Sepsis is a syndrome that occurs when an infection causes the child to become systemically unwell. It is the result of a severe systemic inflammatory response. It is a life threatening condition and there should be a low threshold for treating suspected sepsis.
Recognition of a child with sepsis is essential. The younger the child, the less specific and obvious the symptoms of sepsis can be. It is important to make a judgement about the child’s risk of sepsis based on their presentation, and make a decision about starting antibiotics. This is a frequent task in general practice, emergency medicine and paediatrics.
Sepsis is a medical emergency and should be managed alongside experienced paediatricians and according to local guidelines. This information is for educational purposes only and not for use as a guideline or as the basis for decision making.
The causative pathogens are recognised by macrophages, lymphocytes and mast cells. These cells release vast amounts of cytokines, such as interleukins and tumor necrosis factor, to alert the immune system to the invader. These cytokines activate other parts of the immune system. This immune activation leads to further release of chemicals such as nitrous oxide that causes vasodilation. The immune response causes inflammation throughout the body.
Many of these cytokines cause the endothelial lining of blood vessels to become more permeable. This causes fluid to leak out of the blood into the extracellular space, leading to oedema and a reduction in intravascular volume. The oedema around blood vessels creates a space between the blood and the tissues, reducing the amount of oxygen that reaches the tissues.
Activation of the coagulation system leads to deposition of fibrin throughout the circulation, further compromising organ and tissue perfusion. It also leads to consumption of platelets and clotting factors, as they are being used up to form the blood clots. This leads to thrombocytopenia, haemorrhages and an inability to form clots and stop bleeding. This is called disseminated intravascular coagulopathy (DIC).
Blood lactate rises as a result of anaerobic respiration in the hypo-perfused tissues with an inadequate oxygen. A waste product of anaerobic respiration is lactate.
Septic shock is diagnosed when sepsis has lead to cardiovascular dysfunction. The arterial blood pressure falls, resulting in organ hypo-perfusion. This leads to a rise in blood lactate as the organs begin anaerobic respiration.
Septic shock should be treated aggressively with IV fluids to improve the blood pressure and tissue perfusion. If IV fluid boluses fail to improve the blood pressure and lactate level, children should be escalated to the high dependency or intensive care unit where medication called inotropes (such as noradrenalin) can be considered. Inotropes stimulate the cardiovascular system and improve blood pressure and tissue perfusion.
Signs of Sepsis
Don’t underestimate observing the child from the end of the bed. Consider whether they look well or unwell.
Hard signs to look out for that can indicate sepsis are:
- Deranged physical observations
- Prolonged capillary refill time (CRT)
- Fever or hypothermia
- Deranged behaviour
- Poor feeding
- Inconsolable or high pitched crying
- High pitched or weak cry
- Reduced consciousness
- Reduced body tone (floppy)
- Skin colour changes (cyanosis, mottled pale or ashen)
Shock involves circulatory collapse and hypoperfusion of organs.
There are NICE guidelines from 2019 that cover the assessment of children under 5 year with a fever. They recommend using a traffic light system for the assessment of serious illness in these children. This categorises children as green (low risk), amber (intermediate risk) or red (high risk). Read through the table in the NICE guidelines describing the features of each to familiarise yourself with the signs to look out for. Patients are categorised based on examination findings in various systems:
- Colour: normal colour versus cyanosis, mottled pale or ashen
- Activity: active, happy and responsive versus abnormal responses, drowsy or inconsolable cry
- Respiratory: normal breathing versus respiratory distress, tachypnoea or grunting
- Circulation and hydration: normal skin and moist membranes versus tachycardia, dry membranes or poor skin turgor
- Other: other concerning signs, such as fever > 5 days, non blanching rash, seizures or high temperatures < 6 months
It is worth remembering that all infants under 3 months with a temperature of 38ºC or above need to be treated urgently for sepsis, until proven otherwise.
Where children are low risk and managed at home, parents need clear verbal and written safety-net advice about when and how to seek further medical attention.
Sepsis is a medical emergency and needs to be managed urgently. Call for senior help early for experienced support.
- Give oxygen if the patient has evidence of shock or oxygen saturations are below 94%
- Obtain IV access (cannulation)
- Blood tests, including a FBC, U&E, CRP, clotting screen (INR), blood gas for lactate and acidosis
- Blood cultures, ideally before giving antibiotics
- Urine dipstick and laboratory testing for culture and sensitivities
- Antibiotics according to local guidelines. They should be given within 1 hour of presentation.
- IV fluids. 20ml/kg IV bolus of normal saline if the lactate is above 2 mmol/L or there is shock. This may be repeated.
Additional investigations may be performed depending on the suspected infection:
- Chest xray if pneumonia is suspected
- Abdominal and pelvic ultrasound if intra-abdominal infection is suspected
- Lumbar puncture if meningitis is suspected
- Meningococcal PCR blood test if meningococcal disease is suspected
- Serum cortisol if adrenal crisis is suspected
Continue antibiotics for 5 – 7 days if a bacterial infection is suspected or confirmed. Alter the antibiotic choice and duration once a source of infection is found and an organism is isolated. Bacterial culture and sensitivities can be very helpful in guiding antibiotics. A microbiologist can provide advice on the choice and duration of antibiotics.
Consider stopping antibiotics where there is a low suspicion of bacterial infection, the patient is well and blood cultures and two CRP results are negative at 48 hours.
Last updated January 2020