The management of severe toxic alcohol ingestions at a tertiary care center after the introduction of fomepizole

Extracorporeal treatment for ethylene glycol poisoning: systematic review and recommendations from the EXTRIP workgroup

Ethylene glycol (EG) is metabolized into glycolate and oxalate and may cause metabolic acidemia, neurotoxicity, acute kidney injury (AKI), and death. Historically, treatment of EG toxicity included supportive care, correction of acid-base disturbances and antidotes (ethanol or fomepizole), and extracorporeal treatments (ECTRs), such as hemodialysis. With the wider availability of fomepizole, the indications for ECTRs in EG poisoning are debated. We conducted systematic reviews of the literature following published EXTRIP methods to determine the utility of ECTRs in the management of EG toxicity. The quality of the evidence and the strength of recommendations, either strong ("we recommend") or weak/conditional ("we suggest"), were graded according to the GRADE approach. A total of 226 articles met inclusion criteria. EG was assessed as dialyzable by intermittent hemodialysis (level of evidence = B) as was glycolate (Level of evidence = C). Clinical data were available for analysis on 446 patients, in whom overall mortality was 18.7%. In the subgroup of patients with a glycolate concentration ≤ 12 mmol/L (or anion gap ≤ 28 mmol/L), mortality was 3.6%; in this subgroup, outcomes in patients receiving ECTR were not better than in those who did not receive ECTR. The EXTRIP workgroup made the following recommendations for the use of ECTR in addition to supportive care over supportive care alone in the management of EG poisoning (very low quality of evidence for all recommendations): i) Suggest ECTR if fomepizole is used and EG concentration > 50 mmol/L OR osmol gap > 50; or ii) Recommend ECTR if ethanol is used and EG concentration > 50 mmol/L OR osmol gap > 50; or iii) Recommend ECTR if glycolate concentration is > 12 mmol/L or anion gap > 27 mmol/L; or iv) Suggest ECTR if glycolate concentration 8-12 mmol/L or anion gap 23-27 mmol/L; or v) Recommend ECTR if there are severe clinical features (coma, seizures, or AKI). In most settings, the workgroup recommends using intermittent hemodialysis over other ECTRs. If intermittent hemodialysis is not available, CKRT is recommended over other types of ECTR. Cessation of ECTR is recommended once the anion gap is < 18 mmol/L or suggested if EG concentration is < 4 mmol/L. The dosage of antidotes (fomepizole or ethanol) needs to be adjusted during ECTR.

High risk and low prevalence diseases: Toxic alcohol ingestion

INTRODUCTION

Toxic alcohol ingestion is a rare but serious condition that carries with it a high rate of morbidity and mortality.

OBJECTIVE

This review highlights the pearls and pitfalls of toxic alcohol ingestion, including presentation, diagnosis, and management in the emergency department (ED) based on current evidence.

DISCUSSION

Toxic alcohols include ethylene glycol, methanol, isopropyl alcohol, propylene glycol, and diethylene glycol. These substances can be found in several settings including hospitals, hardware stores, and the household, and ingestion can be accidental or intentional. Toxic alcohol ingestion presents with various degrees of inebriation, acidemia, and end-organ damage depending on the substance. Timely diagnosis is critical to prevent irreversible organ damage or death and is based primarily on clinical history and consideration of this entity. Laboratory evidence of toxic alcohol ingestion includes worsening osmolar gap or anion-gap acidemia and end organ injury. Treatment depends on the ingestion and severity of illness but includes alcohol dehydrogenase blockade with fomepizole or ethanol and special considerations for the initiation of hemodialysis.

CONCLUSIONS

An understanding of toxic alcohol ingestion can assist emergency clinicians in diagnosing and managing this potentially deadly disease.

Methanol poisoning as a new world challenge: A review

BACKGROUND

Methanol poisoning (MP) occurs often via ingestion, inhalation, or dermal exposure to formulations containing methanol in base. Clinical manifestations of MP include gastrointestinal symptoms, central nervous system (CNS) suppression, and decompensated metabolic acidosis occurred with blurred vision and early or late blindness.

OBJECTIVE

This study reviewed the clinical manifestations, laboratory and radiology findings, and treatment approaches in MP.

DISCUSSION

Methanol is usually rapidly absorbed after ingestion and metabolized by alcohol dehydrogenase (ADH), then distributed to the body water to reach a volume distribution approximately equal to 0.77 L/kg. It is also eliminated from the body as unchanged parent compounds. Clinical manifestations of MP alone initiate within 0.5-4 h after ingestion and include gastrointestinal symptoms and CNS suppression. After a latent period of 6-24 h, depending on the absorbed dose, decompensated metabolic acidosis occurs with blurred vision and early or late blindness. Blurred vision with normal consciousness is a strong suspicious sign of an MP. The mortality and severity of intoxication are well associated with the severity of CNS depression, hyperglycemia, and metabolic acidosis, but not with serum methanol concentration. After initial resuscitation, the most important therapeutic action for patients with known or suspected MP is correction of acidosis, inhibition of ADH, and hemodialysis.

CONCLUSION

Since MP is associated with high morbidity and mortality, it should be considered seriously and instantly managed. Delay in treatment may cause complications, permanent damage, and even death.

Diethylene glycol poisoning from transcutaneous absorption

A case of transcutaneous diethylene glycol poisoning with severe acute kidney injury, but a positive outcome, is described. A man without significant medical history was admitted to our hospital due to anuria, gastrointestinal symptoms, and hypertension. Ultrasonography excluded vascular damage and postrenal obstruction. Laboratory tests showed acute kidney injury and metabolic acidosis with increased anion gap; hemodialysis therapy was started. The brother of the patient reported that the patient had been smearing his skin with brake fluid containing diethylene glycol to treat a "dermatitis." Only supportive therapy was given due to the lack of a specific antidote. Continuous venovenous hemofiltration was performed. The kidney biopsy showed acute toxic proximal tubulonecrosis, without deposition of oxalate crystals. His neurologic condition worsened dramatically; supportive care was continued. Over time, acute kidney injury and neurologic damage gradually improved; 33 days after admission, he went to a rehabilitation unit for 5 months, with complete clinical recovery. Historically, diethylene glycol has been the cause of large-scale poisonings from ingestion of contaminated drugs. The clinical evolution is unpredictable. Treatment is not well defined; early hemodialysis treatment reduces levels of toxic metabolites, and fomepizole could be useful in cases with an early diagnosis. A comparison of the characteristics of diethylene glycol versus ethylene glycol poisoning is given.

The safety of ethanol infusions for the treatment of methanol or ethylene glycol intoxication: an observational study

BACKGROUND

Methanol or ethylene glycol ingestion may result in significant morbidity or death without prompt treatment. Despite traditional and widespread use of intravenous ethanol as an antidote, its safety is not well described. An evaluation of the safety and ease of titrating ethanol infusions is necessary given the availability of an alternative antidote.

OBJECTIVE

To evaluate the safety and ease of titrating ethanol infusions for the treatment of methanol or ethylene glycol ingestion.

METHODS

We reviewed the hospital records of adults treated with ethanol at The Ottawa Hospital for methanol or ethylene glycol ingestion over a 9-year period. Using a standardized case report form, a single reviewer identified prespecified adverse events that developed after the start of ethanol therapy and classified dose adjustments during ethanol therapy as appropriate or inappropriate based on a priori criteria.

RESULTS

Forty-nine cases of methanol or ethylene glycol ingestion treated with ethanol were included in the analysis, of which 45 underwent hemodialysis, 38 were admitted to the intensive care unit, and 4 died. At least one adverse event was identified in 45 (92%) cases, including 35 (71%) with agitation requiring chemical or physical restraints and 10 (20%) with a depressed level of consciousness treated with intubation. The median number of ethanol concentration measurements per treatment course was 6 (range 0-24), of which only 27% were within the target range of 22 to 30 mmol/L and 47% were below. When measured concentrations were outside the target, the adjustment in ethanol dosing (or lack thereof) was deemed inappropriate 59% of the time, including 69% of the time during hemodialysis.

CONCLUSION

Based on actual practice in a large academic centre, adverse events occur frequently with intravenous ethanol infusions, and ethanol titration is inefficient. The safety profile and therapeutic drug monitoring considerations for ethanol should be considered when choosing an antidote for methanol or ethylene glycol ingestion.

A systematic review of ethanol and fomepizole use in toxic alcohol ingestions

Objectives. The optimal antidote for the treatment of ethylene glycol or methanol intoxication is not known. The objective of this systematic review is to describe all available data on the use of ethanol and fomepizole for methanol and ethylene glycol intoxication. Data Source. A systematic search of MEDLINE and EMBASE was conducted. Study Selection. Published studies involving the use of ethanol or fomepizole, or both, in adults who presented within 72 hours of toxic alcohol ingestion were included. Our search yielded a total of 145 studies for our analysis. There were no randomized controlled trials, and no head-to-head trials. Data Extraction. Variables were evaluated for all publications by one independent author using a standardized data collection form. Data Synthesis. 897 patients with toxic alcohol ingestion were identified. 720 (80.3%) were treated with ethanol (505 Me, 215 EG), 146 (16.3%) with fomepizole (81 Me, 65 EG), and 33 (3.7%) with both antidotes (18 Me, 15 EG). Mortality in patients treated with ethanol was 21.8% for Me and 18.1% for EG. In those administered fomepizole, mortality was 17.1% for Me and 4.1% for EG. Adverse events were uncommon. Conclusion. The data supporting the use of one antidote is inconclusive. Further investigation is warranted.