Lipid emulsion use precluding renal replacement therapy

Metabolic disturbances potentially attributable to clogging during continuous renal replacement therapy

BACKGROUND

Clogging is characterized by a progressive impairment of transmembrane patency in renal replacement devices and occurs due to obstruction of pores by unknown molecules. If citrate-based anti-coagulation is used, clogging can manifest as a metabolic alkalosis accompanied by hypernatremia and hypercalcemia, primarily a consequence of Na3Citrate infusion. An increased incidence of clogging has been observed during the COVID-19 pandemic. However, precise factors contributing to the formation remain uncertain. This investigation aimed to analyze its incidence and assessed time-varying trajectories of associated factors in critically ill patients on continuous renal replacement therapy (CRRT).

METHODS

In this retrospective, single-center data analysis, we evaluated COVID-19 patients undergoing CRRT and admitted to critical care between March 2020 and December 2021. We assessed the proportional incidence of clogging surrogates in the overall population and subgroups based on the specific CRRT devices employed at our institution, including multiFiltrate (Fresenius Medical Care) and Prismaflex System (Baxter). Moderate and severe clogging were defined as Na > 145 or ≥ 150 mmol/l and HCO3- > 28.0 or ≥ 30 mmol/l, respectively, with a total albumin-corrected calcium > 2.54 mmol/l. A mixed effect model was introduced to investigate factors associated with development of clogging.

RESULTS

Fifty-three patients with 240 CRRT runs were analyzed. Moderate and severe clogging occurred in 15% (8/53) and 19% (10/53) of patients, respectively. Twenty-seven percent (37/136) of CRRTs conducted with a multiFiltrate device met the criteria for clogging, whereas no clogging could be observed in patients dialyzed with the Prismaflex System. Occurrence of clogging was associated with elevated triglyceride plasma levels at filter start (p = 0.013), amount of enteral nutrition (p = 0.002) and an increasing white blood cell count over time (p = 0.002).

CONCLUSIONS

Clogging seems to be a frequently observed phenomenon in critically ill COVID-19 patients. The presence of hypertriglyceridemia, combined with systemic inflammation, may facilitate the development of an impermeable secondary membrane within filters, thereby contributing to compromised membrane patency.

Local anaesthetic systemic toxicity complicating intraoperative intercostal nerve blocks: What do clinicians need to know to prevent similar occurrence?

Local anaesthetic systemic toxicity is a life-threatening adverse event that may occur after administration of local anaesthetics through a variety of routes. Local anaesthetic systemic toxicity is always a potential complication and may occur with all local anaesthetics and in any route of administration. Local anaesthetic systemic toxicity primarily affects the central nervous system and the cardiovascular system and may be fatal. The following is a case of local anaesthetic systemic toxicity complicating surgeon-performed intraoperative intercostal nerve blocks at multiple levels, with a mixture of liposomal bupivacaine and bupivacaine hydrochloride in a patient who underwent video-assisted segmental lung resection for lung cancer under general anaesthesia. Local anaesthetic systemic toxicity presented with seizures and hypotension. The patient was successfully managed and fully recovered. This case illustrates the importance of awareness regarding the prevention, diagnosis and treatment of local anaesthetic systemic toxicity among medical professionals who administer local anaesthetics.

Multi-organ dysfunction as a presentation of calcium channel blocker intoxication

SummaryWe report the case of a 73-year-old woman who intentionally ingested 400 mg of amlodipine in a suicidal attempt who initially presented with hypotension which persisted despite aggressive therapy with fluid resuscitation, multiple pressor support, high-dose insulin therapy and calcium infusion. Her haemodynamic instability evolved to include bradycardia requiring atropine and transcutaneous pacing. Eventually she required salvage therapy with intravenous lipid emulsion (ILE) therapy . Despite all aggressive therapy, she developed multi-organ failure resulting in death. The literature on high-dose insulin euglycaemic therapy (HIET) and ILE therapy shows mixed results with some showing significant improvement in haemodynamic status. In our case, it had no significant positive impact on the outcome.

Bupropion Overdose Complicated by Cardiogenic Shock Requiring Vasopressor Support and Lipid Emulsion Therapy

BACKGROUND

Bupropion overdose is a commonly encountered presentation in the emergency department (ED). While the majority of cases resolve with supportive care, serious adverse effects, including seizures, cardiogenic shock, and death, can occur. Intravenous lipid emulsion (ILE) therapy has been utilized for a multitude of poisonings with varying levels of success. Although a number of cases suggest the value of ILE therapy in cases of bupropion overdose, more recent data propose that its role may be overstated.

CASE REPORT

A young woman presented to the ED with altered mental status complicated by seizure after bupropion overdose. She subsequently developed cardiogenic shock requiring vasopressor support. Bedside echocardiogram revealed a decreased left ventricular ejection fraction (LVEF). She received ILE therapy with significant improvement in both hemodynamic status and LVEF by bedside ultrasound. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Although the majority of patients presenting with bupropion overdose improve with supportive care, life-threatening sequelae are possible. ILE therapy has shown promise in a variety of different overdose situations, although the evidence in cases of bupropion poisoning has been varied, and it has traditionally been utilized as a last-line rescue modality. Based on hemodynamic parameters and bedside ultrasound, this case suggests that early initiation of ILE therapy should be considered in these cases, as the potential benefits likely outweigh the theoretical risks.

Literature review of the evidence regarding intravenous lipid administration in drug-induced cardiotoxicity

Introduction: Intravenous lipid emulsion (ILE) administration is capable of reversing the acute cardiac and neurological toxicity caused by local anesthetic agents. In recent years, ILE has also been explored as a potential antidote for cardiotoxicity caused by non-anesthetic agents too. Areas covered: The potential mechanisms, safety, and efficacy of this approach are considered. Data were sought from published reports listed in PubMed and EMBASE, and abstracts of meetings of the North American Congress of Clinical Toxicology and European Association of Poisons Centres and Clinical Toxicologists. There were reports involving 298 patients where ILE has been administered for severe drug toxicity. Clinical improvement was observed in 57 of 59 patients with local anesthetic toxicity (96.6%); there were 239 patients where toxicity was due to non-anesthetic agents, and ILE apparently improved clinical outcome in 215 (72.1%). Expert opinion: Response rates were similar between ILE treated toxicity caused by lipid soluble and non-lipid soluble drugs. Potential adverse effects of ILE include interference with laboratory assays, acute pancreatitis, and adult respiratory distress syndrome, although the rate of occurrence is difficult to ascertain.

Practical guide for the management of systemic toxicity caused by local anesthetics

Systemic toxicity from local anesthetics can occur in any of the wide range of situations in which these agents are used. This practical guide is created to generate a shared awareness of the prevention, diagnosis, and treatment of local anesthetic systemic toxicity among all medical professionals who perform nerve blocks. Systemic toxicity of local anesthetic is induced by an increase of its protein-unbound plasma concentration. Initial symptoms are characterized by central nervous system signs such as excitation, convulsions, followed by loss of consciousness and respiratory arrest. These symptoms are often accompanied with cardiovascular signs such as hypertension, tachycardia and premature ventricular contractions. Further increase of plasma concentration of local anesthetic induces bradycardia, conduction disturbances, circulatory collapse and asystole. The incidence of local anesthetic systemic toxicity is 1-11 cases per 10,000. Infants, patients with decreased liver function and low cardiac output are vulnerable to systemic toxicity. When performing regional anesthesia, the guideline-directed monitoring, securing a venous line, preparation of medication to treat convulsions and lipid emulsions are required. For prevention of local anesthetic systemic toxicity, small-dose, divided administration, using agents with low toxicity such as ropivacaine and levobupivacaine, performing an aspiration test are recommended. If systemic toxicity is suspected, halt administration of local anesthetic, request assistance, secure venous line, airway, administration of 100% oxygen and if necessary tracheal intubation and artificial respiration should be immediately performed. Benzodiazepines are recommended to treat convulsions. Administration of 20% lipid emulsion according to the protocol is recommended to treat severe hypotension and arrhythmia.

Hemodynamic Effects of Intravenous, High-Dose Lipid Emulsion With and Without Metoprolol Infusion in Healthy Volunteers: A Randomized Clinical Trial

In a double-blinded, randomized, crossover trial, we investigated the hemodynamic effects of high-dose intravenous lipid emulsion (ILE) with/without metoprolol. Ten healthy volunteers each completed 4 trial days (placebo + ILE; metoprolol + placebo; metoprolol + ILE; placebo + placebo) in random order. Metoprolol was administered as an initial bolus (10 mg), followed by an infusion (50 mg) from 5 to 30 minutes. ILE was administered as a bolus at 12.5 minutes (2.5 mL/kg), followed by a 15-minute infusion (0.25 mL/kg per minute). On metoprolol + ILE days (compared with metoprolol + placebo) after 120 minutes, mean heart rates were significantly higher (difference, 5.5 beats per minute (bpm); 95% confidence interval (CI), 3.0-8.1 bpm; P < 0.001), and average relative cardiac output was higher (difference, 10 percentage points; 95% CI, 5-15 percentage points; P < 0.001). The hemodynamic effect of ILE developed gradually. ILE had no effect on plasma metoprolol or major adverse events. In conclusion, high-dose ILE has relatively marginal and delayed hemodynamic effects that may have limited clinical relevance in the short-term clinical toxicological setting.

Lipid emulsion in local anesthetic toxicity

PURPOSE OF REVIEW

Enthusiasm for regional anesthesia has been driven by multimodal benefits to patient outcomes. Despite widespread awareness and improved techniques (including the increasing use of ultrasound guidance for block placement), intravascular sequestration and the attendant risk of local anesthetic systemic toxicity (LAST) remains. Intravenous lipid emulsion (ILE) for the treatment of LAST has been endorsed by anesthetic regulatory societies on the basis of animal study and human case report data. The accumulated mass of reporting now permits objective interrogation of published literature.

RECENT FINDINGS

Although incompletely elucidated the mechanism of action for ILE in LAST seemingly involves beneficial effects on initial drug distribution (i.e., pharmacokinetic effects) and positive cardiotonic and vasoactive effects (i.e., pharmacokinetic effects) acting in concert. Recent systematic review by collaborating international toxicologic societies have provided reserved endorsement for ILE in bupivacaine-induced toxicity, weak support for ILE use in toxicity from other local anesthetics, and largely neutral recommendation for all other drug poisonings. Work since publication of these recommendations has concluded that there is a positive effect on survival for ILE when animal models of LAST are meta-analyzed and evidence of a positive pharmacokinetic effect for lipid in human models of LAST.

SUMMARY

Lipid emulsion remains first-line therapy (in conjunction with standard resuscitative measures) in LAST. Increasing conjecture as to the clinical efficacy of ILE in LAST, however, calls for high-quality human data to refine clinical recommendations.

Hypertriglyceridemia Causing Continuous Renal Replacement Therapy Dysfunction in a Patient with End-stage Liver Disease

Hypertriglyceridemia is infrequently reported as a cause of suboptimal delivery of dialytic therapy in critically ill patients. We report the case of a critically ill liver transplant patient in the Intensive Care Unit who was found to have recurrent filter clotting during continuous renal replacement therapy (CRRT). The patient had increased serum triglycerides (TGs), which was identified approximately 2 weeks into hospitalization and initially believed to be due to prolonged propofol use. The patient's elevated TGs ultimately caused her blood to become lipemic, causing the dialytic circuit to become nonfunctional and placed the patient in imminent danger due to hyperkalemia and metabolic acidosis. Therapeutic plasma exchange was emergently used to lower TG levels, and renal replacement therapy was resumed without any other issues. The patient's persistent hypertriglyceridemia was attributed to a combination of adverse effect of medications and liver graft failure. The high TG level and abnormal liver functions improved after a repeat liver transplantation.

Combination Clearance Therapy and Barbiturate Coma for Severe Carbamazepine Overdose

A 15-year-old female subject presented comatose, in respiratory failure and shock, after the intentional ingestion of ∼280 extended-release 200-mg carbamazepine tablets with a peak serum concentration of 138 µg/mL (583.74 µmol/L). The patient developed clinical seizures and an EEG pattern of stimulus-induced rhythmic, periodic, or ictal discharges, suggestive of significant cortical dysfunction. Due to the extremely high drug serum concentration and clinical instability, a combination of therapies was used, including lipid emulsion therapy, plasmapheresis, hemodialysis, continuous venovenous hemodiafiltration, and endoscopic intestinal decontamination. The patient's elevated serum lactate level with a high mixed venous saturation suggested possible mitochondrial dysfunction, prompting treatment with barbiturate coma to reduce cerebral metabolic demand. The serum carbamazepine concentration declined steadily, with resolution of lactic acidosis, no long-term end-organ damage, and return to baseline neurologic function. The patient was eventually discharged in her usual state of health. In the laboratory, we demonstrated in vitro that the active metabolite of carbamazepine hyperpolarized the mitochondrial membrane potential, supporting the hypothesis that the drug caused mitochondrial dysfunction. We thus successfully treated a life-threatening carbamazepine overdose with a combination of modalities. Future studies are required to validate this aggressive approach. The occurrence of mitochondrial dysfunction must be confirmed in patients with carbamazepine toxicity and the need to treat it validated.

No support for lipid rescue in oral poisoning: A systematic review and analysis of 160 published cases

Lipid rescue is used as treatment of various poisonings despite weak scientific evidence. Some experimental studies have indicated a positive effect, but others have not. Clinical studies are lacking, wherefore a systematic review of virtually all published human case reports is presented. The case reports were searched for in PubMed and Web of Science and examined by two experts according to an assessment form grading the probability for a causal connection between lipid rescue and improved symptoms. A total of 160 cases were finally included, of which 30 had no positive effect of lipid rescue. Among the 130 included cases with alleged positive effect, 94 were oral poisonings and 36 were cases with local anesthetic systemic toxicity (LAST). The experts’ assessment resulted in a “certain” causal connection in three cases with LAST but not in oral poisoning. Moreover, the mean assessment score among the oral poisonings was significantly worse than the corresponding score in the cases with LAST. The average log p-value of the main toxins among the oral poisonings was significantly lower than the corresponding p-value in the cases with LAST. Among the oral poisonings, 91% had received some other resuscitative treatment more or less simultaneously with lipid rescue. Considering the findings of this study and the increasingly reported adverse effects of lipid rescue, it’s reasonable to strictly limit its use in clinical practice. We would not recommend it in oral poisonings.

Systematic review of clinical adverse events reported after acute intravenous lipid emulsion administration

BACKGROUND

Intravenous lipid emulsions (ILEs) were initially developed to provide parenteral nutrition. In recent years, ILE has emerged as a treatment for poisoning by local anesthetics and various other drugs. The dosing regimen for the clinical toxicology indications differs significantly from those used for parenteral nutrition. The evidence on the efficacy of ILE to reverse acute toxicity of diverse substances consists mainly of case reports and animal experiments. Adverse events to ILE are important to consider when clinicians need to make a risk/benefit analysis for this therapy.

METHODS

Multiple publication databases were searched to identify reports of adverse effects associated with acute ILE administration for either treatment of acute poisoning or parenteral nutrition. Articles were selected based on pre-defined criteria to reflect acute use of ILE. Experimental studies and reports of adverse effects as a complication of long-term therapy exceeding 14 days were excluded.

RESULTS

The search identified 789 full-text articles, of which 114 met the study criteria. 27 were animal studies, and 87 were human studies. The adverse effects associated with acute ILE administration included acute kidney injury, cardiac arrest, ventilation perfusion mismatch, acute lung injury, venous thromboembolism, hypersensitivity, fat embolism, fat overload syndrome, pancreatitis, extracorporeal circulation machine circuit obstruction, allergic reaction, and increased susceptibility to infection.

CONCLUSION

The emerging use of ILE administration in clinical toxicology warrants careful attention to its potential adverse effects. The dosing regimen and context of administration leading to the adverse events documented in this review are not generalizable to all clinical toxicology scenarios. Adverse effects seem to be proportional to the rate of infusion as well as total dose received. Further safety studies in humans and reporting of adverse events associated with ILE administration at the doses advocated in current clinical toxicology literature are needed.