Lipid Therapy for Intoxications

Clinical effects and adverse effects of intravenous lipid emulsion treatment in dogs and cats with suspected poisoning

This retrospective study aimed to evaluate the effects on the clinical signs of poisoning and adverse effects of intravenous lipid emulsion treatment in 82 animals (dogs and cats) with suspected poisonings over 18 months. Physical examination parameters and state of consciousness were documented every hour after the intravenous administration of a bolus of 2 ml/kg and 0.25 ml/kg/min over 60 minutes of a 20% intravenous lipid emulsion. The modified Glasgow coma scale and laboratory findings (blood gas analysis, triglyceride, lactate) were evaluated initially and three hours after discontinuing intravenous lipid emulsion administration. A statistical evaluation of the occurrence of adverse effects and the development of laboratory values was performed. A decrease in respiratory rate in the second control (8-12 hours) after ILE was observed. Three hours after completing of the intravenous lipid emulsion, triglyceride concentration increased about 10 times (p <0.001). Venous carbon dioxide partial pressure, bicarbonate, base excess, as well as the electrolytes sodium, potassium and ionized calcium decreased significantly (p <0.001). Patients who experienced a worsening of the modified Glasgow coma scale had a higher increase in triglyceride concentrations (p = 0.041) and plasma lactate (p = 0.034) and a larger decrease in bicarbonate concentrations (p = 0.053) compared to others. About 54% (n = 44) of the patients showed adverse effects which could be attributed to the administration of intravenous lipid emulsion and may be associated with a higher triglyceride increase. All of them were completely reversible within 33 hours. Adverse effects associated with intravenous lipid emulsion therapy were observed in half of the patients and were associated with a higher increase in triglycerides.

Alpha-chloralose poisoning in 25 cats: clinical picture and evaluation of treatment with intravenous lipid emulsion

OBJECTIVES

The aims of this study were to describe the clinical picture and progression in cats with alpha-chloralose (AC) intoxication and to determine if treatment with intravenous (IV) lipid emulsion (ILE) influenced either the serum concentration of AC or the clinical signs.

METHODS

Cats with suspected AC poisoning admitted to a university small animal hospital were included. The cats were randomised into two groups: one receiving 20% ILE at a dose of 300 mg/kg as a 2 min bolus, followed by a 1500 mg/kg continuous rate infusion over 30 mins (IL+ group) and the other receiving IV fluid therapy with Ringer's acetate (IL- group). Serum samples were drawn at 0, 2, 12 and 24 h after admission. Samples were tested for AC with a novel validated, quantitative, ultra-high-performance liquid chromatography-tandem mass spectrometry method. Vital and predefined clinical signs were noted at the times of sampling and patients were scored using a previously described intoxication severity score. Telephone interviews were conducted after discharge to assess outcome.

RESULTS

A total of 25 cats were enrolled: 13 cats in the IL+ group and 12 in the IL- group. The most common clinical signs at presentation were tremor (n = 22, 88.0%), cranial nerve deficits (n = 20, 80.0%) and bradycardia (n = 19, 76.0%). No significant difference in AC concentration or change in intoxication score over time was found between the IL+ and IL- groups at any time point (P >0.05). All cats recovered within 72 h.

CONCLUSIONS AND RELEVANCE

ILE did not have any effect on the AC serum concentration or clinical signs in AC-poisoned cats. All cats survived until follow-up. In cats with an acute onset of the described neurological signs, AC intoxication is an important differential diagnosis with an excellent prognosis.

[Acute poisonings in dogs - a retrospective case study over 5 years]

OBJECTIVE

The aim of this retrospective study was to analyze the clinical signs, confirmed or suspected toxicants, treatments and outcomes of poisoning cases in dogs presented over a 5-year period to the emergency service of a small animal referral center.

MATERIAL AND METHODS

Medical records of 634 dogs were evaluated for a history of confirmed or presumed poisoning, suspected toxicant, clinical signs, treatment, and patient outcome. The probability of poisoning was graded based on the patient history, clinical findings, toxicologic examination and - in some cases - investigation of gastrointestinal contents.

RESULTS

Most dogs were hospitalized (77%) due to poisoning with mostly unknown toxicants (33%), food residues (18%), rodenticides (10%), tremorgenic mycotoxins (8%), medications (7%) and various plants (7%), followed by recreational drugs (5%), chemicals (4%), molluscicides (3%), antiparasitics (2%), feces (2%), nuts (2%), or toxins of animal origin (1%). Patients were presented predominantly showing neurologic signs (56%), reduced general condition (39%), and cardiovascular or hydration status abnormalities (26%). The survival rate was 97%. Most dogs were clinically unremarkable at the time of hospital discharge (70%). An additional 18% of the survivors had no apparent complications by the time of discharge. Toxicant-related complications (20.5%) included hemorrhage (4%), hepatic (4%), renal (4%), respiratory (3%), gastrointestinal (3%), cardiovascular (3%), and/or central nervous system (3%) complications, or clinically relevant hypoglycemia (0.3%).

CONCLUSION AND CLINICAL RELEVANCE

In the present study, poisoning in dogs was mostly associated with the ingestion of food residues, but the causative toxicant remained unidentified in many cases. Neurological signs were the major clinical presentation. The survival rate (97%) in this study was higher compared to those reported by other investigators.

The effect of intravenous lipid emulsion (ILE) on the pharmacokinetic/toxicokinetic dispositions of ivermectin and carprofen in rabbits

Intravenous lipid emulsion (ILE) has been widely used as an effective antidote in both veterinary and human medicine for the treatment of acute intoxications caused by drugs and pesticides with high lipid solubility. This study was conducted to investigate the effect of ILE co-administration on the kinetic dispositions of ivermectin (IVM) and carprofen (CRP) following intravenous bolus administration at subtoxic doses in rabbits.Twenty-four male New Zealand rabbits weighing 2.78 ± 0.2 kg were used in this study. Rabbits were divided into four groups (Group 1: IVM and Group 2: IVM + ILE or Group 3: CRP and Group 4: CRP + ILE), each group consisting of 6 animals. In the IVM study, Group 1 received IVM (0.6 mg/kg) alone while Group 2 received IVM (0.6 mg/kg) and ILE (2.5 ml/kg). In the CRP study, Group 3 received CRP (12 mg/kg) alone while Group 4 received CRP (12 mg/kg) and ILE (2.5 ml/kg). In both drug groups, ILE was administered 3 times as an i.v. bolus at the 10th min and repeated 4th and 8th h after the drug administration. Blood samples were collected from the auricular vein at various times after drug administration. The drug concentrations in plasma samples were determined by high-pressure liquid chromatography. Kinetic parameters were calculated using a non-compartmental model for both CRP and IVM.The C0 and area under the concentration-time curve from zero up to ∞ (AUC0-∞) values were significantly greater with ILE co-administration (2136 ng/ml and 360.84 ng.d/ml) compared to the IVM alone (1340.63 ng/ml and 206 ng.d/ml), respectively. Moreover, the volume of distribution (Vdss) and clearance (Cl) of IVM were reduced by approximately 42% and 46% with ILE co-administration compared to IVM alone resulting in a reduction of the distribution and slower elimination, respectively. Similar differences in C0, and Vdss values were also observed in CRP with ILE co-administration compared to CRP alone. ILE co-administration changed significantly the kinetic profile of both IVM and CRP in rabbits, supporting the lipid sink theory in which highly lipid-soluble compounds are absorbed into the lipid phase of plasma from peripheral organs such as the heart and brain affected by the acute toxicity of the compounds.

Management of acute carbamazepine poisoning: A narrative review

Standard management protocols are lacking and specific antidotes are unavailable for acute carbamazepine (CBZ) poisoning. The objective of this review is to provide currently available information on acute CBZ poisoning, including its management, by describing and summarizing various therapeutic methods for its treatment according to previously published studies. Several treatment methods for CBZ poisoning will be briefly introduced, their advantages and disadvantages will be analyzed and compared, and suggestions for the clinical treatment of CBZ poisoning will be provided. A literature search was performed in various English and Chinese databases. In addition, the reference lists of identified articles were screened for additional relevant studies, including non-indexed reports. Non-peer-reviewed sources were also included. In the present review, 154 articles met the inclusion criteria including case reports, case series, descriptive cohorts, pharmacokinetic studies, and in vitro studies. Data on 67 patients, including 4 fatalities, were reviewed. Based on the summary of cases reported in the included articles, the cure rate of CBZ poisoning after symptomatic treatment was 82% and the efficiency of hemoperfusion was 58.2%. Based on the literature review, CBZ is moderately dialyzable and the recommendation for CBZ poisoning is supportive management and gastric lavage. In severe cases, extracorporeal treatment is recommended, with hemodialysis as the first choice.

Intravenous lipid emulsion for the treatment of poisonings in 313 dogs and 100 cats (2016-2020)

Introduction

The aim of this retrospective study was to analyze the effect and potential adverse effects of intravenous lipid emulsion (ILE) in poisoned dogs and cats over a 5 years period.

Methods

Medical records of 313 dogs and 100 cats receiving ILE between 2016-2020 were analyzed for suspected toxicant, clinical signs, ILE dosages and frequency, the effect and adverse effects of ILE, and patient outcome.

Results

Dogs and cats were poisoned with mostly unidentified toxicants (48%), rodenticides (8%), recreational drugs and nuts (7% each) and other toxicants. Clinical signs included neurologic deficits (63%), cardiovascular signs (29%), thermoregulation (21%) or gastrointestinal abnormalities (17%). Treatment with ILE was initiated within a median of 6.0 h (1.0-91.0 h) after poisoning. Dogs and cats received a total amount of median 8.0 mL/kg (1.5-66.6 mL/kg) and 15.8 mL/kg (1.8-69.4 mL/kg) ILE, respectively. A positive effect was observed in 74% of the patients, whereas clinical signs worsened in 4% of the patients after ILE administration. No subjective effect was detected in 22% of the patients. Suspected or possible adverse effects of ILE occurred in 6% of the patients, including neurological signs (temporarily reduced consciousness and ataxia), bradycardia, hyperthermia, vomiting, diarrhea, respiratory distress, worsening of the general behavior, facial swelling, and thrombophlebitis. The overall survival rate was 96%. One dog who potentially experienced adverse events was euthanized.

Conclusion

ILE treatment was successful in most patients but can be associated with adverse effects. Administration of ILE should be carefully selected on an individual basis after weighing the possible benefits against potential adverse effects.

A retrospective evaluation of confirmed and suspected poisonings in 166 cats between 2016 and 2020

Background and Aim

Poisonings commonly bring cats and dogs to veterinary emergency facilities. This retrospective study aimed to analyze clinical signs, confirmed or suspected toxicants, treatments, and outcomes of feline poisoning cases presented over 5 years to the emergency service of a small animal referral center.

Materials and Methods

Medical records of 166 cats were evaluated for a history of confirmed or presumed poisoning, suspected toxicant, clinical signs, treatment, and outcome. Poisoning probability was determined using patient history, clinical findings, observation, toxicologic examination, and, in some cases, gastric contents.

Results

Most cats were hospitalized (94.0%) due to poisoning with mostly unknown toxicants (48.2%), rodenticides (21.1%), and various toxic plants (12.0%), followed by antiparasitics (6.0%), chemicals (6.0%), drugs (4.2%), tetrahydrocannabinol (1.2%), or inhaled smoke (1.2%). Patients presented predominantly with neurologic deficits (68.7%), reduced general condition (60.2%), and hypothermia (43.4%). The survival rate was 88.6%. Most cats (93.2%) showed no apparent complications at the time of discharge from the hospital. Toxicant-related complications (48.2%) included thermodysregulation (22.9%), central nervous system signs (18.7%), respiratory issues (7.2%), nephrotoxicity (6.0%), gastrointestinal complications (4.8%), evidence of hepatic failure (4.8%), and hemorrhage (1.8%).

Conclusion

In this study, the causative toxicant remained unidentified in many cases. Known poisonings were mostly caused by rodenticides. Neurological signs were the most common clinical presentation. Survival rates were high and comparable with those reported by others.

Intralipid Emulsion Therapy for the Treatment of Suspected Toxicity in 2 Avian Species

Intravenous lipid emulsion (ILE) therapy has shown promise as a treatment option for a variety of lipophilic toxins. Two birds presented for suspected ingestion of a toxic substance. A blue-and-gold macaw (Ara ararauna) presented after chewing a block of bromethalin rodenticide without overt clinical signs at the time of presentation. Additionally, a free-ranging bald eagle (Haliaeetus leucocephalus) was found weak and depressed near a municipal landfill after presumptive ingestion of pentobarbital. Both birds were treated with ILE therapy for potential intoxication without any adverse events. The macaw was clinically normal after 3 days of hospitalization and at a 1-week reevaluation. The eagle was transferred to a rehabilitation center after markedly improved mentation and strength and was released 7 days later. Clinicians should consider ILE therapy for the treatment of lipophilic toxicities; however, monitoring is recommended for persistent lipemia and other adverse effects that have been reported in the veterinary literature.

Outcomes of 434 dogs with non-steroidal anti-inflammatory drug toxicosis treated with fluid therapy, lipid emulsion, or therapeutic plasma exchange

BACKGROUND

Traditional management of non-steroidal anti-inflammatory drug (NSAID) intoxication includes gastrointestinal decontamination, intravenous administration of fluids (IVF), and gastroprotection. Intravenous administration of lipid emulsion (ILE) and therapeutic plasma exchange (TPE) are popular novel therapeutic strategies.

HYPOTHESIS

Compare outcomes of dogs treated with IVF, ILE, and TPE for NSAID intoxications and evaluate outcome predictors for drug subgroups.

ANIMALS

Four hundred thirty-four dogs with NSAID intoxications (2015-2020).

METHODS

Multicenter retrospective study of ibuprofen, carprofen, and naproxen intoxication. An ordinal outcome was defined as mild gastrointestinal, moderate kidney, or signs of severe central nervous system disease.

RESULTS

Signs of neurological disease were overrepresented and acute kidney injury underrepresented in the TPE group among dogs exposed to kidney- or CNS-toxic doses (P = .05), though all TPE dogs with signs of neurological disease had evidence of neurotoxicity at presentation. Dogs treated with IVF had a higher maximal creatinine concentration (median, 1.1 mg/dL; range, 0.4-8.44 mg/dL) compared with IVF + ILE (median, 0.9 mg/dL; range, 0.4-6.2 mg/dL; P = .01). Increased maximum time to presentation (P < .001), higher baseline creatinine (P < .001) and PCV (P = .007), and absence of induced emesis (P < .001) were associated with greater clinical severity. Ibuprofen toxicosis was associated with more severe clinical signs compared with carprofen (P = .03). Overall survival rate was 99%.

CONCLUSIONS AND CLINICAL IMPORTANCE

NSAID toxicosis generally carries an excellent prognosis in dogs. Despite similar outcomes of lower incidence of AKI in the TPE group, and slightly lower maximal creatinine concentration in dogs treated with ILE vs IVF alone, ILE and TPE should be considered in the management of severe NSAID toxicosis.

Successful treatment of ivermectin overdose in a bearded dragon (Pogona vitticeps) using gastric lavage and intravenous lipid emulsion

OBJECTIVE

To describe the clinical signs and outcome following ivermectin overdose in a bearded dragon. This case also describes the novel use of intravenous lipid emulsion (ILE) as a rescue therapy in reptiles, as well as the use of aggressive gastrointestinal decontamination.

CASE SUMMARY

A 4-year-old female intact bearded dragon (Pogona vitticeps) (0.6 kg) was admitted to the ICU at a specialty hospital following accidental overdose of 40 mg (66.7 mg/kg) of ivermectin enterally. The patient was physically inverted to allow passive reflux of the medication, then sedated for gastric lavage. A 20% ILE was administered intravenously due to the high risk for fatality. Additional treatments included 2 doses of activated charcoal, as well as SC fluids, enteral nutrition, and sucralfate. The patient was profoundly sedate until day 4 when mild improvements in mentation were noted. The patient started ambulating on its own on day 6 and was discharged from the hospital on day 13. The patient was alive 720 days postdischarge.

NEW OR UNIQUE INFORMATION PROVIDED

This is the first case report describing the events following ivermectin overdose and the use of ILE therapy and activated charcoal in a bearded dragon. These therapies were tolerated with no adverse effects noted in this patient. This report provides evidence that complete recovery from ivermectin overdose is possible.

Manual plasma exchange to treat an accidental overdose of intravenous lipid emulsion in a dog with baclofen toxicosis

CASE DESCRIPTION

An approximately 2-year-old sexually intact male German Shorthair Pointer was presented for treatment of baclofen toxicosis.

CLINICAL FINDINGS

The dog had signs of severe baclofen toxicosis (no gag reflex, intermittent vocalization, and stupor) and received intravenous lipid emulsion (142 mL/kg) as a constant rate infusion over 11 hours. Severe hypertriglyceridemia (29,221 mg/dL; reference interval, 19 to 133 mg/dL) developed, followed by cardiovascular depression (poor peripheral perfusion, hyperlactatemia, and hypertension), severe hypoglycemia (26 mg/dL), acute kidney injury (serum creatinine, 3.6 mg/dL), intravascular hemolysis, and coagulopathy (hypocoagulable thromboelastogram and marked bilateral epistaxis).

TREATMENT AND OUTCOME

Therapeutic plasma exchange was performed in 4 stages to treat the hypertriglyceridemia. For each stage, an approximately 500-mL aliquot of blood (22 mL/kg) was removed and centrifuged, and the patient’s RBCs and allogenic fresh-frozen plasma were returned to the dog. Approximately 1.2 times the dog’s plasma volume was exchanged, reducing the serum triglyceride concentration to 1,349 mg/dL and improving the dog’s cardiovascular function and coagulation. Hours after the procedure was completed, the dog regurgitated and developed acute respiratory distress as a result of presumptive aspiration pneumonia, and the owner elected to have the dog euthanized.

CLINICAL RELEVANCE

Veterinarians should be aware of possible complications associated with administration of intravenous lipid emulsion, and veterinary-specific guidelines for the maximum dose of intravenous lipid emulsion should be developed to help prevent adverse effects. TPE appears to be an effective method for treating iatrogenic hypertriglyceridemia in dogs.

A successful treatment with intravenous lipid emulsion therapy in a child with verapamil poisoning

In recent years, intravenous lipid emulsion therapy (ILE) was used for lipophilic drug intoxications, and successful results were obtained. In the literature, there is a small number of reported cases about verapamil intoxication and ILE therapy in the pediatric age group. We used ILE therapy in a 14-year-old girl with verapamil intoxication in the 2^nd h of the pediatric intensive care unit stay, before using traditional treatments such as glucagon and hyperinsulinemic euglycemia. She had resistant bradycardia and hypotension which was unresponsive to inotropic agents and a successful result was obtained after using ILE treatment. We believe our report may contribute to the early use of ILE therapy for toxicity with calcium channel blockers such as verapamil in pediatric patients.

Prolonged Anesthetic Recovery after Continuous Infusion of Midazolam in 2 Domestic Cats (Felis catus)

Two healthy research cats involved in a randomized, blinded prospective pharmacodynamics study evaluating midazolam continuous-rate infusion as a means to decrease sevoflurane concentrations experienced unexpectedly prolonged recoveries. Midazolam loading doses, infusion rates, and the targeted plasma midazolam concentrations at steady-state were determined by pharmacokinetic modeling based on the results of a preliminary pharmacokinetic study using a single dose of midazolam. In the pharmacodynamics study, cats remained oversedated after recovery from anesthesia, and plasma concentrations of midazolam and its primary metabolite (1-hydroxymidazolam) remained elevated. The use of flumazenil was unsuccessful in timely treatment of oversedation. Administration of intravenous lipid emulsion was used in one of the cats to facilitate recovery and appeared to be effective in both reducing the depth of midazolam-induced oversedation and significantly reducing the plasma concentration of 1-hydroxymidazolam. The effects after the administration of both treatment modalities on clinical signs and plasma drug concentrations in cats are discussed. The observations suggest that cats may eliminate 1-hydroxymidazolam more slowly than expected; consequently dose adjustments may be required when continuous infusion of midazolam is intended. In addition, intravenous lipid emulsion may facilitate recovery from midazolam oversedation, particularly in cases unresponsive to traditional treatment modalities. However, further investigations are warranted to delineate the efficacy of this modality in the treatment of midazolam oversedation.

Toxicology of Avermectins and Milbemycins (Macrocyclic Lactones) and the Role of P-Glycoprotein in Dogs and Cats

Overdoses of macrocyclic lactones in dogs and cats can result in such signs as tremors, ataxia, seizures, coma, and blindness. Dogs with the ABCB1-1Δ gene defect are predisposed to macrocyclic lactone toxicosis at lower dosages than dogs without the defect. Intravenous lipid emulsion therapy has been suggested for treatment of macrocyclic lactone toxicosis but evidence of efficacy is limited. Initial decontamination and supportive care remain the mainstays of therapy for macrocyclic lactone toxicosis.

Intravenous Lipid Emulsions in Veterinary Clinical Toxicology

Use of intravenous lipid emulsion (ILE) as an antidote for severe cardiotoxicity and neurotoxicity has expanded in the veterinary world in the past decade. Despite advances in understanding of potential mechanisms of action of antidotal ILE, knowledge gaps remain in efficacy, appropriate dosing rates for various toxicants, and potential adverse reactions. Use of ILE in management of toxicoses of veterinary patients should be considered investigational, and should not be first-line treatment of most toxicoses, especially where established treatment protocols have good likelihood of positive outcomes. Use of ILE in veterinary toxicology cases requires judicious assessment of individual cases and proper informed consent of clients.