Sepsis

Question 1

Definition of sepsis?

Answer 1

• Sepsis is a life threatening organ dysfunction caused by dysregulated host response to infection.
• Septic shock: subset of sepsis with circulatory and cellular/metabolic dysfunction associated with higher risk of mortality
• Definition of maternal sepsis: a life threatening condition defined as organ dysfunction resulting from infection during pregnancy, childbirth, post-abortion or postpartum period

Question 2

Clinical criteria to identify patients with sepsis

Answer 2

• Sepsis is considered present if infection is highly
• suspected or proven and two or more of the following
• Systemic inflammatory response syndrome (SIRS)
• criteria are met

Immediate
o New onset of confusion or altered mental state
o Heart Rate > 90 beats per minute
o Body temperature < 36 °C or > 38 °C
o Hyperventilation > 20 breaths per minute or, on blood gas - a PaCO2 less than 32 mmHg

Point of care test
o Blood glucose >7.7mmol in the absence of known diabetes
o White blood cell count < 4 x 109 or > 12 x 109 cells/L, or greater than 10% band forms (immature white blood cells)
o Lactate >2.0mmol

Question 3

Identification of red flags sepsis

Answer 3

• Systolic BP <90mmHg (or 40mmHg fall from baseline)
• Heart rate >130bpm
• Oxygen saturations <91%
• Respiratory rate >25 per minute
• Responds only to voice or pain/unresponsive
• Point of Care test – Lactate >2.0mmol

Question 4

What is sepsis

Answer 4

• The patient is initially injured in some way i.e. infection, trauma or inflammation
• The presence of pathogens (bacterial, viruses, fungi or parasites) in the blood stream elicits an inflammatory response
• However, there is an intricate linkage between inflammation and coagulation

Question 5

Tissue injury of pathogens

Answer 5

• Causes stimulation of monocytes, the leaders of the immune system within tissues
• They produce the cytokines, interleukin-1 (IL-1), interleukin-6 (IL-6) and tumour necrosis factor (TNF)
• Action of cytokines
  o Modulate the release and activation of a series of different agents
  o Interleukin-8, complement, histamine, kinins, serotonin, selectins, ecosanoids and of course neutrophils
  o The result of which is
  
  • local vasodilation (further amplified by inducible nitric oxide, discussed later)
    -Release of various cytotoxic chemicals= destruction of the invading pathogen

Question 6

What can sepsis lead to?

Answer 6

• Sepsis leads to a process invariably occurs within the vasculature
• Most of the damage is to the capillary lining
• The endothelium
  o Unfortunately, the endothelium is not a passive surface
  o Potent endocrine organ
  o Widely involved in the maintenance of circulating volume and in coagulation and fibrinolysis
• Three major sequela occur:-
  o The patient develops a coagulopathy, leading to intravascular thrombosis, tissue factor released from endothelium suppresses fibrinolysis
  o The patient becomes hypotensive due to local metabolites and the release of pathological nitric oxide
  o There is widespread destruction of the capillary endothelium leading to the extravasations of protein rich fluid, causing oedema

Question 7

Complex and multifaceted

Answer 7

• Commonly thought that a person in septic shock will be hot and hypotensive
• But beware may lead to cardiogenic shock were the patient will be cold and hypotensive

Question 8

The patient has undergone a “first hit”

Answer 8

• And is now vulnerable to further injury
• At this point three things may happen
  o The injury and/or inflammatory response may persist
  o The patient may develop a secondary infection such as nosocomial pneumonia or ventilator induced lung injury
  o The patient may develop a bacterial translocation from the gut

Question 9

Risk factors

Answer 9

• Obesity
• Impaired glucose tolerance/diabetes
• Impaired immunity
• Anaemia
• Vaginal discharge
• History of pelvic infection
• History of Strep B
• Amniocentesis, and other invasive intrauterine procedures
• Cervical cerclage
• Prolonged SROM
• Vaginal trauma
• Caesarean section
• Wound haematoma
• Retained products of conception post miscarriage or post delivery

Question 10

Common signs and symptoms

Answer 10

Symptoms

• Fever
• Diarrhoea
• Vomiting
• Abdominal pain
• Rash
• Vaginal discharge, wound infection

Signs

• Tachycardia
• Tachypnoea
• Pyrexia
• Possible elevated white cell count
• Elevated C-reactive protein

Question 11

Features of septic shock

Answer 11

• Tachycardia – over 90bpm
• Tachypnoea – over 20
• Pyrexia – over 38oC
• Hypothermia below - 35oC
• Hypotension – systolic below 90mmHg or below in the absence of other causes e.g bleeding
• Hypoxemia
• Poor peripheral perfusion, mottled skin
• Oliguria
• Metabolic acidosis
• Elevated lactate
• Positive blood cultures
• Abnormal coagulation and bleeding
• Abnormal liver and renal function tests

Question 12

Septic shock

Answer 12

• Persisting hypotension requiring vasopressors to maintain a MAP≥65mmHg
• Serum lactate ≥2mmol/L despite adequate volume resuscitation
• With this criteria hospital mortality in excess of 40%

Question 13

Sepsis 6

Answer 13

• Take an arterial blood gas and give 100% O2 through a non-rebreathe mask, may need humidification
• Take blood cultures – peripheral line, actively seek results after 48hrs
• Commence IV antibiotics – for every hr delay increase in mortality by 7.6%
• Start iv fluids – may require fluid challenge
• Take blood for Hb (less than 7g/ld= Transfuse) and lactate levels (>4mmol/lit = septic shock)
• Measure urine output hrly