Lipid infusion (Intralipid 20%®) for local anaesthetic toxicity

Disclaimer

These guidelines have been produced to guide clinical decision making for the medical, nursing and allied health staff of Perth Children’s Hospital. They are not strict protocols, and they do not replace the judgement of a senior clinician. Clinical common-sense should be applied at all times. These clinical guidelines should never be relied on as a substitute for proper assessment with respect to the particular circumstances of each case and the needs of each patient. Clinicians should also consider the local skill level available and their local area policies before following any guideline.

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Aim

To guide PCH Emergency Department (ED) staff in the administration of lipid infusion (Intralipid 20%^®) for the acute management of local anaesthetic toxicity following inadvertent intravascular injection during regional anaesthesia in the ED.

This guideline can be used for the management of Lipid Rescue for accidental IV administration of local anaesthetic.

Background

Cardiovascular collapse is the most life-endangering complication of intravascular injection during regional anaesthesia. Intravenous lipid emulsion administration is an established clinical practice for treating local anaesthetic systemic toxicity that also shows promise as an effective antidote for other lipophilic drug poisoning.¹

Intravenous Local Anaesthetic Toxicity¹

Local anaesthetic systemic toxicity is generally considered to be resistant to conventional modes of resuscitation.
Only Intralipid® brand should be used for the treatment of acute local anaesthetic toxicity.
The ‘lipid sink’ phenomenon is the most widely accepted mechanism of action for lipids.
- The lipid emulsion infusion creates an expanded lipid phase, and the resulting equilibrium drives toxic drug from tissue to the aqueous plasma phase then into the lipid phase.
- This draws down the content of lipid-soluble local anaesthetics from within the cardiac tissue, thereby improving cardiac conduction, contractility and coronary perfusion.

Indications

The Intralipid^® brand of fat emulsion is reserved solely for the emergency management of local anaesthetics inadvertently administered intravenously. No other brands of lipid emulsions are to be used.
For signs of local anaesthetic toxicity and immediate management, refer to the Local Anaesthetic Toxicity guideline from the Quick Reference Handbook - Association of Anaesthetists 2023²

Lipid rescue

Administration²

Give Lipid Emulsion 20% (Intralipid® brand of Fat Emulsion). Refer to the table below for dose recommendations.

Immediately give an IV bolus of 1.5 mL/kg over 1 minute
And start an IV infusion at 15 mL/kg/hour
A maximum of 2 repeat 1.5 mL/kg IV boluses may be given at least 5 minutes apart if the patient has cardiovascular instability or is in cardiac arrest (Maximum 3 boluses in total)
Increase the rate to 30 mL/kg/hour if haemodynamic stability is not restored after 5 minutes
Continue infusion until haemodynamic stability is restored, up to the maximum dose
Do not exceed a maximum cumulative dose of 12 mL/kg
Base dose on lean body weight in extremely obese patients
Precautions - hypersensitivity to egg yolk, soya or peanut protein

	Patient weight (kg)
	10 kg	15 kg	20 kg	25 kg	30 kg
Bolus volume (mL) administered over 1 minute (Can repeat after 5 minutes to maximum 3 doses)	15 mL	22.5 mL	30 mL	37.5 mL	45 mL
Initial Infusion rate (mL/hour) (based on 15 mL/kg/hour)	150 mL/hour	225 mL/hour	300 mL/hour	375 mL/hour	450 mL/hour
Subsequent infusion rate (mL/hour) (based on 30 mL/kg/hour) Note: Only increase rate if cardiovascular stability not restored after 5 minutes	300 mL/hour	450 mL/hour	600 mL/hour	750 mL/hour	900 mL/hour
MAXIMUM CUMULATIVE DOSE (mL) (initial bolus plus the possible two repeat bolus doses plus infusion volume)
	120 mL	180 mL	240 mL	300 mL	360 mL

Lipid emulsion 20% (Intralipid 20%^®) is given in addition to standard Cardio-Pulmonary Resuscitation.
Prompt and effective airway management must be implemented to prevent hypoxia and respiratory acidosis, which may potentiate local anaesthetic toxicity.

Nursing

All patients with suspected local anaesthetic toxicity must have full cardiorespiratory monitoring.

References

Weinberg GL. Lipid emulsion infusion: resuscitation for local anesthetic and other drug overdose. Anesthesiology. 2012;117:180-7
QRH 3-10 Local Anaesthetic Toxicity v.2 Quick Reference Handbook 2023. Association of Anaesthetists 2023. [Internet. Last updated June 2023. Cited: 31 October 2023] Available from: QRH_complete_June_2023.pdf (anaesthetists.org)
Quick Reference Handbook 2023. Association of Anaesthetists 2023. [Internet. Last updated June 2023. Cited: 31 October 2023] Available from: QRH_complete_June_2023.pdf (anaesthetists.org)

Endorsed by:	Drugs & Therapeutics Committee	Date:	Apr 2022
		Review date:	Jan 2024

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