• Question: In the case of early-onset neonatal sepsis antibiotic prophylaxis must be administered within an hour of diagnosis. Why does the mortality and morbidity risk increase after this period? - Sir William Borlase's Grammar School (prospective paediatric nurse)

    Asked by Kristen to Ceri, Marikka, Matt, Rob, Sally on 10 Nov 2014.
    • Photo: Robert Hampson

      Robert Hampson answered on 10 Nov 2014:

      This is quite a technical question and really necessitates a thorough literature search which I simply don’t have time to do.

      Sepsis is bacteria in the blood, this is incredibly bad news. It kills adults very quickly and will kill babies even faster. It is rare as the immune system can normally keep bacteria out of the blood and localised to an infection area. Generally, sepsis shows that either the immune system has a problem or has completely failed due to the number or the effects of the bacteria. Bacteria grow exponentially (e.g. they double every hour say) so the longer you leave it the more bacteria have to be killed. Antibiotics also take a while to have an effect or circulate through the blood and they often don’t kill all the bacteria. Basically, sepsis in any patient is a race against time but because of their size and new untested immune system it is especially true in neonates.

    • Photo: Sally Cutler

      Sally Cutler answered on 10 Nov 2014:

      Hi Kristen,
      Early onset neonatal sepsis is usually caused by Streptococcus algalacticae (group B Streptococci). This is carried by about a quarter of the population without causing a problem, but can cause life-threatening neonatal infection as you have highlighted. Not quite sure about your wording as prophylaxis is preventative use of antibiotics but then you say within an hour of diagnosis which puzzled me. You can give prophylactic penicillin to reduce the risk of neonatal infection in a carrier mother during vaginal delivery, or treat the neonate if clinical signs develop. Neonates are highly susceptible to many infections as their immune system is not fully developed. Antibodies from the mother are passively transferred offering some protection for the first few months of life for breast-feeding infants.

    • Photo: Ceri Dare

      Ceri Dare answered on 10 Nov 2014:

      I asked my boss about this, because he is a paediatric doctor who has worked with neonates with sepsis, so he knows more about very small babies than me – all my research so far has been in adults. So this is a reply from both of us:

      Bacteria produce toxins. Gram-positive (with thick cell walls) can produce both exo-toxins (which are released from the cell) and endo-toxins which are part of their cell wall.. Gram-negative bacteria (with a thinner cell wall) can only produce exo-toxins. These toxins cause the body cells to release chemical messengers called cytokines, which triggers the body’s pro-inflammatory response. The symptoms of sepsis aren’t caused directly by the bacteria, but caused by the whole body having an inflammatory response, leading to a dramatic drop in blood pressure, which then causes many organs to have problems.

      So the faster antibiotics are given, the less time the bacteria have to make exotoxins and endotoxins, so there’s less to trigger the body’s response of going into shock.

      If neonates are in shock, they crash very quickly, so at the same time as giving antibiotics, doctors would also monitor the baby very carefully, giving fluids, controlling blood sugar, and so on.

      It isn’t just neonates who need antibiotics quickly in sepsis – there’s a big campaign called the ‘Sepsis Six’ which improves survival in all age groups: http://survivesepsis.org/the-sepsis-six/ and http://survivesepsis.org/elearning-demo/

      Good luck with your project, feel free to ask more questions about it, this has been interesting and I have learnt new things whilst writing this! I’d suggest you have a look at some clinical guidelines, as usually they will have already done a systematic literature review.