14.01.07 Sepsis

Six criteria for SIRS (V. low specificity)

• • Temp <36 or >38

    • Hypothermic sepsis has much higher mortality

    • Need neutrophils to raise temp so e.g. Neutropenic sepsis is frequently hypothermic

    • Kids esp. <3 months often go hypothermic

  • RR >20 or pCO2 <4.2

  • HR >90

  • WCC >12 or <4

    • May be normal at presentation - Don't exclude sepsis

    • Severe sepsis can => decreased WCC

  • Confusion

  • Glucose >7.7

Diagnosis

• • Infection + 2 criteria = Sepsis

  • Infection + 2 criteria + organ dysfunction = Severe sepsis

    • Hypoxic, Raised bili, DIC, Hypotension, Reduced urine o/p, etc

  • Infection + 2 criteria + lactate >4 or SBP <90 or MAP <70 after 30 ml/kg fluid bolus = Septic shock

Distinguishing severe sepsis from septic shock

• • Does their hypotension respond to fluid challenge?

  • What's their lactate

    • 2 - 4 = Severe sepsis

    • > 4 = Septic shock

Septic 6 - Within the hour

• • Three investigations

    • Blood cultures

    • ABG for lactate

    • Urine output

      • Catheter or at least collection

  • Three treatments

    • IV antibiotics

    • IV fluids

      • 15 - 30 mins per litre

    • Oxygen

Mortality

• • MI = 10%

  • Stroke = 8%

  • Trauma = 5%

  • Septic shock = 40-60%

    • No start point to recognise (cf e.g. trauma)

    • No clearly defined phases

    • Delayed mortality

EGDT - For severe sepsis or septic shock

• • Early GDT in septic shock => 30% mortality cf 46.5% without

    • Timing is key

    • Start in the ED

  • First fix CVP - Target 8 - 12

    • Measure of pre-load i.e. adequate circulating volume

    • Adjust with fluids or diuretics as required

  • Then (once CVP fixed) fix MAP - Target 65 - 80

    • Measure of after-load / vascular resistance

    • Adjust with noradrenaline or GTN

  • Finally (once MAP fixed) fix ScVO2 - Target >70%

    • Measure of cardiac output

    • Adjust with inotropes (dobutamine, dopexamine)

CV sats

• • Reading of 70%

    • Could be fine

    • Or organs could be dying => Reduced O2 demand

    • Or can be shunting past organs (shut-down, hypotensive)

  • => Monitor CVP (8-12)

  • => Monitor MAP (65-90)

  • => Ensure haematocrit >30%

3 hour sepsis bundle

1) Measure lactate level

2) Obtain blood cultures prior to administration of antibiotics

3) Administer broad spectrum antibiotics

4) Administer 30 ml/kg crystalloid for hypotension or lactate ≥4mmol/L

6 hour sepsis bundle

5) Apply vasopressors (for hypotension that does not respond to initial fluid resuscitation) to maintain a mean arterial pressure (MAP) ≥65 mm Hg

6) In the event of persistent arterial hypotension despite volume resuscitation (septic shock) or initial lactate ≥4 mmol/L (36 mg/dL):

- Measure central venous pressure (CVP) - Target ≥8 mm Hg

- Measure central venous oxygen saturation (ScvO₂) - Target ≥70%

7) Remeasure lactate if initial lactate was elevated - Target normal

Notes

• • Sepsis is a spectrum

    • Condition => SIRS => Sepsis => Severe sepsis => Septic shock

  • Cryptic shock

    • Often young

    • Massive increase in adrenaline keeps BP up but does not ensure tissue perfusion

    • Big lactate rise ensues

  • N+V and cardiomyopathy can be caused by sepsis as well as vice versa

  • NNT

    • 6-7 for early GDT in septic shock

    • 19 for MI thrombolysis

    • 50 for PCI over thrombolysis in MI

  • VBG can show a spuriously high lactate due to peripheral shut-down, long tourniquet time, etc

    • => Recheck lactate with an ABG if raised on VBG

  • Currently no evidence for use of activated protein C in sepsis

  • Originally thought to block TNF production, leukocyte adhesion and thrombin-induced inflammatory response

  • 20% of O2 requirements come from WOB

    • => Can reduce requirements by sedating and ventilating

  • Transfuse if Hb <80 but keep going until >100

  • Keep glucose 4.5 - 6 (sliding scale)

  • Check clotting

  • Send G+S just in case

  • Chicken / Egg : Cardiac ischaemia => Cardiogenic shock or Sepsis => Cardiac ischaemia