Sepsis Flashcards
Definition of sepsis
-life-threatening organ dysfunction caused by dysregulated host response to infection
Definition of septic shock
-can be identified with a clinical construct of sepsis with persisting hypotension requiring vasopressors to maintain MAP >65mmHg and having a serum lactate of >2mmol/l despite adequate volume resuscitation
qSOFA
Prognostic indicator -hypotension systolic BP <100mmHg -altered mental status -tachypnoea RR >22/min Score of 2 or more criteria suggests a greater risk of poor outcome
Pathophysiology of sepsis
- Uncontrolled inflammatory response
- Patients with sepsis have features consistent with immunosuppression:
- Loss of delayed hypersensitivity
- Inability to clear infection
- Predisposition to nosocomial infection
Three phases in the pathogenesis of sepsis
Three phases in the pathogenesis of sepsis
1 -release of bacterial toxins
2 -release of mediators
3 -effects of specific excessive mediators
Release of bacterial toxins
- Bacterial invasion into body tissues is a source of dangerous toxins
- May or may not be neutralised and cleared by existing immune system
Mediator role in sepsis (Th1 vs Th2)
- Two types of mediators can be released
- Pro-inflammatory mediators – causes inflammatory response that characterises sepsis
- Compensatory anti-inflammatory reaction – can cause immunoparalysis
Effects of excessive pro-inflammatory mediators
- Promote endothelial cell – leukocyte adhesion
- Release of arachidonic acid metabolites
- Complement activation
- Vasodilatation of blood vessels by NO
- Increase coagulation by release of tissue factors and membrane coagulants
- Cause hyperthermia
Effects of excessive anti-inflammatory mediators
- Inhibit TNF alpha
- Augment acute phase reaction
- Inhibit activation of coagulation system
- Provide negative feedback mechanisms to pro-inflammatory mediators
General feature of Sepsis
- Fever >38oC – presenting as chills, rigors, flushes, cold sweats, night sweats, etc
- Hypothermia <36oC – especially in the elderly and very young children (remember the immunosuppressed)
- Tachycardia >90 beats/min
- Tachypnoea >20 /min
- Altered mental status – especially in the elderly
- Hyperglycaemia >8mmol/l in the absence of diabetes
Nervous system features of sepsis
- Altered consciousness
- Confusion
- Psychosis
Respiratory system features of sepsis
- Tachypnoea
- PaO2: <70mmHg
- Sats: <90%
Hepatic features of sepsis
- Jaundice
- ↑ Liver enzyment
- ↓ Albumin
- ↑ PT
Cardiac features of sepsis
- Arterial hypotension (systolic <90mmHg or MAP <70mmHg)
- tachycardia
- SvO2 >70%
Blood features of sepsis
↓ Platelets
↓ Protein C
↑ PT/APTT
↑ D-dimer
Renal features of sepsis
- Oliguria (<0.5ml/kg/h)
- Anuria
- ↑ Creatinine
Inflammatory variables in sepsis
- Leucocytosis (WCC > 12,000/ml)
- Leucopenia (WCC < 4,000/ml)
- Normal WCC with greater than 10% immature forms
- High CRP
- High procalcitonin
Tissue perfusion variables in sepsis
- High lactate
- Skin mottling and reduced capillary perfusion
Sepsis 6
Take 3: Give 3
- Blood cultures
- Blood lactate
- Measure urine output
- Oxygen aim sats 94-98%
- IV Antibiotics
- IV fluid challenge (30ml/kg)
When to consider HDU referral for sepsis
- Low BP responsive to fluids
- Lactate >2 despite fluid resuscitation
- Elevated creatinine
- Oliguria
- Liver dysfunction, Bil, PT, Plt
- Bilateral infiltrates, hypoxaemia
When to consider ITU referral for sepsis
- Septic shock
- Multi-organ failure
- Requires sedation, intubation and ventilation
