Post Your Cases > Lipid treatment in suspected LA toxicity

Patient had femoral nerve block for ACL repair using 150 mg ropivicaine. Surgeon, without my knowing, injected the knee joint with an additional 75 mg bupivicaine at the end of the case. Patient arrived in PACU extremely sleepy and upper extremity twitching (uncoordinated movements), but all vital signs were OK. After eliminating other causes to explain the reaction and discovering that extra local anesthetic was administered by the surgeon, toxicity was suspected. Two doses of 50 ml intralidpid were given IV 10 minutes apart. Approximetely a half hour after the second dose was given the patient was awake and the movements were completely gone. The patient recovered completely without any effects. From this scenario I suspect that this was LA toxicity but would have expected to see a quicker response neurologically. Clinically is this what you would expect to see? Are the cardiac and neurologic response thresholds different?
May 4, 2007 | Unregistered CommenterDr. Thomas Olen
Thanks for posting the interesting case. First, I'm reminded of a similar monicare case where the surgeon injected local anesthetic in the incision on the way out of the OR. Just after reaching the PACU the patient was noted to be very bradycardic then in asystole. Of course, the anesthesiologist was blamed at first for allowing the patient to become sufficiently hypoxic to cause her heart to stop (in the 1 minute it took to get to the recovery; hmmmm).

Fortunately, your patient's toxicity never got to the point of cardiovascular compromise. Nevertheless, it points out the importance of getting the surgeons to tell us what they are doing when it comes to injecting drugs....particularly bupivacaine or cocaine, etc. It is my experience that surgeons who have had no adverse reactions are likely to take the position, "in my experience, it is safe to ....(fill in the dangerous blank)". They believe n = 50 or 100 is a significant experience. Until they are disabused of this misapprehension either by a very compelling talk with an anesthesiologist, or something worse.....

As far as the time course of recovery goes, I don't think we have enough experience to answer your question. There are 3 cases coming down the pipe of LA toxicity presenting as obtundation and in those cases, the resolution with lipid was very rapid. However, they both used larger doses (~100mL bolus +). In your case the bolus was divided and given over a longer period of time, so perhaps the net is more like a continuous infusion. I am also aware of a case of cardiovascular collapse treated with an infusion but no bolus. This patient recovered, but more slowly than in reports where 100mL bolus preceded the continuous infusion (20 vs. ~ 1-2min).

Anyway, thanks very much for posting the case here. It goes into the community experience and will enrich everyone's practice as a result. BTW, where do you practice?
guy

May 6, 2007 | Registered Commenter[Guy Weinberg]
Thank you for the quick response. Patient had no adverse sequelae when we followed up the next day. I practice in Midland, Michigan; we stock intralipid in all locations where blocks are being performed.
May 7, 2007 | Unregistered CommenterDr. Thomas Olen
you're just down the road. did you notice the pictures of a lipid rescue kit posted by another michigan resident (dr. alway)? michigan may be a leader in implementation.
g
May 7, 2007 | Registered Commenter[Guy Weinberg]