a patient with rodenticide overdose dr wl yip, aed, qmh
TRANSCRIPT
A patient with rodenticide overdose
Dr WL Yip, AED, QMH
Case report
• F/44, housewife
• Found lying on the floor with decrease in responsiveness
• Found an empty pack of ‘stilnox’ and an empty can of beer lying around
• Argued with her husband one day ago
• Brought to AED ~0730
Examination
• BP 120/60 P 100
• Temp 35.70C
• SaO2 98 with RR 22
• Drowsy, with GCS E4 V5 M5
• H’stix 4.7
• ECG NSR 85/min
Further management
• Bld / Urine samples taken, with result pending
• Admit medical due to full ‘O’ ward
• Patient woke up after 2 hours
• Admitted taken 20 tabs of stilnox and 1 can of beer, and denied other drugs taken
• Pending seeing psychiatrist
Investigation…
• At 1400, found INR 7.7, PT 86.8, PTT 57.1• Repeated… INR 7.6• Further questioning… taken 1 pack of rat
poison bought over the counter few days ago
• Contacted her husband…• found a pack of rat poison ~5 days ago in
dust-bin at home
Other investigation results
• Hb 14.5
• Urine toxicology: BDZs, zolpidem metabolites
• Otherwise unremarkable
Management
• Clinically stable
• No bleeding clinically
• Transfusion of 4 units of FFP
• Daily vitamin K1 10mg
• INR 1.4 the next day
• Seen by psychiatrist – depression
Psychiatric ward
• Form 123, transferred to PYNEH psychiatric ward
• Continued daily oral vitamin K (10mg QD)
• INR finally back to 1.0 after 9 days
• Vitamin K was continued for 1 more week afterwards
INR
Day 0 Day 1 Day 3 Day 6 Day 9
7.7 1.4 2.0 1.7 1.0
FFPvit K1 (iv)
vit K (po)
Rodenticides
• Warfarin / Superwarfarin
• Arsenic
• Cholecalciferol
• Sodium monofluoroacetate
• Strychine
• Thallium
Warfarin / Superwarfarin
Warfarin / Superwarfarin
• Commonest in Hong Kong
• Anticoagulants
• prevent vitamin K from reducing to its active form
• inhibit hepatic synthesis of coagulation factors II, VII, IX, and X and the anticoagulant proteins C and S
Vitamin K metabolism
Coagulation pathway
Initiation of coagulation
Superwarfarin
• Brodifacoum, bromadiolone
• Warfarin-resistance rats
• Clinical effects occur after depletion of the mentioned factors (~3-4 days)
• Longer acting (weeks to months)
• Longer half-life (156 vs. 17 hrs)
• 100-folds more potent
Clinical features
• Rarely symptomatic, unless delayed presentation
• Signs of bleeding• Reported complications: Spontaneous intra-
abdominal hemorrhage, hematuria, hematemesis, spontaneous hemoperitoneum, intracerebral hemorrhage, death
Investigation
• Clotting profile, repeated in 24-48 hours
• Drug level if available
• Pregnancy test for females of childbearing age
Management
• GI decontamination
• Activated charcoal
• Specific treatment– Vitamin K– FFP
Vitamin K
• 15-120mg/d in divided doses
• T1/2 = 6 hours
• Antagonizes effects of warfarin • Indicated in INR>2• ‘reverse’ anticoagulation, but not ‘prevent’ its
effect• Anaphylactoid reaction if given iv• Caution if already anticoagulated for other reasons
Superwarfarin poisoning
• Required higher daily dose and longer duration (in months) of vitamin K
FFP
• Indicated if evidence of bleeding despite use of vitamin K
比山埃毒百倍 警檢鼠藥器皿毒鼠強奪命案枉死增至 243人
16/09/2002
【中國組報道】南京驚天毒殺案後第二日,部分留醫者家屬昨夜收到醫院發出病危通知,死亡人數可能進一步攀升。而摻在受害者早餐中的毒藥,證實是毒性比山埃還要強烈一百倍的老鼠藥「毒鼠強」;警方在案發地點和盛園的水井旁發現殘留毒鼠強的器皿,一名案發後失蹤的和盛園員工成重大疑犯。有消息稱,毒殺案死者人數高達二百四十三名,而非官方公布的四十一人…
Tetramethylene Disulfotetramine
• C4H8N4O4S2
• GABA-antagonist, with CNS excitation• Onset of symptoms several to 30 min (max.
13 hours)• 6-12 mg is sufficient to cause death• Proven to be toxic thru oral, inhalation and
dermal routes• Rapid absorption with slow elimination
Mild toxicity
• Headache
• Dizziness
• Fatigue
• Anorexia
• Nausea and vomiting
• Numbness of lips
• Listlessness
Severe toxicity
• Loss of consciousness
• Seizures
• Foaming at the mouth
• Urinary incontinence
• Coma
• Death from respiratory failure
Management
• Confirm its presence in vomitus, blood or urine
• Symptomatic / supportive treatment
• Gastric lavage and activated charcoal
• Charcoal hemoperfusion
• Hemodialysis
?Antidote
• No specific antidote
• Vitamin B6 and DMPS (2,3-dimercapto-1-sulphonate)
• Inhibit convulsion and reduce mortality in animal studies
• No data a/v in human cases
Thank you