The following represents a case report that occured on March 10. 2009. A 45 year old, 65 kg,white female, ASA 1, presented to the OR for elective arthroscopic shoulder repair. The patient's past medical history was unremarkable, with no drug allergies and no prior anesthetic exposure. After informed consent, the patient had standard monitoring and oxygen applied by nasal cannula. The patient received Midazolam 2 mg, and Fentanyl 50 mcg IV as premedication. She was prepped in the ususal manner, and a 22ga 50mm (B.Braun Medical) Stimuplex insulated block needle was used to locate the brachial plexus attached to a nerve stimulator. A musculocutanous response was elicited at 0.3 mA on the first pass, using a classic approach (mesad, caudad and cephalad angle). A mixture of 30ml of 0.5% Ropivicaine with 30mg of 1% Tetracaine (crystals) was injected with negative frequent aspirate, the block needle was re-directed to obtain a more distal, radial response in the hand and an additional 5ml of 0.5% Ropivicaine was placed. The author has significant experience in advanced regional techniques, and performs all peripheral nerve blocks by observing and aspirating only by himself. At no time was there any evidence of blood in the aspirate, and no signs of hematoma formation at the block site. Approximately 1 minute after the block was completed, the patient became unresponsive and displayed tonic/clonic seizures. The heart rate remained in sinus tachycardia (90-106 bpm) with a stable blood pressure of 145/70. An additional 2mg of Midazolam IV was given, along with bag/mask (Oxygen saturations remained above 90%). An infusion of 20% Intralipid was started immediately through an existing large bore IV. The patient was intubated immediately and without difficulty after giving Propofol 100mg, and Succinycholine 100mg IV. She had, at this point, exhibited 3 full episodes of tonic/clonic seizure activity. Once intubated, there were no further episodes of seizure activity. She was given additional Propofol 100mg, and prepared for ICU transport. At no time did the patient exhibit any episodes of cardiac arrhythmia or instability, she remained hemodynamically stable throughout. Once in the ICU, she was placed briefly on controlled ventilation, and was extubated, fully awake and neurologically intact within one hour of the toxicity episode. She received at total of 250ml of 20% Intralipids, which was discontinued in the ICU due to her rapid emergence and no further seizure episodes. She had no recall of the events, and did in fact, have a complete brachial plexus block in the surgical extremity down to the inferior trunk/medial cord (ulnar distribution), and no signs of trauma/hematoma formation at the block site. This was the first time in over 18 years of practice, that I ever had a patient seize after performing a peripheral nerve block. I believe, personally, that either the last 5ml of block solution may have entered the vascular system, or more likely, that the total dosage received (especially with the addition of Tetracaine 30mg), had exceeded the patient's ability to metabolize on a mg/kg basis. However, the use of the intralipids seemed to maintain cardiovascular stability, and facilitate an incredibly rapid recovery. The patient was kept overnight and discharged to home the next day without incident.
Of further note, one of our anesthesiologists had a similiar event one year ago on a young healthy male for shoulder surgery. After performing an interscalene block (different approach), in which the patient became asystolic for 20 minutes, unrefractory to standard ACLS, and made a complete cardiovascular recovery once intralipid infusion was started. This patient also made a complete recovery.

Steve, thanks for the excellent case description. i think in cases like yours, it will always be impossible to determine whether the patient would have recovered without the lipid treatment....but i trust the eyes that were on the patient at the time as to where things were going - especially experienced eyes. and certainly nothing speaks as loudly as a good outcome. very glad to hear that everything worked out well. now, try to get your colleague to post his case from last year. it was easy, right?
guy

Dr. Weinberg. Thank you for your response, and I will certainly pass this along to my colleague. Your website is gaining recognition in our area, and wanted to let you know that it is certainly making a difference in our (evidence-based) practice.

Sincerly,

Steve DiChiara, MSN, CRNA