Helps to understand basics of posioning and drug overdose managemnt.

1. BASICS OF POISONING
AND OVERDOSE
DR SOURAB HIREMATH
MD INTERNAL MEDICINE
EMERGENCY MEDICINE

2. PRE TEST QUESTIONS (Y/N)
• Gastric lavage is useful upto 24 hours post ingestion
• Gastric lavage is contraindicated in corrosive poisoning
• Detailed history helps us to find the culprit in most poisonings

3. • Activated charcoal prevents absorbption of poison by chemical conversion of
offending agent
• All poisons have antidotes
• All poisons can be dialysed

4. A Tale of 3 Sisters

5. Three sisters named xx, yy and zz were brought to the casualty at around 1 am in the midnight by her father
He narrates the following story , he has come to hospital to show his second eldest daughter YY
His second eldest daughter YY
who is 14 years has
accidentally drank around 10
ml of sulphuric acid around an
hour back
She is complaining of severe
retrosternal pain
Past : no h/o deliberate self
harm
No other significant medical
history
While examining the pt the youngest
daughter ZZ who is around 12 years
old starts throwing convuslions in
casualty .
Which lasts around 5 mins . Following
which convulsions subside
Past : no h/o convulsions
She was playing in the woods for an
hour which is known to have toxic
plants growing
When attending the
convulsing daughter u see
that the eldest daughter XX
21 years had icterus and
petechiaes all over body
The enthusuiastic resident
enquired her . But she was
hesitantly disclosing her
details
She was staying with his
divorced wife and had
returned only an hour before
Only thing her parent
revealed was past h/o self

6. Patient one YY
Vitals : Normal
CVS: Normal
RS : Normal
Oral : ulcers
Endoscopy : Ersions
Patient 2 ZZ
PR : 126
BP: 90/60 mm of hg
RR : 32/ min
Temp 102 F
Flushed
CNS : Agitated, Pupils
dilated
CVS : tachycardia
Eldest daughter
Examined : Icteric , vitals normal
Tender hepatomegaly
LFT : SGOT 1900 , SGPT : 2200
Total bilirubin 8 : D : 5
INR 2.1
HEP B , C , D , E negative
All other serologies and smears : negative
Blood and Urine for routine tox screens : negative
Her mother called to inform father that following
paste was missing from home and was alarmed

7. Diagnosis

8. Pt 1
Corrosive
poisonin
g
Pt 2
Belladona poisoning
Pt 3
Zinc phosphide
poisoning

9. POISON
is a substance that causes damage or injury to the body and endangers one's
life due to its exposure by means of ingestion, inhalation, or contact

10. POISONING
• Poisoning refers to the development of dose-related adverse effects following
exposure to
• Chemicals
• Drugs
• Xenobiotics.
Paracelsus : the dose makes the poison

11. FACTORS INFLUENCING DOSE RELATED EFFECTS
• genetic polymorphism
• enzymatic induction
• inhibition in the presence of other xenobiotics
• acquired tolerance

12. POISONING
Systemi
c
Local

13. EPIDEMIOLOGY
• Act of poisoning can be
Accidental
Intentional
• Worldwide intentional poisoning is one of the important causes for mortality and
morbidity
• Estimated 0.3 million people die every year due to various poisoning agents

14. • Acute pesticide poisoning is one of the most
common causes of intentional deaths
worldwide
• attempted suicide (deliberate self-harm) is
the most common reported reason for
intentional poisoning.
• Recreational use of prescribed and over-
the-counter drugs for psychotropic or
euphoric effects (abuse) or excessive self-
dosing (misuse) is increasingly common and
may also result in unintentional self-
poisoning.

15. UNINTENTIONAL EXPOSURES CAN RESULT FROM
• the improper use of chemicals at work or play
• label misreading
• product mislabeling
• mistaken identification of unlabeled chemicals
• uninformed selfmedication
• and dosing errors by nurses, pharmacists, physicians, parents, and the elderly.

16. Statistics
from a urban
Indian
hospital

17. DIAGNOSIS
Established by the
history
physical examination
routine and toxicologic laboratory evaluations
characteristic clinical course(TOXIDROME)

18. HISTORY
• time, route, duration, and circumstances (location, surrounding events, and intent)
of exposure
• the name and amount of each drug, chemical, or ingredient involved
• the time of onset, nature, and severity of symptoms
• the time and type of first-aid measures provided
• and the medical and psychiatric history.

19. SUSPICIOUS CIRCUMSTANCES
• Unexplained sudden illness in a previously healthy person or
a group of healthy people
• History of psychiatric problems (particularly depression)
• Recent changes in health, economic status, or social
relationships
• Onset of illness during work with chemicals

20. OTHERS
“body packing” or “body stuffing”
(ingesting or concealing illicit drugs in a
body cavity)

21. PHYSICAL EXAMINATION AND CLINICAL COURSE
Focus initially on
vital signs
the cardiopulmonary system
and neurologic status.

22. VITALS
• Pulse
• Blood pressure
• Respiratory rate
• Temperature
Neurologic
status
Stimulated
physiologic state
Depressed
physiologic state
Discordant
Physiologic stateToxidromes

23. STIMULATED PHYSIOLOGIC STATE
• PR
• RR
• TEMPERATURE
• Mydriasis
Anticholinergic toxidrome : mydriaisis plus hot, dry, flushed skin;
decreased bowel sounds and urinary retention.
Sympathetic stimulated : diaphoresis, pallor, and increased bowel
activity
with varying degrees of nausea, vomiting, abnormal distress, and
occasionally diarrhea.

25. THE DEPRESSED PHYSIOLOGIC STATE
depressed physiologic state caused by “functional” sympatholytics
• agents that decrease cardiac function and vascular tone as well as sympathetic
activity
• Cholinergic (muscarinic and nicotinic) agents
• Opioids
• Sedative-hypnotic ( γ-aminobutyric acid GABA)-ergic agents

27. THE DISCORDANT PHYSIOLOGIC STATE
• The discordant physiologic state is characterized by mixed vital-sign and
neuromuscular abnormalities, as observed in
• poisoning by asphyxiants
• membrane-active agents
• anion-gap metabolic acidosis (AGMA)
manifestations of physiologic stimulation and physiologic depression occur together
or at
different times during the clinical course.

29. THE NORMAL PHYSIOLOGIC STATE
• normal physiologic status and physical examination may be due to a nontoxic
exposure, psychogenic illness, or poisoning by “toxic time-bombs”:
agents that are slowly absorbed, are slowly distributed to their sites of action,
require metabolic activation, or disrupt metabolic processes

31. OTHERS
• Examination of the eyes (for nystagmus and pupil size and reactivity)
• Abdomen (for bowel activity and bladder size)
• Skin (for burns, bullae, color, warmth, moisture, pressure sores, and puncture marks) may reveal
findings of diagnostic value.
• When the history is unclear, all orifices should be examined for the presence of chemical burns
and drug packets.
• The odor of breath or vomitus and the color of nails, skin, or urine may provide important
diagnostic clues.

33. TOXIDROMES
Identification of the constellation of signs
and symptoms that define a specific
toxicologic syndrome, or "toxidrome",
may narrow a differential diagnosis to a
specific class of poisons

36. LABORATORY ANALYSIS
• Arterial Blood gas analysis
Increased anion gap : methanol , ethanol, acetaminophen
Renal function tests
Electrolytes
Liver function tests
PT/INR/APTT
RBS

37. TOXICOLOGY SCREENING

38. ECG
ECG CHANGE Drugs
Bradycardia and atrioventricular block α-adrenergic agonists, antiarrhythmic agents,
beta blockers, calcium channel blockers,
cholinergic agents (carbamate and
organophosphate insecticides), cardiac
glycosides, lithium, or tricyclic
antidepressants
QRS- and QT-interval prolongation hyperkalemia, various antidepressants, and
other membrane active drugs
Ventricular tachyarrhythmias cardiac glycosides, fluorides, membrane-
active drugs, methylxanthines,
sympathomimetics, antidepressants, and
agents that cause hyperkalemia or
potentiate the effects of endogenous
catecholamines

39. RADIOLOGY
• Pulmonary edema (adult respiratory
distress syndrome [ARDS]) can be
caused by poisoning with carbon
monoxide, cyanide, an opioid, paraquat,
phencyclidine, a sedative-hypnotic, or
salicylate; by inhalation of irritant fumes
• Aspiration pneumonia is common in
patients with coma, seizures, and
petroleum distillate aspiration.

40. TREATMENT GOALS
• Support of vital signs
• Prevention of further poison absorption (decontamination)
• Enhancement of poison elimination
• Administration of specific antidotes
• Prevention of re exposure

41. SUPPORTIVE CARE
“goal of supportive therapy is to maintain
physiologic homeostasis until detoxification is
accomplished”

42. • ABC
• Intubation to protect Airway
• Mechanical ventilation if severe suppression of respiratory centre and paralysis of patients in
order to prevent or treat hyperthermia, acidosis, and rhabdomyolysis associated with
neuromuscular hyperactivity.

43. Cardiovascular Therapy : Maintenance of normal tissue perfusion is critical for complete recovery to occur
Rx : Volume expansion
: Inotropes
: Arrythmias
Central Nervous System Therapies : Seizures : benzodiazepine or barbiturates
 Bedsores
 cerebral and pulmonary edema
 Pneumonia
 Rhabdomyolysis
 renal failure
 Sepsis
 thromboembolic disease
 generalized organ dysfunction due to hypoxemia or shock.

44. PREVENTION OF POISON ABSORPTION
• Gastrointestinal Decontamination : Golden time : 1 hour
• Factors to consider
• time since ingestion
• the existing and predicted toxicity of the ingestant
• the availability, efficacy
• contraindications of the procedure

45. 1. ACTIVATED CHARCOAL
• Activated charcoal suspension (in
water) is given orally via a cup, straw, or
small-bore nasogastric tube.
• Dose : 1 g/kg body weight
• Charcoal adsorbs ingested poisons
within the gut lumen, allowing the
charcoal-toxin complex to be
evacuated with stool
Charcoal is not recommended in corrosive
poisoning

46. GASTRIC LAVAGE
• Considered for life-threatening poisons
that cannot be treated effectively with
other decontamination, elimination, or
antidotal therapies (e.g., colchicine).
• Method sequentially administering and
aspirating ~5 mL of fluid per kilogram of
body weight through a no. 40 French
orogastric tube (no. 28 French tube for
children).
Lavage decreases ingestant absorption by an
average of
52% if performed within 5 min of ingestion
26% if performed at 30 min
16% if performed at 60 min.

47. GASTRIC LAVAGE CONTRAINDICATIONS
• Corrosive or petroleum distillate ingestions :because
of the respective risks of gastroesophageal
perforation and aspiration pneumonitis.
• Compromised unprotected airway
• At risk for haemorrhage or perforation due to
esophageal or gastric pathology or recent surgery.
• Absolutely contraindicated in combative patients or
those who refuse, as most published complications
involve patient resistance to the procedure.

48. OTHERS
• Dilution (i.e., drinking water, another clear liquid, or milk at avolume of 5
mL/kg of body weight) is recommended only after the ingestion of corrosives
(acids, alkali).
• Endoscopic or surgical removal of poisons : heavy metal (arsenic, iron, mercury,
thallium), or agents that have coalesced into gastric concretions or bezoars (heavy
metals, lithium, salicylates, sustained-release preparations).

49. DECONTAMINATION OF OTHER SITES
• Copious flushing with water, saline, or another available clear, drinkable liquid is
the initial treatment for topical exposures
• Inhalational exposures should be treated initially with fresh air or supplemental
oxygen.
• Solids (drug packets, pills) should be removed manually, preferably under direct
visualization

50. ENHANCEMENT OF POISON ELIMINATION
• Multiple-Dose Activated Charcoal : Doses of 0.5–1 g/kg of body weight every 2–4 h
theophylline, phenobarbital, carbamazepine , dapsone, quinine
• Urinary Alkalinization : producing a urine pH ≥7.5 and a urine output of 3–6 mL/kg of
body weight per hour by the addition of sodium bicarbonate to an IV solution
chlorpropamide, diflunisal, fluoride, methotrexate, phenobarbital, sulfonamides,
and salicylates

51. EXTRACORPOREAL REMOVAL
• Hemodialysis
• charcoal or resin hemoperfusion
• hemofiltration
• Plasmapheresis
• exchange transfusion
carbamazepine, ethylene glycol, isopropyl alcohol, lithium, methanol,theophylline,
salicylates, and valproate

52. ADMINISTRATION OF ANTIDOTES
• By neutralizing them (e.g., antibody-antigen reactions, chelation, chemical
binding)
• By antagonizing their physiologic effects (e.g., activation of opposing nervous
system activity, provision of a competitive metabolic or receptor substrate).

54. PREVENTION OF REEXPOSURE
• Approach to young children and patients with intentional overdose (deliberate
self harm or attempted suicide) is to limit their access to poisons
• Depressed or psychotic patients should undergo psychiatric assessment,
disposition, and follow-up.

55. THANK YOU