1. Management of rodenticide poisoning
Dr Sunil Karanth MD, FNB, EDIC, FCICM
CHAIRMAN OF CRITICAL CARE SERVICES
MANIPAL HEALTH ENTERPRISES (P) LTD
MANIPAL HOSPITAL, BANGALORE
ADJUNT PROFESSOR IN CRITICAL CARE MEDICINE
MANIPAL UNIVERSITY

2. introduction Common source of poisoning in this part of the world
Safety for other animals and humans
Toxicity of agent
Concentration of the active ingredient
Bioaccumulation and persistence in the body tissues
TWO CLINICAL TYPES
Extremely potent and toxic
Sodium fluoroacetate, fluoroacetamide, strychnine, crimidine, yellow phosphorous, zine phosphide, thallium sulphide
Less toxic to humans
Anticoagulants, red squill, indandiones

3. Coumarins and indandiones
Warfarin and related compounds
2 types
First generation – Hydroxy coumarin derivatives – Warfarin, coumachor, coumatetralyl
Second generation – superwarfarins – bromodiolone, brodifacoum, difenacoum
Decrease hepatic synthesis of Vitamin K-dependant factors
Prothrombin time used for diagnosis and monitoring – increases in 24 hours and peaks at about 72 hours

4. coumarins Presents early or late with bleeding manifestations
PT may remain high for days to weeks
Treatment:
Vitamin K1(Phytonadione) – mg, 2-4 times per day
Orally preferable because of a better adverse effect profile
Sometimes, may be needed to be given for months
Consider transfusion of FFPS if active bleeding present at admission

5. Inorganic rodenticides

6. Yellow phosphorous Dermal burns possible Oral ingestion 3 stages
Gastrointestinal
Period of relative improvement
Myocardial, hepatic and CNS involvement – progressing on to multiorgan failure
Toxic hepatitis with hepatic failure
Myocarditis with cardiogenic shock
Mechanism: PHOSPHENE GAS RELEASE

7. Yellow phosphorous MANAGEMENT DECREASE ABSORPTION
Gastric lavage with potassium permanganate – controversial because of the corrosive nature of yellow phosphorus
Gastric lavage with activated charcoal and mineral oil cathartic
HEPATO-PROTECTION
N-Acetyl cysteine
Dose of 150mg/kg over 1 hour followed by 50 mg/kg over 4 hours and 100mg/kg over 15 hours
SUPPORTIVE MEASURES
Fluid resuscitation
Organ specific support
Hepatic encephalopathic measures
High volume plasma exchange – may have a role?
Liver transplantation

8. Zinc phosphide Highly toxic rodenticide
Mechanism of action: - Release of phosphene gas
Clinical profile - similar to yellow phosphorous
3 stages
Lesser corrosive than Yellow phosphorus
III stage
Hepatic, CNS and myocardial involvement
Hepatic failure, shock , CNS manifestations
Multisystem organ failure
Risk of hepatic failure

9. Zinc phosphide MANAGEMENT Supportive care Cardiovascular support
Vasopressors to ECMO if needed
Renal replacement therapy
Liver support
Osmotherapy
Anti-encephalopathic measures
High volume plasma exchange – may decrease transplant free survival
Consider for transplant if appropriate

10. THALIUM SULFATE Absorbed from the gut and skin rapidly
Slow onset of action in comparison to Phosphides
Symptoms start over days
CNS, GI, Hepatic, Renal and integumentary systems affected
Alopecia seen after 2 weeks – more often seen in chronic poisoning
Confirmation by the use of Urinary 24 hour levels which will be elevated
TREATMENT
General supportive care
Role for Hemodialysis in faster elimination of thalium
Use of Prussian blue (potassium ferric ferrocyanide) to enhance faecal excretion of thalium

11. Severe multiorgan metabolic toxicants

12. Sodium fluoroacetate and fluoroacetamide
Readily absorbed from the gut
Forms fluorocitrate in the body causing disruption of the Kreb’s urea cycle blocking intracellular respiration
CNS, Cardiovascular, Metabolic predominantly involved
Management
Largely supportive
Administer large dose of IV calcium gluconate guided by the serum calcium levels

13. STRYCHNINE, CRIMIDINE, TETRAMETHYLENE DISULFOTETRAMINE (TETS)
Seizures and neurotoxicity are the predominant symptoms
Strychnine can also cause severe muscle spasms of the diaphragm and intercostal muscles mimicking tetanus
Potentially powerful CNS toxins
Aggressive control of seizures
Treatment is largely supportive

14. miscellaneous RED SQUILL No longer used as a rodenticide
Generally safe on humans
Cardiac glycoside – induces intense vomiting, hence very poorly absorbed
CHOLECALCIFEROL
All signs of hypercalcemia
Polyuria, polydipsia, Nephrocalcinosis, Hypertension, proteinuria
BROMETHALIN
CNS toxin
Uncoupling of oxidative phosphorylation in the neurons
Cerebral edema, seizures, altered senosrium

15. summary Rodenticide poisoning Problem for many years now
Different levels of toxicity
Developing world – more potent toxins – high levels of mortality
Most lethal toxins require multi-organ support
Common toxins require various forms of liver support
Early data suggest liver transplant as one of the modalities of definitive treatment

16. Thank you