However, the dynamic shuttle or scavenging effect of ILE depends on the lipid’s drug-binding properties and its redistributive effects. According to the lipid sink phenomenon, following administration of ILE, by creating a concentration gradient, all lipophilic substances are drawn from target tissues into the expanded lipid medium and in theory, toxicity is reversed. Even though its exact mechanism is unclear, the proposed mechanisms of the lipid sink phenomenon and the dynamic shuttle effect explain its clinical effects. ILE is a mixture of medium and long-chain fatty acid triglycerides. More recently, ILE therapy also used successfully in patients presenting with non-local anesthetic medication toxicity such as beta-blockers, calcium channel blockers, and tricyclic antidepressants. Spence reported a reversal of neurological symptoms in an obstetric patient, with a rapid administration of ILE. reported successful ILE rescue therapy in a child with local anesthetic-induced ventricular arrhythmia following posterior lumbar plexus block. Its usage is mainly limited to anesthesiology, and there are few case reports in adult patients suggesting successful recovery of local anesthetic systemic toxicity following ILE therapy administration. The first clinical application of ILE therapy reported in an adult patient with presumed bupivacaine-induced cardiac arrest who initially failed with standard resuscitative measures and completely recovered shortly after lipid emulsion infusion. Two decades ago, Weinberg showed the efficacy of ILE therapy in animal models during resuscitation following local anesthetic toxicity. There is limited data regarding the use of ILE as rescue therapy. By the end of lipid infusion, the patient had such a dramatic improvement in her sensorium, she was extubated, and became quite verbal admitting that she ingested about forty 350 mg of each tablet of carisoprodol (14 gm), which was used by her father for chronic lower back pain. She was started on intravenous 20% lipid emulsion at a dose of 1 mL/kg over one hour.
Lipid emulsion therapy trial#
Despite her negative toxicology screen, and her family’s denial of any history drug use in the past or significant potential sources of mood-altering drugs in the house, we considered a trial of ILE therapy secondary to the possibility of a drug overdose. She was continued on invasive mechanical ventilation and intravenous fluids. Over the next 10 hours, her neurological status remained unchanged. Her repeat electrolytes, blood gas, chest X-ray, and electroencephalogram were normal, and electrocardiogram revealed sinus tachycardia with normal PR or QTc intervals. Her propofol infusion was discontinued immediately and on follow-up assessment, she was able to localize to pain. She had no response to painful stimuli but had a normal pupillary examination. At admission to the PICU, her physical examination was notable for normothermia, normotension, and tremulous motor activity. Just prior to transport, she was started on propofol infusion at 20 mcg/kg/min. She received a normal saline bolus, and a dose of ceftriaxone was then transferred to our PICU with a diagnosis of status epilepticus and possible meningitis. In addition, urine toxicology screen, blood alcohol, acetaminophen, and aspirin level were negative. She had normal electrolytes and liver function test. She had an unremarkable brain computerized tomography scan and cerebrospinal fluid studies. She received an additional 1 mg of lorazepam for ongoing tremulous movements with no response. She had symmetric and reactive pupils on examination.
Upon arrival to the outside emergency room, she was unresponsive, normothermic, tachycardic with a heart rate of 150 bpm and with mild hypertension and the blood pressure of 130/84 mmHg. The patient was then transported to a local emergency department, and en route she was given one dose 1 mg lorazepam (0.02 mg/kg) for tremulousness, suspected to be seizure-related, with no response.
Emergency rescue was called and upon their arrival, the patient was intubated at the scene for significant respiratory depression. She was found by her parents in an unresponsive and tremulous state on the morning of admission. A 15-year-old previously healthy female was admitted to our tertiary care pediatric intensive care unit (PICU) from a community emergency room with unresponsiveness.