Bedside formate test to diagnose methanol poisoning

Sensitivity, Specificity, and Acceptability of a Bedside Formate Assay as a Diagnostic Tool in Methanol Poisoning: Prospective Observational and Randomized Studies

This project will test a single-drop bedside formate test to see if it can quickly diagnose methanol poisoning in people with suspected exposure or unexplained metabolic acidosis.

Quick facts

• Study type: Observational
• Enrollment: 6120 (estimated)
• Ages: 16 Years and up
• Sex: All
• Sponsor: University of Edinburgh (Academic / other)
• Locations: 6 sites (Bogra, Bogura and 5 other locations)
• Trial ID: NCT06881641 on ClinicalTrials.gov

What this trial studies

The project develops a point-of-care device that measures blood formate from a single drop to diagnose methanol poisoning without laboratory equipment. Study 1a is an observational comparison of the POC formate assay against the laboratory formate assay to determine sensitivity and specificity. If Study 1a shows sensitivity above 0.80, Study 1b will test the feasibility of a three-arm cluster randomized controlled trial comparing diagnostic approaches. The overall plan is to use this phased approach to inform later trials of clinical- and cost-effectiveness in routine care, especially in low-resource settings.

Who should consider this trial

Good fit: Ideal candidates are people (adolescents 16+ and adults) who present with suspected methanol poisoning or unexplained metabolic acidosis and can consent or have an authorized proxy to consent.

Not a fit: Patients without suspected methanol exposure, those with an identified alternative cause of metabolic acidosis, or those who already have confirmatory laboratory formate results are unlikely to benefit from this test.

Why it matters

Potential benefit: If successful, the bedside formate test could enable faster on-site diagnosis and earlier treatment of methanol poisoning, reducing brain injury and deaths in low-resource settings.

How similar studies have performed: Laboratory formate assays are an established marker for methanol poisoning, but single-drop bedside point-of-care formate testing is novel and has not yet been widely validated.

Eligibility criteria

Inclusion Criteria:

• Patients presenting with suspected methanol poisoning or metabolic acidosis of unknown cause, including:

* Children aged 16-17 years, who are willing to provide assent.
* Parents/Guardians of children who are able and willing to provide consent.
* Adults (aged 18 years with no upper age limit) who are willing to provide informed consent.
* Participants who lack capacity to consent for themselves but who have a relative who is willing and able to provide informed consent on behalf of the participant.

Suspected methanol poisoning will be based on clinician judgement using the following typical indicators of possible methanol ingestion:

1. History of:

   * Intake of illegal/bootleg/spurious alcohol, and/or
   * Other patients admitted with confirmed/suspected methanol poisoning and/or
   * Time from intake to symptoms \>6-12 h
2. Symptoms/clinical findings

   * Coma, and/or
   * Hyperventilation (respiratory rate \[RR\] \>20/min) and/or dyspnea, and/or
   * Visual disturbances (blurred vision, blindness), and/or
   * Gastrointestinal symptoms (vomiting, abdominal pain), and/or
   * Chest pain, and/or
   * Severe/unusual 'hang-over': Feeling very sick the following day, and/or
   * Pseudopapillitis

Metabolic acidosis of unknown origin will be based on the following features:

* Metabolic acidosis of unknown origin = origin not identified. The acidosis is not of unknown origin if the metabolic acidosis can be explained by another cause eg. lactic acidosis (e.g. where base deficit \[BD\] = 15 mM \[i.e., base excess (BE) = -15 mM\] and lactate is 12-15mM).
* An initial ABG shall be drawn. If the BD is \>15mM (BE\<-15mM), the patient shall be included (as long as "unknown origin" - see above). If the patient has a BD between 5-15, the acidosis is only moderate, and there is time to do the "fluid trial" (see below). If the acidosis improves within 1-2 hours after the fluid trial, the acidosis is unlikely to be because of methanol and the patient should not be included. If the acidosis does not improve, the patient should be included.

Exclusion Criteria:

* • Children aged 16-17 years, who are unwilling to provide assent.

  * Parents/Guardians of children who are unable or unwilling to provide consent.
  * Adults (aged 18 years with no upper age limit) who are unwilling to provide informed consent.
  * Participants who lack capacity to consent for themselves and who do not have a relative who is willing and able to provide informed consent on behalf of the participant (i.e. unaccompanied unconscious patients and others)
  * Individuals previously recruited to the study.

Where this trial is running

Bogra, Bogura and 5 other locations

• Szmch — Bogra, Bogura, Bangladesh (Recruiting)
• Rahshahi medical college hospital — Rajshahi, Rajshahi Division, Bangladesh (Recruiting)
• Chittagong Medical College Hospital — Chittagong, Bangladesh (Recruiting)
• Dhaka Medical College Hospital — Dhaka, Bangladesh (Recruiting)
• Mag Osmania Medical College Hospital Sylhet — Sylhet, Bangladesh (Recruiting)
• Pgiemr — Chandigarh, India (Not_yet_recruiting)

Study contacts

• Study coordinator: Prof Michael Eddleston, BA PhDScD FRCPEdin FEAPCCT

Conditions Metabolic Acidosis; methanol toxicity