management of toxicity€¦ · · 2018-02-19all substances are poisons: there is none which is...
TRANSCRIPT
Poison (Toxicant): any substance or agent capable of
producing a deleterious response in a biological system
or living organism.
Poisoning= overdose toxicity
intoxication= toxicity due to foreign substance
All substances are poisons: there is none which is
not a poison. The right dose differentiates a poison
from a remedy.
Highly toxic chemicals can be life saving when
given in appropriate doses.
(Poisons are not harmful at a sufficiently low dose)
An apparently non-toxic chemical can be toxic at
high doses. (Too much of a good thing can be bad!).
“Synthetic” does not meantoxic or poisonous
“Natural” does not meansafe or even low risk
Poisoning episodes
Accidental:Children less than 5 years by sugar coated tablets.Inhalation of organophosphorus pesticides.Overdose.
Suicidal: in response to depression or specific life events.
Homicidal
Parasuicide: attention seeking behavior or attempt at suicide.
It is typically classified as a low lethality method i.e. aim is not death
Routes of toxicant entry:
• Injection:
Through cuts or hypodermic needles into the skin, usually cause highest blood conc
• Inhalation:Through mouth/nose into respiratory system, 2nd highest blood level concentration.
• Ingestion:
Through mouth into stomach and GIT, produces 2nd lowest blood level.
• Dermal (Skin):
By absorption through skin membrane, lowest in blood level
Management of Toxicity
Management Principles:
Immediate and supportive measures.
Absorption prevention.
Elimination of toxicant.
Specific antidote.
1
2
3
4
1) Immediate and Supportive measures
Ensure clear
First:
1) Immediate and Supportive measures
Ensure clear
= Airway
= Breathing
= Circulation
It is of 1st
priority
First:
1) Immediate and Supportive measures
Causes of air way obstruction:
Mucosal swelling.
Increased salivation (↓ Conscious).
Posterior displacement of the tongue.
Swallowing of foreign bodies (ex: Fish bone).
A=Air way
1) Immediate and Supportive measures
Symptoms of airway obstruction:
Dyspnea.Air hunger.
Hoarseness (stridor).Cyanosis.
Diaphoresis. Drooling.
Tachypnea.
A=Air way
1) Immediate and Supportive measures
Management of airway obstruction:
Head tilt and Chin lift maneuver.
A=Air way
Jaw thrust maneuver.
1) Immediate and Supportive measures
Management of airway obstruction:
Nasopharyngeal or Oropharyngeal intubation
A=Air way
1) Immediate and Supportive measures
Management of airway obstruction:
In case of comatosed patients:
Cuffed endotracheal intubation is required
to prevent aspiration because gag reflex
is completely absent in unconscious patients
1) Immediate and Supportive measures
Management of airway obstruction:
Excessive mucosal secretions &/or salivation:
Suction of excessive secretions by the aid of intubation.
A=Air way
In Emergency Cases:
Finally Emergency Cricothyrotomy.
1) Immediate and Supportive measures
Causes of respiratory depression:
Drug-induced respiratory depression (Sedatives & hypnotic such as barbiturates & BDZs).
Pulmonary edema & pneumonitis.
Bronchospasm.
B = Breathing
1) Immediate and Supportive measures
Management of respiratory depression:
Give supplemental oxygen
If necessary positive pressure ventilation ‘artificial respiration’·
Respiratory stimulants for severe respiratory depression
B = Breathing
1) Immediate and Supportive measures
The shock is the clinical picture in which the patient shows signs of inadequate tissue perfusion.
Symptoms of shock:
C =Circulation
SHOCK
Coma
1) Immediate and Supportive measures
Management of shock:
1-Trendlenburg position.
2-Saline Infusion.
C =Circulation
1) Immediate and Supportive measures
Management of shock:If the patient doesn't respond to 2L infusion & the signs of shock persist, the vasopressors should be used:
C =Circulation
3-vasopressors
Dopamine
Norepinephrine
N.B.1) Dopamine at low dose stimulates dopamine receptors renal & mesenteric vasodilatation.
2) Dopamine at medium dose stimulates cardiac β1 receptors ↑cardiac contractility & C.O.P.
3) Dopamine at high dose stimulates α1
receptors systemic vasoconstriction.
2-5 µg/kg/minute infusion up to 20 µg/kg/minute
0.1-0.2 µg/kg/minute.
1) Immediate and Supportive measures
After instituting ABC interventions, more detailed evaluation is required:
A. HISTORY:Collect any evidences (thrown tablets, empty bottles, any syringes, written notes .. etc).
Second:
1) Immediate and Supportive measures
After instituting ABC interventions, more detailed evaluation is required:
B. PHYSICAL EXAMINATIONS- Careful evaluation of S&S searching for toxidromes
Second:
TOXIDROMES
It is a group of signs and symptoms and/or characteristic effects
associated with exposure to a particular substance or class of substances.
Use all your senses, search for the clues
• LOOK
– Pupil Size
• FEEL
– Temperature, Sweating
• SMELL
– Alcohol
1) Immediate and Supportive measures
After instituting ABC interventions, more detailed evaluation is required:
B. PHYSICAL EXAMINATIONS- Careful evaluation of vital signs (B.P, pulse, respiration,
temperature):
Second:
Hypertension Cocaine, amphetamines … etc
Rapid respiration Carbon monoxide.
Hypothermia C.N.S depressants.
1) Immediate and Supportive measures
After instituting ABC interventions, more detailed evaluation is required:
B. PHYSICAL EXAMINATIONS
- Pinpoint miosis is a typical sign of opioids toxicity.- Mydriasis is very common with cocaine.
- Ulcers/signs of burns with corrosives.- Bitter almond odor with cyanide toxicity.- Gingival lead lines with lead intoxication.
Second:
Eye:
Mouth:
1) Immediate and Supportive measures
After instituting ABC interventions, more detailed evaluation is required:
B. PHYSICAL EXAMINATIONS
- Cyanosis may be caused by airway obstruction and methemoglobinemia.
- Hyperactive bowel sound, cramping and diarrhea are associatedwith arsenic intoxication.
Second:
Skin:
Abdomen:
2) Preventing absorption (Gut Decontamination)
It is usually not effective more than 4-6 after poison ingestion.
It is used only for orally ingested poisons.
Methods of gut decontamination:
Most clinical toxicologists recommend administration of activated charcoal.
Emesis Gastric Lavage
ActivatedCharcoal
CatherticsWhole Bowel
Irrigation
2) Preventing absorption (Gut Decontamination)
Method:By the use of syrup of ipeca.The active ingredients are two alkaloids, emetine &cephaeline.Previous popular methods (fingertip stimulation,salt water, apomorphine) are ineffective.
Dose:In children 5-15 ml ipeca syrup + 120 ml water.adults 15-30 ml ipeca + 240 ml water.The dose can be repeated if emesis has not occurred in 30 minutes.If vomiting does not occur gastric lavage or activated charcoal is decided.
EmesisFor alert Pt
2) Preventing absorption (Gut Decontamination)
Complications:
Contraindication: Children up to 6 months of age. Comatose patient because of increased risk of aspiration. Seizures (due to compromised gag reflex). Certain toxins:
Hydrocarbons& volatile substances.Corrosives (Caustics).
Ingestion of sharp objects.
Emesis
Lethargy DrowsinessProlonged vomiting
Diarrhea