Infection and Sepsis

Question 1

Classifications of surgical wounds and risks of SSI

Answer 1

Clean, <5%
Clean contaminated, 5-10%
Contaminated 15-25%
Dirty 25-40%

Question 2

Definition of clean surgical wound procedure. Give example

Answer 2

-no inflammation encountered during procedure
-no break in sterile technique
-respiratory/ailmentary/ genitourinary system no entered
Ex. inguinal hernia repair

Question 3

Definition of clean contaminated surgical wound. Give example.

Answer 3

• incision which respiratory/ alimentary / genitourinary tract entered
• BUT no contamination encountered
  ex. cholecystectomy

Question 4

Definition of contaminated surgical wound. Give example.

Answer 4

-Major break in sterile technique OR
-Gross spillage in GI tract OR
-Incision in acute, non-purulent inflammation encountered OR
-open traumatic wounds more than 12-24 hours old
Ex. appendiectomy

Question 5

Definition of dirty surgical wound. Give example.

Answer 5

-perforated viscera OR
-acute inflammation with pus OR
Traumatic wounds with delayed treatment: gross contamination or revitalised tissue

Question 6

Preoperative prevention of SSI

Answer 6

Showering (night prior to OT)
Hair removal
Patient and staff appropriate non-sterile wear
Antibiotic prophylaxis (within 1 hour of incision)

Question 7

Intraoperative prevention of SSI

Answer 7

Hand decontamination
Incision drapes/ Sterile gown/ Gloves
Antiseptic skin preparation immediately before skin incision
Antibiotics (repeat dose if OT longer than half life of antibiotic, usu >4 hours or blood loss > 1500ml)
Wound dressing

Question 8

SSC: Hour 1 bundle

Answer 8

1) Measure lactate
2) Obtain blood culture before administering antibiotics
3) Broad spectrum antibiotics
4) Rapid administration of 30ml/kg crystalloid of for hypotension or lactate > 40mmol/L
5) Vasopressors if hypotensive (target MAP > 65mmHg)
* remeasure lactate if initial lactate > 2 mmol

Question 9

SSC: Definition of sepsis

Answer 9

Life-threatening organ dysfunction caused by dysregulated host response to infection

Question 10

SSC: Definition of septic shock

Answer 10

Subset of sepsis with circulatory and cellular/metabolic dysfunction associated with high risk of mortality

Question 11

Definition of SIRS

Answer 11

Dysregulated inflammatory response to a non-infectious insult
ex. surgery/ trauma/ pancreatitis/ ischemia/ burns

Question 12

Definition of sepsis

Answer 12

SIRS +

Presence of suspected/proven infection

Question 13

Criteria for SIRS

Answer 13

Any two of the following criteria:
Temp < 36 or > 38.3C
HR >90 bpm
RR >20 or pCO3 < 4.3 kPa
WCC <4 or >12 or >10% immature neutrophils

Question 14

Definition of severe sepsis

Answer 14

Sepsis with evidence of organ dysfunction or tissue hypoperfusion

Question 15

Signs of severe sepsis

Answer 15

Peripheral vasoconstriction
Oliguria
Metabolic acidosis
Change in mental state

Question 16

Definition of septic shock

Answer 16

Sepsis induced hypotension which persists despite adequate fluid resuscitation

Question 17

Definition of MODS (multi-organ dysfunction syndrome)

Answer 17

Failure of 2 or more organs which are unable to maintain homeostasis without intervention

Question 18

Pathogenesis of SIRS

Answer 18

Initiation of inflammatory cascade:
-if infection, by endotoxin/exotoxin
-if non-infection. by local pro-inflammatory cytokines (IL 1,6,8, TNF-alpha)
overwhelming response to inflammatory cascade with dysregulation, excessive cytokines enter systemic circulation leading to SIRS

Question 19

Components of guidelines for Surviving Sepsis Campaign 2016-2018

Answer 19

• Hour 1 bundle
• Initial resuscitation
• Diagnosis
• Antibiotics Therapy
• Source Control
• Fluid therapy
• Vasopressors
• Blood Products
• Mechanical Ventilation for sepsis induced ALI/ARDS
• Glucose Control
• DVT prophylaxis
• Stress Ulcer Prophylaxis

Question 20

Hour 1 sepsis bundle

Answer 20

1) Measure lactate
2) Obtain blood cultures
3) Administer broad spectrum antibiotics
4) rapid administration of 30 ml/kg crystalloid for hypotension or lactate >4 mmol
5) Apply vasopressors to maintain MAP >65mmHg