organisms in normally sterile organs without host response
Which natural defence barriers can be impaired to pre-dispose someone to sepsis?
Loss of gag reflex (decreased GCS, drugs)
Loss of cough reflex (drugs, pain)
Impaired ciliary function (increased oxygen flow, intubation)
Impaired gut mucosal barrier (ischaemia, antibiotics)
Which immune system defences can be impaired to pre-dispose someone to sepsis?
Cell-mediated immunity, humoral immunity and the reticuloendothelial system.
These can be impaired by shock, trauma, sepsis, post-op, malnutrition, age, malignancy, splenectomy and immunosuppressive drugs
What is the physiological response to septic shock.
Increased cardiac output - due to tachycardia despite suppression of cardiac contractility Decreased systemic resistance - due to vasodilation Maldistribution of blood flow Increased vascular permeability
Clinical features of septic shock
Pyrexia Tachycardia Peripherally warm and flushed Hypotension Decreased CVP Lactic acidosis
What are the haemodynamic goals for fluid resuscitation in septic shock?
CVP 8-12mmHg
MAP >/= 65mmHg
Urine output >/= 0.5ml/kg/hr
Culture guidelines in sepsis
Culture prior to antibiotic administration, as long as this doesn’t delay antibiotics
3x separate blood cultures taken in total
Culture other sites as needed e.g. sputum and urine
Antibiotic guidelines in sepsis
Broad spectrum in 1st hour - based on presumed source of infection and local guidelines
Narrow as per culture results
Stop if source is non-infectious e.g. pancreatitis
Complications of sepsis
Metabolic acidosis DIC Multi-organ failure Stress ulcer Pulmonary hypertension Hypercatabolic state Hyperglycaemia Mortality in septic shock - 50%
Definition of cardiovascular failure
HR <45bpm or symptomatic bradycardia
MAP <49mmHg or >70mmHg requiring inotropic support
VT or VF
Serum pH <7.24 with normal pCO2
Definition of respiratory failure
Respiratory rate <5 or >49 breaths per minute
Alveolar-arterial gradient >46.55
Ventilator dependent on day 4 on ITU
paCO2 >6.65kPa
Definition of renal failure
Urine output <479ml/24 hours or <159ml/8 hours
Urea >36mmol/l
Creatinine >310micromol/l
Haemofiltration dependence
Definition of haematological failure
WCC <1/mm3
Platelets <20x10*9/l
Haematocrit <0.2%
DIC
Definition of neurological failure
GCS <6 in absence of sedation
Definition of gastrointestinal failure
Ileus >3 days
Diarrhoea >4 days
GI bleeding
Inability to tolerate enteral feed in the absence of a primary gut pathology
Definition of skin failure
Decubitus ulcers
Definition of endocrine failure
Hypoaldosterinism
Abnormal LFTs
Definition of multiple organ failure
More than one organ has deranged function and needs support
Mortality in multiple organ failure
2 organ failure - day 1 - 50% - day 4 - 66% 3 organ failure - day 1 - 80% - day 4 - 96%
Treatment and prevention of multiple organ failure
Quick treatment of initial insult
Organ specific support
Early nutritional support - preferable parenteral
