Lipid emulsion for xenobiotic overdose: PRO

Apparent local anesthetic systemic toxicity following activation of an epidural catheter for cesarean delivery: diagnosis and management of an uncommon obstetric anesthesia complication

We present a 25-year-old, gravida 2, para 1 woman who developed apparent local anesthetic systemic toxicity (LAST) following activation of an epidural catheter for an urgent cesarean delivery. The patient had a height of 150 cm, weight of 92 kg, body mass index of 41 kg/m2, and calculated ideal body weight of 40 kg. A combined spinal epidural anesthetic was placed and the spinal component did not provide anesthesia to clamping of the abdomen. Subsequently, 300 mg of lidocaine was administered through the epidural catheter in three 5 mL doses over 8 minutes and surgery commenced. Approximately 30 minutes following the final 5 mL dose of epidural lidocaine, the patient had progressive loss of consciousness and was difficult to arouse. A presumptive diagnosis of LAST was made, and 60 mL of 20% intravenous lipid emulsion was administered. The patient's mental status improved to baseline within 5 minutes of lipid emulsion administration, and she made a complete recovery. Anesthesiologists should consider using ideal body weight when calculating the maximum dosage of local anesthetics, and LAST should be part of the differential diagnosis when patients have altered mental status in the setting of local anesthetic administration that exceeds recommended dosages.

Effect of lipid emulsion on neuropsychiatric drug-induced toxicity: A narrative review

Lipid emulsion has been shown to effectively relieve refractory cardiovascular collapse resulting from toxic levels of nonlocal anesthetics. The goal of this study was to examine the effect of lipid emulsions on neuropsychiatric drug-induced toxicity using relevant case reports of human patients, with a particular focus on the Glasgow Coma Scale (GCS) score and corrected QT interval, to analyze drugs that frequently require lipid emulsion treatment. The following keywords were used to retrieve relevant case reports from PubMed: "antidepressant or antipsychotic drug or amitriptyline or bupropion or citalopram or desipramine or dosulepin or dothiepin or doxepin or escitalopram or fluoxetine or haloperidol or olanzapine or phenothiazine or quetiapine or risperidone or trazodone" and "lipid emulsion or Intralipid." Lipid emulsion treatment reversed the corrected QT interval prolongation and decreases in Glasgow Coma Scale scores caused by toxic doses of neuropsychiatric drugs, especially lipid-soluble drugs such as amitriptyline, trazodone, quetiapine, lamotrigine, and citalopram. The log P (octanol/water partition coefficient) of the group which required more than 3 lipid emulsion treatments was higher than that that of the group which required less than 3 lipid emulsion treatments. The main rationale to administer lipid emulsion as an adjuvant was as follows: hemodynamic depression intractable to supportive treatment (88.3%) > lipophilic drugs (8.3%) > suspected overdose or no spontaneous breathing (1.6%). Adjuvant lipid emulsion treatment contributed to the recovery of 98.30% of patients with neuropsychiatric drug-induced toxicity. However, further analyses using many case reports are needed to clarify the effects of lipid emulsion resuscitation.

Effects of Intravenous Lipid Emulsion Administration in Acute Tramadol Poisoning: A Randomized Controlled Trial

BACKGROUND

As the prevalence of tramadol toxicity is increasing, managing these patients with the aim of treatment and complete recovery has become a major challenge for health care professionals.

OBJECTIVE

This study evaluated the short-term effects of IV lipid emulsion (ILE) administration in cases of tramadol poisoning.

METHODS

In this double-blind, randomized controlled trial, 120 patients with pure tramadol poisoning and a Glasgow Coma (GCS) score ≤ 12 referred to a poisoning center in Tehran, Iran were selected and randomly assigned 1:1 to receive ILE 20% (intervention) or 0.9% saline (control) after admission and primary stabilization. The patient's vital signs, GCS score, hospitalization duration, and rate of seizure occurrence were recorded and compared between the two groups.

RESULTS

Mean (SD) age of participants was 25.3 (5.4) years and 84 (70%) were male. Mean (SD) ingested dose of tramadol was 3118 (244) mg, which was not different between the groups. Compared with controls, the ILE group had a higher level of consciousness after treatment (median [interquartile range] GCS score 12 [10-13] vs. 10 [8-12]; p = 0.03). In addition, length of hospitalization (median [interquartile range] (2 [1-3] days vs. 4 [4-6] days; p < 0.01) and rate of seizure occurrence were lower in the intervention group (16/60 vs. 30/60; p < 0.01).

CONCLUSIONS

In the setting of tramadol poisoning with a decreased level of consciousness and based on our study's findings, administration of ILE is suggested to help manage patients in hospital emergency departments. However, larger trials might be needed to confirm these findings before entering the guidelines.

Lipid emulsion therapy during management of the critically-ill poisoned patient: a prospective cohort study

BACKGROUND

Despite conflicting data, intravenous lipid emulsion has emerged as a potential antidote. The "lipid sink" theory suggests that following intravenous administration of lipid, lipophilic drugs are sequestered in the vascular compartment, thereby reducing their tissue concentrations. This study sought to determine if survival is associated with the intoxicant's degree of lipophilicity.

METHODS

We reviewed all cases in the Toxicology Investigators Consortium's lipid sub-registry between May 2012 through December 2018. Information collected included demographics, exposure circumstances, clinical course, management, disposition, and outcome. The primary outcome was survival after lipid emulsion therapy. Survival was stratified by the log of the intoxicant's octanol-water partition coefficient. We also assessed the association between intoxicant lipophilicity and an increase in systolic blood pressure after lipid emulsion administration.

RESULTS

We identified 134 patients, including 81 (60.4%) females. The median age was 40 years (interquartile range 21-75). One hundred and eight (80.6%) patients survived, including 45 (33.6%) with cardiac arrest during their intoxication. Eighty-two (61.2%) were hypotensive, and 98 (73.1%) received mechanical ventilation. There was no relationship between survival and the log of the partition coefficient of the intoxicant on linear analysis (P = 0.89) or polynomial model (P = 0.10). Systolic blood pressure increased in both groups. The median (interquartile range) systolic blood pressure before lipid administration was 68 (60-78) mmHg for those intoxicants with a log partition coefficient < 3.6 compared with 89 (76-104) mmHg after lipid administration. Among those drugs with a log partition coefficient > 3.6, the median (interquartile range) was 69 (60-84) mmHg before lipid and 89 (80-96) mmHg after lipid administration.

CONCLUSION

Most patients in this cohort survived. Lipophilicity was not correlated with survival or the observed changes in blood pressure. The study did not address the efficacy of lipid emulsion.