Toxicology By Dr.Dunia Alhashimi - Alsendibad

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Toxicology
Dr Dunia Alhashimi
Consultant pediatrician
Important areas to be covered
• Activated charcoal, mechanism of action,
indications, contraindications
• Carbon monoxide Poisoning, signs and
management
• Ethylene glycol, common forms, signs and
symptoms,
• Hydrocarbons, types, Mgt
• Common medications:
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Paracetamol, Elimination, S&S, Mgt, Acute vs chronic
TCA ingestion, S&S, Mgt
Salicylates, S&S, Mgt
Antihypertensives
Antihistamines
Multivitamins
Iron tablets
• Caustic injury, types, Mgt
• Organophosphorus poisoning
• Household chemicals
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–
–
–
–
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Detergents
Antiseptics
Silica gel
Mercury thermometers
Drain cleaner
Mothballs
Bleach
Rat poison
Nail polish remover
Ammonia
Window cleaner
Oven cleaner
Dettol
Q1
• A 10kg 14 month old boy is brought to the A&E by his
parents. His parents claim that he possibly ingested
paracetamol, as six 500mg tablets were found to be
missing from the family’s paracetamol container. This
possible ingestion occurred within a 60-min window efore
their presentation to the Emergency department. Which
of th following is the most appropriate management
action?
a. Measure plasma paracetamol levels
b. Administer ipecauanha to induce emesis
c. Perform a gastric lavage
d. Adminster N-acetyl cysteine
e. Administer activated charcoal
Q1 Ans E: Administer activated
charcoal
• The most appropriate management in this
instance would be to administer activated
charcoal, to limit further absorption of
paracetamol, Inducing emesis with ipecuanha is
now generally contraindicated. Measurement of
plasma paracetmol level is useful only after 4
hours of ingestion. A gastric lavage maybe
beneficial, but when you are given these five
choices it would not be the first choice of
treatment. N-acetylcysteine would not be the
first line of treatment either.
Q2
• The nomogram is used to determine when a
patient is give N-acetyl cysteine is administered
in patients even if their levels are below the
nomogram line. Which one of the following is
not a risk factor?
a.
b.
c.
d.
e.
Alcoholism
patient on isoniazide
pt on cimetidine
fasting
malnutrition
Q2 Ans: C
• If the serum level falls between the two
nomogram lines, consider giving NAC if the
patient is at increased risk for toxicity; e.g.
the patient is alcoholic, malnourished or
fasting or is taking drugs that induce P-450
2E1 activity (e.g. isoniazide INH); after
multiple or subacute overdoses; or the
patient is considered uncertain or unreliable.
Prescott Nomogram
High Risk
• Increased oxidation
– Chronic alcohol use
– Drugs
• Reduces glutathione stores
– Malnutrition
– Eating disorders
– Chronic liver disease
Q3
• A 3 year old boy was found with a empty packet of
extended-release paracetamol tablet. The parents
claim that he took 8 500mg tablet. You are called in
the emergency and decide to do a drug level. When is
the best time to do a paracetamol drug level in the
patients
a. Immediately as the dose is very high
b. A level stat and one after 4 hours
c. A level 4 hours after ingestion
d. A level 8 hours after ingestion
e. A level 8 hours and another after 12 hours
Q3 Ans:E
• After ingestion of extended release tablets,
which are designed for prolonged absorption,
there may be a delay before the peak
paracetamol level is reached. This can also
occur after co-ingestion of drugs is reached.
In such circumstances, repeat the serum
paracetamol level at 8 hours and possible
after 12 hours.
Q4
• Which statement is true regarding liver toxicity
from paracetamol overdose?
a. It is likely because paracetamol plasma half-life is
approximately 2 to 3 hours.
b. It usually is evident 12 to 24 hours after ingestion
c. For a given toxic plasma level, children have a
higher incidence of hepatic aminotransferase
elevation than adults have.
d. Hepatic toxicity results from N-acetyl-pbenzoquinonemime (NAPQ1)
e. Diet, nutritional status, and age are not related to
liver toxicity.
Q4 Ans: D
• Liver toxicity results when NAPQ1, a reactive
intermediary, is formed by cytochrome P-450
activity. Glutathione conjugates NAPQ1 to
nontoxic conjugates. In an overdose,
glutathione is depleted, and NAPQ1 binds
covalently with hepatocytes to produce
hepatic necrosis.
N-acetylcysteine
•
•
•
•
Most effective within 8 hours
Precursor for glutathione production
Can cause anaphylactoid reactions
Consider starting before paracetamol result if:
– Presenting > 8 hrs & >150mg/kg taken
– Staggered overdose
Patient X
• 15 year old girl who
presents after taking 24
paracetamol over a
period of 24 hours
• No drug history
• Fit and well
• Blood level 20mg/l
Staggered overdose.
(www.pharmweb.net)
• In patients who have taken several overdoses of
paracetamol over a short period of time, the plasma
paracetamol concentration will be more difficult to
interpret as the treatment graph relates to a single
acute ingestion.
• Such patients should be considered as at serious risk
and considered for treatment with N-acetylcysteine
(NAC).
• They can be discharged after NAC treatment or 24
hours from the last paracetamol dose provided they
are asymptomatic and the International Normalised
Ratio (INR), plasma creatinine and ALT are normal.
PARACETAMOL
DEADLY PITFALLS
•
•
•
•
The Prescott Nomogram High Risk Line
Staggered Overdoses
Management of late presentation
Recheck U&E, LFT, INR after N-acetylcysteine
Q5
• A mother brings in her 1-year-old after he
drank from a Dettol bottle. What is the most
common cause of mortality after Dettol
ingestion?
a.
b.
c.
d.
e.
Neurological depression
Aspiration pneumonia
Gastric strictures
Uncontrolled seizures
Hypoglycemia
Q5 Ans: B
• Dettol liquid (chloroxylenol 4.8%, pine oil and isopropyl alcohol) is a
commonly used household disinfectant.
• Labeled nonpoisonous,
• Serious complications were reported in up to 8% of cases of
ingestion
– included aspirations with gastric content resulting in pneumonia,
– cardiopulmonary arrest, bronchospasm, adult respiratory distress
syndrome
– severe laryngeal edema with upper airways obstruction.
• "Burning" in the mouth and throat with nausea and vomiting. Later
contaminated skin becomes erythematous and there is redness,
swelling and superficial ulceration in the mouth and upper
alimentary tract. The larynx may also be involved leading to
breathlessness and stridor.
Q6
• Which of the following ingestions could be
seen with an increased anion gap?
a.
b.
c.
d.
e.
Paracetamol
Isopropanol
Ethylene glycol
Ethylene dibromide
Methane
Q6 Ans: C
• The etiologies of metabolic acidosis with elevated
anion gap can be recalled with the mnemonic
MUD-PILES:
• Methanol, Uremia,Diabetic ketoacidois,
paraldehyde, Iron, Isoniazid or Inhlaants, Lactic
Acidosis, Ethylene glycol or chronic Ethanol
abuse, Salicylates or Solvents.
• In paracetamol poisoning metabolic acidois is
uncommon.
• Isopropyl alcohol results in high srum keones with
little or no acidosis
Q7
• Ethylene glycol poisoning is characterized by
all of the following except:
a.
b.
c.
d.
e.
Metabolic acidosis
Increased anion gap
Hypocalemia
Hypomagnesemia
Hypokalemia
Q7 Ans: E
• Metabolic acidosis with increased anion gap is
suggestive of methanol and ethylene glycol
ingestion. Ethylene glycol toxicity results from its
metabolite oxalate, which chelates calcium ion to
form insoluble calcium oxalate crystals and
results in hypocalcaemia. Hyopmagmasemia
usually occurs with hypocalcemia. However,
hyperkalemia results from muscle necrosis, the
development of acute tubular necrosis and renal
failure, and metabolic acidosis.
Q8
• A 13-year-old girl comes to the A&E with a history of
ingesting a bottle of diphenhydramine (Benadryl)
tablets. Which of the following signs and symptoms
would be expected on examining the patient?
a. Sweating, lacrimation, salivation, miosis, an blurred
vision.
b. Lethargy, slow respiration, hypotension, and lured
vision.
c. Agitation, tachycardia, sweating, and mydriasis
d. Flushed face, agitation, dry mucous membrane, and
dilated pupils
e. Headache, tachycardia, tachypnoea, cherry red mucous
membrane, and dim vision.
Q8 Ans: D
• Benadryl (diphenhydramine) is an
anticholinergic agent.
• Toxidrome: Hot as a hare, Blind as a bat, Dry
as a bone, Red as a beet, and Mad as a hatter
• A: anticholinesterase inhibitors or cholinergic
agents (organophoshates)
• B: narcotic overdose
• C: sympathomimetic agents (amphetamines)
• E: carbon monoxide poisoning
Common causes
•
•
•
•
•
Antidepressants-Tricyclics
Antihistamines
Atropine
Antipsychotics
Antispasmodics
Cholinergic
•
•
•
•
•
•
•
Brady/tachycardia
Confusion/reduced GCS
Pinpoint pupils
Seizures
Weakness
SLUDGE
Pulmonary oedema
SLUDGE
•
•
•
•
•
•
S
L
U
D
G
E
sweating salivation
lacrymation
urinary frequency
urgency
diarrhoea
gastrointestinal discomfort
eyes pinpoint
Toxidromes
Anticholinergic
dry, tachycardic
mydriasis
Sedative-Opiate
bradycardic
miosis
Sympathomimetic
Cholinergic
wet, tachycardic all wet, bradycardic
mydriasis
miosis
Q9
• A 2-year old is brought to the A&E by his
mother, who says her son may have ingested a
few CBZ (Tegretol) chewable tablets used by his
sibling. Which of the following clinical findings
would best support the possibility of an
ingestion?
a.
b.
c.
d.
e.
Vomiting
Confusion and excitation
Tachycardia
Hyperreflexia
Nystagmus
Q9 Ans: E
• Dizziness, ataxia, and nystagmus with
deviating pupils are the classic triad seen in
CBZ toxicity.
• Although vomiting, confusion and excitement,
tachycardia, and hyperreflexia are all possible
signs of toxicity, the are nonspecific.
Q10
• A grandmother brings in her 15-month-old toddler who may have
swallowed one clonidine tablet (0.1mg) about 30minutes ago. The
child is sitting quietly on her lap with heart rate (HR) 80 beats per
minute, her blood pressure (BP) 130/80 mm Hg, and respiratory
rate (RR) 20 breaths per minute. Which of the following would be
the most appropriate management of this patient?
a.
b.
c.
d.
e.
The patient can be discharged afte initial assessment
Look for other ingestants because hypertension is unlikely with a
clonidine overdose
Nalaxone 0.1mg/kg IV boluis should be given because the patient
is bradycardiac
Emesis should be immediately attempted with syrup of ipecac
Only supportive care and monitoring are needed because most
patients recover in 12 to 24 hours
Q10 Ans: E
• All children who are symptomatic after clonidine
ingestion require admission, monitoring, and
supportive care because symptoms may persist for up
to 24 hours.
• Although the toxic dose of clonidine is not known,
significant toxicity has resulted with as little as 0.1mg
30 minutes after ingestion.
• The central effects of clonidine predominate and cause
tachycardia and hypotension, but initially there maybe
peripheral α2 stimulation and reduced uptake of
epinephrine, resulting in benign, transient paradoxic
hypertension.
Q11
• A 2-year old who swallowed digoxin tablets is found
to have bradycardia. An electrocardiogram (ECG)
shows ventricular bigeminy. Which of the following is
true?
a. ECG findings of T wave depression and scooped ST
segment correlate with significant digoxin toxicity
b. Digoxin immune FAB (Digibind) is indicated for lifethreatening dysrhythmias
c. There is a wide margin between therapeutic and toxic
doses
d. Hyperkalemia is not affected by digoxin immune FAB
(Digibind) therapy
e. Forced alkaline diuresis may increase renal excretion
Q11 Ans: B
• Digoxin immune FAB (Digibind) is indicated for
use in treating life-threatening digoxininduced dysrhythmias and for hyperkalemia.
The ECG finding of T wave depression and
scooped ST segemnts ar known as digitalis
effect but do not indicate toxicity. Alkaline
diuresis is not useful in digitalis elimination.
Q12
• Which of the following regarding caustic injury to the
esophagus is true?
a. Acid burns are usually deeper than alkali burns in the
esophagus and thus cause greater long-term
complications
b. If there are no orophayngeal lesions, esophagoscopy is
not required because esophageal burns are unlikely
c. Patients who ingest caustics appear to have an
increased risk of esophageal carcinoma
d. Only 50% of all stricture formation results within 2
months of ingestion
e. About 10% of first-degree burns results in esophageal
strictures
Q12 Ans: C
• Drain pipe cleaners usually contain sodium hydroxide as their
principal components.
• Patients who ingest caustics have an increased risk of developing
esophageal carcinoma.
• In the esophagus, acid burns usually cause a superficial coagulation
necrosis with eschar formation of the mucosa, which limits
penetration of the injury.
• However, bases causes liquefaction necrosis of the fat and protein
involving the mucosa, submucosa, and muscle and penetrate
deeply, causing the potential for greater tissue damage.
• Oropharyngeal lesions do not predict esophageal burns as only a
third of patients with oral lesions develop esophageal burns, and
about 10% to 15% of those with esophageal burns have no oral
lesions.
• First degree burns do not develop strictures; 15% to 30% of seconddegree do; and almost 100% of third-degree burns do
Q13
• A frantic mother calls you saying that her 2-year-old child just
swallowed some household bleach. She gave him milk, which he
drank without any drooling or vomiting. Which of the following is
the most appropriate action to take?
a.
b.
c.
d.
e.
Tell the mother to give her son syrup of ipecac immediately
Tell the mother to bring her child to the A&E for endoscopy to rule
out esophageal strictures
Reassure the mother that it is a mild irritant and that her son will
do fine as he has been drinking without problems
Warn the mother that because household bleach is an alkali, it can
cause esophageal strictures even if oral lesions are not seen
Tell the mother to give her son antacid to buffer the effect of the
bleach
Q13 Ans: C
• Household bleach contains chlorine or sodium
hypochlorin, which is a mild irritant and
usually causes no tissue destruction.
• Immediate dilution with water or milk is all
that is required.
Salicylate
DEADLY PITFALL
• Salicylate levels can continue to rise following
admission (10% of cases)
– Repeat levels every until peaked
Q14
• Which statement most accurately describes the
effects of insecticides?
a. Carbamates create an irreversible bond with
cholinesterase
b. Organophosphates stimulate the release of excessive
amounts of acetylcholine at the synaptic junction
c. Insecticide poisoning can be confirmed by a rise in
cholinesterase level in the blood
d. Humans have no biotransformation mechanism for
metabolizinig (detoxifying) insecticides
e. Organophosphates inhibit the degradation of
acetylcholine
Q14 Ans: E
• Organophosphates exert their effect by interfering with the
enzyme cholinesterase, which degrades acetylcholine but
rather cause its accumulation by preventing degradation.
• Insecticide poisoning causes cholinesterase levels to fall, and
this test can be used to confirm the clinical impression of
insecticide poisoning.
• Humans are, in fact able to detoxify organophosphates by
conjugation in the liver.
• Carbamates form a reversible bond with cholinesterase.
• In contrast, organophosphates irreversibly bind to
cholinesterase via phosphorylation.
Q15
• Which statement most accurately characterizes
the differences between organophosphate and
carbamate poisoning?
a. Carbamate exposure is more common than
organophosphate exposure
b. Carbamate poisoning is usually of shorter duration
c. Pralidoxime must be started sooner to be effective
in carbamate poisoning
d. Only organophosphates are absorbed through the
skim
e. Both answers B and C are correct.
Q15 Ans: B
Q16
• Which of the following statements concerning
cholinergic poisoning treatment is most correct?
a. Pralidoxime is used to prevent irreversible
deactivation of cholinesterase
b. Atropine restores the biologic activity of
cholinesterase
c. The dose of atropine should not exceed 2 mg
d. Pralidoxime is more useful as a treatment for
Carbamate exposure than for organophosphate
exposure
e. Bronchorrhea must be treated by loop diuretics
because atropine is ineffective for this
Q16 Ans: A
• Pralidoxime reactivates cholinesterase by competing for the
phosphate moiety of the organophosphate compound, thus
releasing if from the cholinesterase enzyme.
• Atropine counteracts the effects of acetylcholine excess but has no
effect on the biological activity of cholinesterase.
• There is no maximum dose of atropine in insecticide poisoning.
• Rather, the dose is titrated to the patient’s clinical response.
• Loop diuretics such as frusemide should be avoided in insecticide
poisoning because they exacerbate already excessive urinary
output.
• Bronchorrhea generally is controlled with ventilation and atropine.
Q17
• A 22-month-old, 15-kg girl is found with an empty bottle of
chewable vitamin tablets (15 mg of elemental iron per tablet).
Although originally 100 tablets were in the bottle, the mother
believes that at least 75 tables are found on the floor in the
house. The child is asymptomatic when she comes to the ED
90minutes after the ingestion. Which of the following is the next
most appropriate action?
a.
b.
c.
d.
e.
Administer an immediate dose of activated charcoal and observe
for 6 hours
Obtain a serum iron level, complete blood count, serum
electrolytes, and liver function test and observe the patient for 6
hours in the ED
Obtain an abdominal radiograph, and if no iron tablets are seen,
discharge the patient.
Administer syrup of ipecac and observe for 6 hours in the ED
Administer a desferoxamine challenge of 50mg/kg intramuscularly
Q17 Ans: B
Q18
• Which of the following regarding Naloxone (Narcan) is
most correct?
a. It can be administered intravenously, intramuscularly,
and endotracheally, but not intraosseously
b. It is often effective in reversing miosis associated with
barbiturate overdose
c. It can reverse the respiratory depression of a clonidine
overdose
d. It is effective with natural and semisynthetic opioids
and is ineffective with synthetic opioid
e. It has agonist as well as antagonist effects at higher
doses
Q18 Ans: C
Q18
• Naloxone has been shown to be effective
antidote in narcotic and clonidine overdose,
although its effect with clonidine is less
consistent.
• Naloxone can be safely administered via all
routes, including all intraosseous infusion.
• It is effective against all forms of opiods, including
synthetic ones, but has no effect on barbiturate
reversal.
• Naloxone is a pure antagonist with no agonist
effects.
Q19
• A 13-year old boy comes in 3 hours after ingestion of
salicylate. The maximal amount ingested is 35g of
salicylate. He is complaining of tinnitus, nausea, and
vomiting. At the time he arrives in the A&E his vital signs
are BP 108/68 mmHg, P 124 beats per minute, and RR 26
breaths per minute. An arterial blood gas reveals a pH of
7.44, and his serum salicylate level is 44 mg/dl. Which of
the following would not be expected in this patient?
a.
b.
c.
d.
e.
Normal anion gap metabolic acidosis
Elevateion of prothrombin time (PT)
Lsctic acidosis
Hypoglycemia
Decreased serum ionized calcium
Q19 Ans :A
• A quick calculation indicates that the child in the scenario ingested
approximately 20mg of elemental iron per kilogram. This is the lower
range at which toxicity can occur.
• However, this child is currently asymptomatic. Because we cannot base
our management approach on history alone, it is best to observe the child
in the ED for symptoms while we wait for laboratory tests.
• Iron does not bind to activated charcoal, and its administration will not be
helpful.
• An abdominal radiograph is useful when it is positive, but a negative
abdominal radiograph is more commonly seen with chewable tablet
ingestions.
• The use of ipecac is questionable in this case.
• A desferoxamine challenge test would be overly aggressive in this
asymptomatic child with an estimated ingestion of 20 mg/kg.
Q20
• Which of the following statements concerning the patient
described is most accurate?
a.
b.
c.
d.
e.
Activated charcoal is unlikely to be of value in this patient’s
management because of the length of time since ingestion
The patient should not receive IV dextrose and NAHCO3
concomitantly because of the risk of cerebral edema
Alkalinization of the urine is unnecessary into his case
because the salicylate level places the patient in the “mild”
category
Effective alkalinization of the urine will require adequate
replacement of potassium
NaHCO3 therapy should be avoided because the patient’s
serum is already alkaline
Q20 Ans: D
Q21
• Which of the following statements concerning the
patient described is correct?
a. Hemodialysis and hemoperfusion would be about
equally effective in removing salicylate from this
patient
b. The serum salicylate level indicates that dialysis will not
be needed
c. An acute ingestion of salicylates is more likely to
require dialysis than a chronic ingestion
d. Hypothermia, seizures, and renal failure are indications
for dialysis
e. If pulmonary edema develops, dialysis should be
avoided
Q21 Ans: A
Q22
• Which of the following statements concerning the
patient described is correct?
a. Hemodialysis and hemoperfusion would be about
equally effective in removing salicylate from this
patient
b. The serum salicylate level indicates that dialysis will not
be needed
c. An acute ingestion of salicylates is more likely to
require dialysis than a chronic ingestion
d. Hypothermia, seizures, and renal failure are indications
for dialysis
e. If pulmonary edema develops, dialysis should be
avoided
Q22 Ans: B
Q23
Which of the following metabolic complications
is most likely to occur in the setting of both
therapeutic use and overdose of valproic
acid?
A.
B.
C.
D.
E.
Elevated ammonia
Elevated calcium
Elevated carnitine
Low sodium
Metabolic alkalosis
Q23 Ans:A
• Disruption of urea cycle
• Metabolic acidosis, hypernatremia,
hypocalcemia, low carnitine, elevated
ammonia (complication of therapeutic use)
• Hyperammonia: MS changes
• Sometimes hepatitis with bumps in AST/ALT.
• Carnitine may be beneficial.
• Very rarely renal failure, urea elevation
Q24
Activated Charcoal will adsorb all the
following meds except:
a. Phenobarbital
b. Theophylline
c. Ferrous sulfate
d. Verapamil
e. Salicylates
Q24
•
a.
b.
c.
d.
e.
Activated Charcoal will adsorb all the
following meds except:
Phenobarbital
Theophylline
Ferrous sulfate
Verapamil
Salicylates
Q25
• A 10-month boy is brought in by his parents after
he turned blue at home. The mother says he has
been fussy recently, which she presumed to be
caused by teething; she has been treating him
with a topical teething gel. On exam, the boy has
marked cyanosis, including the perioral area and
nail beds, mild tachypnea and tachycardia, room
air O2 sat 88% does not improve with oxygen.
Lungs are clear; work of breathing and heart
sounds are normal.
Q25
Which treatment is most likely to be
successful in treating the cyanosis?
A. Botulinum antitoxin
B. Deferoxamine
C. Methylene blue
D. Prostaglandin E1
E. Sodium bicarbonate
Q25 Ans: C
MetHb
• Cyanosis: increased deoxygenated Hb or
abnormal pigments, e.g. silver (argyria)
• Oxidation of Fe in Hb from ferrous 2+ to ferric 3+:
cannot bind O2, impairs 02 release from
remaining normal Hb, shifting curve left
• Overdose: benzocaine (teething gels), amyl
nitrate, pyridium, sulfonamides
• Chocolate-brown blood
• Methylene blue accelerates NADPHmethemoglobin reductase, contraindicated in
G6PD, need exchange transfusion
Availability? USA, 2000
16 recommended ‘antidotes’:
Acetylcysteine
Atropine
Crotalid snake anvenim
Calcium salts
Cyanide antidote kit
Deferoxamine
Digoxin antibodies
Dimercaprol
Ethanol
Fomepizole
Glucagon
No consensus:
Methylene blue
. Flumazenil
Naloxone
. Physostigmine
Pralidoxime
Pyridoxine
Sodium bicarbonate
Antidotes
•
•
•
•
•
•
•
•
Opiates – naloxone
Paracetamol – acetylcysteine/methionine
Beta-blockers – glucagon
Insulin – glucose
Iron – desferrioxamine
Carbon monoxide – oxygen
Methanol - ethanol
(Benzodiazepines – flumazenil)
Common Non toxic ingestions
• A variety of product commonly found around
the home are completely nontoxic or have
little or no toxicity after typical accidental
ingestion
• Treatment is rarely required because the
ingredients are non toxic or potentially
harmful material is present in minimal doses
Confirm ingredients
• In all cases, attempt to confirm the identity
and/or ingredients of the product
• Ensue no other toxic product was involved
• Advise parents that mild GI upset may occur
• Water or other liquid may be given to reduce
the taste and texture of the product
Non toxic products
•
•
•
•
•
•
Crayons
Clay
Silica gel
Supergle
Wax
Zinc oxide ointment
Non toxic products with minimal
gastrointestinal irritation
•
•
•
•
•
•
•
Antibiotic ointment
Baby soap
Bar soap
Bleach ( household, less than 6% hypochlorite)
Hair shampoo
Prednisolone
Toothpaste
Other low toxicity products
• Oral contraceptives:
– In excessive amounts may cause GI upset
– in females even prepubertal my cause vaginal
spotting
• Thermometer:
– Household thermometers contain less than 0.5ml
liquid mercury which is harmless if swallowed.
Clean cautiously to avoid dispersing mercury as
mist or vapor (i.e. Do not vacuum)
Q26
•
a.
b.
c.
d.
e.
Whole bowel irrigation is recommended in
all of the following ingestions except:
Lead paint chips
Cocaine packets
Button batteries
Hydrocarbons
Sustained-release lithium tablets
Q26 Ans:D
•
a.
b.
c.
d.
e.
Whole bowel irrigation is recommended in
all of the following ingestions except:
Lead paint chips
Cocaine packets
Button batteries
Hydrocarbons
Sustained-release lithium tablets
GI Decontamination
• Whole Bowel Irrigation
• Heavy metals
• Sustained-release meds
• GoLytely
500 – 2000 ml/hr
25cc/kg/hr peds
+/- metoclopropamide
4-6 hours duration
Q27
A 14-year-old girl comes to the ED I hour after ingesting 36g of
sustained release-enteric coated aspirin tablets. Which of the following
statements concerning this patient’s condition is true?
a.
b.
c.
d.
e.
It is unlikely that any aspirin remains in the stomach at the time
the patients arrives
Peak serum levels of aspirin will occur at approximately 6 hours
The pills should be visible on a plain radiograph of the abdomen
Management should be withheld until a serum drug level confirms
the overdose or the patient becomes symptomatic
Arrangements should be initiated to perform hemoperfusion for
the patient.
Q27 Ans: A
Q27
• Enteric-coated tablets are often visible on plain x-ray films, especially
enteric –coated salicylate tablets.
• Salicylate induces pyloric spasm and forms concretions that adhere to the
gastric mucosa, thereby making it probable that some aspirin remains in
the stomach.
• Although the Done nomogram uses 6 hours for the peak level in salicylate
overdoses, this is an overdose of enteric-coated tablets, and the
nomogram is therefore unreliable because it is unlikely that the peak level
will achieved in 6 hours.
• Because this is a potentially serious overdose, management should begin
as soon as possible pending the results of the drug level.
• The definitive treatment of choice for salicylate poisoning is hemodialysis,
not hemoperfusion.
• Arrangements need not be instituted until the levels are obtained from
this patient because it is early in the poisoning and hemodialysis might not
be necessary.
Salicylate
• Salicylism
•
•
•
•
•
Dehydration
Confusion /coma
Seizures
Haemetemesis
Hypoglycaemia
Salicylate
• Metabolic and acid-base disturbance
• Complex
• Respiratory alkalosis – direct stimulation to
over breathe
• Metabolic acidosis- acid, impaired normal
metabolism, production of lactic acid
• Check ABG / VBG
Salicylate
• Severity of ingested dose:
• >150 mg/kg:
• >250 mg/kg:
• >500 mg/kg:
mild
moderate
severe
Salicylate management
• Tailor treatment to symptoms
• Fluids
• Reduce absorption:
• Activated charcoal
• Gastric lavage (>500 mg/kg and <1 hour)
• Increase elimination:
• Urinary alkalinisation
• Cooling
• Glucose if hypoglycaemic
Salicylate management
•
•
•
•
<350mg/L:
oral fluids
>350mg/L:
urinary alkalinisation
>700mg/L:
haemodialysis
DISCUSS WITH NPIS
Q28
• Which of the following household substance,
if ingested by a toddler, should cause the most
concern?
a. Silica gel (dehumidifying packets)
b. Pencil lead
c. Eye make up
d. Mercury from a broken thermometer
e. A whole cigarette
Q28 Ans: E
Q28
• A whole cigarette can produce symptomatic
nicotine poisoning in a small child.
• Pencil lead, of course is not lead but carbon.
• Silica gel and eye make up are nontoxic
• The amount of mercury ingested from a
broken thermometer would also be non toxic,
especially because its absorption would be
minimal.

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