The fat part of intravenous (parenteral) nutrition
Lipid emulsion
The fat part of feeding given into a vein, providing energy and essential fats, and also used as an emergency antidote for severe local-anaesthetic toxicity.
What is Lipid emulsion?
A lipid emulsion is the fat-containing part of nutrition given directly into a vein when someone cannot be fed in the usual way. It provides energy and the essential fats the body needs. It is also used in hospital as an emergency antidote for severe poisoning from local anaesthetics. The main things to watch for are infusion reactions, the blood becoming overloaded with fat if it is given too fast, and effects on the liver with long-term use, so blood fats and liver tests are monitored. Because some preparations are made from egg and soya, it is used with care in people with those allergies.
Education and reference only. This is a plain-language guide to Lipid emulsion — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
A lipid emulsion is a milky preparation of fats suspended in water, designed to be given into a vein. It is one of the building blocks of parenteral nutrition, the term for feeding someone directly into the bloodstream when the gut cannot be used, and it supplies both energy and the essential fatty acids the body cannot make for itself. The same type of preparation has a second, very different use: in an emergency, it can act as an antidote for severe toxicity from local anaesthetics. It is prepared and given by hospital teams under careful supervision.
How it works
As part of intravenous feeding, a lipid emulsion delivers fat droplets straight into the bloodstream, where the body uses them for energy and to supply essential fats, much as it would use fat absorbed from food. The droplets are made small and stable so they can travel safely in the blood. In its antidote role, the fat is thought to act like a sponge in the bloodstream, drawing in local-anaesthetic molecules that have caused toxicity and helping the heart and circulation recover. Because the body can only handle so much fat at once, the rate it is given matters, and giving it too quickly can overload the blood with fat.
Company & origin
Originated / developed by: Specialist manufacturers.
A specialist preparation used in UK hospitals as the fat component of feeding given into a vein, and also as an emergency antidote for severe local-anaesthetic toxicity.
Practical use
How to take Lipid emulsion
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- It is given into a vein by trained hospital staff, usually slowly and as part of a feeding plan.
- The rate is kept within safe limits, as giving fat too quickly can overload the blood.
- Blood fat levels and liver tests are checked during treatment, particularly with long-term feeding.
- Tell the team about any egg or soya allergy, as some preparations are made from these.
- In its emergency antidote role for local-anaesthetic toxicity, it is given by hospital teams following a set protocol.
Weighing it up
Advantages & disadvantages of Lipid emulsion
Advantages
- Supplies energy and essential fats to people who cannot be fed in the usual way.
- An important part of complete intravenous nutrition.
- Also serves as a life-saving emergency antidote for severe local-anaesthetic toxicity.
Disadvantages
- Can cause infusion reactions such as flushing, fever or breathlessness.
- Giving it too fast or in too large an amount can overload the blood with fat.
- Long-term use can affect the liver, and some preparations are made from egg and soya.
Practical use
Good to know
There are a few important safety points. First, lipid emulsions can cause infusion reactions, such as flushing, fever, chills or breathlessness, especially when first started, so they are given carefully. Second, the blood can only clear so much fat at a time, so giving it too fast or in too large an amount can cause fat overload, with effects on breathing, the liver and blood clotting; this is why blood fat levels are checked. Third, long-term intravenous feeding can affect the liver, so liver tests are monitored. Many preparations are derived from egg and soya, so they are used with caution in people with egg or soya allergy. In its emergency antidote role for local-anaesthetic toxicity, it is given by hospital teams following a set protocol alongside other resuscitation measures.
Who should not take it / use with caution
- People with severe disturbances of blood fat handling may not be able to receive it, or only with care.
- People with a known allergy to egg or soya are treated with caution, as some preparations contain these.
- It is given only under hospital supervision, with monitoring of blood fats and liver function.
Monitoring
- Checking blood fat levels to make sure the blood is not overloaded.
- Monitoring liver function, particularly with long-term intravenous feeding.
- Watching for infusion reactions while it is being given.
Side effects
- Infusion reactions such as flushing, fever, chills or breathlessness, especially early on.
- Fat overload if given too fast, affecting breathing, the liver and blood clotting.
- With long-term use, changes in liver blood tests.
Key interactions
- It is one part of a carefully balanced feeding plan, so the whole mix is reviewed together.
- It can affect some blood tests, so labs should know it is being given.
- Other medicines added to a drip must be checked for compatibility before mixing.
Available as: An emulsion given into a vein, usually as part of intravenous nutrition.
Answers
Lipid emulsion: frequently asked questions
What is a lipid emulsion used for?
It is the fat part of feeding given into a vein, supplying energy and essential fats, and it is also used as an emergency antidote for severe local-anaesthetic toxicity.
Why is it given slowly?
The blood can only clear so much fat at a time, so giving it too fast can overload the blood with fat, which is why the rate is kept within safe limits.
Does it affect the liver?
Long-term intravenous feeding can affect the liver, so liver blood tests are monitored during treatment.
Is it safe if I am allergic to egg or soya?
Some preparations are made from egg and soya, so it is used with caution in people with those allergies; always tell the team about your allergies.
How can fat be an antidote?
In severe local-anaesthetic toxicity, the fat is thought to act like a sponge in the blood, soaking up the anaesthetic and helping the heart and circulation recover.
Authoritative sources
- BNF
- NICE CKS
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