Medical: Sepsis and Septicemia

1. Definitions

• Systemic inflammatory response syndrome (SIRS)
- the body's response to a variety of severe clinical insults
   presence of two or more of:
           - temperature >38°C or <36°C
           - heart rate > 90/min
          - respiratory rate > 20/min
           - PaCO2 <4.3kPa
           - white cell count > 12 x 10⁹/l - < 4 x 10⁹/l or greater than 10% immature
           neutrophils

• Sepsis is defined as SIRS in response to infection.

• Severe sepsis is sepsis associated with:

organ dysfunction

hypotension (systolic blood pressure < 90mmHg or a reduction of > 40 mmHg from the patient's normal in the absence of other causes of hypotension)

organ hypoperfusion (revealed by signs such as lactic acidosis, oliguria, acute alteration of mental status)

• Septic shock describes sepsis with hypotension despite adequate fluid
          resuscitation

• Multiple organ dysfunction syndrome (MODS) describes a state where
          dysfunction is seen in several organs.

2. Etiology

-          generalized infection spreading into the whole body

-          hypovolaemia, increased venous capacitance and high pulmonary vascular resistance à low left ventricular preload à low cardiac output.

-          it can persist after fluid resuscitation à results from a high cardiac output with low peripheral vascular resistance

-          this is clinically evident as warm peripheries and bounding pulses.

-          later in sepsis à myocardial dysfunction may contribute to shock by causing a low cardiac output

-          these patients tend to be peripherally cold, sweaty, with weak pulses

-          septicaemia is leading to microcirculation disturbances

3. Initial Management of Septicemia

- ABC

- brief history and perform a limited examination of the relevant body systems

- Fluid-Resuscitation as soon as sepsis is recognised

- Aim for mean arterial pressure greater than 60mmHg

- Initially infuse IV crystalloid or colloid rapidly guided by the clinical response.

- There is no evidence that either type of fluid is superior.

- Warm, vasodilated patients, with a high cardiac output, may require several litres of fluid to establish adequate intravascular filling.

- Measurement of central venous pressure (CVP) can guide fluid resuscitation and provide a route for infusion of vasopressors or inotropes.
A one-off reading of CVP may be misleading but following a trend of measurements and their response to fluid challenges is helpful.

- Measure urine output hourly and aim to achieve > 0.5 ml/kg/hour

- Keep RGB < 8,4 mmol/l for better outcome

- high dose hydrocortisone scheme in septic shock (100mg/hourly and then 50mg/hourls/24h)

4. Induction of anaesthesia and intubation in critically ill patients

-          anaesthesia for intubation and ventilation of critically ill patients is hazardous and often poorly tolerated

-          Consider the following points:
• A trained assistant or second anaesthetist should be present.
• Never leave a hypoxic patient unattended. Give high concentrations of oxygen whilst preparing equipment.
• Obtain wide-bore intravenous access (14G or 16G canula).

     • Severe hypotension following induction of anaesthesia is common !
- Induce slowly using small doses of IV anaesthetic agents
- Ketamine, Etomidate or diazepam may provide greater haemodynamic stability
- IV vasopressors should be prepared before induction
     ephedrine 6 - 9mg IV
     epinephrine (adrenaline) 1:10 000 in 0.5 - 1ml doses IV
• Respiratory reserve may be poor - preoxygenate for three minutes via a tight-fitting mask        
• Rapid sequence induction and intubation with application of cricoid pressure should be     used. Avoid suxamethonium if hyperkalaemia is likely.
• Pass a nasogastric tube and urinary catheter

-          Maintain anaesthesia with midazolam/ketamine or ether.