Review of the effect of intravenous lipid emulsion on laboratory analyses

Intravenous lipid emulsion interference in coagulation testing: an ex vivo analysis

INTRODUCTION

Intravenous lipid emulsion is used in the rescue treatment of certain poisonings. A complication is interference with laboratory analyses. The aim of this study was to determine the impact of intravenous lipid emulsion on routine laboratory analysis of coagulation parameters ex vivo and determine if any of the analytical techniques remain reliable.

METHODS

Samples were obtained from 19 healthy volunteers and divided in triplicate. One sample served as a control, and the other two were diluted to simulate the treatment of an average adult with Intralipid® 20 per cent Fresenius Kabi 100 mL (dilution-1) or 500 mL (dilution-2). Coagulation tests performed were prothrombin time, activated prothrombin time, D-dimer concentration and fibrinogen. Coagulation testing was performed by three techniques. Test-1 was performed on a Sysmex CN6000 analyzer. Test-2 was performed with a manual mechanical endpoint method using the semi-automated Stago KC4 Delta. Test-3 involved high-speed centrifugation before repeat testing on the Sysmex CN6000 analyzer.

RESULTS

For test-1, only nine (47 per cent) samples in dilution-1 could be analyzed for coagulation tests, and no coagulation tests could be analyzed for dilution-2 because of lipaemia. For test-2 and test-3, all samples could be analyzed, and all results of both testing methods fell within the limits of the laboratory reference range.

DISCUSSION

Difficulties in laboratory analysis of patients having received intravenous lipid emulsion are due to multiple factors. Most automated coagulation analyzers use optical measurements, which can be unreliable in the presence of a high intravenous lipid concentration. By altering the lipaemia in the testing solution using high-speed centrifugation or by using manual mechanical endpoint detection, we were able to obtain reliable results. These findings are limited by the use of an ex vivo method and healthy volunteers.

CONCLUSIONS

This ex vivo model confirms that Intralipid® interferes with routine coagulation studies. It is important that clinicians are aware and inform their laboratories of its administration.

The Clinical Toxicology Recommendations Collaborative: purpose, organization, and methodology

INTRODUCTION

Scientific societies aim to provide a collective voice and unified stance on important issues. The Clinical Toxicology Recommendations Collaborative was formed in 2016 to develop evidence- and consensus-based recommendations for the management of patients exposed to common and/or serious poisonings for which the management is unclear or controversial.

ORGANIZATION

The Clinical Toxicology Recommendations Collaborative is led jointly by the American Academy of Clinical Toxicology, the Asia Pacific Association of Medical Toxicology, and the European Association of Poison Centres and Clinical Toxicologists. The Governance Committee is chaired by a Past-President of one of these Societies and comprised of the six Presidents and Immediate Past-Presidents of the three Societies. A Steering Committee oversees the process of each project workgroup.

METHODOLOGY

The overall process is guided by standards set forth by the Institute of Medicine for developing trustworthy guidelines and the Appraisal of Guidelines for Research and Evaluation Instrument. Systematic reviews are produced using the framework set in the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) methodology. Workgroup members jointly review the evidence and prepare statements on which they vote anonymously using a 9-point Likert scale. A two-round modified Delphi method is used to reach a consensus on clinical recommendations using the RAND/UCLA Appropriateness Method. Final recommendations are approved by unanimous consent of the workgroup and are expressed as both levels of evidence and strength of recommendations.

LIMITATIONS

The major limitations of the Clinical Toxicology Recommendations Collaborative process centre around the amount and quality of evidence, the assessment of that evidence, and the voting of the panel.

CONCLUSIONS

By using a transparent evidence- and consensus-based approach to produce systematic reviews and clinical recommendations, the Clinical Toxicology Recommendations Collaborative aims to create an international framework for clinical toxicology education and decision-making and foster positive change for the benefit of poisoned patients.

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.

Determination of lipemia acceptance thresholds for 31 immunoassay analytes

BACKGROUND

Lipemia is one of common endogenous interferences that can compromises sample quality and potentially influence results of various laboratory methods. Determination of the lipemic index or triglyceride concentrations are used to define the degree of lipemia. This study was aimed to establish lipemic index (LI) and triglyceride thresholds above where significant interference exists for 31 immunoassay analytes measured on Roche Cobas 6000.

MATERIALS AND METHODS

The study was carried out following CLSI C56-A and EP07-ED3:2018 guidelines using sample pools spiked with increasing concentrations of lipid emulsion solution, reaching 70 mmol/L. To define the LI and triglyceride thresholds, the bias from concentration in the native sample was calculated at different lipemia degree and compared with allowable error limits based on biological variation or state-of-the-art technology.

RESULTS

No lipemia interference was observed for 27 out of 31 analytes even at the highest concentrations of lipid emulsion (LI ranging from 1737 to 2086 mg/dL, triglyceride concentration 60.34-73.99 mmol/L). However, progesterone, 25-OH vitamin D, testosterone, and estradiol were negatively affected by lipemia at 217 mg/dL (9.58 mmol/L), 222 mg/dL (10.66 mmol/L), 478 mg/dL (18.81 mmol/L), and 941 mg/dL (35.82 mmol/L) of the LI (triglyceride concentration), respectively.

CONCLUSION

Most immunoassays evaluated in this study were found to be robust to lipemia interference. By using these thresholds, laboratories can report the immunoassay results from analyzing a lipemic patient sample in many cases.

Lipid Emulsion to Treat Acute Poisonings: Mechanisms of Action, Indications, and Controversies

Biodetoxification using intravenous lipid emulsion (ILE) in acute poisoning is of growing interest. As well as for local anesthetics, ILE is currently used to reverse toxicity caused by a broad-spectrum of lipophilic drugs. Both pharmacokinetic and pharmacodynamic mechanisms have been postulated to explain its possible benefits, mainly combining a scavenging effect called "lipid sink" and cardiotonic activity. Additional mechanisms based on ILE-attributed vasoactive and cytoprotective properties are still under investigation. Here, we present a narrative review on lipid resuscitation, focusing on the recent literature with advances in understanding ILE-attributed mechanisms of action and evaluating the evidence supporting ILE administration that enabled the international recommendations. Many practical aspects are still controversial, including the optimal dose, the optimal administration timing, and the optimal duration of infusion for clinical efficacy, as well as the threshold dose for adverse effects. Present evidence supports the use of ILE as first-line therapy to reverse local anesthetic-related systemic toxicity and as adjunct therapy in lipophilic non-local anesthetic drug overdoses refractory to well-established antidotes and supportive care. However, the level of evidence is low to very low, as for most other commonly used antidotes. Our review presents the internationally accepted recommendations according to the clinical poisoning scenario and provides the precautions of use to optimize the expected efficacy of ILE and limit the inconveniences of its futile administration. Based on their absorptive properties, the next generation of scavenging agents is additionally presented. Although emerging research shows great potential, several challenges need to be overcome before parenteral detoxifying agents could be considered as an established treatment for severe poisonings.

Propofol-induced interference with activated partial thromboplastin time-based monitoring of therapeutic heparin anticoagulation

PURPOSE

The activated partial thromboplastin time (aPTT) is a coagulation assay commonly utilized for monitoring therapeutic heparin anticoagulation. aPTT methods based on optical detection are vulnerable to spectral interference from hemolysis, icterus, lipemia, and other substances. Intravenous lipid emulsions of primarily 20% have been shown to interfere with multiple clinical laboratory assays, including those measuring aPTT by optical methods, but there is limited data on propofol's effect. The primary objective of this study was to determine the rate of interference of propofol with aPTT measurements in patients receiving both propofol and intravenous heparin.

METHODS

A retrospective observational cohort study of intensive care unit patients who received concomitant propofol and heparin infusions (N = 38 patients) and whose heparin therapy was monitored by aPTT (N = 531 aPTTs) was conducted. Review of the electronic medical record was completed to obtain relevant clinical and laboratory data, while the laboratory information system was queried for analytical interference with the aPTT assay.

RESULTS

A total of 109 aPTTs (21%) spanning 21 patients (55%) had documented aPTT interference. All 21 patients had at least one aPTT requiring ultracentrifugation prior to reporting, and 12 aPTTs from 4 patients were unreportable due to interference. Patients with and without aPTT interference received similar doses of propofol. None of the cases of aPTT interference were caused by hemolysis or hyperbilirubinemia.

CONCLUSION

A potential medication-assay interaction was observed in approximately half of patients who received concomitant propofol and heparin infusions and had aPTT measured for anticoagulation management. Sample ultracentrifugation removes the optical interference in most cases but significantly prolongs aPTT reporting and delays appropriate adjustments to heparin dosing.

Cardio Protective Effects of Lipid Emulsion against Ropivacaine-Induced Local Anesthetic Systemic Toxicity—An Experimental Study

Inadvertent intravascular injection of local anesthetics (LA) during regional anesthesia causes Local Anesthetic Systemic Toxicity (LAST). Theories of lipid rescue in the case of LAST proved that the administration of lipids in LAST has beneficial effects. One possible mechanism of action is based on the lipophilic properties of LA which allow plasma-free LA to be bound by the molecules of Lipid Emulsion (LE). The association LA–LE is shuttled towards organs such as liver and the kidneys, and the half-life of LA is shortened. The main objective of this experimental study was to assess the possible cardio-prophylactic effect of LE administration before the induction of LAST by intravenous administration of Ropivacaine. This was an experimental, interventional, prospective, and non-randomized study. The subjects were divided into groups and received, under general anesthesia, LE 20% first 0.3–0.4 mL, followed by 0.1 mL Ropivacaine 2 mg/mL, or Ropivacaine alone. At the end of the experiment, the subjects were sacrificed, and tissue samples of kidney, heart and liver were harvested for histopathological examination. LE, when administered as prophylaxis in Ropivacaine-induced LAST, had protective cardiac effects in rats. The LE known side effects were not produced if the substance was administered in the low doses used for LAST prophylaxis.

Successful treatment of local anaesthetic toxicity using intralipid 20% emulsion following intrathoracic bupivacaine overdose in a cat

Case summary

An 8.75-year-old male neutered Burmese cat was referred for treatment of pyothorax. The cat was responsive, cardiovascularly stable and tachypnoeic (40 breaths/min) on arrival. Medical management of pyothorax was initiated, bilateral thoracic drains were placed and thoracic lavage using aliquots of saline 0.9% was performed every 4 h. Regional analgesia was provided using 1 mg/kg of intrapleural bupivacaine divided equally between the left and right hemithoraxes every 6 h. On the second day of hospitalisation, the cat developed hypersalivation, mydriasis and tonic–clonic seizure activity 25 mins after accidental intrapleural administration of a 10 mg/kg bupivacaine overdose. Cardiovascular compromise was also noted; the cat became bradycardic (120 beats/min) and blood pressure decreased to 110 mmHg. Clinical signs resolved after administration of intravenous lipid emulsion (ILE) as an intravenous (IV) bolus (1.5 ml/kg over 5 mins), followed by a continuous rate infusion (0.25 ml/kg/min over 25 mins). Local anaesthetic intrapleural anaesthesia was discontinued. There was recrudescence of clinical signs 10 h post-overdose and repeat ILE 20% infusion was required. The cat was discharged with no ongoing complications.

Relevance and novel information

Treatment of IV local anaesthetic systemic toxicity with ILE has been reported in cats. To our knowledge, this is the first reported case of intrapleural bupivacaine overdose with initial response and resolution of clinical signs followed by recrudescence and subsequent successful treatment using ILE.

Methods to reduce lipemic interference in clinical chemistry tests: a systematic review and recommendations

OBJECTIVES

Lipemia is the presence of abnormally high lipoprotein concentrations in serum or plasma samples that can interfere with laboratory testing. There is little guidance available from manufacturers or professional bodies on processing lipemic samples to produce clinically acceptable results. This systematic review summarizes existing literature on the effectiveness of lipid removal techniques in reducing interference in clinical chemistry tests.

METHODS

A PubMed search using terms relating to lipid removal from human samples for clinical chemistry tests produced 1,558 studies published between January 2010 and July 2021. 15 articles met the criteria for further analyses.

RESULTS

A total of 66 analytes were investigated amongst the 15 studies, which showed highly heterogenous study designs. High-speed centrifugation was consistently effective for 13 analytes: albumin, alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin, creatine kinase (CK), creatinine (Jaffe method), gamma-glutamyl transferase (GGT), glucose (hexokinase-based method), lactate dehydrogenase (LDH), phosphate, potassium, and urea. Lipid-clearing agents were uniformly effective for seven analytes: ALT, AST, total bilirubin, CK, creatinine (Jaffe method), lipase, and urea. Mixed results were reported for the remaining analytes.

CONCLUSIONS

For some analytes, high-speed centrifugation and/or lipid-clearing agents can be used in place of ultracentrifugation. Harmonized protocols and acceptability criteria are required to allow pooled data analysis and interpretation of different lipemic interference studies.

Les médicaments qui interfèrent avec les bilans biologiques : revue de la littérature

BACKGROUND

Biological assessment is an integral part of the diagnostic process that guides therapeutic management decisions. However, these analyses remain subject to interference from endogenous or exogenous factors, which may alter the results.

OBJECTIVE

To provide an up-to-date and comprehensive overview of the most commonly documented types of interference attributable to medications, to ensure reliable interpretation of test results and better management of patients.

DATA SOURCES

This comprehensive systematic review of the literature was carried out in 2018. The bibliographic search was carried out in various online databases, specifically PubMed, ScienceDirect and Google Scholar.

STUDY SELECTION

Only publications in French or English concerning medicinal products for human use were retained. The investigators' examination of drug-related interference with laboratory tests was limited to blood assays (serum or plasma).

DATA EXTRACTION

An Excel spreadsheet was used to analyze the results. A total of 82 articles were selected. The interferences studied affected 47 biological parameters corresponding to various types of assessment: hormonal, hepatic, and renal.

DATA SYNTHESIS

The mechanisms reported in the literature identified were analytical (56.9%), physiological (17.82%), and pharmacological (20.11%). The remainder of the mechanisms (5.17%) were not defined.

CONCLUSIONS

Clinicians should be vigilant in validating and interpreting laboratory test results for patients receiving these types of drugs. Dialogue between clinicians and biological scientists is the best way to avoid unnecessary additional testing, which is often cumbersome and costly.

Antidotal use of lipid emulsion - the pendulum swings

Intravenous lipid emulsion (ILE) is a widely accepted treatment for local anesthetic systemic toxicity (LAST), particularly resulting from bupivacaine. The past decade has seen interest in antidotal use of ILE for other poisonings wax and wane. Numerous anecdotes have raised enthusiasm while more rigorous reviews have cast skepticism. The truth may lie between these two poles.We illustrate the recent trends in published reports on ILE. We highlight the gaps in our knowledge and suggest sources of data that may clarify how useful ILE may be for poisonings other than LAST. We offer the example of bupropion, which is hazardous in overdose and which has a Log P (octanol-water partition coefficient) similar to that of bupivacaine.Current data sources including the AAPCC National Poison Data System (NPDS), the ACMT Toxic Investigators Consortium (ToxIC), and a voluntary online registry (www.lipidrescue.org) each give an incomplete view of the problem. We propose analysis of newer NPDS data, which will include ILE as a treatment field code beginning with the 2019 data, and a structured, prospective registry of antidotal use of ILE for poisonings other than LAST.

A case of local anesthetic toxicity that wasn't: lipid rescue from self-administered benzodiazepine overdose in labor

A 32-year-old G2P1 woman presented for induction of labor at term. Her past medical history included polysubstance use disorder and methadone maintenance, scant prenatal care, morbid obesity, and intimate partner violence. Her induction was progressing smoothly until the acute onset of altered mental status near to the time of delivery, several minutes after a clinician-administered epidural local anesthetic bolus for significant pain. Given concern about local anesthetic systemic toxicity, lipid emulsion was administered and resulted in an immediate and drastic clinical response. The epidural infusion bag and pump system were evaluated and found to be correct and there was no clinical suspicion of an intravascular epidural catheter. The woman remained stable and was transferred to the postpartum unit, where she experienced a similar episode of altered mental status approximately 12 h postpartum. This episode self-resolved and she was managed conservatively. Shortly after this event, it was discovered that the patient had been self-administering benzodiazepines throughout the course of her labor, in addition to her hospital staff-administered medications. Presumably, her intrapartum altered mental status was a result of self-administered benzodiazepine that was then "rescued" with lipid emulsion. This case illustrates the potential for lipid emulsion as a reversal agent for medications other than local anesthetics.

Clinical Pearls in Medical Toxicology: Updates Ranging From Decontamination to Elimination

Such as any field of medicine, it is imperative to stay current with the latest advances and treatment modalities in toxicology. With the absence of rigorous randomized controlled trials, many updated guidelines are created by expert consensus and/or case reports and clinical experience. Over the past 10 years, there have been several changes in the management of drug overdoses in light of new data available. Although this is not a comprehensive review of all available antidotes, this article will focus on several important interventions including the use of gastrointestinal decontamination, hyperinsulinemic-euglycemic therapy, methylene blue, intravenous lipid emulsion, hemodialysis, and extracorporeal membrane oxygenation.

Precision, accuracy, cross reactivity and comparability of serum indices measurement on Abbott Architect c8000, Beckman Coulter AU5800 and Roche Cobas 6000 c501 clinical chemistry analyzers

BACKGROUND

The aim of our study was to perform verification of serum indices on three clinical chemistry platforms.

METHODS

This study was done on three analyzers: Abbott Architect c8000, Beckman Coulter AU5800 (BC) and Roche Cobas 6000 c501. The following analytical specifications were verified: precision (two patient samples), accuracy (sample with the highest concentration of interferent was serially diluted and measured values compared to theoretical values), comparability (120 patients samples) and cross reactivity (samples with increasing concentrations of interferent were divided in two aliquots and remaining interferents were added in each aliquot. Measurements were done before and after adding interferents).

RESULTS

Best results for precision were obtained for the H index (0.72%-2.08%). Accuracy for the H index was acceptable for Cobas and BC, while on Architect, deviations in the high concentration range were observed (y=0.02 [0.01-0.07]+1.07 [1.06-1.08]x). All three analyzers showed acceptable results in evaluating accuracy of L index and unacceptable results for I index. The H index was comparable between BC and both, Architect (Cohen's κ [95% CI]=0.795 [0.692-0.898]) and Roche (Cohen's κ [95% CI]=0.825 [0.729-0.922]), while Roche and Architect were not comparable. The I index was not comparable between all analyzer combinations, while the L index was only comparable between Abbott and BC. Cross reactivity analysis mostly showed that serum indices measurement is affected when a combination of interferences is present.

CONCLUSIONS

There is heterogeneity between analyzers in the hemolysis, icteria, lipemia (HIL) quality performance. Verification of serum indices in routine work is necessary to establish analytical specifications.

Effects of high-dose, intravenous lipid emulsion on laboratory tests in humans: a randomized, placebo-controlled, double-blind, clinical crossover trial

Background

Intravenous lipid emulsion (ILE) is used to treat drug poisonings. The resultant hyperlipemia may affect laboratory tests but the consequences are poorly characterized. In a clinical trial we therefore investigated the effects of ILE on laboratory tests analyzed on common analytical platforms (Roche®cobas 8000 and SYSMEX®flow-cytometry).

Methods

Ten healthy participants each completed 4 trial days (two with ILE and two with placebo). ILE (5.25 mL/kg) was administered from 12.5 to 30 min from baseline. At 0, 30 and 60 min, blood samples were drawn for measurement of 20 analytes. We investigated the effects of ILE on analyte levels and frequencies of exceedance of predefined analyzer hemolysis (H) or lipemia (L)-index cut-offs and test-specific reference change values (RCVs) on ILE-days. If the results were blocked due to exceedance of index values, we manually extracted the results.

Results

Sixteen out of 20 tests were blocked because H- or L-index cut-offs were exceeded on ILE-days. Differences in analyte levels between ILE- and placebo-days above the RCV were observed for aspartate aminotransferase, total calcium, lactate dehydrogenase (LDH), sodium and neutrophils. Mean values outside the normal range after ILE were observed for LDH (219 U/L), sodium (135.3 mmol/L) and total calcium (2.1 mmol/L).

Conclusions

ILE-infusion caused report failure of nearly all laboratory tests performed on a cobas 8000-platform, but it was possible to manually retrieve the results. For most test results – particularly alkaline phosphatase, bilirubin, phosphate and carbamide – the consequences of ILE were marginal, and the effects of ILE were reduced at the 60-min timepoint.

Use of lipid emulsion therapy in local anesthetic overdose

The use of intravenous lipid emulsion (ILE) therapy as antidote in systemic toxicity of certain agents has gained widespread support. There are increasing data suggesting use of ILE in reversing from local anesthetic-induced systemic toxicity severe, life-threatening cardiotoxicity, although findings are contradictory. Efficiency of ILE was demonstrated in animal studies in the treatment of severe impairment of cardiac functions, via a mechanism for trapping lipophilic drugs in an expanded plasma lipid compartment (“lipid sink”). In patients with hemodynamic compromise and/or cardiovascular collapse due to lipid-soluble agents, ILE may be considered for resuscitation in the acute setting by emergency physicians. The most common adverse effects from standard ILE include hypertriglyceridemia, fat embolism, infection, vein irritation, pancreatitis, electrolyte disturbances and allergic reactions. The advantages of ILE include an apparent wide margin of safety, relatively low cost, long shelf-life, and ease of administration.

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.

Variability and Error in Cardiac Troponin Testing: An ACLPS Critical Review

OBJECTIVES

To provide a comprehensive overview of the complexities associated with cardiac troponin (cTn) testing. An emphasis is placed on the sources of error, organized into the preanalytical, analytical, and postanalytical phases of the testing pathway. Controversial areas are also explored.

METHODS

A case scenario and review of the relevant literature describing laboratory considerations involving cTn testing are described.

RESULTS

Advanced comprehension of the specific assay used in a given laboratory is necessary for optimal reporting, utilization, and quality monitoring of cTn.

CONCLUSIONS

cTn assays are reliable diagnostic tests for acute myocardial infarction, but understanding their limitations is required for appropriate result interpretation.

Frequency and causes of lipemia interference of clinical chemistry laboratory tests

Objectives

The aims of this study were to identify the causes of severe lipemia in an academic medical center patient population and to determine the relationship between lipemia and hemolysis.

Design and methods

Retrospective study was done on the data from the core clinical laboratory at an academic medical center. Lipemic indices were available for all chemistry specimens analyzed over a 16-month period (n=552,029 specimens) and for serum/plasma triglycerides concentrations ordered for clinical purposes over a 16-year period (n=393,085 specimens). Analysis was performed on Roche Diagnostics cobas 8000 analyzers. Extensive chart review was done for all specimens with lipemic index greater than 500 (severely lipemic) and for all specimens with serum/plasma triglycerides greater than 2000 mg/dL. We also determined the relationship between lipemia and hemolysis.

Results

The most frequent suspected causes of very high lipemic index (>500) were found to be lipid-containing intravenous infusions (54.4% of total; fat emulsions for parenteral nutrition – 47%; propofol −7.4%) and diabetes mellitus (25% of total, mainly type 2). The most frequent suspected causes of very elevated serum/plasma triglycerides (>2000 mg/dL) was diabetes mellitus (64%, mainly type 2) and hyperlipidemia (16.9%). The frequency of hemolysis increased with increasing lipemic index.

Conclusions

Intravenous lipid infusions and type 2 diabetes were the most common causes of severe lipemia in this study at an academic medical center. Given that iatrogenic factors are the most common cause of severe lipemia, education and intervention may be helpful in reducing frequency of severe lipemia in patient specimens.

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Intravenous lipids and type 2 diabetes were most common causes of severe lipemia.

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The frequency of hemolysis increased with increasing lipemic index.

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Diabetes type 2 was the most common cause of extreme hypertriglyceridemia.

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Education and intervention may be helpful in reducing frequency of lipemia.

Lipid Therapy for Intoxications

This review discusses the use of intravenous lipid emulsion (ILE) in the treatment of intoxications with lipophilic agents in veterinary medicine. Despite growing scientific evidence that ILE has merit in the treatment of certain poisonings, there is still uncertainty on the optimal composition of the lipid emulsion, the dosing, the mechanism of action, and the efficacy. Therefore, a critical view of the clinician on the applicability of this modality in intoxications is still warranted. The use of ILE therapy is advocated as an antidote in cases of intoxications with some lipophilic substances.

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.

Who gets antidotes? choosing the chosen few

An understanding of mechanisms, potential benefits and risks of antidotes is essential for clinicians who manage poisoned patients. Of the dozens of antidotes currently available, only a few are regularly used. These include activated charcoal, acetylcysteine, naloxone, sodium bicarbonate, atropine, flumazenil, therapeutic antibodies and various vitamins. Even then, most are used in a minority of poisonings. There is little randomized trial evidence to support the use of most antidotes. Consequently, decisions about when to use them are often based on a mechanistic understanding of the poisoning and the expected influence of the antidote on the patient's clinical course. For some antidotes, such as atropine and insulin, the doses employed can be orders of magnitude higher than standard dosing. Importantly, most poisoned patients who reach hospital can recover with supportive care alone. In low risk patients, the routine use of even low risk antidotes such as activated charcoal is unwarranted. In more serious poisonings, decisions regarding antidote use are generally guided by a risk/benefit assessment based on low quality evidence.