Treatment Regimens
FIRST, A WARNING:
There are no standard methods for lipid emulsion therapy. In fact, there are many more questions than answers:
Should the lipid dose be titrated, by patient weight, local anesthetic dose, or the symptoms/signs/severity of toxicity? What is the best rate and total dose of the following infusion? Is there a safe upper limit of lipid dosing? What are the possible complications or adverse effects of lipid infusion? Should lipid be used alone or in combination with epinephrine, and other components of standard resuscitative cocktails? What is better, 20% or 30% lipid? What formulation is best? Intralipid has been used predominantly so far, but is there a better choice? Do the other available lipid emulsions work as well?
Obviously, a great deal of research in this area is required to determine a treatment protocol that optimizes outcome. What is known about dosing?
In animal studies, large doses of local anesthetic were used in order to make the most stringent possible tests for methods of treatment. Hence the doses of lipid used in rats and dogs (mL/kg) are probably excessive compared to what should work in humans who, by weight, have generally much smaller doses introduced into their circulation.
Data from humans are limited to two case reports (see News) and no prospective epidemiologic study is possible since numbers are too small; and ethical considerations rule out experiments on volunteers. So these data are very limited as well. Both patients received bolus injections of 100 mL 20% Intralipid followed by continuous infusions at either 0.5 mL/kg/min for 2 hours, or 10 mL/min for 10 minutes. In both cases, the same general approach was used as in the animal experiments, namely a bolus followed by a continuous infusion.
Given an understanding of these limitations in our method we recommend you start with the sample protocol given on the 'Emergency' page of this site. Or you can visit this ASRA site. The basis of this approach can be summarized as follows; note this should be used in conjunction with high quality BLS and ACLS as indicated by the patient's condition:
20% lipid emulsion:
1.5 mL/kg as an initial bolus, followed by
0.25 mL/kg/min for 30-60 minutes
Bolus could be repeated 1-2 times for persistent asystole
Infusion rate could be increased if the BP declines.
See the Instructions link in the Navigator to find sample protocols for LipidRescue as Word files that you can print and laminate . These could then be attached to lipid emulsion bags stored for this purpose near your block rooms.