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Toxicity, Rodenticide: Differential Diagnoses & Workup

Author: Steven Marcus, MD, Professor, Department of Preventive Medicine and Community Health, Associate Professor, Department of Pediatrics, New Jersey Medical School, University of Medicine and Dentistry of New Jersey; Executive and Medical Director, New Jersey Poison Information and Education System; Consulting Staff, Departments of Pediatrics and Internal Medicine, University Hospital, University of Medicine and Dentistry of New Jersey; Consulting Staff, Department of Pediatrics, Newark Beth Israel Medical Center
Contributor Information and Disclosures

Updated: Oct 29, 2009

Differential Diagnoses

Acute Respiratory Distress Syndrome
Salmonella Infection
Diabetic Ketoacidosis
Snake Envenomations, Rattle
Disseminated Intravascular Coagulation
Toxicity, Ammonia
Gastroenteritis
Toxicity, Arsenic
Hypocalcemia
Toxicity, Chlorine Gas
Hypokalemia
Toxicity, Clonidine
Pediatrics, Gastroenteritis
Toxicity, Cyanide
Pediatrics, Gastrointestinal Bleeding
Toxicity, Fluoride
Plant Poisoning, Glycosides - Coumarin
Toxicity, Hydrogen Sulfide
Respiratory Distress Syndrome, Adult
Toxicity, Mushroom - Disulfiramlike Toxins

Other Problems to Be Considered

Congenital deficiency in clotting factor VII may present with bleeding associated with an abnormal prothrombin time (PT) but a normal activated partial thromboplastin time (aPTT). At first, this may appear to be anticoagulation from a rodenticide or Coumadin; however, with the marked prolongation in PT, some abnormality in aPTT should be present, except in specific factor VII deficiency.

Workup

Laboratory Studies

  • Obtain glucose fingerstick in every patient with altered mental status.
  • Order electrolytes, serum glucose level, and ketones in patients suspected of exposure to vacor (PNU).
  • Measure PT and aPTT if the ingested substance is an anticoagulant. Possibly consider bleeding time and platelet count measurements in patients with evidence of bleeding. Requesting quantitative coagulation factors may be helpful and available far before actual analysis for suspect anticoagulant levels.
    • Initial elevated PT and aPTT may suggest possibility of chronic exposure.
    • Patients suspected of anticoagulants exposure may require INR check on a daily basis for a couple days to rule out or to confirm toxicity.
  • Because the availability of RBC cholinesterase is so poor, do not depend on supporting laboratory evidence when an exposure to an organophosphate-containing substance is suspected.
  • Laboratory verification of the anticoagulant rodenticides (eg, brodifacoum, difenacoum) is available; however, the result takes several days and does not guide therapy.
  • Blood tests for arsenic, thallium, mercury, and lead may be useful but are usually considerably time consuming.
  • Obtain pregnancy tests in women of childbearing age.
  • Obtain serum acetaminophen level in every intentional exposure.
  • Obtain CBC in patients with evidence of bleeding or hemolysis.
  • Order CPKs and lactic acid in patients suspected of exposure to strychnine (eg, "conscious seizures").

Imaging Studies

  • If a metal rodenticide (eg, thallium, arsenic, barium) is considered, using an abdominal plain film x-ray may be helpful because these metals are radio-opaque.

Other Tests

  • ECG should be obtained for an evaluation of conduction abnormalities due to electrolyte disturbances or the effects of cardioactive drugs (eg, TCAs).

More on Toxicity, Rodenticide

Overview: Toxicity, Rodenticide
Differential Diagnoses & Workup: Toxicity, Rodenticide
Treatment & Medication: Toxicity, Rodenticide
Follow-up: Toxicity, Rodenticide
References
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References

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Further Reading

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Keywords

rodenticide ingestion, rat poison, rat poison ingestion, rodenticide toxicity, rodenticide poisoning, red squill, strychnine, thallium, arsenic, yellow phosphorus, warfarin-type anticoagulants, brodifacoum, Vacor, zinc phosphide, bromethalin, norbormide, cyanide

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Contributor Information and Disclosures

Author

Steven Marcus, MD, Professor, Department of Preventive Medicine and Community Health, Associate Professor, Department of Pediatrics, New Jersey Medical School, University of Medicine and Dentistry of New Jersey; Executive and Medical Director, New Jersey Poison Information and Education System; Consulting Staff, Departments of Pediatrics and Internal Medicine, University Hospital, University of Medicine and Dentistry of New Jersey; Consulting Staff, Department of Pediatrics, Newark Beth Israel Medical Center
Steven Marcus, MD is a member of the following medical societies: Academy of Medicine of New Jersey, American Academy of Clinical Toxicology, American Academy of Pediatrics, American College of Emergency Physicians, American College of Medical Toxicology, American Medical Association, and Medical Society of New Jersey
Disclosure: Nothing to disclose.

Medical Editor

Assaad J Sayah, MD, Chief, Department of Emergency Medicine, Cambridge Health Alliance
Assaad J Sayah, MD is a member of the following medical societies: National Association of EMS Physicians
Disclosure: Nothing to disclose.

Pharmacy Editor

John T VanDeVoort, PharmD, Regional Director of Pharmacy, Sacred Heart & St. Joseph's Hospitals
John T VanDeVoort, PharmD is a member of the following medical societies: American Society of Health-System Pharmacists
Disclosure: Nothing to disclose.

Managing Editor

Fred Harchelroad, MD, FACMT, FAAEM, FACEP, Chair, Department of Emergency Medicine, Director of Medical Toxicology - Allegheny General Hospital, Associate Professor, Department of Emergency Medicine, Drexel University College of Medicine
Disclosure: Nothing to disclose.

CME Editor

John D Halamka, MD, MS, Associate Professor of Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center; Chief Information Officer, CareGroup Healthcare System and Harvard Medical School; Attending Physician, Division of Emergency Medicine, Beth Israel Deaconess Medical Center
John D Halamka, MD, MS is a member of the following medical societies: American College of Emergency Physicians, American Medical Informatics Association, Phi Beta Kappa, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

Chief Editor

Asim Tarabar, MD, Assistant Professor, Director, Medical Toxicology, Department of Emergency Medicine, Yale University School of Medicine; Consulting Staff, Department of Emergency Medicine, Yale-New Haven Hospital
Disclosure: Nothing to disclose.

 
 
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