This is a quick post about an anesthesia pharmacology keyword video I stumbled on https://www.youtube.com/watch?v=J3MEKwg6GKM
Giving epinephrine’s can increase the during a local anesthetic – It has little effect on long acting local anesthetics like bupivacaine, but epinephrine can prolong the effects a short acting drug like lidocaine
An IV regional Bier block, decrease the bf flow in and out to keep the anesthetics rapid onset and rapid recovery. Inflate the cuff to 250mmHg or 100mmHg over the patient’s systolic BP. A Bier block block simultaneously provides muscle relaxation. Do not give bupivacaine with a Bier block, if it leaks there could cause local anesthetic systemic toxicity(LAST). During a Bier block the anesthetics diffuse through the vein to the nerves, don’t preform a Bier block for more than 2 hours, to avoid any problems with ischemia. After completion of procedure, slowly deflate over 25 minutes because when the pressure is released the analgesics dissipate quickly – then start opioids to control pain.
Epinephrine increase the effect on local anesthetic duration. Local anesthetic vasodilate(except cocaine) so epinephrine will cause vasoconstriction, decrease absorption of local anesthetic, and thereby decrease the peak concentration needed. Epinephrine administration will also increase the duration and quality of anesthesia. Epi doesn’t have much effect on bupivacaine, but it does on lidocaine – so when giving epidural blocks/and other nerve blocks EPI increases the effects of lidocaine(short acting), but not bupivacaine(long acting).
Mentioned earlier if bupivacaine leaks from a Bier block it can cause local anesthesia systemic toxicity. Local anesthesia systemic toxicity occurs when a large dose of local anesthetic goes systemic which causes a bunch of problems. If there are initially CNS symptoms – give benzos to control any seizures. If there is hypotension, manage the airway and hyperventilate the patient with 100 o2. Escaped local anesthetics can block the sodium channels in the heart causing a low cardio output, hypotensive state. A lipid emulsion should be given quickly(not propofol). I got some good information on how the lipid emulsion works from the blog below. To my understanding the lipid emulsion increases the lipid “container” or as the blog puts it a “sink”, that reduces the effective amount of systemic anesthetic.
The Syncytium 