This document defines important terms related to sepsis: infection, bacteraemia, systemic inflammatory response syndrome (SIRS), sepsis, severe sepsis, septic shock, and multi-organ dysfunction syndrome (MODS). Sepsis is defined as infection plus systemic manifestations of infection, including general, inflammatory, and hemodynamic variables. Severe sepsis is sepsis plus sepsis-induced organ dysfunction or tissue hypoperfusion. Septic shock is sepsis-induced hypotension persisting despite fluid resuscitation. MODS involves progressive organ dysfunction such that homeostasis cannot be maintained without intervention.

1. Important Definitions in Sepsis
Dr Rosalind O’Reilly

2. Overview
• Origins of definitions
• Infection
• Bacteraemia
• Systemic Inflammatory Response Syndrome
• Sepsis
• Severe Sepsis
• Multi Organ Dysfunction Syndrome

3. Origin of Definitions
• Initially defined in 1991
– Consensus panel convened by ACCP and SSCM
• Reconsidered in 2001 International Sepsis
Definitions Conference
– ACCP, SCCM, ATS, ESICM, SIS
• Reconsidered again 2012
– SSCM and ESICM

4. INFECTION
Invasion
of
normally sterile tissue
by
organisms

5. BACTERAEMIA
presence
of
viable bacteria
in
blood

6. SYSTEMIC INFLAMMATORY
RESPONSE SYNDROME
clinical syndrome
from
dysregulated inflammatory response
to
noninfectious insult

7. SEPSIS
Infection
+
systemic manifestations of infection

8. Systemic Manifestations
• General variables
– Temp >38.3 °C <36 °C
– HR >90 /min
– Tachypnoea
– Altered mental status
– Significant oedema or
positive fluid balance
>20mL/kg over 24hr
– Hyperglycaemia
>7.7mmol/L in absence
of diabetes
• Inflammatory variables
– WCC >12, <4 x109/L
– Normal WCC
>10%immature
– CRP > 2SD
– Procalcitonin >2SD
• Haemodynamic variables
– SBP <90mmHg or decrease
>40mmHg
– MAP <70mmHg

9. Systemic Manifestations
• Organ dysfunction
– Arterial hypoxaemia
(PaO2/FiO2 <40kPa /
300mmHg)
– Acute oliguria (urine
output <0.5mL/kg/hr for at
least 2 hrs despite
adequate fluid
resuscitation)
– Creatinine increase
44.2μmol/L
– Coagulation abnormalities
(INR >1.5 or APTT >60s)
– Ileus (absent bowels
sounds)
– Thrombocytopenia (plt
<100 x103/mm3)
– Hyperbilirubinaemia
• Tissue perfusion variables
– Hyperlactatemia >1mmol/L
– Decreased capillary refill or
mottling

10. SEVERE SEPSIS
Sepsis
+
sepsis-induced organ dysfunction
or
tissue hypoperfusion

11. Tissue hypoperfusion or organ dysfunction
• Sepsis-induced hypotension
• Lactate above upper limits
• Urine output < 0.5mL/kg/hr for more than 2 hrs despite
adequate fluid resuscitation
• Acute lung injury with PaO2/FiO2 < 33kPa (250mmHg) in the
absence of pneumonia as infection or source
• Acute lung injury with PaO2/FiO2 in the presence of
pneumonia as infection source
• Creatinine > 176.8 μmol/L
• Bilirubin >32 μmol/L
• Platelet count <100 x109 /mm3
• Coagulopathy (PT or APTT > 1.5 x control)

12. SEPTIC SHOCK
Sepsis-induced hypotension
persisting
despite adequate fluid resuscitation

13. MULTI ORGAN DYSFUNCTION
SYNDROME
Progressive organ dysfunction
+
homeostasis cannot be maintained
without intervention

14. MODS
• PRIMARY
– well-defined insult
– early organ dysfunction
– directly attributable
• SECONDARY
– organ failure not in
direct response to the
insult
– is a consequence of the
host’s response

15. MODS
• No universally accepted criteria for individual
organ dysfunction in MODS
• Progressive abnormalities of
– PaO2/FiO2 ratio
– Platelet count
– Serum bilirubin
– Serum creatinine
– Glasgow coma score
– Hypotension

16. Questions???