There are some issues with definition that need to be cleared up
- SIRS (systemic inflammatory response syndrome) - body's defensive response to an acute, serious systemic illness. Outlined in further details below as sepsis is a major cause.
- Sepsis - infection with SIRS
- Bacteraemia - presence of bacteria in blood
- Severe sepsis - sepsis with signs of end-organ failure (see below)
- Septic shock - shock due to sepsis
Septicaemia is an obsolete term (though still used instead of sepsis) which is an inaccurate combination of bacteraemia and sepsis.
Whenever you get an infection, it's not great. However, when it enters your bloodstream, things tend to get markedly worse.
Having an infection.
Then, you need to look at SIRS which is where 2 of the following are present:
Often, with septic patients you will know from the clincal features where the problem is. But if you don't, these are the following investigations you should do as a part of a septic screen.
The most important things are:
- Bloods - FBC (raised WCC), U+E (dehyrdation), CRP (raised in inflammation and infection, blood cultures
- CXR - to rule out pneumonia
- Urinalysis - to rule out UTI
If you're still unsure
- throat swab - laryngitis
- stool culture - strictly this should be part of any septic screen but is usually reserved for those with diarrhoea
These are the six things you need to do for anybody with sepsis and they should be done within one hour. They should also be done in this order of priority.
- Blood culture - these should be done before antibioitics are administered
- Antibiotics - probably the most important thing. Mortality is reduced by 50% in severe sepsis if these are given within an hour of diagnosis. Speed is important.
- Oxygen - even if they are not desaturating, if they are severe sepsis, give 100% at 15L/m via a non-rebreath mask.
- Fluids - they are highly likely to develop hypovoloemia as the [inflammatory]] response leads to fluid shifting into the tissues.
- Lactate - remember talking about lactic acid at school? It's a sign of anaerobic respiration and it's bad. A lactate above 2 means ITU involvement.
- Catheterise - you need to monitor urine output. The only way to do this completely accurately is a catheter attached to a urometer (a special catheter bag with a accurate measuring bit) and hourly urine output measurement.
If severe sepsis gets to intensive care, the mortality is about 50%. It can be reduced significantly with timely intervention. For more information, see the Surviving Sepsis campaign