Common Poisoning in Medical Practice วินัย วนานุกูล ศูนยพิษวิทยา ภาควิชาอายุรศาสตร คณะแพทยศาสตร โรงพยาบาลรามาธิบดี
Common Poisoning
in Medical Practiceวินัย วนานุกูล
ศูนยพิษวิทยา
ภาควิชาอายุรศาสตร
คณะแพทยศาสตร โรงพยาบาลรามาธิบดี
Common poison exposureRamathibodi Poison Center: 2001-2005
กลุมสาร จํานวน %
สารปองกันกําจัดศัตรูพืช (pesticides) 9,327 39.9
สารใชในบาน (household products) 4,421 18.9
ยา (pharmaceutical products) 4,397 18.8
สารใชในงานอุตสาหกรรม (occupational products) 2,537 10.9
พืชพิษ (plant toxins/poisonous plants) 977 4.2
สัตวพิษ (poisonous animals) 621 2.7
รวม 23,368
Outline
Pesticides
– Organophosphorus & Carbamate
Household products
– Caustic ingestion
Pharmaceutical products
– Paracetamol
– Psychotropic drugs
Common pesticide exposure and their death rateRamathibodi Poison Center: 2001-2005
สารปองกันกาํจัดศัตรูพืช จํานวนผูปวย (%) จํานวนผูเสียชีวิต อัตราการตาย
สารปองกันกาํจัดแมลง (insecticide) 4,832 50.0 470 9.7
สารปองกันกาํจัดวัชพืช (herbicide) 2,426 25.1 295 12.2
สารปองกันกาํจัดหนู (rodenticide) 1,301 13.5 27 2.1
สารปองกันกาํจัดหอย (mollusicide) 428 4.4 5 1.2
สารปองกันกาํจัดปลวก (miticide) 147 1.5 34 23.1
อื่นๆ 527 5.5 11 2.1
รวม 9,661 842 8.7
ชาย 20 ป
มีผูพบผูปวยนอนหมดสติอยูในสวน มีน้ําลายฟูมปาก พบขวดสารฆาแมลงตกอยูขางตัว
ตรวจรางกาย ที่ ER
BP 160/80 mmHg, HR 180/min., RR 20/min. shallow respiration
T 36.5 C
Unconscious, not response to pain stimuli, pupils 2 mm.
Hypersecretion with bilateral wheezes
Increased bowel sounds
ชาย 20 ป
การวินิจฉัย: ผูปวยมีภาวะเปนพิษจากสารชนิดใด?
ก. Abamectin
ข. Carbamate
ค. Organophosphate
ง. Organochlorine
จ. Pyrethroid
ACh synthesis, stroage and release
ACh- AhE Reaction
What is the mechanism of OP &CB poisoning?
Acetylcholine (Ach)
ToxidromesToxidrome Cholinergic Muscarinic Cholinergic Nicotinic
Vital signs ↓HR, ↓BP ↑HR, ↑BP
Mental Stutus Lethargy-coma
Symptoms Diarrhea, vomitting,
blurred vision
Motor weakness
Signs Salivation, diaphoresis, miosis
Fassiculation
Paralysis
Substances Pilocarpine
Mushroom
Organophosphates
Carbamates
Tobacco
Organophosphates
Carbamates
ชาย 20 ป
มีผูพบผูปวยนอนหมดสติอยูในสวน มีน้ําลายฟูมปาก พบขวดสารฆาแมลงตกอยูขางตัว
ตรวจรางกาย ที่ ER
BP 160/80 mmHg, HR 180/min., RR 20/min. shallow respiration
T 36.5 C
Unconscious, not response to pain stimuli, pupils 2 mm.
Hypersecretion with bilateral wheezes
Increased bowel sounds
CNSNicotinic
Muscarinic
ชาย 20 ป
Diagnosis:
Organophosphorus or Carbamate poisoning
Differential Diagnosis of “Unconsciousness with hypersecretion and small pupils”
– Abamectin insecticide poisoning
Abamectin
ชาย 20 ป
Diagnosis:
Organophosphorus or Carbamate poisoning
Differential Diagnosis of “Unconsciousness with
hypersecretion and small pupils”
– Abamectin insecticide poisoning
– Pyrethroid insecticide poisoning
lambda-cyhalothrin 2.5% W/V
ชาย 20 ป
Diagnosis:
Organophosphate or Carbamate poisoning
Differential Diagnosis of “Unconsciousness with hypersecretion and
small pupils”
– Abamectin insecticide poisoning
– Pyrethroid insecticide poisoning
– Chlorophenoxy herbicide poisonings
Chlorophenoxy herbicides (2,4-D)
ชาย 20 ป
Diagnosis:
Organophosphate or Carbamate poisoning
Differential Diagnosis of “Unconsciousness with hypersecretion and small pupils”
– Abamectin insecticide poisoning
– Pyrethroid insecticide poisoning
– Chlorophenoxy herbicide poisonings
– Mushroom poisoning (Amanita pantherina, เห็ดเกลด็ดาว)
– Cholinergic drugs poisoning
Classification of Insecticide Exposure(Ramathibodi Poison Center: 2001-2006)
6,740 Cases
Organophosphorus
21%
Pyrethroid
25%
Abamectin
3%
Others
5%
Combined
12%
Unknown
5%Organochlorine
4%
Carbamate
25%
Anticholinesterase-AChE Reactions
Organophosphorus VS. Carbamate Poisoning
Reversible vs. Irreversible Inhibition
– Reversible vs. Irreversible clinical poisoning
– Time to recover (duration of clinical course)
Management of
Organophosphate & Carbamate Poisoning
General Management
Specific Treatment
Management of OP & CB Poisoning
Supportive Care
– Vital signs
– Respiration: • secretion block and airway obstruction
• respiratory motor weakness
– Seizure
Specific Treatment
Airway
Skin
Parenteral
GI.
Tissues &Organs
MDAC.
Decontamination Increase Elimination
Antidotes
Hemodialysis, Hemoperfusion
Specific Treatment
Decontamination:
– NG tube irrigation
Head DownLeft Lateral
Decubitus In Awake Patient
Limit! 1 hours after ingestion only
Specific Treatment
Decontamination:
– NG tube irrigation
– Activated Charcoal 1 g/kg orally or per gastric tube
Antidotes
Antimuscarinic effects
“ Atropine”
Antinicotinic effects
“ 2 PAM ”
CNS (seizure)
“Diazepam”
Muscarinic Effects
SecretionHeart RatePupil size
Atropine
Atropine
Clinical Parameters for titration
– Secretion
– Heart rate
– Pupil diameters
Choices for administration
– intermittent iv. bolus
– continuous iv. infusion
Atropine
Endpoints:
– Minimal secretion AND/OR
– Heart rate > 60/min., or stable hemodynamics
ESTERATICSITE
Nicotinic EffectsMuscarinic Effects
(Muscle Weakness)
2-PAM
หญิงอายุ 20 ป
PI 6 ชั่วโมงกอน กินน้ํายาลางหองน้ํา “เปดโปร” ประมาณ 50 ml.
หลังกินมีอาการแสบคอมาก และปวดทองโดยเฉพาะบริเวณลิ้นป
PE P 110/min, BP 90/60, RR 24/min, T 37.8 ๐C
Erythema or soft palate and posterior pharynx, no stridor
Lung : clear
Abdomen : tender at epigastrium,
no guarding or rigidity, normal bowel sound
Hydrochloric acid 8.5%
Sodium hypochlorite 2.7%
Hydrochloric acid 15%
Caustic Agents
Irritant Corrosive (caustic) agent
SoapNonionic detergentAnionic detergent
AcidAlkali
Cathionic detergentHypochlorite
Head DownLeft Lateral
Decubitus In Awake Patient
Limit! 1 hours after ingestion only
Contraindication for Gastric Lavage
Corrosive Agents
Drugs caused rapid deterioration of consciousness
Ineffectiveness of Activated Charcoal
Strong Acid & Alkali
Alcohol
Cyanide
Elemental Metal
Management of Caustic ingestion
Mild gastroesophageal injury– Supportive treament only
Moderate to Severe (significant) gastroesophageal injury– Supportive treatment
– Endosccopy for evaluation the injury
– Parenteral nutrion (TPN, PPN)
– + steroid
– Observe for its complication• GI Bleeding
• GI perferation
• Infection
ชาย 22 ป
มีญาตพิบหมดสตใินหองนอนกอนมา รพ. ครึ่งชั่วโมง
PE BP 80/50 mmHg, HR 110/min, RR 8/min, T 36 C
Unconscious, not response to pain
Pupil 1 mm. in diameter, not react to light
No localizing sign
Lung: fine crepitation bilateral
Otherwise: normal
Therapeutic Diagnosis for Unconscious Patients
50% Dextrose in Water 50 ml.
Naloxone 2-10 mg iv
Thiamine 50 -100 mg iv.
Psychotropic Agents
Sedative Hypnotics
Benzodiazepines
Antidepressants
– Tricyclic antidepressants
– Selective serotonin reuptake inhibitors
Antipsychotics
Opiates
Barbiturates
Stimulant Hallucinogens
Amphetamine & derivatives
Cocaine
Caffeine
Marihuana
LSD
Ketamine
Volatile substance
Autonomic (ANS.) Signs
Pulse
Blood Pressure
Respiration
Temperature
Skin
Secretion
Bowel sound & Bowel
movement
Urinary Bladder
Pupils
Differentiate between Structural vs. Metabolic
– Equal in Size?
– React to light?
Differentiate Among the Causative Agents
– Nonspecific
– Interpretation with Precaution
ชาย 22 ป
มีญาตพิบหมดสตใินหองนอนกอนมา รพ. ครึ่งชั่วโมง
PE BP 80/50 mmHg, HR 110/min, RR 8/min, T 36 C
Unconscious, not response to pain
Pupil 1 mm. in diameter, not react to light
No localizing sign
Lung: fine crepitation bilateral
Otherwise: normal
Suspected CNS Suppression Intoxication
Anticholinergic Signs
Respiratory Suppression
Constricted Pupils
Opiates
Yes
Yes
No
Opiod Overdose
Diagnostic Tools
– Therapeutic Diagnostic: Naloxone
– Urine opiod
Suspected CNS Suppression Intoxication
Anticholinergic Signs
Respiratory Suppression
Constricted Pupils
Opiates
Barbiturate
Yes
Yes
No
No
Barbiturate Overdose
Diagnostic Tools
– Can mimic brain death
– Skin Blisters (6%)
Barbiturate Overdose
Diagnostic Tools
– Can mimic brain death
– Skin Blisters (6%)
– Blood & urine barbiturate
– Therapeutic diagnostic: None,
– But need to R/O opiate toxicity
Drugs Eliminated by
Multiple Doses of Activated Charcoal
Phenobarbital
Phenytoin
Theophylline
Salicylates
Carbamazepine
Dapsone
Choice of Hemodialysis & Hemoperfusion
Hemodialysis
Lithium
Bromide
Ethanol
Methanol
Ethylene Glycol
Salicylates
Hemoperfusion
Barbiturate
Theophylline
Disopyramide
Meprobamate
Suspected CNS Suppression Intoxication
Anticholinergic Signs
Respiratory Suppression
Constricted Pupils
Benzodiazepine
Opiates
Barbiturate
Yes
Yes
No
No
No
Benzodiazepine Overdose
Diagnostic Tools
– Blood & Urine Benzodiazepine
– Therapeutic Diagnostic: ?? Flumazenil
Suspected CNS Suppression Intoxication
Anticholinergic Signs
Respiratory Suppression
Constricted Pupils
Dilated PupilsTCA
Benzodiazepine
Opiates
Barbiturate
YesYes
Yes
Yes
No
No
No
Tricyclic Antidepressants (TCA) Overdose
Diagnostic Tools
– Blood & Urine TCAs
– EKG: Widening of QRS complexes
R in aVR
– Therapeutic Diagnostic: None
QRS Complexes As a Predictor for TCAs Toxicity
QRS Duration Risk
> 0.10 sec Seizure
>0.16 sec Ventricular Arrhythmias
Suspected CNS Suppression Intoxication
Anticholinergic Signs
Respiratory Suppression
Constricted Pupils
Dilated PupilsTCA
Phenothiazine
Benzodiazepine
Opiates
Barbiturate
YesYes
Yes
Yes
NoNo
No
No
หญงิ 20 ป นักศึกษา
6 ชั่วโมงกอน รับประทานยาพาราเซทตามอล 60 เม็ด
2 ชั่วโมงกอน มีอาการคลื่นไสอาเจยีนหลายครั้ง ญาตจิึง
นําสง รพ.
ตรวจรางกายไมพบความผิดปกตใิดๆ
OH
NHCOCH3
Glucoronide
NHCOCH3
Sulfate
NHCOCH3
O
NHCOCH3
OH
NHCOCH3
OH
NHCOCH3
X
Glutathione
GSH
+
Cell Death
KIDNEYS
NAPQI
PARACETAMOL
Clinical Stages of Paracetamol Poisoning
Stage 1 (12 - 24 hours post-ingestion):
nausea, vomiting, anorexia, diaphoresis
Stage 2 ( 24 - 48 hours):
Clinically improved,
↑Transaminase enzymes, ↑ Bilirubin, ↑ Prothrombin Time
Stage 3 (72 - 96 hours):
Peak hepatotoxicity
Stage 4 (7 - 8 days):
Recovery
What should predict the risk to develop paracetamol
induced hepatic injury in the early phase?
The blood paracetamol level
4 248 12 16 20 Hours after ingestion
200150
90% of cases will have enzyme > 1,000 if no Treatment
60% of cases will have enzyme > 1,000 if no Treatment
300
Recommending of Treatment
From Rumack BH, et al. Arch Intren Med 1981;141:380-5.
OH
NHCOCH3
Glucoronide
NHCOCH3
Sulfate
NHCOCH3
O
NHCOCH3
OH
NHCOCH3
OH
NHCOCH3
X
Glutathione
GSH
+
Cell Death
KIDNEYS
NAPQI
N-Acetylcysteine
PARACETAMOL
N-acetylcysteine regimens
Oral Regimen
– LD 140 mg/kg
– MD 70 mg/kg every 4 hours 17 doses
IV. Regimen
– LD 150 mg/kg iv drip in 15 -30 min.
– MD 50 mg/kg iv. drip in 4 hours followed by
100 mg/kg iv. drip in 16 hours
Hepatic injury and Dead in patients treated with NAC(Line 200)
Treatment group N % of liver
injury
% Dead from
liver failure
Supportive treatment only 57 58.0 5.3
Time of delayed NAC treatment
< 10 hrs 527 6.1 0.0
10 -24 hrs 953 26.4 1.1
< 24 hrs 1,462 19.1 0.7
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